[PATCH V6 1/3] x86/Hyper-V: Set x2apic destination mode to physical when x2apic is available
From: <hidden>
Date: 2019-02-27 14:54:42
Also in:
linux-iommu, lkml
Subsystem:
hyper-v/azure core and drivers, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Lan Tianyu <redacted>
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.
Reviewed-by: Thomas Gleixner <redacted>
Reviewed-by: Michael Kelley <redacted>
Signed-off-by: Lan Tianyu <redacted>
---
Change since v5:
- Fix comile error due to x2apic_phys
Change since v2:
- Fix compile error due to x2apic_phys
- Fix comment indent
Change since v1:
- Remove redundant extern for x2apic_phys
---
arch/x86/kernel/cpu/mshyperv.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index e81a2db..3fa238a 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c@@ -328,6 +328,18 @@ 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. + */ +# ifdef CONFIG_X86_X2APIC + if (x2apic_supported()) + x2apic_phys = 1; +# endif + #endif }
--
2.7.4