On Fri, Jul 20, 2012 at 10:50:11AM -0600, Bruce Rogers wrote: > When a guest is migrated, a time offset is generated in order to > maintain the correct kvmclock based time for the guest. Detect when > all kvmclock time pages are deleted so that the kvmclock offset can > be safely reset to zero. > > Cc: Glauber Costa <[email protected]> > Cc: Zachary Amsden <[email protected]> > Signed-off-by: Bruce Rogers <[email protected]> > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/x86.c | 5 ++++- > 2 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index db7c1f2..112415c 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -524,6 +524,7 @@ struct kvm_arch { > > unsigned long irq_sources_bitmap; > s64 kvmclock_offset; > + unsigned int n_time_pages; > raw_spinlock_t tsc_write_lock; > u64 last_tsc_nsec; > u64 last_tsc_write; > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 14c290d..350c51b 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1511,6 +1511,8 @@ static void kvmclock_reset(struct kvm_vcpu *vcpu) > if (vcpu->arch.time_page) { > kvm_release_page_dirty(vcpu->arch.time_page); > vcpu->arch.time_page = NULL; > + if (--vcpu->kvm->arch.n_time_pages == 0) > + vcpu->kvm->arch.kvmclock_offset = 0; > } > } > > @@ -1624,7 +1626,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, > u64 data) > if (is_error_page(vcpu->arch.time_page)) { > kvm_release_page_clean(vcpu->arch.time_page); > vcpu->arch.time_page = NULL; > - } > + } else > + vcpu->kvm->arch.n_time_pages++; > break; > } > case MSR_KVM_ASYNC_PF_EN:
Userspace is responsible for configuring a correct kvmclock_offset AFAICS? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
