Commit-ID: 5fcee53ce705d49c766f8a302c7e93bdfc33c124 Gitweb: http://git.kernel.org/tip/5fcee53ce705d49c766f8a302c7e93bdfc33c124 Author: Jiang Liu <[email protected]> AuthorDate: Wed, 7 Jan 2015 15:31:38 +0800 Committer: Thomas Gleixner <[email protected]> CommitDate: Thu, 15 Jan 2015 11:24:23 +0100
x86/apic: Only disable CPU x2apic mode when necessary When interrupt remapping hardware is not in X2APIC, CPU X2APIC mode will be disabled if: 1) Maximum CPU APIC ID is bigger than 255 2) hypervisior doesn't support x2apic mode. But we should only check whether hypervisor supports X2APIC mode when hypervisor(CONFIG_HYPERVISOR_GUEST) is enabled, otherwise X2APIC will always be disabled when CONFIG_HYPERVISOR_GUEST is disabled and IR doesn't work in X2APIC mode. Signed-off-by: Jiang Liu <[email protected]> Tested-by: Joerg Roedel <[email protected]> Cc: Tony Luck <[email protected]> Cc: [email protected] Cc: H. Peter Anvin <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: David Rientjes <[email protected]> Cc: HATAYAMA Daisuke <[email protected]> Cc: Jan Beulich <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Oren Twaig <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/kernel/apic/apic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 04aec6b..2f16116 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1601,7 +1601,8 @@ static __init void try_to_enable_x2apic(int ir_stat) * under KVM */ if (max_physical_apicid > 255 || - !hypervisor_x2apic_available()) { + (IS_ENABLED(CONFIG_HYPERVISOR_GUEST) && + !hypervisor_x2apic_available())) { pr_info("IRQ remapping doesn't support X2APIC mode, disable x2apic.\n"); if (x2apic_preenabled) disable_x2apic(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
