6.4-stable review patch. If anyone has any objections, please let me know.
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From: Dexuan Cui decui@microsoft.com
commit 04bbe863241a9be7d57fb4cf217ee4a72f480e70 upstream.
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.
Link: https://lore.kernel.org/r/20230816175939.21566-1-decui@microsoft.com Fixes: dc2b453290c4 ("PCI: hv: Rework MSI handling") Signed-off-by: Dexuan Cui decui@microsoft.com Signed-off-by: Lorenzo Pieralisi lpieralisi@kernel.org Reviewed-by: sathyanarayanan.kuppuswamy@linux.intel.com Reviewed-by: Michael Kelley mikelley@microsoft.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/controller/pci-hyperv.c | 3 +++ 1 file changed, 3 insertions(+)
--- 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 struct msi_desc *entry; int ret = 0;
+ if (!pdev->msi_enabled && !pdev->msix_enabled) + return 0; + msi_lock_descs(&pdev->dev); msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) { irq_data = irq_get_irq_data(entry->irq);