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Date: Tue, 16 Feb 2016 10:45:44 -0600
From: Bjorn Helgaas <helgaas@...nel.org>
To: jakeo@...rosoft.com
Cc: bhelgaas@...gle.com, linux-pci@...r.kernel.org,
gregkh@...uxfoundation.org, kys@...rosoft.com,
linux-kernel@...r.kernel.org, devel@...uxdriverproject.org,
olaf@...fle.de, apw@...onical.com, vkuznets@...hat.com,
tglx@...utronix.de, haiyangz@...rosoft.com, marc.zyngier@....com,
haddenh@...rosoft.com
Subject: Re: [PATCH RESEND v2 3/3] PCI: hv: New paravirtual PCI front-end for
Hyper-V VMs
Hi Jake,
Looks good to me overall; I marked a few nits below.
The only real question I have is about domain number allocation. See
the note below.
On Tue, Feb 09, 2016 at 07:24:28PM +0000, jakeo@...rosoft.com wrote:
> From: Jake Oshins <jakeo@...rosoft.com>
>
> This patch introduces a new driver which exposes a root PCI bus whenever a
> PCI Express device is passed through to a guest VM under Hyper-V. The
> device can be single- or multi-function. The interrupts for the devices
> are managed by an IRQ domain, implemented within the driver.
>
> Signed-off-by: Jake Oshins <jakeo@...rosoft.com>
> ---
> MAINTAINERS | 1 +
> drivers/pci/Kconfig | 7 +
> drivers/pci/host/Makefile | 1 +
> drivers/pci/host/pci-hyperv.c | 2373 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 2382 insertions(+)
> create mode 100644 drivers/pci/host/pci-hyperv.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 30aca4a..b68c015 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5193,6 +5193,7 @@ F: arch/x86/kernel/cpu/mshyperv.c
> F: drivers/hid/hid-hyperv.c
> F: drivers/hv/
> F: drivers/input/serio/hyperv-keyboard.c
> +F: drivers/pci/host/pci-hyperv.c
> F: drivers/net/hyperv/
> F: drivers/scsi/storvsc_drv.c
> F: drivers/video/fbdev/hyperv_fb.c
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index 73de4ef..54a5441 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -118,4 +118,11 @@ config PCI_LABEL
> def_bool y if (DMI || ACPI)
> select NLS
>
> +config PCI_HYPERV
> + tristate "Hyper-V PCI Frontend"
> + depends on PCI && X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
> + help
> + The PCI device frontend driver allows the kernel to import arbitrary
> + PCI devices from a PCI backend to support PCI driver domains.
> +
> source "drivers/pci/host/Kconfig"
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index 7b2f20c..152daf9 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -2,6 +2,7 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
> obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
> obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
> obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
> +obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o
> obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
> obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
> obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> new file mode 100644
> index 0000000..2ca43f1
> --- /dev/null
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -0,0 +1,2373 @@
> +/*
> + * Copyright (c) Microsoft Corporation.
> + *
> + * Author:
> + * Jake Oshins <jakeo@...rosoft.com>
> + *
> + * This driver acts as a paravirtual front-end for PCI Express root buses.
> + * When a PCI Express function (either an entire device or an SR-IOV
> + * Virtual Function) is being passed through to the VM, this driver exposes
> + * a new bus to the guest VM. This is modeled as a root PCI bus because
> + * no bridges are being exposed to the VM. In fact, with a "Generation 2"
> + * VM within Hyper-V, there may seem to be no PCI bus at all in the VM
> + * until a device as been exposed using this driver.
> + *
> + * Each root PCI bus has its own PCI domain, which is called "Segment" in
> + * the PCI Firmware Specifications. Thus while each device passed through
> + * to the VM using this front-end will appear at "device 0", the domain will
> + * be unique. Typically, each bus will have one PCI function on it, though
> + * this driver does support more than one.
> + *
> + * In order to map the interrupts from the device through to the guest VM,
> + * this driver also implements an IRQ Domain, which handles interrupts (either
> + * MSI or MSI-X) associated with the functions on the bus. As interrupts are
> + * set up, torn down, or reaffined, this driver communicates with the
> + * underlying hypervisor to adjust the mappings in the I/O MMU so that each
> + * interrupt will be delivered to the correct virtual processor at the right
> + * vector. This driver does not support level-triggered (line-based)
> + * interrupts, and will report that the Interrupt Line register in the
> + * function's configuration space is zero.
> + *
> + * The rest of this driver mostly maps PCI concepts onto underlying Hyper-V
> + * facilities. For instance, the configuration space of a function exposed
> + * by Hyper-V is mapped into a single page of memory space, and the
> + * read and write handlers for config space must be aware of this mechanism.
> + * Similarly, device setup and teardown involves messages sent to and from
> + * the PCI back-end driver in Hyper-V.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
> + * NON INFRINGEMENT. See the GNU General Public License for more
> + * details.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/semaphore.h>
> +#include <linux/irqdomain.h>
> +#include <asm/irqdomain.h>
> +#include <asm/apic.h>
> +#include <linux/msi.h>
> +#include <linux/hyperv.h>
> +#include <asm/mshyperv.h>
> +
> +/*
> + * Protocol versions. The low word is the minor version, the high word the major
> + * version.
> + */
> +
> +#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (major)))
> +#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16)
> +#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff)
> +
> +enum {
> + PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1),
> + PCI_PROTOCOL_VERSION_CURRENT = PCI_PROTOCOL_VERSION_1_1
> +};
> +
> +#define PCI_CONFIG_MMIO_LENGTH 0x2000
> +#define CFG_PAGE_OFFSET 0x1000
> +#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
> +
> +#define MAX_SUPPORTED_MSI_MESSAGES 0x400
> +
> +/*
> + * Message Types
> + */
> +
> +enum pci_message_type {
> + /*
> + * Version 1.1
> + */
> + PCI_MESSAGE_BASE = 0x42490000,
> + PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0,
> + PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1,
> + PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4,
> + PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5,
> + PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6,
> + PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7,
> + PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8,
> + PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9,
> + PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA,
> + PCI_EJECT = PCI_MESSAGE_BASE + 0xB,
> + PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC,
> + PCI_REENABLE = PCI_MESSAGE_BASE + 0xD,
> + PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE,
> + PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF,
> + PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10,
> + PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11,
> + PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12,
> + PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13,
> + PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14,
> + PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15,
> + PCI_MESSAGE_MAXIMUM
> +};
> +
> +/*
> + * Structures defining the virtual PCI Express protocol.
> + */
> +
> +union pci_version {
> + struct {
> + u16 minor_version;
> + u16 major_version;
> + } parts;
> + u32 version;
> +} __packed;
> +
> +/*
> + * Function numbers are 8-bits wide on Express, as interpreted through ARI,
> + * which is all this driver does. This representation is the one used in
> + * Windows, which is what is expected when sending this back and forth with
> + * the Hyper-V parent partition.
> + */
> +union win_slot_encoding {
> + struct {
> + u32 func:8;
> + u32 reserved:24;
> + } bits;
> + u32 slot;
> +} __packed;
> +
> +/*
> + * Pretty much as defined in the PCI Specifications.
> + */
> +struct pci_function_description {
> + u16 v_id; /* vendor ID */
> + u16 d_id; /* device ID */
> + u8 rev;
> + u8 prog_intf;
> + u8 subclass;
> + u8 base_class;
> + u32 subsystem_id;
> + union win_slot_encoding win_slot;
> + u32 ser; /* serial number */
> +} __packed;
> +
> +/**
> + * struct hv_msi_desc
> + * @vector: IDT entry
> + * @delivery_mode: As defined in Intel's Programmer's
> + * Reference Manual, Volume 3, Chapter 8.
> + * @vector_count: Number of contiguous entries in the
> + * Interrupt Descriptor Table that are
> + * occupied by this Message-Signaled
> + * Interrupt. For "MSI", as first defined
> + * in PCI 2.2, this can be between 1 and
> + * 32. For "MSI-X," as first defined in PCI
> + * 3.0, this must be 1, as each MSI-X table
> + * entry would have its own descriptor.
> + * @reserved: Empty space
> + * @cpu_mask: All the target virtual processors.
> + */
> +struct hv_msi_desc {
> + u8 vector;
> + u8 delivery_mode;
> + u16 vector_count;
> + u32 reserved;
> + u64 cpu_mask;
> +} __packed;
> +
> +/**
> + * struct tran_int_desc
> + * @reserved: unused, padding
> + * @vector_count: same as in hv_msi_desc
> + * @data: This is the "data payload" value that is
> + * written by the device when it generates
> + * a message-signaled interrupt, either MSI
> + * or MSI-X.
> + * @address: This is the address to which the data
> + * payload is written on interrupt
> + * generation.
> + */
> +struct tran_int_desc {
> + u16 reserved;
> + u16 vector_count;
> + u32 data;
> + u64 address;
> +} __packed;
> +
> +/*
> + * A generic message format for virtual PCI.
> + * Specific message formats are defined later in the file.
> + */
> +
> +struct pci_message {
> + u32 message_type;
> +} __packed;
> +
> +struct pci_child_message {
> + u32 message_type;
> + union win_slot_encoding wslot;
> +} __packed;
> +
> +struct pci_incoming_message {
> + struct vmpacket_descriptor hdr;
> + struct pci_message message_type;
> +} __packed;
> +
> +struct pci_response {
> + struct vmpacket_descriptor hdr;
> + s32 status; /* negative values are failures*/
> +} __packed;
> +
> +struct pci_packet {
> + void (*completion_func)(void *context, struct pci_response *resp,
> + int resp_packet_size);
> + void *compl_ctxt;
> + struct pci_message message;
> +};
> +
> +/*
> + * Specific message types supporting the PCI protocol.
> + */
> +
> +/*
> + * Version negotiation message. Sent from the guest to the host.
> + * The guest is free to try different versions until the host
> + * accepts the version.
