Re: [PATCH Part1 RFC v4 03/36] x86/sev: Add support for hypervisor feature VMGEXIT

[Borislav Petkov]

On Wed, Jul 07, 2021 at 01:14:33PM -0500, Brijesh Singh wrote:
> diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
> index 11b7d9cea775..23929a3010df 100644
> --- a/arch/x86/include/asm/sev-common.h
> +++ b/arch/x86/include/asm/sev-common.h
> @@ -45,6 +45,15 @@
>  		(((unsigned long)reg & GHCB_MSR_CPUID_REG_MASK) << GHCB_MSR_CPUID_REG_POS) | \
>  		(((unsigned long)fn) << GHCB_MSR_CPUID_FUNC_POS))
>  
> +/* GHCB Hypervisor Feature Request */
> +#define GHCB_MSR_HV_FT_REQ	0x080
> +#define GHCB_MSR_HV_FT_RESP	0x081
> +#define GHCB_MSR_HV_FT_POS	12
> +#define GHCB_MSR_HV_FT_MASK	GENMASK_ULL(51, 0)
> +
> +#define GHCB_MSR_HV_FT_RESP_VAL(v)	\
> +	(((unsigned long)((v) >> GHCB_MSR_HV_FT_POS) & GHCB_MSR_HV_FT_MASK))

As I suggested...

> @@ -215,6 +216,7 @@
>  	{ SVM_VMGEXIT_NMI_COMPLETE,	"vmgexit_nmi_complete" }, \
>  	{ SVM_VMGEXIT_AP_HLT_LOOP,	"vmgexit_ap_hlt_loop" }, \
>  	{ SVM_VMGEXIT_AP_JUMP_TABLE,	"vmgexit_ap_jump_table" }, \
> +	{ SVM_VMGEXIT_HYPERVISOR_FEATURES,	"vmgexit_hypervisor_feature" }, \

	SVM_VMGEXIT_HV_FEATURES

>  	{ SVM_EXIT_ERR,         "invalid_guest_state" }
>  
>  
> diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
> index 19c2306ac02d..34821da5f05e 100644
> --- a/arch/x86/kernel/sev-shared.c
> +++ b/arch/x86/kernel/sev-shared.c
> @@ -23,6 +23,9 @@
>   */
>  static u16 ghcb_version __section(".data..ro_after_init");
>  
> +/* Bitmap of SEV features supported by the hypervisor */
> +u64 sev_hv_features __section(".data..ro_after_init") = 0;

__ro_after_init

> diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
> index 66b7f63ad041..540b81ac54c9 100644
> --- a/arch/x86/kernel/sev.c
> +++ b/arch/x86/kernel/sev.c
> @@ -96,6 +96,9 @@ struct ghcb_state {
>  static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
>  DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
>  
> +/* Bitmap of SEV features supported by the hypervisor */
> +EXPORT_SYMBOL(sev_hv_features);

Why is this exported and why not a _GPL export?

-- 
Regards/Gruss,
    Boris.

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