-----Original Message----- From: liulongfang <liulongfang@huawei.com> Sent: Tuesday, June 10, 2025 7:33 AM To: alex.williamson@redhat.com; jgg@nvidia.com; Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>; Jonathan Cameron <jonathan.cameron@huawei.com> Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org; linuxarm@openeuler.org; liulongfang <liulongfang@huawei.com> Subject: [PATCH v4 1/3] migration: update BAR space size

On the new hardware platform, the live migration configuration region is moved from VF to PF. The VF's own configuration space is restored to the complete 64KB, and there is no need to divide the size of the BAR configuration space equally.

Signed-off-by: Longfang Liu <liulongfang@huawei.com> --- .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 36 ++++++++++++++----- 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 2149f49aeec7..b16115f590fd 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -1250,6 +1250,28 @@ static struct hisi_qm *hisi_acc_get_pf_qm(struct pci_dev *pdev) return !IS_ERR(pf_qm) ? pf_qm : NULL; }

+static size_t hisi_acc_get_resource_len(struct vfio_pci_core_device *vdev, + unsigned int index) +{ + struct hisi_acc_vf_core_device *hisi_acc_vdev = + hisi_acc_drvdata(vdev->pdev); + + /* + * On the old HW_V3 device, the ACC VF device BAR2 + * region encompasses both functional register space + * and migration control register space. + * only the functional region should be report to Guest. + * + * On the new HW device, the migration control register + * has been moved to the PF device BAR2 region. + * The VF device BAR2 is entirely functional register space. + */ + if (hisi_acc_vdev->pf_qm->ver == QM_HW_V3) + return (pci_resource_len(vdev->pdev, index) >> 1); + + return pci_resource_len(vdev->pdev, index); +} + static int hisi_acc_pci_rw_access_check(struct vfio_device *core_vdev, size_t count, loff_t *ppos, size_t *new_count) @@ -1260,8 +1282,9 @@ static int hisi_acc_pci_rw_access_check(struct vfio_device *core_vdev,

if (index == VFIO_PCI_BAR2_REGION_INDEX) { loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; - resource_size_t end = pci_resource_len(vdev->pdev, index) / 2; + resource_size_t end;

+ end = hisi_acc_get_resource_len(vdev, index); /* Check if access is for migration control region */ if (pos >= end) return -EINVAL; @@ -1282,8 +1305,9 @@ static int hisi_acc_vfio_pci_mmap(struct vfio_device *core_vdev, index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT); if (index == VFIO_PCI_BAR2_REGION_INDEX) { u64 req_len, pgoff, req_start; - resource_size_t end = pci_resource_len(vdev->pdev, index) / 2; + resource_size_t end;

+ end = PAGE_ALIGN(hisi_acc_get_resource_len(vdev, index));

I think I have commented on this before. The above PAGE_ALIGN will change the behavior on HW_V3 with 64K PAGE_SIZE kernel. The end will become 64K which is not what we want on HW_V3. Could you please check that again. Thanks, Shameer

req_len = vma->vm_end - vma->vm_start; pgoff = vma->vm_pgoff & ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1); @@ -1330,7 +1354,6 @@ static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int if (cmd == VFIO_DEVICE_GET_REGION_INFO) { struct vfio_pci_core_device *vdev = container_of(core_vdev, struct vfio_pci_core_device, vdev); - struct pci_dev *pdev = vdev->pdev; struct vfio_region_info info; unsigned long minsz;

@@ -1345,12 +1368,7 @@ static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int if (info.index == VFIO_PCI_BAR2_REGION_INDEX) { info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);

- /* - * ACC VF dev BAR2 region consists of both functional - * register space and migration control register space. - * Report only the functional region to Guest. - */ - info.size = pci_resource_len(pdev, info.index) / 2; + info.size = hisi_acc_get_resource_len(vdev, info.index);

info.flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE | -- 2.24.0