Re: [PATCH RFC v8 51/56] KVM: SVM: Add module parameter to enable the SEV-SNP

[Zhi Wang]

On Mon, 20 Feb 2023 12:38:42 -0600
Michael Roth <michael.roth@xxxxxxx> wrote:

> From: Brijesh Singh <brijesh.singh@xxxxxxx>
> 
> Add a module parameter than can be used to enable or disable the SEV-SNP
> feature. Now that KVM contains the support for the SNP set the GHCB
> hypervisor feature flag to indicate that SNP is supported.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
> ---
>  arch/x86/kvm/svm/sev.c | 7 ++++---
>  arch/x86/kvm/svm/svm.h | 2 +-
>  2 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index bedec90d034f..70d5650d8d95 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -55,14 +55,15 @@ module_param_named(sev, sev_enabled, bool, 0444);
>  /* enable/disable SEV-ES support */
>  static bool sev_es_enabled = true;
>  module_param_named(sev_es, sev_es_enabled, bool, 0444);
> +
> +/* enable/disable SEV-SNP support */
> +static bool sev_snp_enabled = true;
> +module_param_named(sev_snp, sev_snp_enabled, bool, 0444);
>  #else
>  #define sev_enabled false
>  #define sev_es_enabled false

Guess we also need #define sev_snp_enabled false.

>  #endif /* CONFIG_KVM_AMD_SEV */
>  
> -/* enable/disable SEV-SNP support */
> -static bool sev_snp_enabled;
> -
>  #define AP_RESET_HOLD_NONE		0
>  #define AP_RESET_HOLD_NAE_EVENT		1
>  #define AP_RESET_HOLD_MSR_PROTO		2
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index 857b674e68f0..221b38d3c845 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -694,7 +694,7 @@ void avic_refresh_virtual_apic_mode(struct kvm_vcpu *vcpu);
>  #define GHCB_VERSION_MAX	2ULL
>  #define GHCB_VERSION_MIN	1ULL
>  
> -#define GHCB_HV_FT_SUPPORTED	0
> +#define GHCB_HV_FT_SUPPORTED	(GHCB_HV_FT_SNP | GHCB_HV_FT_SNP_AP_CREATION)

This is not related to the topic of this patch, should be merged into related
patches.

>  
>  extern unsigned int max_sev_asid;
>