diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-11-01 00:39:48 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-11-02 20:03:07 +0100 |
| commit | ea26e4ec08d4727e3a9e48a6b74695861effcbd9 (patch) | |
| tree | be3ae8868bd0e93e6029cfd9ce0512fe69dc39ab /arch/x86/kvm/svm.c | |
| parent | bd768e146624cbec7122ed15dead8daa137d909d (diff) | |
KVM: x86: drop TSC offsetting kvm_x86_ops to fix KVM_GET/SET_CLOCK
Since commit a545ab6a0085 ("kvm: x86: add tsc_offset field to struct
kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is
cached and need not be fished out of the VMCS or VMCB. This means
that we can implement adjust_tsc_offset_guest and read_l1_tsc
entirely in generic code. The simplification is particularly
significant for VMX code, where vmx->nested.vmcs01_tsc_offset
was duplicating what is now in vcpu->arch.tsc_offset. Therefore
the vmcs01_tsc_offset can be dropped completely.
More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK
which, after commit 108b249c453d ("KVM: x86: introduce get_kvmclock_ns",
2016-09-01) called read_l1_tsc while the VMCS was not loaded.
It thus returned bogus values on Intel CPUs.
Fixes: 108b249c453dd7132599ab6dc7e435a7036c193f
Reported-by: Roman Kagan <rkagan@virtuozzo.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f8157a36ab09..8ca1eca5038d 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1138,21 +1138,6 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } -static void svm_adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment) -{ - struct vcpu_svm *svm = to_svm(vcpu); - - svm->vmcb->control.tsc_offset += adjustment; - if (is_guest_mode(vcpu)) - svm->nested.hsave->control.tsc_offset += adjustment; - else - trace_kvm_write_tsc_offset(vcpu->vcpu_id, - svm->vmcb->control.tsc_offset - adjustment, - svm->vmcb->control.tsc_offset); - - mark_dirty(svm->vmcb, VMCB_INTERCEPTS); -} - static void avic_init_vmcb(struct vcpu_svm *svm) { struct vmcb *vmcb = svm->vmcb; @@ -3449,12 +3434,6 @@ static int cr8_write_interception(struct vcpu_svm *svm) return 0; } -static u64 svm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc) -{ - struct vmcb *vmcb = get_host_vmcb(to_svm(vcpu)); - return vmcb->control.tsc_offset + host_tsc; -} - static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { struct vcpu_svm *svm = to_svm(vcpu); @@ -5422,8 +5401,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .has_wbinvd_exit = svm_has_wbinvd_exit, .write_tsc_offset = svm_write_tsc_offset, - .adjust_tsc_offset_guest = svm_adjust_tsc_offset_guest, - .read_l1_tsc = svm_read_l1_tsc, .set_tdp_cr3 = set_tdp_cr3, |