AMD Motherboards : BIOS update destroyed my KVM/vfio setup.

Author: pantato
Subject: BIOS update destroyed my KVM/vfio setup.
Posted: 19 May 2019 at 11:49am

There is a "fix" that you can use to patch the linux kernel that sort of works. I can boot my VM now once per host boot on my rx580 after applying the patch.

https://clbin.com/GGnxm


Save that as a .patch file and look up how to compile the kernel with a patch for your respective distro. You must edit the 2nd to last 2 lines on the patch for your PCI-E ids.
eg. the "ls iommu" script given on the arch wiki (made a link here: http://ix.io/1Jqt ) shows my guest GPU PC id(s) like so:

IOMMU Group 16 24:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e7)
IOMMU Group 16 24:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere HDMI Audio [Radeon RX 470/480 / 570/580/590] [1002:aaf0]

So I had to edit the patch to look like this:

[daniel@satori ~]$ cat build/linux/trunk/quirks.patch
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index e2a879e93d86..62b754253318 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5118,3 +5118,7 @@ SWITCHTEC_QUIRK(0x8573); /* PFXI 48XG3 */
SWITCHTEC_QUIRK(0x8574); /* PFXI 64XG3 */
SWITCHTEC_QUIRK(0x8575); /* PFXI 80XG3 */
SWITCHTEC_QUIRK(0x8576); /* PFXI 96XG3 */
+
+DECLARE_PCI_FIXUP_HEADER(0x1002, 0x67df, quirk_no_bus_reset);
+DECLARE_PCI_FIXUP_HEADER(0x1002, 0xaaf0, quirk_no_bus_reset);
+DECLARE_PCI_FIXUP_HEADER(0x1022, 0x145f, quirk_no_bus_reset);


Let me know if you want more help with this, I know how painful this mess is.