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Message-ID: <6bdb9280-3530-dc1f-d33e-5bc1c5ac927b@redhat.com>
Date: Thu, 23 Jun 2022 16:11:08 +1000
From: Gavin Shan <gshan@...hat.com>
To: kvmarm@...ts.cs.columbia.edu
Cc: maz@...nel.org, shijie@...eremail.onmicrosoft.com,
linux-kernel@...r.kernel.org, eauger@...hat.com,
shan.gavin@...il.com, Jonathan.Cameron@...wei.com,
pbonzini@...hat.com, vkuznets@...hat.com, will@...nel.org,
oliver.upton@...ux.dev, Oliver Upton <oupton@...gle.com>,
James Morse <james.morse@....com>,
Mark Rutland <mark.rutland@....com>
Subject: Re: [PATCH v7 00/22] Support SDEI Virtualization
Hi Oliver,
On 5/27/22 6:02 PM, Gavin Shan wrote:
> This series intends to virtualize Software Delegated Exception Interface
> (SDEI), which is defined by DEN0054C (v1.1). It allows the hypervisor to
> deliver NMI-alike SDEI event to guest and it's needed by Async PF to
> deliver page-not-present notification from hypervisor to guest. The code
> and the required qemu changes can be found from:
>
> https://developer.arm.com/documentation/den0054/c
> https://github.com/gwshan/linux ("kvm/arm64_sdei")
> https://github.com/gwshan/qemu ("kvm/arm64_sdei")
>
> The design is quite strightforward by following the specification. The
> (SDEI) events are classified into the shared and private ones according
> to their scope. The shared event is system or VM scoped, but the private
> event is vcpu scoped. This implementation doesn't support the shared
> event because all the needed events are private. Besides, the critial
> events aren't supported by the implementation either. It means all events
> are normal in terms of priority.
>
> There are several objects (data structures) introduced to help on the
> event registration, enablement, disablement, unregistration, reset,
> delivery and handling.
>
> * kvm_sdei_event_handler
> SDEI event handler, which is provided through EVENT_REGISTER
> hypercall, is called when the SDEI event is delivered from
> host to guest.
>
> * kvm_sdei_event_context
> The saved (preempted) context when SDEI event is delivered
> for handling.
>
> * kvm_sdei_vcpu
> SDEI events and their states.
>
> The patches are organized as below:
>
> PATCH[01-02] Preparatory work to extend smccc_get_argx() and refactor
> hypercall routing mechanism
> PATCH[03] Adds SDEI virtualization infrastructure
> PATCH[04-16] Supports various SDEI hypercalls and event handling
> PATCH[17] Exposes SDEI capability
> PATCH[18-19] Support SDEI migration
> PATCH[20] Adds document about SDEI
> PATCH[21-22] SDEI related selftest cases
>
> The previous revisions can be found:
>
> v6: https://lore.kernel.org/lkml/20220403153911.12332-4-gshan@redhat.com/T/
> v5: https://lore.kernel.org/kvmarm/20220322080710.51727-1-gshan@redhat.com/
> v4: https://lore.kernel.org/kvmarm/20210815001352.81927-1-gshan@redhat.com/
> v3: https://lore.kernel.org/kvmarm/20210507083124.43347-1-gshan@redhat.com/
> v2: https://lore.kernel.org/kvmarm/20210209032733.99996-1-gshan@redhat.com/
> v1: https://lore.kernel.org/kvmarm/20200817100531.83045-1-gshan@redhat.com/
>
Copying Oliver's new email address (oliver.upton@...ux.dev).
Please let me know if I need to rebase and repost the series.
Thanks,
Gavin
> Testing
> =======
> [1] The selftest case included in this series works fine. The default SDEI
> event, whose number is zero, can be registered, enabled, raised. The
> SDEI event handler can be invoked.
