Commit-ID: 5fcee53ce705d49c766f8a302c7e93bdfc33c124 Gitweb: http://git.kernel.org/tip/5fcee53ce705d49c766f8a302c7e93bdfc33c124 Author: Jiang Liu <jiang....@linux.intel.com> AuthorDate: Wed, 7 Jan 2015 15:31:38 +0800 Committer: Thomas Gleixner <t...@linutronix.de> 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 <jiang....@linux.intel.com> Tested-by: Joerg Roedel <j...@8bytes.org> Cc: Tony Luck <tony.l...@intel.com> Cc: io...@lists.linux-foundation.org Cc: H. Peter Anvin <h...@linux.intel.com> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Yinghai Lu <ying...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: David Rientjes <rient...@google.com> Cc: HATAYAMA Daisuke <d.hatay...@jp.fujitsu.com> Cc: Jan Beulich <jbeul...@suse.com> Cc: Richard Weinberger <rich...@nod.at> Cc: Oren Twaig <o...@scalemp.com> Link: http://lkml.kernel.org/r/1420615903-28253-12-git-send-email-jiang....@linux.intel.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
