From: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx> Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic, set x2apic destination mode to physcial mode when x2apic is available and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs have 8-bit APIC id. Signed-off-by: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx> --- arch/x86/kernel/cpu/mshyperv.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index e81a2db..9d62f33 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -36,6 +36,8 @@ struct ms_hyperv_info ms_hyperv; EXPORT_SYMBOL_GPL(ms_hyperv); +extern int x2apic_phys; + #if IS_ENABLED(CONFIG_HYPERV) static void (*vmbus_handler)(void); static void (*hv_stimer0_handler)(void); @@ -328,6 +330,18 @@ static void __init ms_hyperv_init_platform(void) # ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu; # endif + +/* + * Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic, + * set x2apic destination mode to physcial mode when x2apic is available + * and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs + * have 8-bit APIC id. + */ +# if IS_ENABLED(CONFIG_HYPERV_IOMMU) + if (x2apic_supported()) + x2apic_phys = 1; +# endif + #endif } -- 2.7.4 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