>
> [host]# pwd
> /home/gavin/sandbox/linux.main/tools/testing/selftests/kvm
> [root@...tlab-arm01 kvm]# ./aarch64/sdei
>
> NR_VCPUS: 2 SDEI Event: 0x00000000
>
> --- VERSION
> Version: 1.1 (vendor: 0x4b564d)
> --- FEATURES
> Shared event slots: 0
> Private event slots: 0
> Relative mode: No
> --- PRIVATE_RESET
> --- SHARED_RESET
> --- PE_UNMASK
> --- EVENT_GET_INFO
> Type: Private
> Priority: Normal
> Signaled: Yes
> --- EVENT_REGISTER
> --- EVENT_ENABLE
> --- EVENT_SIGNAL
> Handled: Yes
> IRQ: No
> Status: Registered-Enabled-Running
> PC/PSTATE: 000000000040232c 00000000600003c5
> Regs: 0000000000000000 0000000000000000
> 0000000000000000 0000000000000000
> --- PE_MASK
> --- EVENT_DISABLE
> --- EVENT_UNREGISTER
>
> Result: OK
>
> [2] There are additional patches in the following repositories to create
> procfs entries, allowing to inject SDEI event from host side. The
> SDEI client in the guest side registers the SDEI default event, whose
> number is zero. Also, the QEMU exports SDEI ACPI table and supports
> migration for SDEI.
>
> https://github.com/gwshan/linux ("kvm/arm64_sdei")
> https://github.com/gwshan/qemu ("kvm/arm64_sdei")
>
> [2.1] Start the guests and migrate the source VM to the destination
> VM.
>
> [host]# /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \
> -accel kvm -machine virt,gic-version=host \
> -cpu host -smp 6,sockets=2,cores=3,threads=1 \
> -m 1024M,slots=16,maxmem=64G \
> : \
> -kernel /home/gavin/sandbox/linux.guest/arch/arm64/boot/Image \
> -initrd /home/gavin/sandbox/images/rootfs.cpio.xz \
> -append earlycon=pl011,mmio,0x9000000 \
> :
>
> [host]# /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \
> -accel kvm -machine virt,gic-version=host \
> -cpu host -smp 6,sockets=2,cores=3,threads=1 \
> -m 1024M,slots=16,maxmem=64G \
> : \
> -kernel /home/gavin/sandbox/linux.guest/arch/arm64/boot/Image \
> -initrd /home/gavin/sandbox/images/rootfs.cpio.xz \
> -append earlycon=pl011,mmio,0x9000000 \
> -incoming tcp:0:4444 \
> :
>
> [2.2] Check kernel log on the source VM. The SDEI service is enabled
> and the default SDEI event (0x0) is enabled.
>
> [guest-src]# dmesg | grep -i sdei
> ACPI: SDEI 0x000000005BC80000 000024 \
> (v00 BOCHS BXPC 00000001 BXPC 00000001)
> sdei: SDEIv1.1 (0x4b564d) detected in firmware.
> SDEI TEST: Version 1.1, Vendor 0x4b564d
> sdei_init: SDEI event (0x0) registered
> sdei_init: SDEI event (0x0) enabled
>
>
> (qemu) migrate -d tcp:localhost:4444
>
> [2.3] Migrate the source VM to the destination VM. Inject SDEI event
> to the destination VM. The event is raised and handled.
>
> (qemu) migrate -d tcp:localhost:4444
>
> [host]# echo 0 > /proc/kvm/kvm-5360/vcpu-1
>
> [guest-dst]#
> =========== SDEI Event (CPU#1) ===========
> Event: 0000000000000000 Parameter: 00000000dabfdabf
> PC: ffff800008cbb554 PSTATE: 00000000604000c5 SP: ffff800009c7bde0
> Regs: 00000000000016ee ffff00001ffd2e28 00000000000016ed 0000000000000001
> ffff800016c28000 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000 0000000000000000 0000000000000000 ffff800009399008
> ffff8000097d9af0 ffff8000097d99f8 ffff8000093a8db8 ffff8000097d9b18
> 0000000000000000 0000000000000000 ffff000000339d00 0000000000000000
> 0000000000000000 ffff800009c7bde0 ffff800008cbb5c4
> Context: 00000000000016ee ffff00001ffd2e28 00000000000016ed 0000000000000001
> ffff800016c28000 03ffffffffffffff 000000024325db59 ffff8000097de190
> ffff00000033a790 ffff800008cbb814 0000000000000a30 0000000000000000
>
> Changelog
> =========
> v7:
