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authorThomas Gleixner <tglx@linutronix.de>2022-04-28 15:50:54 +0200
committerThomas Gleixner <tglx@linutronix.de>2022-04-29 14:37:39 +0200
commit7e0815b3e09986d2fe651199363e135b9358132a (patch)
tree24772d1751a2da2d535ab838cb6dcdf00e6e4e55 /arch
parentbug: Have __warn() prototype defined unconditionally (diff)
downloadlinux-7e0815b3e09986d2fe651199363e135b9358132a.tar.xz
linux-7e0815b3e09986d2fe651199363e135b9358132a.zip
x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests
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
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/pci/xen.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 9bb1e2941179..b94f727251b6 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -467,7 +467,6 @@ static __init void xen_setup_pci_msi(void)
else
xen_msi_ops.setup_msi_irqs = xen_setup_msi_irqs;
xen_msi_ops.teardown_msi_irqs = xen_pv_teardown_msi_irqs;
- pci_msi_ignore_mask = 1;
} else if (xen_hvm_domain()) {
xen_msi_ops.setup_msi_irqs = xen_hvm_setup_msi_irqs;
xen_msi_ops.teardown_msi_irqs = xen_teardown_msi_irqs;
@@ -481,6 +480,11 @@ static __init void xen_setup_pci_msi(void)
* in allocating the native domain and never use it.
*/
x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain;
+ /*
+ * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely
+ * controlled by the hypervisor.
+ */
+ pci_msi_ignore_mask = 1;
}
#else /* CONFIG_PCI_MSI */