diff options
| author | Wanpeng Li <wanpengli@tencent.com> | 2020-04-10 10:47:03 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-21 09:13:10 -0400 |
| commit | a9ab13ff6e844ad5b3ed39339e6db9a76bb539ad (patch) | |
| tree | baeae7a8f3432482d785309797a7124a3c6da7aa /arch/x86/kvm/x86.c | |
| parent | 873e1da16918a83cc7440e299dda0dc7ab6db34c (diff) | |
KVM: X86: Improve latency for single target IPI fastpath
IPI and Timer cause the main MSRs write vmexits in cloud environment
observation, let's optimize virtual IPI latency more aggressively to
inject target IPI as soon as possible.
Running kvm-unit-tests/vmexit.flat IPI testing on SKX server, disable
adaptive advance lapic timer and adaptive halt-polling to avoid the
interference, this patch can give another 7% improvement.
w/o fastpath -> x86.c fastpath 4238 -> 3543 16.4%
x86.c fastpath -> vmx.c fastpath 3543 -> 3293 7%
w/o fastpath -> vmx.c fastpath 4238 -> 3293 22.3%
Cc: Haiwei Li <lihaiwei@tencent.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200410174703.1138-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8104dc9ff5b2..8d9bcd5faac5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8179,7 +8179,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_int_win = dm_request_for_irq_injection(vcpu) && kvm_cpu_accept_dm_intr(vcpu); - enum exit_fastpath_completion exit_fastpath = EXIT_FASTPATH_NONE; + enum exit_fastpath_completion exit_fastpath; bool req_immediate_exit = false; @@ -8406,7 +8406,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD; } - kvm_x86_ops.run(vcpu); + exit_fastpath = kvm_x86_ops.run(vcpu); /* * Do this here before restoring debug registers on the host. And @@ -8438,7 +8438,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) vcpu->mode = OUTSIDE_GUEST_MODE; smp_wmb(); - kvm_x86_ops.handle_exit_irqoff(vcpu, &exit_fastpath); + kvm_x86_ops.handle_exit_irqoff(vcpu); /* * Consume any pending interrupts, including the possible source of |