From: Zhao Liu <zhao1.liu@intel.com>
Date: Wed, 6 Nov 2024 03:07:21 +0000 (+0800)
Subject: target/i386/kvm: Only save/load kvmclock MSRs when kvmclock enabled
X-Git-Tag: v10.0.0-rc0~86^2~16
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=86e032bb7b5ac5a319cef914aa779825fe39a2e2;p=thirdparty%2Fqemu.git

target/i386/kvm: Only save/load kvmclock MSRs when kvmclock enabled

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>
Link: https://lore.kernel.org/r/20241106030728.553238-5-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 7870820a2b..7536a3c9fd 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -3973,8 +3973,10 @@ 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 | CPUID_KVM_CLOCK2)) {
+            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);
         }
@@ -4451,8 +4453,10 @@ 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 | CPUID_KVM_CLOCK2)) {
+        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);
     }