> + *
> + * pci_version: The protocol version requested.
> + * is_last_attempt: If TRUE, this is the last version guest will request.
> + * reservedz: Reserved field, set to zero.
> + */
> +
> +struct pci_version_request {
> + struct pci_message message_type;
> + enum pci_message_type protocol_version;
> +} __packed;
> +
> +/*
> + * Bus D0 Entry. This is sent from the guest to the host when the virtual
> + * bus (PCI Express port) is ready for action.
> + */
> +
> +struct pci_bus_d0_entry {
> + struct pci_message message_type;
> + u32 reserved;
> + u64 mmio_base;
> +} __packed;
> +
> +struct pci_bus_relations {
> + struct pci_incoming_message incoming;
> + u32 device_count;
> + struct pci_function_description func[1];
> +} __packed;
> +
> +struct pci_q_res_req_response {
> + struct vmpacket_descriptor hdr;
> + s32 status; /* negative values are failures*/
> + u32 probed_bar[6];
> +} __packed;
> +
> +struct pci_set_power {
> + struct pci_message message_type;
> + union win_slot_encoding wslot;
> + u32 power_state; /* In Windows terms */
> + u32 reserved;
> +} __packed;
> +
> +struct pci_set_power_response {
> + struct vmpacket_descriptor hdr;
> + s32 status; /* negative values are failures*/
> + union win_slot_encoding wslot;
> + u32 resultant_state; /* In Windows terms */
> + u32 reserved;
> +} __packed;
> +
> +struct pci_resources_assigned {
> + struct pci_message message_type;
> + union win_slot_encoding wslot;
> + u8 memory_range[0x14][6]; /* not used here */
> + u32 msi_descriptors;
> + u32 reserved[4];
> +} __packed;
> +
> +struct pci_create_interrupt {
> + struct pci_message message_type;
> + union win_slot_encoding wslot;
> + struct hv_msi_desc int_desc;
> +} __packed;
> +
> +struct pci_create_int_response {
> + struct pci_response response;
> + u32 reserved;
> + struct tran_int_desc int_desc;
> +} __packed;
> +
> +struct pci_delete_interrupt {
> + struct pci_message message_type;
> + union win_slot_encoding wslot;
> + struct tran_int_desc int_desc;
> +} __packed;
> +
> +struct pci_dev_incoming {
> + struct pci_incoming_message incoming;
> + union win_slot_encoding wslot;
> +} __packed;
> +
> +struct pci_eject_response {
> + u32 message_type;
> + union win_slot_encoding wslot;
> + u32 status;
> +} __packed;
> +
> +static int pci_ring_size = (4 * PAGE_SIZE);
> +
> +/*
> + * Definitions or interrupt steering hypercall.
> + */
> +#define HV_PARTITION_ID_SELF ((u64)-1)
> +#define HVCALL_RETARGET_INTERRUPT 0x7e
> +
> +struct retarget_msi_interrupt {
> + u64 partition_id; /* use "self" */
> + u64 device_id;
> + u32 source; /* 1 for MSI(-X) */
> + u32 reserved1;
> + u32 address;
> + u32 data;
> + u64 reserved2;
> + u32 vector;
> + u32 flags;
> + u64 vp_mask;
> +} __packed;
> +
> +/*
> + * Driver specific state.
> + */
> +
> +enum hv_pcibus_state {
> + hv_pcibus_init = 0,
> + hv_pcibus_probed,
> + hv_pcibus_installed,
> + hv_pcibus_maximum
> +};
> +
> +struct hv_pcibus_device {
> + struct pci_sysdata sysdata;
> + enum hv_pcibus_state state;
> + atomic_t remove_lock;
> + struct hv_device *hdev;
> + resource_size_t low_mmio_space;
> + resource_size_t high_mmio_space;
> + struct resource *mem_config;
> + struct resource *low_mmio_res;
> + struct resource *high_mmio_res;
> + struct completion *survey_event;
> + struct completion remove_event;
> + struct pci_bus *pci_bus;
> + spinlock_t config_lock; /* Avoids two threads writing index page */
> + spinlock_t device_list_lock; /* Protects lists below */
> + void __iomem *cfg_addr;
> +
> + struct semaphore enum_sem;
> + struct list_head resources_for_children;
> +
> + struct list_head children;
> + struct list_head dr_list;
> + struct work_struct wrk;
> +
> + struct msi_domain_info msi_info;
> + struct msi_controller msi_chip;
> + struct irq_domain *irq_domain;
> +};
> +
> +/*
> + * Tracks "Device Relations" messages from the host, which must be both
> + * processed in order and deferred so that they don't run in the context
> + * of the incoming packet callback.
> + */
> +struct hv_dr_work {
> + struct work_struct wrk;
> + struct hv_pcibus_device *bus;
> +};
> +
> +struct hv_dr_state {
> + struct list_head list_entry;
> + u32 device_count;
> + struct pci_function_description func[1];
> +};
> +
> +enum hv_pcichild_state {
> + hv_pcichild_init = 0,
> + hv_pcichild_requirements,
> + hv_pcichild_resourced,
> + hv_pcichild_ejecting,
> + hv_pcichild_maximum
> +};
> +
> +enum hv_pcidev_ref_reason {
> + hv_pcidev_ref_invalid = 0,
> + hv_pcidev_ref_initial,
> + hv_pcidev_ref_by_slot,
> + hv_pcidev_ref_packet,
> + hv_pcidev_ref_pnp,
> + hv_pcidev_ref_childlist,
> + hv_pcidev_irqdata,
> + hv_pcidev_ref_max
> +};
> +
> +static char *hv_pcidev_ref_debug[hv_pcidev_ref_max] = {
> + "hv_pcidev_ref_invalid",
> + "hv_pcidev_ref_initial",
> + "hv_pcidev_ref_by_slot",
> + "hv_pcidev_ref_packet",
> + "hv_pcidev_ref_pnp",
> + "hv_pcidev_ref_childlist",
> + "hv_pcidev_irqdata"
> +};
> +
> +struct hv_pci_dev {
> + /* List protected by pci_rescan_remove_lock */
> + struct list_head list_entry;
> + atomic_t refs;
> + enum hv_pcichild_state state;
> + struct pci_function_description desc;
> + bool reported_missing;
> + struct hv_pcibus_device *hbus;
> + struct work_struct wrk;
> +
> + /*
> + * What would be observed if one wrote 0xFFFFFFFF to a BAR and then
> + * read it back, for each of the BAR offsets within config space.
> + */
> + u32 probed_bar[6];
> +};
> +
> +struct hv_pci_compl {
> + struct completion host_event;
> + s32 completion_status;
> +};
> +
> +/**
> + * hv_pci_generic_compl() - Invoked for a completion packet
> + * @context: Set up by the sender of the packet.
> + * @resp: The response packet
> + * @resp_packet_size: Size in bytes of the packet
> + *
> + * This function is used to trigger an event and report status
> + * for any message for which the completion packet contains a
> + * status and nothing else.
> + */
> +static
> +void
> +hv_pci_generic_compl(void *context, struct pci_response *resp,
> + int resp_packet_size)
> +{
> + struct hv_pci_compl *comp_pkt = context;
> +
> + if (resp_packet_size >= offsetofend(struct pci_response, status))
> + comp_pkt->completion_status = resp->status;
> + complete(&comp_pkt->host_event);
> +}
> +
> +static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
> + u32 wslot);
> +static void get_pcichild(struct hv_pci_dev *hv_pcidev,
> + enum hv_pcidev_ref_reason reason);
> +static void put_pcichild(struct hv_pci_dev *hv_pcidev,
> + enum hv_pcidev_ref_reason reason);
> +
> +static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus);
> +static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus);
> +
> +/**
> + * devfn_to_wslot() - Convert from Linux PCI slot to Windows
> + * @devfn: The Linux representation of PCI slot
> + *
> + * Windows uses a slightly different representation of PCI slot.
> + *
> + * Return: The Windows representation
> + */
> +static u32 devfn_to_wslot(int devfn)
> +{
> + union win_slot_encoding wslot;
> +
> + wslot.slot = 0;
> + wslot.bits.func = PCI_SLOT(devfn) | (PCI_FUNC(devfn) << 5);
> +
> + return wslot.slot;
> +}
> +
> +/**
> + * wslot_to_devfn() - Convert from Windows PCI slot to Linux
> + * @wslot: The Windows representation of PCI slot
> + *
> + * Windows uses a slightly different representation of PCI slot.
> + *
> + * Return: The Linux representation
> + */
> +static int wslot_to_devfn(u32 wslot)
> +{
> + union win_slot_encoding slot_no;
> +
> + slot_no.slot = wslot;
> + return PCI_DEVFN(0, slot_no.bits.func);
> +}
> +
> +/*
> + * PCI Configuration Space for these root PCI buses is implemented as a pair
> + * of pages in memory-mapped I/O space. Writing to the first page choses
s/choses/chooses/
> + * the PCI function being written or read. Once the first page has been
> + * written to, the following page maps in the entire configuration space of
> + * the function.
> + */
> +
> +/**
> + * _hv_pcifront_read_config() - Internal PCI config read
> + * @hpdev: The PCI driver's representation of the device
> + * @where: Offset within config space
> + * @size: Size of the transfer
> + * @val: Pointer to the buffer receiving the data
> + */
> +static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where,
> + int size, u32 *val)
> +{
> + unsigned long flags;
> + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
> +
> + /*
> + * If the attempt is to read the IDs or the ROM BAR, simulate that.
> + */
> + if (where + size <= PCI_COMMAND) {
> + memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size);
> + } else if (where >= PCI_CLASS_REVISION && where + size <=
> + PCI_CACHE_LINE_SIZE) {
> + memcpy(val, ((u8 *)&hpdev->desc.rev) + where -
> + PCI_CLASS_REVISION, size);
> + } else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <=
> + PCI_ROM_ADDRESS) {
> + memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where -
> + PCI_SUBSYSTEM_VENDOR_ID, size);
> + } else if (where >= PCI_ROM_ADDRESS && where + size <=
> + PCI_CAPABILITY_LIST) {
> + /* ROM BARs are unimplemented */
> + *val = 0;
> + } else if (where >= PCI_INTERRUPT_LINE && where + size <=
> + PCI_INTERRUPT_PIN) {
> + /*
> + * Interrupt Line and Interrupt PIN are hard-wired to zero
> + * because this front-end only supports message-signaled
> + * interrupts.
