diff options
| author | Nadav Har'El <nyh@il.ibm.com> | 2011-08-02 16:54:20 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-09-25 20:18:02 +0400 |
| commit | d5c1785d2f3aabe284d91bc7fc8f0abc58525dc9 (patch) | |
| tree | 1db45488a6ecee728245e9af6f4fe59c4dc6ac4a /arch/x86/kvm/svm.c | |
| parent | e1a72ae287f3ea4fea63b6f14a662a15e8c11960 (diff) | |
| download | linux-d5c1785d2f3aabe284d91bc7fc8f0abc58525dc9.tar.xz | |
KVM: L1 TSC handling
KVM assumed in several places that reading the TSC MSR returns the value for
L1. This is incorrect, because when L2 is running, the correct TSC read exit
emulation is to return L2's value.
We therefore add a new x86_ops function, read_l1_tsc, to use in places that
specifically need to read the L1 TSC, NOT the TSC of the current level of
guest.
Note that one change, of one line in kvm_arch_vcpu_load, is made redundant
by a different patch sent by Zachary Amsden (and not yet applied):
kvm_arch_vcpu_load() should not read the guest TSC, and if it didn't, of
course we didn't have to change the call of kvm_get_msr() to read_l1_tsc().
[avi: moved callback to kvm_x86_ops tsc block]
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Acked-by: Zachary Amsdem <zamsden@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f043168a5ab1..590d1d2d620b 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2910,6 +2910,13 @@ static int cr8_write_interception(struct vcpu_svm *svm) return 0; } +u64 svm_read_l1_tsc(struct kvm_vcpu *vcpu) +{ + struct vmcb *vmcb = get_host_vmcb(to_svm(vcpu)); + return vmcb->control.tsc_offset + + svm_scale_tsc(vcpu, native_read_tsc()); +} + static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data) { struct vcpu_svm *svm = to_svm(vcpu); @@ -4201,6 +4208,7 @@ static struct kvm_x86_ops svm_x86_ops = { .write_tsc_offset = svm_write_tsc_offset, .adjust_tsc_offset = svm_adjust_tsc_offset, .compute_tsc_offset = svm_compute_tsc_offset, + .read_l1_tsc = svm_read_l1_tsc, .set_tdp_cr3 = set_tdp_cr3, |