[PATCH] QEMU: Fix KVM XSAVE feature bit enumeration

[PATCH] QEMU: Fix KVM XSAVE feature bit enumeration

[Andre Przywara]

When iterating through the XSAVE feature enumeration CPUID leaf (0xD)
we should not stop at the first zero EAX, but instead keep scanning
since there are gaps in the enumeration (ECX=1 for instance).
This fixes the proper usage of AVX in KVM guests.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
---
 target-i386/kvm.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index faedc6c..4a97f78 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -448,6 +448,8 @@ int kvm_arch_init_vcpu(CPUState *env)
         case 0xb:
         case 0xd:
             for (j = 0; ; j++) {
+                if (i == 0xd && j == 64)
+                    break;
                 c->function = i;
                 c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                 c->index = j;
@@ -460,7 +462,7 @@ int kvm_arch_init_vcpu(CPUState *env)
                     break;
                 }
                 if (i == 0xd && c->eax == 0) {
-                    break;
+                    continue;
                 }
                 c = &cpuid_data.entries[cpuid_i++];
             }
-- 
1.6.4

Re: [PATCH] QEMU: Fix KVM XSAVE feature bit enumeration

[Jan Kiszka]

On 2011-06-10 14:08, Andre Przywara wrote:
> When iterating through the XSAVE feature enumeration CPUID leaf (0xD)
> we should not stop at the first zero EAX, but instead keep scanning
> since there are gaps in the enumeration (ECX=1 for instance).
> This fixes the proper usage of AVX in KVM guests.
> 
> Signed-off-by: Andre Przywara <andre.przywara@amd.com>
> ---
>  target-i386/kvm.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> index faedc6c..4a97f78 100644
> --- a/target-i386/kvm.c
> +++ b/target-i386/kvm.c
> @@ -448,6 +448,8 @@ int kvm_arch_init_vcpu(CPUState *env)
>          case 0xb:
>          case 0xd:
>              for (j = 0; ; j++) {
> +                if (i == 0xd && j == 64)
> +                    break;

checkpatch.pl?

>                  c->function = i;
>                  c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
>                  c->index = j;
> @@ -460,7 +462,7 @@ int kvm_arch_init_vcpu(CPUState *env)
>                      break;
>                  }
>                  if (i == 0xd && c->eax == 0) {
> -                    break;
> +                    continue;
>                  }
>                  c = &cpuid_data.entries[cpuid_i++];
>              }

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux

[PATCH] KVM: Fix XSAVE feature bit enumeration

[Andre Przywara]

When iterating through the XSAVE feature enumeration CPUID leaf (0xD)
we should not stop at the first zero EAX, but instead keep scanning
since there are gaps in the enumeration (ECX=1 for instance).
This fixes the proper usage of AVX in KVM guests.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
---
 target-i386/kvm.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index faedc6c..37a972f 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -448,6 +448,9 @@ int kvm_arch_init_vcpu(CPUState *env)
         case 0xb:
         case 0xd:
             for (j = 0; ; j++) {
+                if (i == 0xd && j == 64) {
+                    break;
+                }
                 c->function = i;
                 c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                 c->index = j;
@@ -460,7 +463,7 @@ int kvm_arch_init_vcpu(CPUState *env)
                     break;
                 }
                 if (i == 0xd && c->eax == 0) {
-                    break;
+                    continue;
                 }
                 c = &cpuid_data.entries[cpuid_i++];
             }
-- 
1.6.4

Re: [PATCH] KVM: Fix XSAVE feature bit enumeration

[Avi Kivity]

On 06/10/2011 04:56 PM, Andre Przywara wrote:
> When iterating through the XSAVE feature enumeration CPUID leaf (0xD)
> we should not stop at the first zero EAX, but instead keep scanning
> since there are gaps in the enumeration (ECX=1 for instance).
> This fixes the proper usage of AVX in KVM guests.

Thanks, applied to uq/master.

-- 
error compiling committee.c: too many arguments to function