Thomas Gleixner ad604cbd1d x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests
commit 7e0815b3e09986d2fe651199363e135b9358132a upstream.

When a XEN_HVM guest uses the XEN PIRQ/Eventchannel mechanism, then
PCI/MSI[-X] masking is solely controlled by the hypervisor, but contrary to
XEN_PV guests this does not disable PCI/MSI[-X] masking in the PCI/MSI
layer.

This can lead to a situation where the PCI/MSI layer masks an MSI[-X]
interrupt and the hypervisor grants the write despite the fact that it
already requested the interrupt. As a consequence interrupt delivery on the
affected device is not happening ever.

Set pci_msi_ignore_mask to prevent that like it's done for XEN_PV guests
already.

Fixes: 809f9267bbab ("xen: map MSIs into pirqs")
Reported-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Reported-by: Dusty Mabe <dustymabe@redhat.com>
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Noah Meyerhans <noahm@debian.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87tuaduxj5.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-09 09:05:00 +02:00
..
2020-10-23 10:06:38 -07:00
2021-11-26 10:39:19 +01:00
2022-01-27 10:54:06 +01:00
2021-11-26 10:39:12 +01:00
2022-04-08 14:40:44 +02:00