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| author | Xiaoming Gao <newtongao@tencent.com> | 2014-06-19 19:14:57 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-09 11:18:27 -0700 |
| commit | 4c8c5a45d44452212a26af9a80f580707f1f77d1 (patch) | |
| tree | 1f910611fb4c4e2fe0248e3f345b6b4361d7bf1c | |
| parent | a46438472e31a9766352c97e37caaa2848ddea10 (diff) | |
| download | lwn-4c8c5a45d44452212a26af9a80f580707f1f77d1.tar.gz lwn-4c8c5a45d44452212a26af9a80f580707f1f77d1.zip | |
kvm: fix wrong address when writing Hyper-V tsc page
commit e1fa108d24697b78348fd4e5a531029a50d0d36d upstream.
When kvm_write_guest writes the tsc_ref structure to the guest, or it will lead
the low HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT bits of the TSC page address
must be cleared, or the guest can see a non-zero sequence number.
Otherwise Windows guests would not be able to get a correct clocksource
(QueryPerformanceCounter will always return 0) which causes serious chaos.
Signed-off-by: Xiaoming Gao <newtongao@tencnet.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ee0c3b554a38..8fbd1a772272 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1866,7 +1866,7 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data) if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE)) break; gfn = data >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT; - if (kvm_write_guest(kvm, data, + if (kvm_write_guest(kvm, gfn << HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT, &tsc_ref, sizeof(tsc_ref))) return 1; mark_page_dirty(kvm, gfn); |