KVM: x86: Save L1 TSC offset in 'struct kvm_vcpu_arch'

Save L1's TSC offset in 'struct kvm_vcpu_arch' and drop the kvm_x86_ops
hook read_l1_tsc_offset().  This avoids a retpoline (when configured)
when reading L1's effective TSC, which is done at least once on every
VM-Exit.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson
2020-05-01 21:32:25 -07:00
committed by Paolo Bonzini
parent 1af1bb0562
commit 56ba77a459
4 changed files with 5 additions and 29 deletions

View File

@@ -951,16 +951,6 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type)
seg->base = 0;
}
static u64 svm_read_l1_tsc_offset(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
if (is_guest_mode(vcpu))
return svm->nested.hsave->control.tsc_offset;
return vcpu->arch.tsc_offset;
}
static u64 svm_write_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -4075,7 +4065,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.has_wbinvd_exit = svm_has_wbinvd_exit,
.read_l1_tsc_offset = svm_read_l1_tsc_offset,
.write_l1_tsc_offset = svm_write_l1_tsc_offset,
.load_mmu_pgd = svm_load_mmu_pgd,