[RFC PATCH v1 19/28] KVM: SVM: prepare to reserve asid for SEV guest

[Paolo Bonzini]

On 23/08/2016 01:27, Brijesh Singh wrote:
> In current implementation, asid allocation starts from 1, this patch
> adds a min_asid variable in svm_vcpu structure to allow starting asid
> from something other than 1.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh at amd.com>
> ---
>  arch/x86/kvm/svm.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 211be94..f010b23 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -470,6 +470,7 @@ struct svm_cpu_data {
>  	u64 asid_generation;
>  	u32 max_asid;
>  	u32 next_asid;
> +	u32 min_asid;
>  	struct kvm_ldttss_desc *tss_desc;
>  
>  	struct page *save_area;
> @@ -726,6 +727,7 @@ static int svm_hardware_enable(void)
>  	sd->asid_generation = 1;
>  	sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
>  	sd->next_asid = sd->max_asid + 1;
> +	sd->min_asid = 1;
>  
>  	native_store_gdt(&gdt_descr);
>  	gdt = (struct desc_struct *)gdt_descr.address;
> @@ -1887,7 +1889,7 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
>  {
>  	if (sd->next_asid > sd->max_asid) {
>  		++sd->asid_generation;
> -		sd->next_asid = 1;
> +		sd->next_asid = sd->min_asid;
>  		svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ALL_ASID;
>  	}
>  
> 
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Reviewed-by: Paolo Bonzini <pbonzini at redhat.com>