diff options
| author | Jan Kiszka <jan.kiszka@siemens.com> | 2010-03-01 19:10:31 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-03-04 00:29:30 -0300 |
| commit | ea64305139357e89f58fc05ff5d48dc233d44d87 (patch) | |
| tree | 0b3ebd229d76fc2f770dc3228dcd81379a362a14 | |
| parent | ea375f9ab8c76686dca0af8cb4f87a4eb569cad3 (diff) | |
KVM: x86: Restrict writeback of VCPU state
Do not write nmi_pending, sipi_vector, and mpstate unless we at least go
through a reset. And TSC as well as KVM wallclocks should only be
written on full sync, otherwise we risk to drop some time on state
read-modify-write.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| -rw-r--r-- | target-i386/kvm.c | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 2c834dfdcc..40f83037d6 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -546,7 +546,7 @@ static void kvm_msr_entry_set(struct kvm_msr_entry *entry, entry->data = value; } -static int kvm_put_msrs(CPUState *env) +static int kvm_put_msrs(CPUState *env, int level) { struct { struct kvm_msrs info; @@ -560,7 +560,6 @@ static int kvm_put_msrs(CPUState *env) kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_EIP, env->sysenter_eip); if (kvm_has_msr_star(env)) kvm_msr_entry_set(&msrs[n++], MSR_STAR, env->star); - kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSC, env->tsc); #ifdef TARGET_X86_64 /* FIXME if lm capable */ kvm_msr_entry_set(&msrs[n++], MSR_CSTAR, env->cstar); @@ -568,8 +567,12 @@ static int kvm_put_msrs(CPUState *env) kvm_msr_entry_set(&msrs[n++], MSR_FMASK, env->fmask); kvm_msr_entry_set(&msrs[n++], MSR_LSTAR, env->lstar); #endif - kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_msr); - kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr); + if (level == KVM_PUT_FULL_STATE) { + kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSC, env->tsc); + kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME, + env->system_time_msr); + kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr); + } msr_data.info.nmsrs = n; @@ -782,7 +785,7 @@ static int kvm_get_mp_state(CPUState *env) return 0; } -static int kvm_put_vcpu_events(CPUState *env) +static int kvm_put_vcpu_events(CPUState *env, int level) { #ifdef KVM_CAP_VCPU_EVENTS struct kvm_vcpu_events events; @@ -806,8 +809,11 @@ static int kvm_put_vcpu_events(CPUState *env) events.sipi_vector = env->sipi_vector; - events.flags = - KVM_VCPUEVENT_VALID_NMI_PENDING | KVM_VCPUEVENT_VALID_SIPI_VECTOR; + events.flags = 0; + if (level >= KVM_PUT_RESET_STATE) { + events.flags |= + KVM_VCPUEVENT_VALID_NMI_PENDING | KVM_VCPUEVENT_VALID_SIPI_VECTOR; + } return kvm_vcpu_ioctl(env, KVM_SET_VCPU_EVENTS, &events); #else @@ -899,15 +905,17 @@ int kvm_arch_put_registers(CPUState *env, int level) if (ret < 0) return ret; - ret = kvm_put_msrs(env); + ret = kvm_put_msrs(env, level); if (ret < 0) return ret; - ret = kvm_put_mp_state(env); - if (ret < 0) - return ret; + if (level >= KVM_PUT_RESET_STATE) { + ret = kvm_put_mp_state(env); + if (ret < 0) + return ret; + } - ret = kvm_put_vcpu_events(env); + ret = kvm_put_vcpu_events(env, level); if (ret < 0) return ret; |