Re: [PATCH] kvm:x86/svm: enable SVM lock if host supports it

[Joerg Roedel <joro@8bytes.org>]

On Wed, Apr 17, 2013 at 11:03:33PM +0530, prasadjoshi.linux@gmail.com wrote:
> From: Prasad Joshi <prasadjoshi.linux@gmail.com>
> 
> SVM lock features allows software from preventing update to EFER.SVME.
> Enable the SVM lock in guest if it is supported on host machine.
> 
> Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
> ---
>  arch/x86/kvm/svm.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index e1b1ce2..fcdfdea 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -4031,6 +4031,10 @@ static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
>  		if (boot_cpu_has(X86_FEATURE_NRIPS))
>  			entry->edx |= SVM_FEATURE_NRIP;
>  
> +		/* support SVM Lock if host supports it */
> +		if (boot_cpu_has(X86_FEATURE_SVML))
> +			entry->edx |= SVM_FEATURE_SVML;
> +

No. SVM lock is way more complex to emulate than just setting the CPUID
bit.


	Joerg