> + */
> + *val = 0;
> + } else if (where + size <= CFG_PAGE_SIZE) {
> + spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
> + /* Choose the function to be read. (See comment above) */
> + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
> + /* Read from that function's config space. */
> + switch (size) {
> + case 1:
> + *val = readb(addr);
> + break;
> + case 2:
> + *val = readw(addr);
> + break;
> + default:
> + *val = readl(addr);
> + break;
> + }
> + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
> + } else {
> + dev_err(&hpdev->hbus->hdev->device,
> + "Attempt to read beyond a function's config space.\n");
> + }
> +}
> +
> +/**
> + * _hv_pcifront_write_config() - Internal PCI config write
> + * @hpdev: The PCI driver's representation of the device
> + * @where: Offset within config space
> + * @size: Size of the transfer
> + * @val: The data being transferred
> + */
> +static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where,
> + int size, u32 val)
> +{
> + unsigned long flags;
> + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
> +
> + if (where >= PCI_SUBSYSTEM_VENDOR_ID &&
> + where + size <= PCI_CAPABILITY_LIST) {
> + /* SSIDs and ROM BARs are read-only */
> + } else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) {
> + spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
> + /* Choose the function to be written. (See comment above) */
> + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
> + /* Write to that function's config space. */
> + switch (size) {
> + case 1:
> + writeb(val, addr);
> + break;
> + case 2:
> + writew(val, addr);
> + break;
> + default:
> + writel(val, addr);
> + break;
> + }
> + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
> + } else {
> + dev_err(&hpdev->hbus->hdev->device,
> + "Attempt to write beyond a function's config space.\n");
> + }
> +}
> +
> +/**
> + * hv_pcifront_read_config() - Read configuration space
> + * @bus: PCI Bus structure
> + * @devfn: Device/function
> + * @where: Offset from base
> + * @size: Byte/word/dword
> + * @val: Value to be read
> + *
> + * Return: PCIBIOS_SUCCESSFUL on success
> + * PCIBIOS_DEVICE_NOT_FOUND on failure
> + */
> +static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 *val)
> +{
> + struct hv_pcibus_device *hbus =
> + container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
> + struct hv_pci_dev *hpdev;
> +
> + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
> + if (!hpdev)
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + _hv_pcifront_read_config(hpdev, where, size, val);
> +
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +/**
> + * hv_pcifront_write_config() - Write configuration space
> + * @bus: PCI Bus structure
> + * @devfn: Device/function
> + * @where: Offset from base
> + * @size: Byte/word/dword
> + * @val: Value to be written to device
> + *
> + * Return: PCIBIOS_SUCCESSFUL on success
> + * PCIBIOS_DEVICE_NOT_FOUND on failure
> + */
> +static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 val)
> +{
> + struct hv_pcibus_device *hbus =
> + container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
> + struct hv_pci_dev *hpdev;
> +
> + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
> + if (!hpdev)
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + _hv_pcifront_write_config(hpdev, where, size, val);
> +
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +/* PCIe operations */
> +static struct pci_ops hv_pcifront_ops = {
> + .read = hv_pcifront_read_config,
> + .write = hv_pcifront_write_config,
> +};
> +
> +/* Interrupt management hooks */
> +static void hv_int_desc_free(struct hv_pci_dev *hpdev,
> + struct tran_int_desc *int_desc)
> +{
> + struct pci_delete_interrupt *int_pkt;
> + struct {
> + struct pci_packet pkt;
> + u8 buffer[sizeof(struct pci_delete_interrupt) -
> + sizeof(struct pci_message)];
> + } ctxt;
> +
> + memset(&ctxt, 0, sizeof(ctxt));
> + int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;
> + int_pkt->message_type.message_type =
> + PCI_DELETE_INTERRUPT_MESSAGE;
> + int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
> + int_pkt->int_desc = *int_desc;
> + vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt,
> + sizeof(*int_pkt),
> + (unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND,
> + 0);
> + kfree(int_desc);
> +}
> +
> +/**
> + * hv_msi_free() - Free the MSI.
> + * @domain: The interrupt domain pointer
> + * @info: Extra MSI-related context
> + * @irq: Identifies the IRQ.
> + *
> + * The Hyper-V parent partition and hypervisor are tracking the
> + * messages that are in use, keeping the interrupt redirection
> + * table up to date. This callback sends a message that frees
> + * the IRT entry and related tracking nonsense.
> + */
> +static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
> + unsigned int irq)
> +{
> + struct hv_pcibus_device *hbus;
> + struct hv_pci_dev *hpdev;
> + struct pci_dev *pdev;
> + struct tran_int_desc *int_desc;
> + struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq);
> + struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
> +
> + pdev = msi_desc_to_pci_dev(msi);
> + hbus = info->data;
> + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
> + if (!hpdev)
> + return;
> +
> + int_desc = irq_data_get_irq_chip_data(irq_data);
> + if (int_desc) {
> + irq_data->chip_data = NULL;
> + hv_int_desc_free(hpdev, int_desc);
> + }
> +
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> +}
> +
> +static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest,
> + bool force)
> +{
> + struct irq_data *parent = data->parent_data;
> +
> + return parent->chip->irq_set_affinity(parent, dest, force);
> +}
> +
> +void hv_irq_mask(struct irq_data *data)
> +{
> + pci_msi_mask_irq(data);
> +}
> +
> +/**
> + * hv_irq_unmask() - "Unmask" the IRQ by setting its current
> + * affinity.
> + * @data: Describes the IRQ
> + *
> + * Build new a destination for the MSI and make a hypercall to
> + * update the Interrupt Redirection Table. "Device Logical ID"
> + * is built out of this PCI bus's instance GUID and the function
> + * number of the device.
> + */
> +void hv_irq_unmask(struct irq_data *data)
> +{
> + struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
> + struct irq_cfg *cfg = irqd_cfg(data);
> + struct retarget_msi_interrupt params;
> + struct hv_pcibus_device *hbus;
> + struct cpumask *dest;
> + struct pci_bus *pbus;
> + struct pci_dev *pdev;
> + int cpu;
> +
> + dest = irq_data_get_affinity_mask(data);
> + pdev = msi_desc_to_pci_dev(msi_desc);
> + pbus = pdev->bus;
> + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
> +
> + memset(¶ms, 0, sizeof(params));
> + params.partition_id = HV_PARTITION_ID_SELF;
> + params.source = 1; /* MSI(-X) */
> + params.address = msi_desc->msg.address_lo;
> + params.data = msi_desc->msg.data;
> + params.device_id = (hbus->hdev->dev_instance.b[5] << 24) |
> + (hbus->hdev->dev_instance.b[4] << 16) |
> + (hbus->hdev->dev_instance.b[7] << 8) |
> + (hbus->hdev->dev_instance.b[6] & 0xf8) |
> + PCI_FUNC(pdev->devfn);
> + params.vector = cfg->vector;
> +
> + for_each_cpu_and(cpu, dest, cpu_online_mask)
> + params.vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu));
> +
> + hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, ¶ms, NULL);
> +
> + pci_msi_unmask_irq(data);
> +}
> +
> +struct compose_comp_ctxt {
> + struct hv_pci_compl comp_pkt;
> + struct tran_int_desc int_desc;
> +};
> +
> +static void hv_pci_compose_compl(void *context, struct pci_response *resp,
> + int resp_packet_size)
> +{
> + struct compose_comp_ctxt *comp_pkt = context;
> + struct pci_create_int_response *int_resp =
> + (struct pci_create_int_response *)resp;
> +
> + comp_pkt->comp_pkt.completion_status = resp->status;
> + comp_pkt->int_desc = int_resp->int_desc;
> + complete(&comp_pkt->comp_pkt.host_event);
> +}
> +
> +/**
> + * hv_compose_msi_msg() - Supplies a valid MSI address/data
> + * @data: Everything about this MSI
> + * @msg: Buffer that is filled in by this function
> + *
> + * This function unpacks the IRQ looking for target CPU set, IDT
> + * vector and mode and sends a message to the parent partition
> + * asking for a mapping for that tuple in this partition. The
> + * response supplies a data value and address to which that data
> + * should be written to trigger that interrupt.
> + */
> +static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + struct irq_cfg *cfg = irqd_cfg(data);
> + struct hv_pcibus_device *hbus;
> + struct hv_pci_dev *hpdev;
> + struct pci_bus *pbus;
> + struct pci_dev *pdev;
> + struct pci_create_interrupt *int_pkt;
> + struct compose_comp_ctxt comp;
> + struct tran_int_desc *int_desc;
> + struct cpumask *affinity;
> + struct {
> + struct pci_packet pkt;
> + u8 buffer[sizeof(struct pci_create_interrupt) -
> + sizeof(struct pci_message)];
> + } ctxt;
> + int cpu;
> + int ret;
> +
> + pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));
> + pbus = pdev->bus;
> + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
> + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
> +
> + if (!hpdev)
> + goto return_null_message;
> +
> + /* Free any previous message that might have already been composed. */
> + if (data->chip_data) {
> + int_desc = data->chip_data;
> + data->chip_data = NULL;
> + hv_int_desc_free(hpdev, int_desc);
> + }
> +
> + int_desc = kzalloc(sizeof(*int_desc), GFP_KERNEL);
> + if (!int_desc)
> + goto drop_reference;
> +
> + memset(&ctxt, 0, sizeof(ctxt));
> + init_completion(&comp.comp_pkt.host_event);
> + ctxt.pkt.completion_func = hv_pci_compose_compl;
> + ctxt.pkt.compl_ctxt = ∁
> + int_pkt = (struct pci_create_interrupt *)&ctxt.pkt.message;
> + int_pkt->message_type.message_type = PCI_CREATE_INTERRUPT_MESSAGE;
> + int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
> + int_pkt->int_desc.vector = cfg->vector;
> + int_pkt->int_desc.vector_count = 1;
> + int_pkt->int_desc.delivery_mode =
> + (apic->irq_delivery_mode == dest_LowestPrio) ? 1 : 0;
> +
> + /*
> + * This bit doesn't have to work on machines with more than 64
> + * processors because Hyper-V only supports 64 in a guest.
