Files
xen/xen/include
Roger Pau Monné f9aea52a97 vpci/msix: improve handling of bogus MSI-X capabilities
I've had the luck to come across a PCI card that exposes a MSI-X capability
where the BIR of the vector and PBA tables points at a BAR that has 0 size.

This doesn't play nice with the code in vpci_make_msix_hole(), as it would
still use the address of such empty BAR (0) and attempt to carve a hole in
the p2m.  This leads to errors like the one below being reported by Xen:

d0v0 0000:22:00.0: existing mapping (mfn: 181c4300 type: 0) at 0 clobbers MSIX MMIO area

And the device left unable to enable memory decoding due to the failure
reported by vpci_make_msix_hole().

Introduce checking in init_msix() to ensure the BARs containing the MSI-X
tables are usable.  This requires checking that the BIR points to a
non-empty BAR, and the offset and size of the MSI-X tables can fit in the
target BAR.

This fixes booting PVH dom0 on Supermicro AS -2126HS-TN servers with AMD
EPYC 9965 processors.  The broken device is:

22:00.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 93)

There are multiple of those integrated controllers in the system, all
broken in the same way.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
master commit: 53859596c0
master date: 2025-10-10 11:02:39 +0200
2025-10-21 15:20:33 +02:00
..
2024-10-09 09:56:43 +02:00
2024-08-26 10:27:53 +02:00
2025-04-29 11:42:47 +02:00