From a80597900b8a0f1a9e87360164695f6a0a10556c Mon Sep 17 00:00:00 2001 From: Longfang Liu Date: Tue, 13 Oct 2026 15:19:29 +0800 Subject: [PATCH] hisi_acc_vfio_pci: reject live migration on 64KB page with QM_HW_V3 hardware On QM_HW_V3 (VF_CTRL mode) hardware with 64KB pages, the functional region and migration registers share one BAR2 physical page with no isolation, which leaks migration registers to the guest and causes guest kernel calltrace under the KVM emulated device scheme. The previous fix rejected the device in hisi_acc_vf_qm_init() during open_device, returning -EINVAL and breaking passthrough entirely. Move the drv_mode check into a helper called from probe() so that a VF_CTRL device on a 64KB page is bound to the generic ops, keeping passthrough working while disabling live migration. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu Link: https://lore.kernel.org/r/20261013071929.3988687-3-liulongfang@huawei.com Signed-off-by: Alex Williamson --- .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 32 ++++++++++++------- 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 2bdd625b0bce..c82c59246a3f 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -1195,13 +1195,6 @@ static int hisi_acc_vf_qm_init(struct hisi_acc_vf_core_device *hisi_acc_vdev) struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm; struct hisi_qm *pf_qm = hisi_acc_vdev->pf_qm; struct pci_dev *vf_dev = vdev->pdev; - u32 val; - - val = readl(pf_qm->io_base + QM_MIG_REGION_SEL); - if (pf_qm->ver > QM_HW_V3 && (val & QM_MIG_REGION_EN)) - hisi_acc_vdev->drv_mode = HW_ACC_MIG_PF_CTRL; - else - hisi_acc_vdev->drv_mode = HW_ACC_MIG_VF_CTRL; if (hisi_acc_vdev->drv_mode == HW_ACC_MIG_PF_CTRL) { /* @@ -1665,21 +1658,34 @@ static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device *hisi_acc_vd hisi_acc_vdev->debug_migf = NULL; } +static enum hw_drv_mode hisi_acc_vf_get_drv_mode(struct hisi_qm *pf_qm) +{ + u32 val; + + val = readl(pf_qm->io_base + QM_MIG_REGION_SEL); + if (pf_qm->ver > QM_HW_V3 && (val & QM_MIG_REGION_EN)) + return HW_ACC_MIG_PF_CTRL; + + return HW_ACC_MIG_VF_CTRL; +} + static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct hisi_acc_vf_core_device *hisi_acc_vdev; const struct vfio_device_ops *ops = &hisi_acc_vfio_pci_ops; + enum hw_drv_mode drv_mode = HW_ACC_MIG_VF_CTRL; + resource_size_t func_len; struct hisi_qm *pf_qm; - int vf_id; int ret; pf_qm = hisi_acc_get_pf_qm(pdev); if (pf_qm && pf_qm->ver >= QM_HW_V3) { - vf_id = pci_iov_vf_id(pdev); - if (vf_id >= 0) - ops = &hisi_acc_vfio_pci_migrn_ops; + func_len = pci_resource_len(pdev, VFIO_PCI_BAR2_REGION_INDEX) >> 1; + drv_mode = hisi_acc_vf_get_drv_mode(pf_qm); + if (drv_mode == HW_ACC_MIG_VF_CTRL && func_len < PAGE_SIZE) + pci_warn(pdev, "migration not supported on 64KB pages with QM_HW_V3\n"); else - pci_warn(pdev, "migration support failed, continue with generic interface\n"); + ops = &hisi_acc_vfio_pci_migrn_ops; } hisi_acc_vdev = vfio_alloc_device(hisi_acc_vf_core_device, @@ -1687,6 +1693,8 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device if (IS_ERR(hisi_acc_vdev)) return PTR_ERR(hisi_acc_vdev); + hisi_acc_vdev->drv_mode = drv_mode; + dev_set_drvdata(&pdev->dev, hisi_acc_vdev); ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device); if (ret)