From 0e4ccb1505a9e29c50170742ce26ac4655baab2d Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 6 Nov 2013 16:16:56 -0500 Subject: PCI: Add x86_msi.msi_mask_irq() and msix_mask_irq() Certain platforms do not allow writes in the MSI-X BARs to setup or tear down vector values. To combat against the generic code trying to write to that and either silently being ignored or crashing due to the pagetables being marked R/O this patch introduces a platform override. Note that we keep two separate, non-weak, functions default_mask_msi_irqs() and default_mask_msix_irqs() for the behavior of the arch_mask_msi_irqs() and arch_mask_msix_irqs(), as the default behavior is needed by x86 PCI code. For Xen, which does not allow the guest to write to MSI-X tables - as the hypervisor is solely responsible for setting the vector values - we implement two nops. This fixes a Xen guest crash when passing a PCI device with MSI-X to the guest. See the bugzilla for more details. [bhelgaas: add bugzilla info] Reference: https://bugzilla.kernel.org/show_bug.cgi?id=64581 Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Bjorn Helgaas CC: Sucheta Chakraborty CC: Zhenzhong Duan --- arch/x86/pci/xen.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'arch/x86/pci') diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 48e8461057b..5eee4959785 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -382,7 +382,14 @@ static void xen_teardown_msi_irq(unsigned int irq) { xen_destroy_irq(irq); } - +static u32 xen_nop_msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) +{ + return 0; +} +static u32 xen_nop_msix_mask_irq(struct msi_desc *desc, u32 flag) +{ + return 0; +} #endif int __init pci_xen_init(void) @@ -406,6 +413,8 @@ int __init pci_xen_init(void) x86_msi.setup_msi_irqs = xen_setup_msi_irqs; x86_msi.teardown_msi_irq = xen_teardown_msi_irq; x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs; + x86_msi.msi_mask_irq = xen_nop_msi_mask_irq; + x86_msi.msix_mask_irq = xen_nop_msix_mask_irq; #endif return 0; } @@ -485,6 +494,8 @@ int __init pci_xen_initial_domain(void) x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs; x86_msi.teardown_msi_irq = xen_teardown_msi_irq; x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs; + x86_msi.msi_mask_irq = xen_nop_msi_mask_irq; + x86_msi.msix_mask_irq = xen_nop_msix_mask_irq; #endif xen_setup_acpi_sci(); __acpi_register_gsi = acpi_register_gsi_xen; -- cgit v1.2.3-70-g09d2