> + */
> + affinity = irq_data_get_affinity_mask(data);
> + for_each_cpu_and(cpu, affinity, cpu_online_mask) {
> + int_pkt->int_desc.cpu_mask |=
> + (1ULL << vmbus_cpu_number_to_vp_number(cpu));
> + }
> +
> + ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt,
> + sizeof(*int_pkt), (unsigned long)&ctxt.pkt,
> + VM_PKT_DATA_INBAND,
> + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> + if (!ret)
> + wait_for_completion(&comp.comp_pkt.host_event);
> +
> + if (comp.comp_pkt.completion_status < 0) {
> + dev_err(&hbus->hdev->device,
> + "Request for interrupt failed: 0x%x",
> + comp.comp_pkt.completion_status);
> + goto free_int_desc;
> + }
> +
> + /*
> + * Record the assignment so that this can be unwound later. Using
> + * irq_set_chip_data() here would be appropriate, but the lock it takes
> + * is already held.
> + */
> + *int_desc = comp.int_desc;
> + data->chip_data = int_desc;
> +
> + /* Pass up the result. */
> + msg->address_hi = comp.int_desc.address >> 32;
> + msg->address_lo = comp.int_desc.address & 0xffffffff;
> + msg->data = comp.int_desc.data;
> +
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> + return;
> +
> +free_int_desc:
> + kfree(int_desc);
> +drop_reference:
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> +return_null_message:
> + msg->address_hi = 0;
> + msg->address_lo = 0;
> + msg->data = 0;
> +}
> +
> +/* HW Interrupt Chip Descriptor */
> +static struct irq_chip hv_msi_irq_chip = {
> + .name = "Hyper-V PCIe MSI",
> + .irq_compose_msi_msg = hv_compose_msi_msg,
> + .irq_set_affinity = hv_set_affinity,
> + .irq_ack = irq_chip_ack_parent,
> + .irq_mask = hv_irq_mask,
> + .irq_unmask = hv_irq_unmask,
> +};
> +
> +static irq_hw_number_t hv_msi_domain_ops_get_hwirq(struct msi_domain_info *info,
> + msi_alloc_info_t *arg)
> +{
> + return arg->msi_hwirq;
> +}
> +
> +static struct msi_domain_ops hv_msi_ops = {
> + .get_hwirq = hv_msi_domain_ops_get_hwirq,
> + .msi_prepare = pci_msi_prepare,
> + .set_desc = pci_msi_set_desc,
> + .msi_free = hv_msi_free,
> +};
> +
> +/**
> + * hv_pcie_init_irq_domain() - Initialize IRQ domain
> + * @hbus: The root PCI bus
> + *
> + * This function creates an IRQ domain which will be used for
> + * interrupts from devices that have been passed through. These
> + * devices only support MSI and MSI-X, not line-based interrupts
> + * or simulations of line-based interrupts through PCIe's
> + * fabric-layer messages. Because interrupts are remapped, we
> + * can support multi-message MSI here.
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
> +{
> + hbus->msi_info.chip = &hv_msi_irq_chip;
> + hbus->msi_info.ops = &hv_msi_ops;
> + hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
> + MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
> + MSI_FLAG_PCI_MSIX);
> + hbus->msi_info.handler = handle_edge_irq;
> + hbus->msi_info.handler_name = "edge";
> + hbus->msi_info.data = hbus;
> + hbus->irq_domain = pci_msi_create_irq_domain(hbus->sysdata.fwnode,
> + &hbus->msi_info,
> + x86_vector_domain);
> + if (!hbus->irq_domain) {
> + dev_err(&hbus->hdev->device,
> + "Failed to build an MSI IRQ domain\n");
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * get_bar_size() - Get the address space consumed by a BAR
> + * @bar_val: Value that a BAR returned after -1 was written
> + * to it.
> + *
> + * This function returns the size of the BAR, rounded up to 1
> + * page. It has to be rounded up because the hypervisor's page
> + * table entry that maps the BAR into the VM can't specify an
> + * offset within a page. The invariant is that the hypervisor
> + * must place any BARs of smaller than page length at the
> + * beginning of a page.
> + *
> + * Return: Size in bytes of the consumed MMIO space.
> + */
> +static u64 get_bar_size(u64 bar_val)
> +{
> + return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)),
> + PAGE_SIZE);
> +}
> +
> +/**
> + * survey_child_resources() - Total all MMIO requirements
> + * @hbus: Root PCI bus, as understood by this driver
> + */
> +static void survey_child_resources(struct hv_pcibus_device *hbus)
> +{
> + struct list_head *iter;
> + struct hv_pci_dev *hpdev;
> + resource_size_t bar_size = 0;
> + unsigned long flags;
> + struct completion *event;
> + u64 bar_val;
> + int i;
> +
> + /* If nobody is waiting on the answer, don't compute it. */
> + event = xchg(&hbus->survey_event, NULL);
> + if (!event)
> + return;
> +
> + /* If the answer has already been computed, go with it. */
> + if (hbus->low_mmio_space || hbus->high_mmio_space) {
> + complete(event);
> + return;
> + }
> +
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> +
> + /*
> + * Due to an interesting quirk of the PCI spec, all memory regions
> + * for a child device are a power of 2 in size and aligned in memory,
> + * so it's sufficient to just add them up without tracking alignment.
> + */
> + list_for_each(iter, &hbus->children) {
> + hpdev = container_of(iter, struct hv_pci_dev, list_entry);
> + for (i = 0; i < 6; i++) {
> + if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO)
> + dev_err(&hbus->hdev->device,
> + "There's an I/O BAR in this list!\n");
> +
> + if (hpdev->probed_bar[i] != 0) {
> + /*
> + * A probed BAR has all the upper bits set that
> + * can be changed.
> + */
> +
> + bar_val = hpdev->probed_bar[i];
> + if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
> + bar_val |=
> + ((u64)hpdev->probed_bar[++i] << 32);
> + else
> + bar_val |= 0xffffffff00000000ULL;
> +
> + bar_size = get_bar_size(bar_val);
> +
> + if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
> + hbus->high_mmio_space += bar_size;
> + else
> + hbus->low_mmio_space += bar_size;
> + }
> + }
> + }
> +
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> + complete(event);
> +}
> +
> +/**
> + * prepopulate_bars() - Fill in BARs with defaults
> + * @hbus: Root PCI bus, as understood by this driver
> + *
> + * The core PCI driver code seems much, much happier if the BARs
> + * for a device have values upon first scan. So fill them in.
> + * The algorithm below works down from large sizes to small,
> + * attempting to pack the assignments optimally. The assumption,
> + * enforced in other parts of the code, is that the beginning of
> + * the memory-mapped I/O space will be aligned on the largest
> + * BAR size.
> + */
> +static void prepopulate_bars(struct hv_pcibus_device *hbus)
> +{
> + resource_size_t high_size = 0;
> + resource_size_t low_size = 0;
> + resource_size_t high_base = 0;
> + resource_size_t low_base = 0;
> + resource_size_t bar_size;
> + struct hv_pci_dev *hpdev;
> + struct list_head *iter;
> + unsigned long flags;
> + u64 bar_val;
> + u32 command;
> + bool high;
> + int i;
> +
> + if (hbus->low_mmio_space) {
> + low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
> + low_base = hbus->low_mmio_res->start;
> + }
> +
> + if (hbus->high_mmio_space) {
> + high_size = 1ULL <<
> + (63 - __builtin_clzll(hbus->high_mmio_space));
> + high_base = hbus->high_mmio_res->start;
> + }
> +
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> +
> + /* Pick addresses for the BARs. */
> + do {
> + list_for_each(iter, &hbus->children) {
> + hpdev = container_of(iter, struct hv_pci_dev,
> + list_entry);
> + for (i = 0; i < 6; i++) {
> + bar_val = hpdev->probed_bar[i];
> + if (bar_val == 0)
> + continue;
> + high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64;
> + if (high) {
> + bar_val |=
> + ((u64)hpdev->probed_bar[i + 1]
> + << 32);
> + } else {
> + bar_val |= 0xffffffffULL << 32;
> + }
> + bar_size = get_bar_size(bar_val);
> + if (high) {
> + if (high_size != bar_size) {
> + i++;
> + continue;
> + }
> + _hv_pcifront_write_config(hpdev,
> + PCI_BASE_ADDRESS_0 + (4 * i),
> + 4,
> + (u32)(high_base & 0xffffff00));
> + i++;
> + _hv_pcifront_write_config(hpdev,
> + PCI_BASE_ADDRESS_0 + (4 * i),
> + 4, (u32)(high_base >> 32));
> + high_base += bar_size;
> + } else {
> + if (low_size != bar_size)
> + continue;
> + _hv_pcifront_write_config(hpdev,
> + PCI_BASE_ADDRESS_0 + (4 * i),
> + 4,
> + (u32)(low_base & 0xffffff00));
> + low_base += bar_size;
> + }
> + }
> + if (high_size <= 1 && low_size <= 1) {
> + /* Set the memory enable bit. */
> + _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2,
> + &command);
> + command |= PCI_COMMAND_MEMORY;
> + _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2,
> + command);
> + break;
> + }
> + }
> +
> + high_size >>= 1;
> + low_size >>= 1;
> + } while (high_size || low_size);
> +
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +}
> +
> +/**
> + * create_root_hv_pci_bus() - Expose a new root PCI bus
> + * @hbus: Root PCI bus, as understood by this driver
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
> +{
> + /* Register the device */
> + hbus->pci_bus = pci_create_root_bus(&hbus->hdev->device,
> + 0, /* bus number is always zero */
> + &hv_pcifront_ops,
> + &hbus->sysdata,
> + &hbus->resources_for_children);
> + if (!hbus->pci_bus)
> + return -ENODEV;
> +
> + hbus->pci_bus->msi = &hbus->msi_chip;
> + hbus->pci_bus->msi->dev = &hbus->hdev->device;
> +
> + pci_scan_child_bus(hbus->pci_bus);
> + pci_bus_assign_resources(hbus->pci_bus);
> + pci_bus_add_devices(hbus->pci_bus);
> + hbus->state = hv_pcibus_installed;
> + return 0;
> +}
> +
> +struct q_res_req_compl {
> + struct completion host_event;
> + struct hv_pci_dev *hpdev;
> +};
> +
> +/**
> + * q_resource_requirements() - Query Resource Requirements
> + * @context: The completion context.
