x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests

stable inclusion
from stable-v5.10.114
commit ad604cbd1d54ba9b2944da72f97cd4669c8fcc1a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5IY1V

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ad604cbd1d54ba9b2944da72f97cd4669c8fcc1a

--------------------------------

commit 7e0815b3 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: 809f9267 ("xen: map MSIs into pirqs")
Reported-by: NJeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Reported-by: NDusty Mabe <dustymabe@redhat.com>
Reported-by: NSalvatore Bonaccorso <carnil@debian.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NNoah Meyerhans <noahm@debian.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87tuaduxj5.ffs@tglxSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

arch/x86/pci/xen.c

@@ -476,7 +476,6 @@ static __init void xen_setup_pci_msi(void)
 			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;
@@ -490,6 +489,11 @@ 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 */