[Qemu-devel] [PATCH] target-i386: assert that KVM_GET/SET_MSRS can set all requested MSRs

[Paolo Bonzini <pbonzini@redhat.com>]

This would have caught the bug in the previous patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target-i386/kvm.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 19e2d94..799fdfa 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -141,6 +141,7 @@ static int kvm_get_tsc(CPUState *cs)
         return ret;
     }
 
+    assert(ret == 1);
     env->tsc = msr_data.entries[0].data;
     return 0;
 }
@@ -1446,6 +1447,7 @@ static int kvm_put_tscdeadline_msr(X86CPU *cpu)
         struct kvm_msr_entry entries[1];
     } msr_data;
     struct kvm_msr_entry *msrs = msr_data.entries;
+    int ret;
 
     if (!has_msr_tsc_deadline) {
         return 0;
@@ -1457,7 +1459,13 @@ static int kvm_put_tscdeadline_msr(X86CPU *cpu)
         .nmsrs = 1,
     };
 
-    return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
+    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
+    if (ret < 0) {
+        return ret;
+    }
+
+    assert(ret == 1);
+    return 0;
 }
 
 /*
@@ -1472,6 +1480,11 @@ static int kvm_put_msr_feature_control(X86CPU *cpu)
         struct kvm_msrs info;
         struct kvm_msr_entry entry;
     } msr_data;
+    int ret;
+
+    if (!has_msr_feature_control) {
+        return 0;
+    }
 
     kvm_msr_entry_set(&msr_data.entry, MSR_IA32_FEATURE_CONTROL,
                       cpu->env.msr_ia32_feature_control);
@@ -1480,7 +1493,13 @@ static int kvm_put_msr_feature_control(X86CPU *cpu)
         .nmsrs = 1,
     };
 
-    return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
+    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
+    if (ret < 0) {
+        return ret;
+    }
+
+    assert(ret == 1);
+    return 0;
 }
 
 static int kvm_put_msrs(X86CPU *cpu, int level)
@@ -1492,6 +1511,7 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
     } msr_data;
     struct kvm_msr_entry *msrs = msr_data.entries;
     int n = 0, i;
+    int ret;
 
     kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_CS, env->sysenter_cs);
     kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_ESP, env->sysenter_esp);
@@ -1685,8 +1705,13 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
         .nmsrs = n,
     };
 
-    return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
+    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
+    if (ret < 0) {
+        return ret;
+    }
 
+    assert(ret == n);
+    return 0;
 }
 
 
@@ -2055,6 +2080,7 @@ static int kvm_get_msrs(X86CPU *cpu)
         return ret;
     }
 
+    assert(ret == n);
     for (i = 0; i < ret; i++) {
         uint32_t index = msrs[i].index;
         switch (index) {
@@ -2511,7 +2537,7 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
 
     assert(cpu_is_stopped(cpu) || qemu_cpu_is_self(cpu));
 
-    if (level >= KVM_PUT_RESET_STATE && has_msr_feature_control) {
+    if (level >= KVM_PUT_RESET_STATE) {
         ret = kvm_put_msr_feature_control(x86_cpu);
         if (ret < 0) {
             return ret;
-- 
2.5.5