From: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> commit 63ba51db24ed1b8f8088a897290eb6c036c5435d upstream. 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: ata4: softreset failed (1st FIS failed) ... ata4.00: qc timeout after 5000 msecs (cmd 0xec) ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4) Forcing the "bus" reset method before unbinding & binding the adapter to the vfio-pci driver solves this issue, e.g.: echo "bus" > /sys/bus/pci/devices/<ID>/reset_method gives a working guest OS, indicating that the default FLR reset method doesn't work correctly. Apply quirk_no_flr() to AMD FCH AHCI devices to work around this issue. Link: https://lore.kernel.org/r/20230128013951.523247-1-damien.lemoal@xxxxxxxxxxxxxxxxxx Reported-by: Niklas Cassel <niklas.cassel@xxxxxxx> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/quirks.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -5302,6 +5302,7 @@ static void quirk_no_flr(struct pci_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);
