Re: [Qemu-devel] [PATCH 4/4] kvm pv features PART I

[Glauber Costa <glommer@gmail.com>]

On Thu, Jan 29, 2009 at 3:19 PM, Glauber Costa <glommer@redhat.com> wrote:
> Signed-off-by: Glauber Costa <glommer@redhat.com>

Shame on you, what a great changelog entry!

This is where temporary becomes definitive by accident ;-)

Anthony, let me know if you are okay with this patch, and if so, I'll
provide a more
meaningful changelog (that would be easy).

> ---
>  kvm.h                |    5 +++++
>  target-i386/helper.c |   19 ++++++++++++++++++-
>  target-i386/kvm.c    |   30 ++++++++++++++++++++++++++++++
>  3 files changed, 53 insertions(+), 1 deletions(-)
>
> diff --git a/kvm.h b/kvm.h
> index efce145..49a2653 100644
> --- a/kvm.h
> +++ b/kvm.h
> @@ -17,6 +17,8 @@
>  #include "config.h"
>
>  #ifdef CONFIG_KVM
> +#include <linux/kvm.h>
> +#include <linux/kvm_para.h>
>  extern int kvm_allowed;
>
>  #define kvm_enabled() (kvm_allowed)
> @@ -76,4 +78,7 @@ int kvm_arch_init(KVMState *s, int smp_cpus);
>
>  int kvm_arch_init_vcpu(CPUState *env);
>
> +/* x86 specific */
> +uint32_t kvm_get_para_features(CPUState *env);
> +
>  #endif
> diff --git a/target-i386/helper.c b/target-i386/helper.c
> index 1410002..6bcd94d 100644
> --- a/target-i386/helper.c
> +++ b/target-i386/helper.c
> @@ -1405,7 +1405,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
>                    uint32_t *ecx, uint32_t *edx)
>  {
>     /* test if maximum index reached */
> -    if (index & 0x80000000) {
> +    if (index & 0x40000000) {
> +        /* Those are KVM-specific, dodge them without messing with
> +         * exposed cpuid_level */
> +    } else if (index & 0x80000000) {
>         if (index > env->cpuid_xlevel)
>             index = env->cpuid_level;
>     } else {
> @@ -1511,6 +1514,20 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
>         *ecx = 0;
>         *edx = 0;
>         break;
> +    case 0x40000000:
> +        if (kvm_enabled()) {
> +            /* KVM CPUID signature */
> +            *eax = 0;
> +            *ebx = 0x4b4d564b; /* KVMKVMK */
> +            *ecx = 0x564b4d56; /* VMKV */
> +            *edx = 0x0000004d; /* M */
> +        }
> +        break;
> +    case 0x40000001:
> +        if (kvm_enabled()) {
> +            *eax = kvm_get_para_features(env);
> +        }
> +        break;
>     case 0x80000000:
>         *eax = env->cpuid_xlevel;
>         *ebx = env->cpuid_vendor1;
> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> index 64b24db..c9f0272 100644
> --- a/target-i386/kvm.c
> +++ b/target-i386/kvm.c
> @@ -56,6 +56,36 @@ static void kvm_fill_cpuid(CPUState *env, KVMCpuid *cpuid_data,
>     }
>  }
>
> +static struct kvm_para_features {
> +    int cap;
> +    int feature;
> +} para_features[] = {
> +#ifdef KVM_CAP_CLOCKSOURCE
> +       { KVM_CAP_CLOCKSOURCE, KVM_FEATURE_CLOCKSOURCE },
> +#endif
> +#ifdef KVM_CAP_NOP_IO_DELAY
> +       { KVM_CAP_NOP_IO_DELAY, KVM_FEATURE_NOP_IO_DELAY },
> +#endif
> +#ifdef KVM_CAP_PV_MMU
> +       { KVM_CAP_PV_MMU, KVM_FEATURE_MMU_OP },
> +#endif
> +#ifdef KVM_CAP_CR3_CACHE
> +       { KVM_CAP_CR3_CACHE, KVM_FEATURE_CR3_CACHE },
> +#endif
> +};
> +
> +uint32_t kvm_get_para_features(CPUState *env)
> + {
> +    uint32_t i, features = 0;
> +
> +    for (i = 0; i < ARRAY_SIZE(para_features); i++) {
> +        if (kvm_ioctl(env->kvm_state, KVM_CHECK_EXTENSION, para_features[i].cap))
> +            features |= (1 << para_features[i].feature);
> +    }
> +
> +    return features;
> +}
> +
>  int kvm_arch_init_vcpu(CPUState *env)
>  {
>     KVMCpuid cpuid_data;
> --
> 1.5.6.5
>
>
>
>



-- 
Glauber  Costa.
"Free as in Freedom"
http://glommer.net

"The less confident you are, the more serious you have to act."