> + * @resp: The response that came from the host.
> + * @resp_packet_size: The size in bytes of resp.
> + *
> + * This function is invoked on completion of a Query Resource
> + * Requirements packet.
> + */
> +static void q_resource_requirements(void *context, struct pci_response *resp,
> + int resp_packet_size)
> +{
> + struct q_res_req_compl *completion = context;
> + struct pci_q_res_req_response *q_res_req =
> + (struct pci_q_res_req_response *)resp;
> + int i;
> +
> + if (resp->status < 0) {
> + dev_err(&completion->hpdev->hbus->hdev->device,
> + "query resource requirements failed: %x\n",
> + resp->status);
> + } else {
> + for (i = 0; i < 6; i++) {
> + completion->hpdev->probed_bar[i] =
> + q_res_req->probed_bar[i];
> + }
> + }
> +
> + complete(&completion->host_event);
> +}
> +
> +static void get_pcichild(struct hv_pci_dev *hpdev,
> + enum hv_pcidev_ref_reason reason)
> +{
> + pr_devel("+%s %p\n", hv_pcidev_ref_debug[reason], hpdev);
This looks like debug code that should be removed (sorry, I should
have mentioned this the first time).
> + atomic_inc(&hpdev->refs);
> +}
> +
> +static void put_pcichild(struct hv_pci_dev *hpdev,
> + enum hv_pcidev_ref_reason reason)
> +{
> + pr_devel("-%s %p\n", hv_pcidev_ref_debug[reason], hpdev);
> + if (atomic_dec_and_test(&hpdev->refs)) {
> + pr_devel("Freeing hv_pcidev %p\n", hpdev);
> + kfree(hpdev);
> + }
> +}
> +
> +/**
> + * new_pcichild_device() - Create a new child device
> + * @hbus: The internal struct tracking this root PCI bus.
> + * @desc: The information supplied so far from the host
> + * about the device.
> + *
> + * This function creates the tracking structure for a new child
> + * device and kicks off the process of figuring out what it is.
> + *
> + * Return: Pointer to the new tracking struct
> + */
> +static
> +struct hv_pci_dev *
> +new_pcichild_device(struct hv_pcibus_device *hbus,
> + struct pci_function_description *desc)
Indent like the rest of the file (as much as possible on one line),
e.g.,
static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
struct pci_function_description *desc)
> +{
> + struct hv_pci_dev *hpdev;
> + struct pci_child_message *res_req;
> + struct q_res_req_compl comp_pkt;
> + union {
> + struct pci_packet init_packet;
> + u8 buffer[0x100];
> + } pkt;
> + unsigned long flags;
> + int ret;
> +
> + hpdev = kzalloc(sizeof(*hpdev), GFP_ATOMIC);
> + if (!hpdev)
> + return NULL;
> +
> + pr_devel("New child device (%p) [%04x:%04x] at %04x:00:00.%02x\n",
> + hpdev, desc->v_id, desc->d_id, (u16)hbus->sysdata.domain,
> + desc->win_slot.bits.func);
Can this be removed or made a dev_info()? I assume the PCI core
already prints all this information (except the hpdev pointer)?
If you need this output, can you use "pci_domain_nr(hbus->pci_bus)"
instead of "(u16)hbus->sysdata.domain" to remove this x86 dependency?
> +
> + hpdev->hbus = hbus;
> +
> + memset(&pkt, 0, sizeof(pkt));
> + init_completion(&comp_pkt.host_event);
> + comp_pkt.hpdev = hpdev;
> + pkt.init_packet.compl_ctxt = &comp_pkt;
> + pkt.init_packet.completion_func = q_resource_requirements;
> + res_req = (struct pci_child_message *)&pkt.init_packet.message;
> + res_req->message_type = PCI_QUERY_RESOURCE_REQUIREMENTS;
> + res_req->wslot.slot = desc->win_slot.slot;
> +
> + ret = vmbus_sendpacket(hbus->hdev->channel, res_req,
> + sizeof(struct pci_child_message),
> + (unsigned long)&pkt.init_packet,
> + VM_PKT_DATA_INBAND,
> + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> + if (ret)
> + goto error;
> +
> + wait_for_completion(&comp_pkt.host_event);
> +
> + hpdev->desc = *desc;
> + get_pcichild(hpdev, hv_pcidev_ref_initial);
> + get_pcichild(hpdev, hv_pcidev_ref_childlist);
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + list_add_tail(&hpdev->list_entry, &hbus->children);
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> + return hpdev;
> +
> +error:
> +
> + kfree(hpdev);
> + return NULL;
> +}
> +
> +/**
> + * get_pcichild_wslot() - Find device from slot
> + * @hbus: Root PCI bus, as understood by this driver
> + * @wslot: Location on the bus
> + *
> + * This function looks up a PCI device and returns the internal
> + * representation of it. It acquires a reference on it, so that
> + * the device won't be deleted while somebody is using it. The
> + * caller is responsible for calling put_pcichild() to release
> + * this reference.
> + *
> + * Return: Internal representation of a PCI device
> + */
> +static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
> + u32 wslot)
> +{
> + unsigned long flags;
> + struct hv_pci_dev *iter, *hpdev = NULL;
> +
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + list_for_each_entry(iter, &hbus->children, list_entry) {
> + if (iter->desc.win_slot.slot == wslot) {
> + hpdev = iter;
> + get_pcichild(hpdev, hv_pcidev_ref_by_slot);
> + break;
> + }
> + }
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +
> + return hpdev;
> +}
> +
> +/**
> + * pci_devices_present_work() - Handle new list of child devices
> + * @work: Work struct embedded in struct hv_dr_work
> + *
> + * "Bus Relations" is the Windows term for "children of this
> + * bus." The terminology is preserved here for people trying to
> + * debug the interaction between Hyper-V and Linux. This
> + * function is called when the parent partition reports a list
> + * of functions that should be observed under this PCI Express
> + * port (bus).
> + *
> + * This function updates the list, and must tolerate being
> + * called multiple times with the same information. The typical
> + * number of child devices is one, with very atypical cases
> + * involving three or four, so the algorithms used here can be
> + * simple and inefficient.
> + *
> + * It must also treat the omission of a previously observed device as
> + * notification that the device no longer exists.
> + *
> + * Note that this function is a work item, and it may not be
> + * invoked in the order that it was queued. Back to back
> + * updates of the list of present devices may involve queuing
> + * multiple work items, and this one may run before ones that
> + * were sent later. As such, this function only does something
> + * if is the last one in the queue.
> + */
> +static void pci_devices_present_work(struct work_struct *work)
> +{
> + u32 child_no;
> + bool found;
> + struct list_head *iter;
> + struct pci_function_description *new_desc;
> + struct hv_pci_dev *hpdev;
> + struct hv_pcibus_device *hbus;
> + struct list_head removed;
> + struct hv_dr_work *dr_wrk;
> + struct hv_dr_state *dr = NULL;
> + unsigned long flags;
> +
> + dr_wrk = container_of(work, struct hv_dr_work, wrk);
> + hbus = dr_wrk->bus;
> + kfree(dr_wrk);
> +
> + INIT_LIST_HEAD(&removed);
> +
> + if (down_interruptible(&hbus->enum_sem)) {
> + put_hvpcibus(hbus);
> + return;
> + }
> +
> + /* Pull this off the queue and process it if it was the last one. */
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + while (!list_empty(&hbus->dr_list)) {
> + dr = list_first_entry(&hbus->dr_list, struct hv_dr_state,
> + list_entry);
> + list_del(&dr->list_entry);
> +
> + /* Throw this away if the list still has stuff in it. */
> + if (!list_empty(&hbus->dr_list)) {
> + kfree(dr);
> + continue;
> + }
> + }
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +
> + if (!dr) {
> + up(&hbus->enum_sem);
> + put_hvpcibus(hbus);
> + return;
> + }
> +
> + /* First, mark all existing children as reported missing. */
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + list_for_each(iter, &hbus->children) {
> + hpdev = container_of(iter, struct hv_pci_dev,
> + list_entry);
> + hpdev->reported_missing = true;
> + }
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +
> + /* Next, add back any reported devices. */
> + for (child_no = 0; child_no < dr->device_count; child_no++) {
> + found = false;
> + new_desc = &dr->func[child_no];
> +
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + list_for_each(iter, &hbus->children) {
> + hpdev = container_of(iter, struct hv_pci_dev,
> + list_entry);
> + if ((hpdev->desc.win_slot.slot ==
> + new_desc->win_slot.slot) &&
> + (hpdev->desc.v_id == new_desc->v_id) &&
> + (hpdev->desc.d_id == new_desc->d_id) &&
> + (hpdev->desc.ser == new_desc->ser)) {
> + hpdev->reported_missing = false;
> + found = true;
> + }
> + }
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +
> + if (!found) {
> + hpdev = new_pcichild_device(hbus, new_desc);
> + if (!hpdev)
> + dev_err(&hbus->hdev->device,
> + "couldn't record a child device.\n");
> + }
> + }
> +
> + /* Move missing children to a list on the stack. */
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + do {
> + found = false;
> + list_for_each(iter, &hbus->children) {
> + hpdev = container_of(iter, struct hv_pci_dev,
> + list_entry);
> + if (hpdev->reported_missing) {
> + found = true;
> + put_pcichild(hpdev, hv_pcidev_ref_childlist);
> + list_del(&hpdev->list_entry);
> + list_add_tail(&hpdev->list_entry, &removed);
> + break;
> + }
> + }
> + } while (found);
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +
> + /* Delete everything that should no longer exist. */
> + while (!list_empty(&removed)) {
> + hpdev = list_first_entry(&removed, struct hv_pci_dev,
> + list_entry);
> + list_del(&hpdev->list_entry);
> + put_pcichild(hpdev, hv_pcidev_ref_initial);
> + }
> +
> + /* Tell the core to rescan bus because there may have been changes. */
> + if (hbus->state == hv_pcibus_installed) {
> + pci_lock_rescan_remove();
> + pci_scan_child_bus(hbus->pci_bus);
> + pci_unlock_rescan_remove();
> + } else {
> + survey_child_resources(hbus);
> + }
> +
> + up(&hbus->enum_sem);
> + put_hvpcibus(hbus);
> + kfree(dr);
> +}
> +
> +/**
> + * hv_pci_devices_present() - Handles list of new children
> + * @hbus: Root PCI bus, as understood by this driver
> + * @relations: Packet from host listing children
> + *
> + * This function is invoked whenever a new list of devices for
> + * this bus appears.
