6.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dexuan Cui <decui@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx Fixes: dc2b453290c4 ("PCI: hv: Rework MSI handling") Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx> Reviewed-by: sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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);
