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| author | Leonid Shatz <leonid.shatz@oracle.com> | 2018-11-06 12:14:25 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-11-27 12:50:10 +0100 |
| commit | 326e742533bf0a23f0127d8ea62fb558ba665f08 (patch) | |
| tree | e347b3ba50e3338957d9fca8971fe083b94065c1 /arch/x86/kvm/x86.c | |
| parent | 1e4329ee2c52692ea42cc677fb2133519718b34a (diff) | |
| download | lwn-326e742533bf0a23f0127d8ea62fb558ba665f08.tar.gz lwn-326e742533bf0a23f0127d8ea62fb558ba665f08.zip | |
KVM: nVMX/nSVM: Fix bug which sets vcpu->arch.tsc_offset to L1 tsc_offset
Since commit e79f245ddec1 ("X86/KVM: Properly update 'tsc_offset' to
represent the running guest"), vcpu->arch.tsc_offset meaning was
changed to always reflect the tsc_offset value set on active VMCS.
Regardless if vCPU is currently running L1 or L2.
However, above mentioned commit failed to also change
kvm_vcpu_write_tsc_offset() to set vcpu->arch.tsc_offset correctly.
This is because vmx_write_tsc_offset() could set the tsc_offset value
in active VMCS to given offset parameter *plus vmcs12->tsc_offset*.
However, kvm_vcpu_write_tsc_offset() just sets vcpu->arch.tsc_offset
to given offset parameter. Without taking into account the possible
addition of vmcs12->tsc_offset. (Same is true for SVM case).
Fix this issue by changing kvm_x86_ops->write_tsc_offset() to return
actually set tsc_offset in active VMCS and modify
kvm_vcpu_write_tsc_offset() to set returned value in
vcpu->arch.tsc_offset.
In addition, rename write_tsc_offset() callback to write_l1_tsc_offset()
to make it clear that it is meant to set L1 TSC offset.
Fixes: e79f245ddec1 ("X86/KVM: Properly update 'tsc_offset' to represent the running guest")
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Leonid Shatz <leonid.shatz@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7e4be1f2f253..d02937760c3b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1665,8 +1665,7 @@ EXPORT_SYMBOL_GPL(kvm_read_l1_tsc); static void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { - kvm_x86_ops->write_tsc_offset(vcpu, offset); - vcpu->arch.tsc_offset = offset; + vcpu->arch.tsc_offset = kvm_x86_ops->write_l1_tsc_offset(vcpu, offset); } static inline bool kvm_check_tsc_unstable(void) @@ -1794,7 +1793,8 @@ EXPORT_SYMBOL_GPL(kvm_write_tsc); static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment) { - kvm_vcpu_write_tsc_offset(vcpu, vcpu->arch.tsc_offset + adjustment); + u64 tsc_offset = kvm_x86_ops->read_l1_tsc_offset(vcpu); + kvm_vcpu_write_tsc_offset(vcpu, tsc_offset + adjustment); } static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment) |