diff mbox

target-i386: assert that KVM_GET/SET_MSRS can set all requested MSRs

Message ID 1459371583-4824-2-git-send-email-pbonzini@redhat.com
State New
Headers show

Commit Message

Paolo Bonzini March 30, 2016, 8:59 p.m. UTC
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(-)

Comments

Laszlo Ersek March 31, 2016, 1:01 p.m. UTC | #1
On 03/30/16 22:59, Paolo Bonzini wrote:
> This would have caught the bug in the previous patch.

Should this patch share a series with
<http://thread.gmane.org/gmane.comp.emulators.qemu/404245>? Otherwise
they could be separated by other patches in the commit history, and then
"previous patch" would be misleading.

(Alternatively, the reference to "previous patch" could be made by subject.)

> 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;
>  }

This changes the return value of kvm_put_tscdeadline_msr() -- and
friends below -- for successful invocations. I guess that's fine, but a
note about it in the commit message would be nice.

Anyway, I'm not an "expert" in this area, so the best I can offer for
this two-part (almost-) series, with the commit message nits fixed, is

Acked-by: Laszlo Ersek <lersek@redhat.com>

Thanks
Laszlo

>  
>  /*
> @@ -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;
>
Paolo Bonzini March 31, 2016, 1:03 p.m. UTC | #2
On 31/03/2016 15:01, Laszlo Ersek wrote:
> On 03/30/16 22:59, Paolo Bonzini wrote:
>> This would have caught the bug in the previous patch.
> 
> Should this patch share a series with
> <http://thread.gmane.org/gmane.comp.emulators.qemu/404245>?

They need not, but indeed the commit message has to be adjusted (unless
I send both of them in the same pull request, and then they effectively
become 1/2 and 2/2).

Paolo

> Otherwise
> they could be separated by other patches in the commit history, and then
> "previous patch" would be misleading.
> 
> (Alternatively, the reference to "previous patch" could be made by subject.)
> 
>> 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;
>>  }
> 
> This changes the return value of kvm_put_tscdeadline_msr() -- and
> friends below -- for successful invocations. I guess that's fine, but a
> note about it in the commit message would be nice.
> 
> Anyway, I'm not an "expert" in this area, so the best I can offer for
> this two-part (almost-) series, with the commit message nits fixed, is
> 
> Acked-by: Laszlo Ersek <lersek@redhat.com>
> 
> Thanks
> Laszlo
> 
>>  
>>  /*
>> @@ -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;
>>
>
Eduardo Habkost March 31, 2016, 4:51 p.m. UTC | #3
On Thu, Mar 31, 2016 at 03:01:29PM +0200, Laszlo Ersek wrote:
> On 03/30/16 22:59, Paolo Bonzini wrote:
> > This would have caught the bug in the previous patch.
> 
> Should this patch share a series with
> <http://thread.gmane.org/gmane.comp.emulators.qemu/404245>? Otherwise
> they could be separated by other patches in the commit history, and then
> "previous patch" would be misleading.
> 
> (Alternatively, the reference to "previous patch" could be made by subject.)
> 
> > 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;
> >  }
> 
> This changes the return value of kvm_put_tscdeadline_msr() -- and
> friends below -- for successful invocations. I guess that's fine, but a
> note about it in the commit message would be nice.

All these functions have only one caller each, that only checks
if ret < 0.

(As they are all static functions with a single caller in
target-i386/kvm.c, I don't mind if this is not mentioned in the
commit message.)

> 
> Anyway, I'm not an "expert" in this area, so the best I can offer for
> this two-part (almost-) series, with the commit message nits fixed, is
> 
> Acked-by: Laszlo Ersek <lersek@redhat.com>
> 
> Thanks
> Laszlo
> 
> >  
> >  /*
> > @@ -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;
> > +    }

This is not strictly needed to implement what's described in the
commit message, but it makes kvm_put_msr_feature_control() safer
and harder to break.

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

> >  
> >      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;
> > 
>
diff mbox

Patch

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;