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authorMichael S. Tsirkin <mst@redhat.com>2022-10-26 02:11:21 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-01-18 11:41:49 +0100
commit65bd0962992abd42e77a05e68c7b40e7c73726d1 (patch)
tree0f6364ce0fd3373bce25fac5f3e25ef712f01ee6
parentd23006f2a56e11a3103de0ca8b843bf7fd7d76fc (diff)
PCI: Fix pci_device_is_present() for VFs by checking PF
commit 98b04dd0b4577894520493d96bc4623387767445 upstream. pci_device_is_present() previously didn't work for VFs because it reads the Vendor and Device ID, which are 0xffff for VFs, which looks like they aren't present. Check the PF instead. Wei Gong reported that if virtio I/O is in progress when the driver is unbound or "0" is written to /sys/.../sriov_numvfs, the virtio I/O operation hangs, which may result in output like this: task:bash state:D stack: 0 pid: 1773 ppid: 1241 flags:0x00004002 Call Trace: schedule+0x4f/0xc0 blk_mq_freeze_queue_wait+0x69/0xa0 blk_mq_freeze_queue+0x1b/0x20 blk_cleanup_queue+0x3d/0xd0 virtblk_remove+0x3c/0xb0 [virtio_blk] virtio_dev_remove+0x4b/0x80 ... device_unregister+0x1b/0x60 unregister_virtio_device+0x18/0x30 virtio_pci_remove+0x41/0x80 pci_device_remove+0x3e/0xb0 This happened because pci_device_is_present(VF) returned "false" in virtio_pci_remove(), so it called virtio_break_device(). The broken vq meant that vring_interrupt() skipped the vq.callback() that would have completed the virtio I/O operation via virtblk_done(). [bhelgaas: commit log, simplify to always use pci_physfn(), add stable tag] Link: https://lore.kernel.org/r/20221026060912.173250-1-mst@redhat.com Reported-by: Wei Gong <gongwei833x@gmail.com> Tested-by: Wei Gong <gongwei833x@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/pci/pci.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ec741f92246d..b7ca261f5e75 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6093,6 +6093,8 @@ bool pci_device_is_present(struct pci_dev *pdev)
{
u32 v;
+ /* Check PF if pdev is a VF, since VF Vendor/Device IDs are 0xffff */
+ pdev = pci_physfn(pdev);
if (pci_dev_is_disconnected(pdev))
return false;
return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);