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| author | Marcelo Tosatti | 2012-11-28 02:28:47 +0100 |
|---|---|---|
| committer | Marcelo Tosatti | 2012-11-28 02:29:05 +0100 |
| commit | 78c0337a38450f809113dd46fe038874b93909f1 (patch) | |
| tree | d94852e4860760f70a5a01986c47e060413fd9bb /arch/x86/kvm/x86.c | |
| parent | KVM: remove unnecessary return value check (diff) | |
| download | kernel-qcow2-linux-78c0337a38450f809113dd46fe038874b93909f1.tar.gz kernel-qcow2-linux-78c0337a38450f809113dd46fe038874b93909f1.tar.xz kernel-qcow2-linux-78c0337a38450f809113dd46fe038874b93909f1.zip | |
KVM: x86: retain pvclock guest stopped bit in guest memory
Otherwise its possible for an unrelated KVM_REQ_UPDATE_CLOCK (such as due to CPU
migration) to clear the bit.
Noticed by Paolo Bonzini.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c31f75dd24d4..1dfe9d318734 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1145,6 +1145,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) unsigned long this_tsc_khz; s64 kernel_ns, max_kernel_ns; u64 tsc_timestamp; + struct pvclock_vcpu_time_info *guest_hv_clock; u8 pvclock_flags; /* Keep irq disabled to prevent changes to the clock */ @@ -1228,13 +1229,6 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) vcpu->last_kernel_ns = kernel_ns; vcpu->last_guest_tsc = tsc_timestamp; - pvclock_flags = 0; - if (vcpu->pvclock_set_guest_stopped_request) { - pvclock_flags |= PVCLOCK_GUEST_STOPPED; - vcpu->pvclock_set_guest_stopped_request = false; - } - - vcpu->hv_clock.flags = pvclock_flags; /* * The interface expects us to write an even number signaling that the @@ -1245,6 +1239,18 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) shared_kaddr = kmap_atomic(vcpu->time_page); + guest_hv_clock = shared_kaddr + vcpu->time_offset; + + /* retain PVCLOCK_GUEST_STOPPED if set in guest copy */ + pvclock_flags = (guest_hv_clock->flags & PVCLOCK_GUEST_STOPPED); + + if (vcpu->pvclock_set_guest_stopped_request) { + pvclock_flags |= PVCLOCK_GUEST_STOPPED; + vcpu->pvclock_set_guest_stopped_request = false; + } + + vcpu->hv_clock.flags = pvclock_flags; + memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock, sizeof(vcpu->hv_clock)); |