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Diffstat (limited to 'arch/x86/kvm/vmx.c')
-rw-r--r--arch/x86/kvm/vmx.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 03df703c8f20..97b64543d4ed 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1748,6 +1748,21 @@ static u64 guest_read_tsc(void)
}
/*
+ * Like guest_read_tsc, but always returns L1's notion of the timestamp
+ * counter, even if a nested guest (L2) is currently running.
+ */
+u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu)
+{
+ u64 host_tsc, tsc_offset;
+
+ rdtscll(host_tsc);
+ tsc_offset = is_guest_mode(vcpu) ?
+ to_vmx(vcpu)->nested.vmcs01_tsc_offset :
+ vmcs_read64(TSC_OFFSET);
+ return host_tsc + tsc_offset;
+}
+
+/*
* Empty call-back. Needs to be implemented when VMX enables the SET_TSC_KHZ
* ioctl. In this case the call-back should update internal vmx state to make
* the changes effective.
@@ -7010,6 +7025,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.write_tsc_offset = vmx_write_tsc_offset,
.adjust_tsc_offset = vmx_adjust_tsc_offset,
.compute_tsc_offset = vmx_compute_tsc_offset,
+ .read_l1_tsc = vmx_read_l1_tsc,
.set_tdp_cr3 = vmx_set_cr3,