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Message-ID: <bd69bdb6e0664667be868ff799e8629e@huawei.com>
Date: Tue, 8 Feb 2022 15:48:16 +0000
From: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@...wei.com>
To: Jason Gunthorpe <jgg@...dia.com>
CC: "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>,
"alex.williamson@...hat.com" <alex.williamson@...hat.com>,
"cohuck@...hat.com" <cohuck@...hat.com>,
"mgurtovoy@...dia.com" <mgurtovoy@...dia.com>,
"yishaih@...dia.com" <yishaih@...dia.com>,
Linuxarm <linuxarm@...wei.com>,
liulongfang <liulongfang@...wei.com>,
"Zengtao (B)" <prime.zeng@...ilicon.com>,
Jonathan Cameron <jonathan.cameron@...wei.com>,
"Wangzhou (B)" <wangzhou1@...ilicon.com>
Subject: RE: [RFC v4 7/8] hisi_acc_vfio_pci: Add support for VFIO live
migration
> -----Original Message-----
> From: Jason Gunthorpe [mailto:jgg@...dia.com]
> Sent: 08 February 2022 15:22
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@...wei.com>
> Cc: kvm@...r.kernel.org; linux-kernel@...r.kernel.org;
> linux-crypto@...r.kernel.org; alex.williamson@...hat.com;
> cohuck@...hat.com; mgurtovoy@...dia.com; yishaih@...dia.com; Linuxarm
> <linuxarm@...wei.com>; liulongfang <liulongfang@...wei.com>; Zengtao (B)
> <prime.zeng@...ilicon.com>; Jonathan Cameron
> <jonathan.cameron@...wei.com>; Wangzhou (B) <wangzhou1@...ilicon.com>
> Subject: Re: [RFC v4 7/8] hisi_acc_vfio_pci: Add support for VFIO live
> migration
>
> On Tue, Feb 08, 2022 at 01:34:24PM +0000, Shameer Kolothum wrote:
>
> Overall this looks like a fine implementation, as far as I can tell it
> meets the uAPI design perfectly.
>
> Why did you decide not to do the P2P support?
I need to check that with our hardware folks. May be it is in pipeline.
> > +static struct file *
> > +hisi_acc_vf_set_device_state(struct hisi_acc_vf_core_device *hisi_acc_vdev,
> > + u32 new)
> > +{
> > + u32 cur = hisi_acc_vdev->mig_state;
> > + int ret;
> > +
> > + if (cur == VFIO_DEVICE_STATE_RUNNING && new ==
> VFIO_DEVICE_STATE_STOP) {
> > + ret = hisi_acc_vf_stop_device(hisi_acc_vdev);
> > + if (ret)
> > + return ERR_PTR(ret);
>
> Be mindful that qemu doesn't handle a failure here very well, I'm not
> sure we will be able to fix this in the short term.
Ok. I will check that and see how big of a problem it is.
> > +static int hisi_acc_vfio_pci_init(struct hisi_acc_vf_core_device
> *hisi_acc_vdev)
> > +{
> > + struct vfio_pci_core_device *vdev = &hisi_acc_vdev->core_device;
> > + struct pci_dev *vf_dev = vdev->pdev;
> > + struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
> > +
> > + /*
> > + * ACC VF dev BAR2 region consists of both functional register space
> > + * and migration control register space. For migration to work, we
> > + * need access to both. Hence, we map the entire BAR2 region here.
> > + * But from a security point of view, we restrict access to the
> > + * migration control space from Guest(Please see mmap/ioctl/read/write
> > + * override functions).
> > + *
> > + * Also the HiSilicon ACC VF devices supported by this driver on
> > + * HiSilicon hardware platforms are integrated end point devices
> > + * and has no capability to perform PCIe P2P.
> > + */
> > + vf_qm->io_base =
> > + ioremap(pci_resource_start(vf_dev, VFIO_PCI_BAR2_REGION_INDEX),
> > + pci_resource_len(vf_dev, VFIO_PCI_BAR2_REGION_INDEX));
> > + if (!vf_qm->io_base)
> > + return -EIO;
> > +
> > + vf_qm->fun_type = QM_HW_VF;
> > + vf_qm->pdev = vf_dev;
> > + mutex_init(&vf_qm->mailbox_lock);
>
> mailbox_lock seems unused
I think we need that as that will be used in the QM driver APIs. I will add a
comment here.
> > + hisi_acc_vdev->vf_id = PCI_FUNC(vf_dev->devfn);
>
> Does this need to use the pci_iov_vf_id() function? funcs don't need
> to be tightly packed, necessarily.