> + */
> +static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
> + struct pci_bus_relations *relations)
> +{
> + struct hv_dr_state *dr;
> + struct hv_dr_work *dr_wrk;
> + unsigned long flags;
> +
> + dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
> +
> + if (!dr_wrk)
> + return;
> +
> + dr = kzalloc(offsetof(struct hv_dr_state, func) +
> + (sizeof(struct pci_function_description) *
> + (relations->device_count)), GFP_NOWAIT);
> +
> + if (!dr) {
> + kfree(dr_wrk);
> + return;
> + }
> +
> + INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
> + dr_wrk->bus = hbus;
> + dr->device_count = relations->device_count;
> + if (dr->device_count != 0) {
> + memcpy(dr->func, relations->func,
> + sizeof(struct pci_function_description) *
> + dr->device_count);
> + }
> +
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> + list_add_tail(&dr->list_entry, &hbus->dr_list);
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> +
> + get_hvpcibus(hbus);
> + schedule_work(&dr_wrk->wrk);
> +}
> +
> +/**
> + * hv_eject_device_work() - Asynchronously handles ejection
> + * @work: Work struct embedded in internal device struct
> + *
> + * This function handles ejecting a device. Windows will
> + * attempt to gracefully eject a device, waiting 60 seconds to
> + * hear back from the guest OS that this completed successfully.
> + * If this timer expires, the device will be forcibly removed.
> + */
> +static void hv_eject_device_work(struct work_struct *work)
> +{
> + struct pci_eject_response *ejct_pkt;
> + struct hv_pci_dev *hpdev;
> + struct pci_dev *pdev;
> + unsigned long flags;
> + int wslot;
> + struct {
> + struct pci_packet pkt;
> + u8 buffer[sizeof(struct pci_eject_response) -
> + sizeof(struct pci_message)];
> + } ctxt;
> +
> + hpdev = container_of(work, struct hv_pci_dev, wrk);
> +
> + if (hpdev->state != hv_pcichild_ejecting) {
> + put_pcichild(hpdev, hv_pcidev_ref_pnp);
> + return;
> + }
> +
> + wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
> + pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
> + wslot);
Can you use "pci_domain_nr(hpdev->hbus->pci_bus)" here as well?
> + if (pdev) {
> + pci_stop_and_remove_bus_device(pdev);
> + pci_dev_put(pdev);
> + }
> +
> + memset(&ctxt, 0, sizeof(ctxt));
> + ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
> + ejct_pkt->message_type = PCI_EJECTION_COMPLETE;
> + ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
> + vmbus_sendpacket(hpdev->hbus->hdev->channel, ejct_pkt,
> + sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
> + VM_PKT_DATA_INBAND, 0);
> +
> + spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
> + list_del(&hpdev->list_entry);
> + spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
> +
> + put_pcichild(hpdev, hv_pcidev_ref_childlist);
> + put_pcichild(hpdev, hv_pcidev_ref_pnp);
> + put_hvpcibus(hpdev->hbus);
> +}
> +
> +/**
> + * hv_pci_eject_device() - Handles device ejection
> + * @hpdev: Internal device tracking struct
> + *
> + * This function is invoked when an ejection packet arrives. It
> + * just schedules work so that we don't re-enter the packet
> + * delivery code handling the ejection.
> + */
> +static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
> +{
> + hpdev->state = hv_pcichild_ejecting;
> + get_pcichild(hpdev, hv_pcidev_ref_pnp);
> + INIT_WORK(&hpdev->wrk, hv_eject_device_work);
> + get_hvpcibus(hpdev->hbus);
> + schedule_work(&hpdev->wrk);
> +}
> +
> +/**
> + * hv_pci_onchannelcallback() - Handles incoming packets
> + * @context: Internal bus tracking struct
> + *
> + * This function is invoked whenever the host sends a packet to
> + * this channel (which is private to this root PCI bus).
> + */
> +static void hv_pci_onchannelcallback(void *context)
> +{
> + const int packet_size = 0x100;
> + int ret;
> + struct hv_pcibus_device *hbus = context;
> + u32 bytes_recvd;
> + u64 req_id;
> + struct vmpacket_descriptor *desc;
> + unsigned char *buffer;
> + int bufferlen = packet_size;
> + struct pci_packet *comp_packet;
> + struct pci_response *response;
> + struct pci_incoming_message *new_message;
> + struct pci_bus_relations *bus_rel;
> + struct pci_dev_incoming *dev_message;
> + struct hv_pci_dev *hpdev;
> +
> + buffer = kmalloc(bufferlen, GFP_ATOMIC);
> + if (!buffer)
> + return;
> +
> + while (1) {
> + ret = vmbus_recvpacket_raw(hbus->hdev->channel, buffer,
> + bufferlen, &bytes_recvd, &req_id);
> +
> + if (ret == -ENOBUFS) {
> + kfree(buffer);
> + /* Handle large packet */
> + bufferlen = bytes_recvd;
> + buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
> + if (!buffer)
> + return;
> + continue;
> + }
> +
> + /*
> + * All incoming packets must be at least as large as a
> + * response.
> + */
> + if (bytes_recvd <= sizeof(struct pci_response)) {
> + kfree(buffer);
> + return;
> + }
> + desc = (struct vmpacket_descriptor *)buffer;
> +
> + switch (desc->type) {
> + case VM_PKT_COMP:
> +
> + /*
> + * The host is trusted, and thus it's safe to interpret
> + * this transaction ID as a pointer.
> + */
> + comp_packet = (struct pci_packet *)req_id;
> + response = (struct pci_response *)buffer;
> + comp_packet->completion_func(comp_packet->compl_ctxt,
> + response,
> + bytes_recvd);
> + kfree(buffer);
> + return;
> +
> + case VM_PKT_DATA_INBAND:
> +
> + new_message = (struct pci_incoming_message *)buffer;
> + switch (new_message->message_type.message_type) {
> + case PCI_BUS_RELATIONS:
> +
> + bus_rel = (struct pci_bus_relations *)buffer;
> + if (bytes_recvd <
> + offsetof(struct pci_bus_relations, func) +
> + (sizeof(struct pci_function_description) *
> + (bus_rel->device_count))) {
> + dev_err(&hbus->hdev->device,
> + "bus relations too small\n");
> + break;
> + }
> +
> + hv_pci_devices_present(hbus, bus_rel);
> + break;
> +
> + case PCI_EJECT:
> +
> + dev_message = (struct pci_dev_incoming *)buffer;
> + hpdev = get_pcichild_wslot(hbus,
> + dev_message->wslot.slot);
> + if (hpdev) {
> + hv_pci_eject_device(hpdev);
> + put_pcichild(hpdev,
> + hv_pcidev_ref_by_slot);
> + }
> + break;
> +
> + default:
> + dev_warn(&hbus->hdev->device,
> + "Unimplemented protocol message %x\n",
> + new_message->message_type.message_type);
> + break;
> + }
> + break;
> +
> + default:
> + dev_err(&hbus->hdev->device,
> + "unhandled packet type %d, tid %llx len %d\n",
> + desc->type, req_id, bytes_recvd);
> + break;
> + }
> + break;
> + }
> +}
> +
> +/**
> + * hv_pci_protocol_negotiation() - Set up protocol
> + * @hdev: Vmbus's tracking struct for this root PCI bus
> + *
> + * This driver is intended to support running on Windows 10
> + * (server) and later versions. It will not run on earlier
> + * versions, as they assume that many of the operations which
> + * Linux needs accomplished with a spinlock held were done via
> + * asynchronous messaging via VMBus. Windows 10 increases the
> + * surface area of PCI emulation so that these actions can take
> + * place by suspending a virtual processor for their duration.
> + *
> + * This function negotiates the channel protocol version,
> + * failing if the host doesn't support the necessary protocol
> + * level.
> + */
> +static int hv_pci_protocol_negotiation(struct hv_device *hdev)
> +{
> + struct pci_version_request *version_req;
> + struct hv_pci_compl comp_pkt;
> + struct pci_packet *pkt;
> + int ret;
> +
> + /*
> + * Initiate the handshake with the host and negotiate
> + * a version that the host can support. We start with the
> + * highest version number and go down if the host cannot
> + * support it.
