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| author | Jason Baron <jbaron@akamai.com> | 2021-01-14 22:27:56 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 05:27:30 -0500 |
| commit | b3646477d458fbe7694a15b9c78fbe2fa426b703 (patch) | |
| tree | 6b2c5379acb1a28e4ffce63fc589fc76c18fd678 /arch/x86/include/asm/kvm_host.h | |
| parent | 9af5471bdbb2a26a1a46cd834e9fda6db6a9670e (diff) | |
| download | lwn-b3646477d458fbe7694a15b9c78fbe2fa426b703.tar.gz lwn-b3646477d458fbe7694a15b9c78fbe2fa426b703.zip | |
KVM: x86: use static calls to reduce kvm_x86_ops overhead
Convert kvm_x86_ops to use static calls. Note that all kvm_x86_ops are
covered here except for 'pmu_ops and 'nested ops'.
Here are some numbers running cpuid in a loop of 1 million calls averaged
over 5 runs, measured in the vm (lower is better).
Intel Xeon 3000MHz:
|default |mitigations=off
-------------------------------------
vanilla |.671s |.486s
static call|.573s(-15%)|.458s(-6%)
AMD EPYC 2500MHz:
|default |mitigations=off
-------------------------------------
vanilla |.710s |.609s
static call|.664s(-6%) |.609s(0%)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Message-Id: <e057bf1b8a7ad15652df6eeba3f907ae758d3399.1610680941.git.jbaron@akamai.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/kvm_host.h')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 25502e6a6bc0..fa7b2df6422b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1374,7 +1374,7 @@ void kvm_arch_free_vm(struct kvm *kvm); static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm) { if (kvm_x86_ops.tlb_remote_flush && - !kvm_x86_ops.tlb_remote_flush(kvm)) + !static_call(kvm_x86_tlb_remote_flush)(kvm)) return 0; else return -ENOTSUPP; @@ -1767,14 +1767,12 @@ static inline bool kvm_irq_is_postable(struct kvm_lapic_irq *irq) static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) { - if (kvm_x86_ops.vcpu_blocking) - kvm_x86_ops.vcpu_blocking(vcpu); + static_call_cond(kvm_x86_vcpu_blocking)(vcpu); } static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) { - if (kvm_x86_ops.vcpu_unblocking) - kvm_x86_ops.vcpu_unblocking(vcpu); + static_call_cond(kvm_x86_vcpu_unblocking)(vcpu); } static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} |