On 10/9/25 03:23, Roger Pau Monné wrote: > On Wed, Oct 08, 2025 at 09:17:30AM -0400, Stewart Hildebrand wrote: >> On 10/8/25 10:39, Roger Pau Monne wrote: >>> 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 severs with AMD
s/severs/servers/ >>> 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 <[email protected]> >>> Released-Acked-By: Oleksii Kurochko<[email protected]> >>> --- >>> Cc: Stewart Hildebrand <[email protected]> >>> Cc: Oleksii Kurochko <[email protected]> >>> --- >>> Changes since v1: >>> - Introduce a DEVICE BUG prefix. >>> - Remove extra newline. >>> - Fix typo in commit message. >>> --- >>> xen/drivers/vpci/msix.c | 50 ++++++++++++++++++++++++++++++++++++----- >>> xen/include/xen/lib.h | 3 +++ >>> 2 files changed, 48 insertions(+), 5 deletions(-) >>> >>> diff --git a/xen/drivers/vpci/msix.c b/xen/drivers/vpci/msix.c >>> index 54a5070733aa..4ddcefbcb274 100644 >>> --- a/xen/drivers/vpci/msix.c >>> +++ b/xen/drivers/vpci/msix.c >> >> Do we need to #include <xen/lib.h>? > > Can do, With that adjusted: Reviewed-by: Stewart Hildebrand <[email protected]> > it's the same header that has the declarations for the printk > functions that we already use in msix.c, so if it wasn't indirectly > included the file won't build already. > > Thanks, Roger.