> + */
> +
> + pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL);
> + if (!pkt)
> + return -ENOMEM;
> +
> + init_completion(&comp_pkt.host_event);
> + pkt->completion_func = hv_pci_generic_compl;
> + pkt->compl_ctxt = &comp_pkt;
> + version_req = (struct pci_version_request *)&pkt->message;
> + version_req->message_type.message_type = PCI_QUERY_PROTOCOL_VERSION;
> + version_req->protocol_version = PCI_PROTOCOL_VERSION_CURRENT;
> +
> + ret = vmbus_sendpacket(hdev->channel, version_req,
> + sizeof(struct pci_version_request),
> + (unsigned long)pkt, VM_PKT_DATA_INBAND,
> + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> + if (ret)
> + goto exit;
> +
> + wait_for_completion(&comp_pkt.host_event);
> +
> + if (comp_pkt.completion_status < 0) {
> + dev_err(&hdev->device,
> + "PCI Pass-through VSP failed version request %x\n",
> + comp_pkt.completion_status);
> + ret = -EPROTO;
> + goto exit;
> + }
> +
> + ret = 0;
> +
> +exit:
> +
> + kfree(pkt);
> + return ret;
> +}
> +
> +/**
> + * hv_pci_free_bridge_windows() - Release memory regions for the
> + * bus
> + * @hbus: Root PCI bus, as understood by this driver
> + */
> +static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus)
> +{
> + /*
> + * Set the resources back to the way they looked when they
> + * were allocated by setting IORESOURCE_BUSY again.
> + */
> +
> + if (hbus->low_mmio_space && hbus->low_mmio_res) {
> + hbus->low_mmio_res->flags |= IORESOURCE_BUSY;
> + release_mem_region(hbus->low_mmio_res->start,
> + resource_size(hbus->low_mmio_res));
> + }
> +
> + if (hbus->high_mmio_space && hbus->high_mmio_res) {
> + hbus->high_mmio_res->flags |= IORESOURCE_BUSY;
> + release_mem_region(hbus->high_mmio_res->start,
> + resource_size(hbus->high_mmio_res));
> + }
> +}
> +
> +/**
> + * hv_pci_allocate_bridge_windows() - Allocate memory regions
> + * for the bus
> + * @hbus: Root PCI bus, as understood by this driver
> + *
> + * This function calls vmbus_allocate_mmio(), which is itself a
> + * bit of a compromise. Ideally, we might change the pnp layer
> + * in the kernel such that it comprehends either PCI devices
> + * which are "grandchildren of ACPI," with some intermediate bus
> + * node (in this case, VMBus) or change it such that it
> + * understands VMBus. The pnp layer, however, has been declared
> + * deprecated, and not subject to change.
> + *
> + * The workaround, implemented here, is to ask VMBus to allocate
> + * MMIO space for this bus. VMBus itself knows which ranges are
> + * appropriate by looking at its own ACPI objects. Then, after
> + * these ranges are claimed, they're modified to look like they
> + * would have looked if the ACPI and pnp code had allocated
> + * bridge windows. These descriptors have to exist in this form
> + * in order to satisfy the code which will get invoked when the
> + * endpoint PCI function driver calls request_mem_region() or
> + * request_mem_region_exclusive().
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus)
> +{
> + resource_size_t align;
> + int ret;
> +
> + if (hbus->low_mmio_space) {
> + align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
> + ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0,
> + (u64)(u32)0xffffffff,
> + hbus->low_mmio_space,
> + align, false);
> + if (ret) {
> + dev_err(&hbus->hdev->device,
> + "Need %#llx of low MMIO space. Consider reconfiguring the VM.\n",
> + hbus->low_mmio_space);
> + return ret;
> + }
> +
> + /* Modify this resource to become a bridge window. */
> + hbus->low_mmio_res->flags |= IORESOURCE_WINDOW;
> + hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY;
> + pci_add_resource(&hbus->resources_for_children,
> + hbus->low_mmio_res);
> + }
> +
> + if (hbus->high_mmio_space) {
> + align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space));
> + ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev,
> + 0x100000000, -1,
> + hbus->high_mmio_space, align,
> + false);
> + if (ret) {
> + dev_err(&hbus->hdev->device,
> + "Need %#llx of high MMIO space. Consider reconfiguring the VM.\n",
> + hbus->high_mmio_space);
> + goto release_low_mmio;
> + }
> +
> + /* Modify this resource to become a bridge window. */
> + hbus->high_mmio_res->flags |= IORESOURCE_WINDOW;
> + hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY;
> + pci_add_resource(&hbus->resources_for_children,
> + hbus->high_mmio_res);
> + }
> +
> + return 0;
> +
> +release_low_mmio:
> +
> + if (hbus->low_mmio_res) {
> + release_mem_region(hbus->low_mmio_res->start,
> + resource_size(hbus->low_mmio_res));
> + }
> +
> + return ret;
> +}
> +
> +/**
> + * hv_allocate_config_window() - Find MMIO space for PCI Config
> + * @hbus: Root PCI bus, as understood by this driver
> + *
> + * This function claims memory-mapped I/O space for accessing
> + * configuration space for the functions on this bus.
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_allocate_config_window(struct hv_pcibus_device *hbus)
> +{
> + int ret;
> +
> + /*
> + * Set up a region of MMIO space to use for accessing configuration
> + * space.
> + */
> + ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1,
> + PCI_CONFIG_MMIO_LENGTH, 0x1000, false);
> + if (ret)
> + return ret;
> +
> + /*
> + * vmbus_allocate_mmio() gets used for allocating both device endpoint
> + * resource claims (those which cannot be overlapped) and the ranges
> + * which are valid for the children of this bus, which are intended
> + * to be overlapped by those children. Set the flag on this claim
> + * meaning that this region can't be overlapped.
> + */
Comment indentation error.
> + hbus->mem_config->flags |= IORESOURCE_BUSY;
> +
> + return 0;
> +}
> +
> +static void hv_free_config_window(struct hv_pcibus_device *hbus)
> +{
> + release_mem_region(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
> +}
> +
> +/**
> + * hv_pci_enter_d0() - Bring the "bus" into the D0 power state
> + * @hdev: Vmbus's tracking struct for this root PCI bus
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_pci_enter_d0(struct hv_device *hdev)
> +{
> + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
> + struct pci_bus_d0_entry *d0_entry;
> + struct hv_pci_compl comp_pkt;
> + struct pci_packet *pkt;
> + int ret;
> +
> + /*
> + * Tell the host that the bus is ready to use, and moved into the
> + * powered-on state. This includes telling the host which region
> + * of memory-mapped I/O space has been chosen for configuration space
> + * access.
> + */
> +
> + pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL);
> + if (!pkt)
> + return -ENOMEM;
> +
> + init_completion(&comp_pkt.host_event);
> + pkt->completion_func = hv_pci_generic_compl;
> + pkt->compl_ctxt = &comp_pkt;
> + d0_entry = (struct pci_bus_d0_entry *)&pkt->message;
> + d0_entry->message_type.message_type = PCI_BUS_D0ENTRY;
> + d0_entry->mmio_base = hbus->mem_config->start;
> +
> + ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),
> + (unsigned long)pkt, VM_PKT_DATA_INBAND,
> + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> + if (ret)
> + goto exit;
> + wait_for_completion(&comp_pkt.host_event);
> +
> + if (comp_pkt.completion_status < 0) {
> + dev_err(&hdev->device,
> + "PCI Pass-through VSP failed D0 Entry with status %x\n",
> + comp_pkt.completion_status);
> + ret = -EPROTO;
> + goto exit;
> + }
> +
> + ret = 0;
> +
> +exit:
> +
> + kfree(pkt);
> + return ret;
> +}
> +
> +/**
> + * hv_pci_query_relations() - Ask host to send list of child
> + * devices
> + * @hdev: Vmbus's tracking struct for this root PCI bus
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_pci_query_relations(struct hv_device *hdev)
> +{
> + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
> + struct pci_message message;
> + struct completion comp;
> + int ret;
> +
> + /*
> + * Ask the host to send along the list of child devices.
> + */
> +
> + init_completion(&comp);
> + if (cmpxchg(&hbus->survey_event, NULL, &comp))
> + return -ENOTEMPTY;
> +
> + memset(&message, 0, sizeof(message));
> + message.message_type = PCI_QUERY_BUS_RELATIONS;
> +
> + ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),
> + 0, VM_PKT_DATA_INBAND, 0);
> + if (ret)
> + return ret;
> +
> + wait_for_completion(&comp);
> + return 0;
> +}
> +
> +/**
> + * hv_send_resources_allocated() - Report local resource choices
> + * @hdev: Vmbus's tracking struct for this root PCI bus
> + *
> + * The host OS is expecting to be sent a request as a message
> + * which contains all the resources that the device will use.
> + * The response contains those same resources, "translated"
> + * which is to say, the values which should be used by the
> + * hardware, when it delivers an interrupt. (MMIO resources are
> + * used in local terms.) This is nice for Windows, and lines up
> + * with the FDO/PDO split, which doesn't exist in Linux. Linux
> + * is deeply expecting to scan an emulated PCI configuration
> + * space. So this message is sent here only to drive the state
> + * machine on the host forward.
