diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-09-05 14:22:55 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-09-10 19:18:29 +0200 |
| commit | 1edce0a9eb239b7a2768d10cf7d21dd83e269d5b (patch) | |
| tree | bd0f6dafd4ea0904a810717fe7577caec8dcd1a7 /arch/x86/kvm/vmx | |
| parent | f20935d85a23c33f5361661747ffa975549f56d5 (diff) | |
KVM: x86: Add kvm_emulate_{rd,wr}msr() to consolidate VXM/SVM code
Move RDMSR and WRMSR emulation into common x86 code to consolidate
nearly identical SVM and VMX code.
Note, consolidating RDMSR introduces an extra indirect call, i.e.
retpoline, due to reaching {svm,vmx}_get_msr() via kvm_x86_ops, but a
guest kernel likely has bigger problems if increasing the latency of
RDMSR VM-Exits by ~70 cycles has a measurable impact on overall VM
performance. E.g. the only recurring RDMSR VM-Exits (after booting) on
my system running Linux 5.2 in the guest are for MSR_IA32_TSC_ADJUST via
arch_cpu_idle_enter().
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 29 |
1 files changed, 2 insertions, 27 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index c8af21ce52a7..024cb9bf5ad3 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4866,37 +4866,12 @@ static int handle_cpuid(struct kvm_vcpu *vcpu) static int handle_rdmsr(struct kvm_vcpu *vcpu) { - u32 ecx = kvm_rcx_read(vcpu); - struct msr_data msr_info; - - msr_info.index = ecx; - msr_info.host_initiated = false; - if (vmx_get_msr(vcpu, &msr_info)) { - trace_kvm_msr_read_ex(ecx); - kvm_inject_gp(vcpu, 0); - return 1; - } - - trace_kvm_msr_read(ecx, msr_info.data); - - kvm_rax_write(vcpu, msr_info.data & -1u); - kvm_rdx_write(vcpu, (msr_info.data >> 32) & -1u); - return kvm_skip_emulated_instruction(vcpu); + return kvm_emulate_rdmsr(vcpu); } static int handle_wrmsr(struct kvm_vcpu *vcpu) { - u32 ecx = kvm_rcx_read(vcpu); - u64 data = kvm_read_edx_eax(vcpu); - - if (kvm_set_msr(vcpu, ecx, data) != 0) { - trace_kvm_msr_write_ex(ecx, data); - kvm_inject_gp(vcpu, 0); - return 1; - } - - trace_kvm_msr_write(ecx, data); - return kvm_skip_emulated_instruction(vcpu); + return kvm_emulate_wrmsr(vcpu); } static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu) |