diff options
Diffstat (limited to 'arch/x86/pci')
| -rw-r--r-- | arch/x86/pci/xen.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 1370716907e1..37914ef19c0a 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -23,6 +23,8 @@ #include <xen/features.h> #include <xen/events.h> #include <asm/xen/pci.h> +#include <asm/xen/cpuid.h> +#include <asm/apic.h> #include <asm/i8259.h> static int xen_pcifront_enable_irq(struct pci_dev *dev) @@ -434,6 +436,20 @@ int __init pci_xen_init(void) #ifdef CONFIG_PCI_MSI void __init xen_msi_init(void) { + if (!disable_apic) { + /* + * If hardware supports (x2)APIC virtualization (as indicated + * by hypervisor's leaf 4) then we don't need to use pirqs/ + * event channels for MSI handling and instead use regular + * APIC processing + */ + uint32_t eax = cpuid_eax(xen_cpuid_base() + 4); + + if (((eax & XEN_HVM_CPUID_X2APIC_VIRT) && x2apic_mode) || + ((eax & XEN_HVM_CPUID_APIC_ACCESS_VIRT) && cpu_has_apic)) + return; + } + x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs; x86_msi.teardown_msi_irq = xen_teardown_msi_irq; } |