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_send_resources_allocated(struct hv_device *hdev)
> +{
> + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
> + struct pci_resources_assigned *res_assigned;
> + struct hv_pci_compl comp_pkt;
> + struct hv_pci_dev *hpdev;
> + struct pci_packet *pkt;
> + u32 wslot;
> + int ret;
> +
> + pkt = kmalloc(sizeof(*pkt) + sizeof(*res_assigned), GFP_KERNEL);
> + if (!pkt)
> + return -ENOMEM;
> +
> + ret = 0;
> +
> + for (wslot = 0; wslot < 256; wslot++) {
> + hpdev = get_pcichild_wslot(hbus, wslot);
> + if (!hpdev)
> + continue;
> +
> + memset(pkt, 0, sizeof(*pkt) + sizeof(*res_assigned));
> + init_completion(&comp_pkt.host_event);
> + pkt->completion_func = hv_pci_generic_compl;
> + pkt->compl_ctxt = &comp_pkt;
> + pkt->message.message_type = PCI_RESOURCES_ASSIGNED;
> + res_assigned = (struct pci_resources_assigned *)&pkt->message;
> + res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
> +
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> +
> + ret = vmbus_sendpacket(
> + hdev->channel, &pkt->message,
> + sizeof(*res_assigned),
> + (unsigned long)pkt,
> + VM_PKT_DATA_INBAND,
> + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> + if (ret)
> + break;
> +
> + wait_for_completion(&comp_pkt.host_event);
> +
> + if (comp_pkt.completion_status < 0) {
> + ret = -EPROTO;
> + dev_err(&hdev->device,
> + "resource allocated returned 0x%x",
> + comp_pkt.completion_status);
> + break;
> + }
> + }
> +
> + kfree(pkt);
> + return ret;
> +}
> +
> +/**
> + * hv_send_resources_released() - Report local resources
> + * released
> + * @hdev: Vmbus's tracking struct for this root PCI bus
%s/Vmbus/VMBus/g
I mentioned this last time, but there are still a few left.
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_send_resources_released(struct hv_device *hdev)
> +{
> + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
> + struct pci_child_message pkt;
> + struct hv_pci_dev *hpdev;
> + u32 wslot;
> + int ret;
> +
> + for (wslot = 0; wslot < 256; wslot++) {
> + hpdev = get_pcichild_wslot(hbus, wslot);
> + if (!hpdev)
> + continue;
> +
> + memset(&pkt, 0, sizeof(pkt));
> + pkt.message_type = PCI_RESOURCES_RELEASED;
> + pkt.wslot.slot = hpdev->desc.win_slot.slot;
> +
> + put_pcichild(hpdev, hv_pcidev_ref_by_slot);
> +
> + ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,
> + VM_PKT_DATA_INBAND, 0);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void get_hvpcibus(struct hv_pcibus_device *hbus)
> +{
> + pr_devel("+> %d %p\n", atomic_read(&hbus->remove_lock) + 1, hbus);
> + atomic_inc(&hbus->remove_lock);
> +}
> +
> +static void put_hvpcibus(struct hv_pcibus_device *hbus)
> +{
> + pr_devel("-> %d %p\n", atomic_read(&hbus->remove_lock) - 1, hbus);
> + if (atomic_dec_and_test(&hbus->remove_lock))
> + complete(&hbus->remove_event);
> +}
> +
> +/**
> + * hv_pci_probe() - New VMBus channel probe, for a root PCI bus
> + * @hdev: Vmbus's tracking struct for this root PCI bus
> + * @dev_id: Identifies the device itself
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_pci_probe(struct hv_device *hdev,
> + const struct hv_vmbus_device_id *dev_id)
> +{
> + struct hv_pcibus_device *hbus;
> + int ret;
> +
> + hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> + if (!hbus)
> + return -ENOMEM;
> +
> + /*
> + * The PCI bus "domain" is what is called "segment" in
> + * ACPI and other specs. Pull it from the instance ID,
> + * to get something unique. Bytes 8 and 9 are what is used
> + * in Windows guests, so do the same thing for consistency.
> + */
> +
> + hbus->sysdata.domain = hdev->dev_instance.b[9] |
> + hdev->dev_instance.b[8] << 8;
How do we know this is unique? We don't have any idea what the
platform will put in _SEG, so I think there's a potential conflict
here. The Intel VMD driver (arch/x86/pci/vmd.c) has a similar
problem, and it looks for unused domain numbers starting at 0x10000
(see vmd_find_free_domain()).
> + pr_devel("New virtual PCIe bus: %p for domain %04x\n", hbus,
> + hbus->sysdata.domain);
> +
> + hbus->hdev = hdev;
> + atomic_inc(&hbus->remove_lock);
> + INIT_LIST_HEAD(&hbus->children);
> + INIT_LIST_HEAD(&hbus->dr_list);
> + INIT_LIST_HEAD(&hbus->resources_for_children);
> + spin_lock_init(&hbus->config_lock);
> + spin_lock_init(&hbus->device_list_lock);
> + sema_init(&hbus->enum_sem, 1);
> + init_completion(&hbus->remove_event);
> +
> + ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
> + hv_pci_onchannelcallback, hbus);
> + if (ret)
> + goto free_bus;
> +
> + hv_set_drvdata(hdev, hbus);
> +
> + ret = hv_pci_protocol_negotiation(hdev);
> + if (ret)
> + goto close;
> +
> + ret = hv_allocate_config_window(hbus);
> + if (ret)
> + goto close;
> +
> + hbus->cfg_addr = ioremap(hbus->mem_config->start,
> + PCI_CONFIG_MMIO_LENGTH);
> + if (!hbus->cfg_addr) {
> + dev_err(&hdev->device,
> + "Unable to map a virtual address for config space\n");
> + ret = -ENOMEM;
> + goto free_config;
> + }
> +
> + hbus->sysdata.fwnode = irq_domain_alloc_fwnode(hbus);
> + if (!hbus->sysdata.fwnode) {
> + ret = -ENOMEM;
> + goto unmap;
> + }
> +
> + ret = hv_pcie_init_irq_domain(hbus);
> + if (ret)
> + goto free_fwnode;
> +
> + ret = hv_pci_query_relations(hdev);
> + if (ret)
> + goto free_irq_domain;
> +
> + ret = hv_pci_enter_d0(hdev);
> + if (ret)
> + goto free_irq_domain;
> +
> + ret = hv_pci_allocate_bridge_windows(hbus);
> + if (ret)
> + goto free_irq_domain;
> +
> + ret = hv_send_resources_allocated(hdev);
> + if (ret)
> + goto free_windows;
> +
> + prepopulate_bars(hbus);
> +
> + hbus->state = hv_pcibus_probed;
> +
> + ret = create_root_hv_pci_bus(hbus);
> + if (ret)
> + goto free_windows;
> +
> + return 0;
> +
> +free_windows:
> + hv_pci_free_bridge_windows(hbus);
> +free_irq_domain:
> + irq_domain_remove(hbus->irq_domain);
> +free_fwnode:
> + irq_domain_free_fwnode(hbus->sysdata.fwnode);
> +unmap:
> + iounmap(hbus->cfg_addr);
> +free_config:
> + hv_free_config_window(hbus);
> +close:
> + vmbus_close(hdev->channel);
> +free_bus:
> + kfree(hbus);
> + return ret;
> +}
> +
> +/**
> + * hv_pci_remove() - Remove routine for this VMBus channel
> + * @hdev: VMBus's tracking struct for this root PCI bus
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int hv_pci_remove(struct hv_device *hdev)
> +{
> + int ret;
> + struct hv_pcibus_device *hbus;
> + union {
> + struct pci_packet teardown_packet;
> + u8 buffer[0x100];
> + } pkt;
> + struct pci_bus_relations relations;
> + struct hv_pci_compl comp_pkt;
> +
> + hbus = hv_get_drvdata(hdev);
> +
> + ret = hv_send_resources_released(hdev);
> + if (ret)
> + dev_err(&hdev->device,
> + "Couldn't send resources released packet(s)\n");
> +
> + memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet));
> + init_completion(&comp_pkt.host_event);
> + pkt.teardown_packet.completion_func = hv_pci_generic_compl;
> + pkt.teardown_packet.compl_ctxt = &comp_pkt;
> + pkt.teardown_packet.message.message_type = PCI_BUS_D0EXIT;
> +
> + ret = vmbus_sendpacket(hdev->channel, &pkt.teardown_packet.message,
> + sizeof(struct pci_message),
> + (unsigned long)&pkt.teardown_packet,
> + VM_PKT_DATA_INBAND,
> + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> + if (!ret)
> + wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ);
> +
> + if (hbus->state == hv_pcibus_installed) {
> + /* Remove the bus from PCI's point of view. */
> + pci_lock_rescan_remove();
> + pci_stop_root_bus(hbus->pci_bus);
> + pci_remove_root_bus(hbus->pci_bus);
> + pci_unlock_rescan_remove();
> + }
> +
> + vmbus_close(hdev->channel);
> +
> + /* Delete any children which might still exist. */
> + memset(&relations, 0, sizeof(relations));
> + hv_pci_devices_present(hbus, &relations);
> +
> + iounmap(hbus->cfg_addr);
> + hv_free_config_window(hbus);
> + pci_free_resource_list(&hbus->resources_for_children);
> + hv_pci_free_bridge_windows(hbus);
> + irq_domain_remove(hbus->irq_domain);
> + irq_domain_free_fwnode(hbus->sysdata.fwnode);
> + put_hvpcibus(hbus);
> + wait_for_completion(&hbus->remove_event);
> + kfree(hbus);
> + return 0;
> +}
> +
> +static const struct hv_vmbus_device_id hv_pci_id_table[] = {
> + /* PCI Pass-through Class ID */
> + /* 44C4F61D-4444-4400-9D52-802E27EDE19F */
> + { HV_PCIE_GUID, },
> + { },
> +};
> +
> +MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table);
> +
> +static struct hv_driver hv_pci_drv = {
> + .name = "hv_pci",
> + .id_table = hv_pci_id_table,
> + .probe = hv_pci_probe,
> + .remove = hv_pci_remove,
> +};
> +
> +static void __exit exit_hv_pci_drv(void)
> +{
> + vmbus_driver_unregister(&hv_pci_drv);
> +}
> +
> +static int __init init_hv_pci_drv(void)
> +{
> + return vmbus_driver_register(&hv_pci_drv);
> +}
> +
> +module_init(init_hv_pci_drv);
> +module_exit(exit_hv_pci_drv);
> +
> +MODULE_DESCRIPTION("Hyper-V PCI");
> +MODULE_LICENSE("GPL v2");
> --
> 1.9.1
>
> --
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