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authorSean Christopherson <seanjc@google.com>2021-01-15 14:03:53 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2021-02-04 05:27:22 -0500
commitdb7d8e476821df85dce0cfd1e654c72c7db879dc (patch)
tree99210d85ddac21209e9556a1390b7747d05d6a96 /arch/x86/kernel/apic/apic.c
parentc32b1b896d2ab30ac30bc39194bac47a09f7f497 (diff)
downloadlinux-db7d8e476821df85dce0cfd1e654c72c7db879dc.tar.gz
x86/apic: Export x2apic_mode for use by KVM in "warm" path
Export x2apic_mode so that KVM can query whether x2APIC is active
without having to incur the RDMSR in x2apic_enabled().  When Posted
Interrupts are in use for a guest with an assigned device, KVM ends up
checking for x2APIC at least once every time a vCPU halts.  KVM could
obviously snapshot x2apic_enabled() to avoid the RDMSR, but that's
rather silly given that x2apic_mode holds the exact info needed by KVM.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210115220354.434807-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
-rw-r--r--arch/x86/kernel/apic/apic.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 6bd20c0de8bc..dea2b44966ca 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1743,6 +1743,7 @@ void apic_ap_setup(void)
 
 #ifdef CONFIG_X86_X2APIC
 int x2apic_mode;
+EXPORT_SYMBOL_GPL(x2apic_mode);
 
 enum {
 	X2APIC_OFF,