PCI passthrough to VMs does not work with AMD FCH AHCI adapters: the guest OS fails to correctly probe devices attached to the controller due to FIS communication failures. Forcing the "bus" reset method before unbinding & binding the adapter to the vfio-pci driver solves this issue. I.e.: echo "bus" > /sys/bus/pci/devices/<ID>/reset_method gives a working guest OS, thus indicating that the default flr reset method is defective, resulting in the adapter not being reset correctly. This patch applies the no_flr quirk to AMD FCH AHCI devices to permanently solve this issue. Reported-by: Niklas Cassel <niklas.cassel@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> --- drivers/pci/quirks.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 285acc4aaccc..20ac67d59034 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -5340,6 +5340,7 @@ static void quirk_no_flr(struct pci_dev *dev) DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x1487, quirk_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x148c, quirk_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x149c, quirk_no_flr); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x7901, quirk_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_no_flr); -- 2.39.1
