diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2022-04-28 16:50:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-06 09:33:48 +0300 |
| commit | 4f0750839421c64e3e3ab152cfd443f282682bc4 (patch) | |
| tree | 2e7bf8c27de60e01d7c0b66f0751627218b69b74 /arch | |
| parent | 8bb828229da903bb5710d21065e0a29f9afd30e0 (diff) | |
| download | linux-4f0750839421c64e3e3ab152cfd443f282682bc4.tar.xz | |
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
[nmeyerha@amazon.com: backported to 5.4]
Signed-off-by: Noah Meyerhans <nmeyerha@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/pci/xen.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 5c11ae66b5d8..9cf8f5417e7f 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -442,6 +442,11 @@ void __init xen_msi_init(void) x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs; x86_msi.teardown_msi_irq = xen_teardown_msi_irq; + /* + * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely + * controlled by the hypervisor. + */ + pci_msi_ignore_mask = 1; } #endif |