>
> This should be set when the structure is allocated, not at open time.
Ok. I will change and move it.
> > + hisi_acc_vdev->vf_dev = vf_dev;
> > + vf_qm->dev_name = hisi_acc_vdev->pf_qm->dev_name;
>
> Also unused
I will see if we can get rid of it if it is not used by QM driver APIs used here.
>
> > + hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
> > +
> > + return 0;
> > +}
> >
> > static int hisi_acc_pci_rw_access_check(struct vfio_device *core_vdev,
> > size_t count, loff_t *ppos,
> > @@ -129,63 +1067,96 @@ static long hisi_acc_vfio_pci_ioctl(struct
> vfio_device *core_vdev, unsigned int
> >
> > static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
> > {
> > - struct vfio_pci_core_device *vdev =
> > - container_of(core_vdev, struct vfio_pci_core_device, vdev);
> > + struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(core_vdev,
> > + struct hisi_acc_vf_core_device, core_device.vdev);
> > + struct vfio_pci_core_device *vdev = &hisi_acc_vdev->core_device;
> > int ret;
> >
> > ret = vfio_pci_core_enable(vdev);
> > if (ret)
> > return ret;
> >
> > - vfio_pci_core_finish_enable(vdev);
> > + if (!hisi_acc_vdev->migration_support) {
>
> This should just test the core flag and get rid of migration_support:
Ok.
>
> hisi_acc_vdev->core_device.vdev.migration_flags =
> VFIO_MIGRATION_STOP_COPY;
>
> > +++ b/drivers/vfio/pci/hisi_acc_vfio_pci.h
> > @@ -0,0 +1,119 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/* Copyright (c) 2021 HiSilicon Ltd. */
> > +
> > +#ifndef HISI_ACC_VFIO_PCI_H
> > +#define HISI_ACC_VFIO_PCI_H
> > +
> > +#include <linux/hisi_acc_qm.h>
> > +
> > +#define VDM_OFFSET(x) offsetof(struct vfio_device_migration_info, x)
> > +
> > +#define HISI_ACC_MIG_REGION_DATA_OFFSET \
> > + (sizeof(struct vfio_device_migration_info))
> > +
> > +#define HISI_ACC_MIG_REGION_DATA_SIZE (sizeof(struct acc_vf_data))
>
> These three are not used any more
True.
>
> > +struct acc_vf_data {
> > +#define QM_MATCH_SIZE 32L
> > + /* QM match information */
> > + u32 qp_num;
> > + u32 dev_id;
> > + u32 que_iso_cfg;
> > + u32 qp_base;
> > + /* QM reserved 4 match information */
> > + u32 qm_rsv_state[4];
> > +
> > + /* QM RW regs */
> > + u32 aeq_int_mask;
> > + u32 eq_int_mask;
> > + u32 ifc_int_source;
> > + u32 ifc_int_mask;
> > + u32 ifc_int_set;
> > + u32 page_size;
> > +
> > + /* QM_EQC_DW has 7 regs */
> > + u32 qm_eqc_dw[7];
> > +
> > + /* QM_AEQC_DW has 7 regs */
> > + u32 qm_aeqc_dw[7];
> > +
> > + /* QM reserved 5 regs */
> > + u32 qm_rsv_regs[5];
> > +
> > + /* qm memory init information */
> > + dma_addr_t eqe_dma;
> > + dma_addr_t aeqe_dma;
> > + dma_addr_t sqc_dma;
> > + dma_addr_t cqc_dma;
>
> You can't put dma_addr_t in a structure that needs to go
> on-the-wire. This should be u64
Ok.
Thanks,
Shameer
> > +};
> > +
> > +struct hisi_acc_vf_migration_file {
> > + struct file *filp;
> > + struct mutex lock;
> > + bool disabled;
> > +
> > + struct acc_vf_data vf_data;
> > + size_t total_length;
> > +};
> > +
> > +struct hisi_acc_vf_core_device {
> > + struct vfio_pci_core_device core_device;
> > + u8 migration_support:1;
> > + /* for migration state */
> > + struct mutex state_mutex;
> > + enum vfio_device_mig_state mig_state;
> > + struct pci_dev *pf_dev;
> > + struct pci_dev *vf_dev;
> > + struct hisi_qm *pf_qm;
> > + struct hisi_qm vf_qm;
> > + int vf_id;
> > +
> > + struct hisi_acc_vf_migration_file *resuming_migf;
> > + struct hisi_acc_vf_migration_file *saving_migf;
> > +};
> > +#endif /* HISI_ACC_VFIO_PCI_H */
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