> * Rebased to v5.19.rc1 (Gavin)
> * Add hypercall ranges for routing (Oliver)
> * Remove support to the critical event and redesigned
> data structures. Function names are also modified
> as Oliver suggested (Oliver)
> * Deliver event when it's enabled or the specific PE
> is unmasked (Oliver)
> * Improve EVENT_COMPLETE_AND_RESUME hypercall to resume
> from the specified address (Oliver)
> * Add patches for SDEI migration and documentation (Gavin)
> * Misc comments from Oliver Upon (Oliver)
> v6:
> * Rebased to v5.18.rc1 (Gavin)
> * Pass additional argument to smccc_get_arg() (Oliver)
> * Add preparatory patch to route hypercalls based on their
> owners (Oliver)
> * Remove the support for shared event. (Oliver/Gavin)
> * Remove the support for migration and add-on patches to
> support it in future (Oliver)
> * The events are exposed by KVM instead of VMM (Oliver)
> * kvm_sdei_state.h is dropped and all the structures are
> folded into the corresponding ones in kvm_sdei.h (Oliver)
> * Rename 'struct kvm_sdei_registered_event' to
> 'struct kvm_sdei_event' (Oliver)
> * Misc comments from Oliver Upon (Oliver)
> v5/v4/v3/v2/v1:
> * Skipped here and please visit the history by
> https://lore.kernel.org/lkml/20220403153911.12332-4-gshan@redhat.com/T/
>
> Gavin Shan (22):
> KVM: arm64: Extend smccc_get_argx()
> KVM: arm64: Route hypercalls based on their owner
> KVM: arm64: Add SDEI virtualization infrastructure
> KVM: arm64: Support EVENT_REGISTER hypercall
> KVM: arm64: Support EVENT_{ENABLE, DISABLE} hypercall
> KVM: arm64: Support EVENT_CONTEXT hypercall
> KVM: arm64: Support EVENT_UNREGISTER hypercall
> KVM: arm64: Support EVENT_STATUS hypercall
> KVM: arm64: Support EVENT_GET_INFO hypercall
> KVM: arm64: Support PE_{MASK, UNMASK} hypercall
> KVM: arm64: Support {PRIVATE, SHARED}_RESET hypercall
> KVM: arm64: Support event injection and delivery
> KVM: arm64: Support EVENT_{COMPLETE, COMPLETE_AND_RESUME} hypercall
> KVM: arm64: Support EVENT_SIGNAL hypercall
> KVM: arm64: Support SDEI_FEATURES hypercall
> KVM: arm64: Support SDEI_VERSION hypercall
> KVM: arm64: Expose SDEI capbility and service
> KVM: arm64: Allow large sized pseudo firmware registers
> KVM: arm64: Support SDEI event migration
> KVM: arm64: Add SDEI document
> selftests: KVM: aarch64: Add SDEI case in hypercall tests
> selftests: KVM: aarch64: Add SDEI test case
>
> Documentation/virt/kvm/api.rst | 11 +
> Documentation/virt/kvm/arm/hypercalls.rst | 4 +
> Documentation/virt/kvm/arm/sdei.rst | 64 ++
> arch/arm64/include/asm/kvm_host.h | 3 +
> arch/arm64/include/asm/kvm_sdei.h | 81 +++
> arch/arm64/include/uapi/asm/kvm.h | 18 +
> arch/arm64/kvm/Makefile | 2 +-
> arch/arm64/kvm/arm.c | 8 +
> arch/arm64/kvm/hypercalls.c | 182 +++--
> arch/arm64/kvm/psci.c | 14 +-
> arch/arm64/kvm/pvtime.c | 2 +-
> arch/arm64/kvm/sdei.c | 676 ++++++++++++++++++
> arch/arm64/kvm/trng.c | 4 +-
> include/kvm/arm_hypercalls.h | 19 +-
> include/linux/arm-smccc.h | 7 +
> include/uapi/linux/arm_sdei.h | 8 +
> include/uapi/linux/kvm.h | 1 +
> tools/testing/selftests/kvm/Makefile | 1 +
> .../selftests/kvm/aarch64/hypercalls.c | 11 +-
> tools/testing/selftests/kvm/aarch64/sdei.c | 450 ++++++++++++
> 20 files changed, 1499 insertions(+), 67 deletions(-)
> create mode 100644 Documentation/virt/kvm/arm/sdei.rst
> create mode 100644 arch/arm64/include/asm/kvm_sdei.h
> create mode 100644 arch/arm64/kvm/sdei.c
> create mode 100644 tools/testing/selftests/kvm/aarch64/sdei.c
>
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