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| author | Radim Krčmář <rkrcmar@redhat.com> | 2015-09-18 18:54:30 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-09-28 14:06:37 +0300 |
| commit | 9bac175d8ed0b1dd3d3611c0713666b724eeace3 (patch) | |
| tree | d36059e4f2db727e978a55eaa8e2009063f944ae /arch | |
| parent | 9ffecb10283508260936b96022d4ee43a7798b4c (diff) | |
| download | linux-9bac175d8ed0b1dd3d3611c0713666b724eeace3.tar.xz | |
Revert "KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR"
Shifting pvclock_vcpu_time_info.system_time on write to KVM system time
MSR is a change of ABI. Probably only 2.6.16 based SLES 10 breaks due
to its custom enhancements to kvmclock, but KVM never declared the MSR
only for one-shot initialization. (Doc says that only one write is
needed.)
This reverts commit b7e60c5aedd2b63f16ef06fde4f81ca032211bc5.
And adds a note to the definition of PVCLOCK_COUNTS_FROM_ZERO.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/pvclock-abi.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 4 |
2 files changed, 1 insertions, 4 deletions
diff --git a/arch/x86/include/asm/pvclock-abi.h b/arch/x86/include/asm/pvclock-abi.h index 655e07a48f6c..67f08230103a 100644 --- a/arch/x86/include/asm/pvclock-abi.h +++ b/arch/x86/include/asm/pvclock-abi.h @@ -41,6 +41,7 @@ struct pvclock_wall_clock { #define PVCLOCK_TSC_STABLE_BIT (1 << 0) #define PVCLOCK_GUEST_STOPPED (1 << 1) +/* PVCLOCK_COUNTS_FROM_ZERO broke ABI and can't be used anymore. */ #define PVCLOCK_COUNTS_FROM_ZERO (1 << 2) #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_PVCLOCK_ABI_H */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 991466bf8dee..92511d4b7236 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1708,8 +1708,6 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) vcpu->pvclock_set_guest_stopped_request = false; } - pvclock_flags |= PVCLOCK_COUNTS_FROM_ZERO; - /* If the host uses TSC clocksource, then it is stable */ if (use_master_clock) pvclock_flags |= PVCLOCK_TSC_STABLE_BIT; @@ -2007,8 +2005,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) &vcpu->requests); ka->boot_vcpu_runs_old_kvmclock = tmp; - - ka->kvmclock_offset = -get_kernel_ns(); } vcpu->arch.time = data; |