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| author | Wanpeng Li <wanpengli@tencent.com> | 2020-04-28 09:23:28 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-05-15 19:26:21 +0300 |
| commit | ae95f566b3d22ade75c67827f1171594dacc9a03 (patch) | |
| tree | 844a39327fc4c0862899716f7c59cd01e693878f /arch/x86/kvm/x86.c | |
| parent | 199a8b84c455cfeb81bc060c6824dea473e54dc3 (diff) | |
| download | linux-ae95f566b3d22ade75c67827f1171594dacc9a03.tar.xz | |
KVM: X86: TSCDEADLINE MSR emulation fastpath
This patch implements a fast path for emulation of writes to the TSCDEADLINE
MSR. Besides shortcutting various housekeeping tasks in the vCPU loop,
the fast path can also deliver the timer interrupt directly without going
through KVM_REQ_PENDING_TIMER because it runs in vCPU context.
Tested-by: Haiwei Li <lihaiwei@tencent.com>
Cc: Haiwei Li <lihaiwei@tencent.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1588055009-12677-7-git-send-email-wanpengli@tencent.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 | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 71749fcb229e..7fb7c1a8f1a5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1608,6 +1608,15 @@ static int handle_fastpath_set_x2apic_icr_irqoff(struct kvm_vcpu *vcpu, u64 data return 1; } +static int handle_fastpath_set_tscdeadline(struct kvm_vcpu *vcpu, u64 data) +{ + if (!kvm_can_use_hv_timer(vcpu)) + return 1; + + kvm_set_lapic_tscdeadline_msr(vcpu, data); + return 0; +} + fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu) { u32 msr = kvm_rcx_read(vcpu); @@ -1622,6 +1631,13 @@ fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu) ret = EXIT_FASTPATH_EXIT_HANDLED; } break; + case MSR_IA32_TSCDEADLINE: + data = kvm_read_edx_eax(vcpu); + if (!handle_fastpath_set_tscdeadline(vcpu, data)) { + kvm_skip_emulated_instruction(vcpu); + ret = EXIT_FASTPATH_REENTER_GUEST; + } + break; default: break; } |