Messages in this thread | | | Date | Wed, 16 Aug 2023 11:12:01 -0700 | Subject | Re: [PATCH v2] PCI: hv: Fix a crash in hv_pci_restore_msi_msg() during hibernation | From | Kuppuswamy Sathyanarayanan <> |
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On 8/16/2023 10:59 AM, Dexuan Cui wrote: > When a Linux VM with an assigned PCI device runs on Hyper-V, if the PCI > device driver is not loaded yet (i.e. MSI-X/MSI is not enabled on the > device yet), doing a VM hibernation triggers a panic in > hv_pci_restore_msi_msg() -> msi_lock_descs(&pdev->dev), because > pdev->dev.msi.data is still NULL. > > Avoid the panic by checking if MSI-X/MSI is enabled. > > Fixes: dc2b453290c4 ("PCI: hv: Rework MSI handling") > Signed-off-by: Dexuan Cui <decui@microsoft.com> > --- > > Changes in v2: > Replaced the test "if (!pdev->dev.msi.data)" with > "if (!pdev->msi_enabled && !pdev->msix_enabled)". > Thanks Michael! > Updated the changelog accordingly. > > drivers/pci/controller/pci-hyperv.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c > index 2d93d0c4f10d..bed3cefdaf19 100644 > --- a/drivers/pci/controller/pci-hyperv.c > +++ b/drivers/pci/controller/pci-hyperv.c > @@ -3983,6 +3983,9 @@ static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg) > struct msi_desc *entry; > int ret = 0; > > + if (!pdev->msi_enabled && !pdev->msix_enabled) > + return 0; Isn't this is a error condition? Don't you want to return error here? > + > msi_lock_descs(&pdev->dev); > msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) { > irq_data = irq_get_irq_data(entry->irq);
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