[PATCH v5 04/11] target/i386/kvm: Only save/load kvmclock MSRs when kvmclock enabled

Zhao Liu
2024-11-06T02:50:01Z

MSR_KVM_SYSTEM_TIME and MSR_KVM_WALL_CLOCK are attached with the (old)
kvmclock feature (KVM_FEATURE_CLOCKSOURCE).

So, just save/load them only when kvmclock (KVM_FEATURE_CLOCKSOURCE) is
enabled.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Zide Chen <zide.chen@intel.com>
---
target/i386/kvm/kvm.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 54520a77d6af..4aba034865bb 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -3958,8 +3958,10 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
*/
if (level >= KVM_PUT_RESET_STATE) {
kvm_msr_entry_add(cpu, MSR_IA32_TSC, env->tsc);
- kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME, env->system_time_msr);
- kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
+ if (env->features[FEAT_KVM] & CPUID_KVM_CLOCK) {
+ kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME, env->system_time_msr);
+ kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
+ }
if (env->features[FEAT_KVM] & CPUID_KVM_ASYNCPF_INT) {
kvm_msr_entry_add(cpu, MSR_KVM_ASYNC_PF_INT, env->async_pf_int_msr);
}
@@ -4436,8 +4438,10 @@ static int kvm_get_msrs(X86CPU *cpu)
}
}
#endif
- kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME, 0);
- kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK, 0);
+ if (env->features[FEAT_KVM] & CPUID_KVM_CLOCK) {
+ kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME, 0);
+ kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK, 0);
+ }
if (env->features[FEAT_KVM] & CPUID_KVM_ASYNCPF_INT) {
kvm_msr_entry_add(cpu, MSR_KVM_ASYNC_PF_INT, 0);
}
--
2.34.1