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| author |   Sean Christopherson <seanjc@google.com> | 2021-01-15 14:03:53 -0800 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 05:27:22 -0500 |
| commit | db7d8e476821df85dce0cfd1e654c72c7db879dc (patch) | |
| tree | 99210d85ddac21209e9556a1390b7747d05d6a96 /arch/x86/kernel/apic/apic.c | |
| parent | KVM: X86: Add the Document for KVM_CAP_X86_BUS_LOCK_EXIT (diff) | |
| download | linux-dev-db7d8e476821df85dce0cfd1e654c72c7db879dc.tar.xz linux-dev-db7d8e476821df85dce0cfd1e654c72c7db879dc.zip | |
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.c | 1 |
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, |