On Mon, Jul 24, 2017 at 03:02:51PM -0500, Brijesh Singh wrote:
> SEV hardware uses ASIDs to associate memory encryption key with the
> guest VMs. During the guest creation time, we use SEV_CMD_ACTIVATE

"VM"

> command to bind a particular ASID to the guest. Lets make sure that
> VMCB is programmed with the binded ASID before a VMRUN.

"the VMCB"                      binded? you mean "bound"

> 
> Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
> ---
>  arch/x86/kvm/svm.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 49 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index e99a572..72f7c27 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -213,6 +213,9 @@ struct vcpu_svm {
>        */
>       struct list_head ir_list;
>       spinlock_t ir_list_lock;
> +
> +     /* which host cpu was used for running this vcpu */

s/cpu/CPU/

> +     unsigned int last_cpuid;

... and since it is a CPU, then "last_cpu" I guess.

>  };
>  
>  /*
> @@ -573,6 +576,8 @@ struct svm_cpu_data {
>       struct kvm_ldttss_desc *tss_desc;
>  
>       struct page *save_area;
> +
> +     struct vmcb **sev_vmcbs;  /* index = sev_asid, value = vmcb pointer */

Put that comment above it.

>  static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
> @@ -886,6 +891,7 @@ static void svm_cpu_uninit(int cpu)
>               return;
>  
>       per_cpu(svm_data, raw_smp_processor_id()) = NULL;
> +     kfree(sd->sev_vmcbs);
>       __free_page(sd->save_area);
>       kfree(sd);
>  }
> @@ -904,6 +910,14 @@ static int svm_cpu_init(int cpu)
>       if (!sd->save_area)
>               goto err_1;
>  
> +     if (svm_sev_enabled()) {
> +             sd->sev_vmcbs = kmalloc((max_sev_asid + 1) * sizeof(void *),
> +                                     GFP_KERNEL);

You can let that line stick out.

> +             r = -ENOMEM;

That assignment usually is done before the call. I know, this function
does it differently but you can fix it up while you're touching it.

> +             if (!sd->sev_vmcbs)
> +                     goto err_1;
> +     }
> +
>       per_cpu(svm_data, cpu) = sd;
>  
>       return 0;
> @@ -4442,12 +4456,40 @@ static void reload_tss(struct kvm_vcpu *vcpu)
>       load_TR_desc();
>  }
>  
> +static void pre_sev_run(struct vcpu_svm *svm)
> +{
> +     int cpu = raw_smp_processor_id();
> +     int asid = sev_get_asid(svm->vcpu.kvm);
> +     struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
> +
> +     /* Assign the asid allocated with this SEV guest */
> +     svm->vmcb->control.asid = asid;
> +
> +     /*
> +      * Flush guest TLB:
> +      *
> +      * 1) when different VMCB for the same ASID is to be run on the same 
> host CPU.
> +      * 2) or this VMCB was executed on different host cpu in previous 
> VMRUNs.

s/cpu/CPU/

> +      */
> +     if (sd->sev_vmcbs[asid] == svm->vmcb &&
> +             svm->last_cpuid == cpu)
> +             return;
> +
> +     svm->last_cpuid = cpu;
> +     sd->sev_vmcbs[asid] = svm->vmcb;
> +     svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
> +     mark_dirty(svm->vmcb, VMCB_ASID);
> +}
> +
>  static void pre_svm_run(struct vcpu_svm *svm)
>  {
>       int cpu = raw_smp_processor_id();
>  
>       struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
>  
> +     if (sev_guest(svm->vcpu.kvm))
> +             return pre_sev_run(svm);

Just pass @cpu here so that you don't have to do raw_smp_processor_id()
again above.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 
(AG Nürnberg)
-- 

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