On 1/31/23 01:04, Bjorn Helgaas wrote: > On Mon, Jan 30, 2023 at 03:46:06PM +0000, Niklas Cassel wrote: >> On Mon, Jan 30, 2023 at 09:21:11AM -0600, Bjorn Helgaas wrote: >>> On Sat, Jan 28, 2023 at 10:39:51AM +0900, Damien Le Moal wrote: >>>> 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. >>> >>> What does a FIS communication failure look like? Can we include a >>> line or two of dmesg output here to help users find this fix? >> >> It looks like this: >> >> [ 22.402368] ata4: softreset failed (1st FIS failed) >> [ 32.417855] ata4: softreset failed (1st FIS failed) >> [ 67.441641] ata4: softreset failed (1st FIS failed) >> [ 67.453227] ata4: limiting SATA link speed to 3.0 Gbps >> [ 72.661738] ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 320) >> [ 78.121263] ata4.00: qc timeout after 5000 msecs (cmd 0xec) >> [ 78.134413] ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4) >> >> Basically, we can read and write MMIO registers in the AHCI HBA, >> but the communication between the AHCI HBA and the ATA device does >> not work properly. >> >> (Because the AHCI HBA did not get reset when binding/unbinding the >> device.) >> >> The exact same kernel, using the same generic AHCI driver within the VM, >> can communicate perfectly fine when using e.g. an Intel AHCI HBA. >> >> (With both the AMD and Intel AHCI HBAs being bound to the vfio-pci driver >> in the host.) >> >> We can send a v2 with the above dmesg output. > > Don't bother, I added the above and applied this to pci/virtualization > for v6.2, thanks! Thanks ! -- Damien Le Moal Western Digital Research
