From 623db856476806124e9ae45fbc39e75012261570 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 4 Dec 2025 18:26:57 +0100 Subject: [PATCH] virtio: Fix crash when sriov-pf is set for non-PCI-Express device Setting the sriov-pf property on devices that aren't PCI Express causes an assertion failure: $ qemu-system-x86_64 \ -blockdev null-co,node-name=null \ -blockdev null-co,node-name=null2 \ -device virtio-blk,drive=null,id=pf \ -device virtio-blk,sriov-pf=pf,drive=null2 qemu-system-x86_64: ../hw/pci/pcie.c:1062: void pcie_add_capability(PCIDevice *, uint16_t, uint8_t, uint16_t, uint16_t): Assertion `offset >= PCI_CONFIG_SPACE_SIZE' failed. This is because proxy->last_pcie_cap_offset is only initialised to a non-zero value in virtio_pci_realize() if it's a PCI Express device, and then virtio_pci_device_plugged() still tries to use it. To fix this, just skip the SR-IOV code for !pci_is_express(). Then the next thing pci_qdev_realize() does is call pcie_sriov_register_device(), which returns the appropriate error. Cc: qemu-stable@nongnu.org Fixes: d0c280d3fac6 ('pcie_sriov: Make a PCI device with user-created VF ARI-capable') Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Message-Id: <20251204172657.174391-1-kwolf@redhat.com> --- hw/virtio/virtio-pci.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index b273eb2691..1e8f90df34 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -2183,15 +2183,17 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) PCI_BASE_ADDRESS_SPACE_IO, &proxy->bar); } - if (pci_is_vf(&proxy->pci_dev)) { - pcie_ari_init(&proxy->pci_dev, proxy->last_pcie_cap_offset); - proxy->last_pcie_cap_offset += PCI_ARI_SIZEOF; - } else { - res = pcie_sriov_pf_init_from_user_created_vfs( - &proxy->pci_dev, proxy->last_pcie_cap_offset, errp); - if (res > 0) { - proxy->last_pcie_cap_offset += res; - virtio_add_feature(&vdev->host_features, VIRTIO_F_SR_IOV); + if (pci_is_express(&proxy->pci_dev)) { + if (pci_is_vf(&proxy->pci_dev)) { + pcie_ari_init(&proxy->pci_dev, proxy->last_pcie_cap_offset); + proxy->last_pcie_cap_offset += PCI_ARI_SIZEOF; + } else { + res = pcie_sriov_pf_init_from_user_created_vfs( + &proxy->pci_dev, proxy->last_pcie_cap_offset, errp); + if (res > 0) { + proxy->last_pcie_cap_offset += res; + virtio_add_feature(&vdev->host_features, VIRTIO_F_SR_IOV); + } } } } -- 2.47.3