Re: [PATCH V6.1] x86/hyper-v: Add hyperv Isolation VM check in the cc_platform_has()

[Tianyu Lan]

On 12/8/2021 10:52 PM, Tianyu Lan wrote:
> From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
>
> Hyper-V provides Isolation VM which encrypt guest memory. In
> isolation VM, swiotlb bounce buffer size needs to adjust
> according to memory size in the sev_setup_arch(). Add GUEST_MEM_
> ENCRYPT check in the Isolation VM.
>
> Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>

Hi Boris:
	Could you check whether this version is ok with you?

Thanks.

> ---
> Change since v6:
> 	* Change the order in the cc_platform_has() and check sev first.
>
> Change since v3:
> 	* Change code style of checking GUEST_MEM attribute in the
> 	  hyperv_cc_platform_has().
> ---
>   arch/x86/kernel/cc_platform.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/arch/x86/kernel/cc_platform.c b/arch/x86/kernel/cc_platform.c
> index 03bb2f343ddb..6cb3a675e686 100644
> --- a/arch/x86/kernel/cc_platform.c
> +++ b/arch/x86/kernel/cc_platform.c
> @@ -11,6 +11,7 @@
>   #include <linux/cc_platform.h>
>   #include <linux/mem_encrypt.h>
>   
> +#include <asm/mshyperv.h>
>   #include <asm/processor.h>
>   
>   static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr)
> @@ -58,12 +59,19 @@ static bool amd_cc_platform_has(enum cc_attr attr)
>   #endif
>   }
>   
> +static bool hyperv_cc_platform_has(enum cc_attr attr)
> +{
> +	return attr == CC_ATTR_GUEST_MEM_ENCRYPT;
> +}
>   
>   bool cc_platform_has(enum cc_attr attr)
>   {
>   	if (sme_me_mask)
>   		return amd_cc_platform_has(attr);
>   
> +	if (hv_is_isolation_supported())
> +		return hyperv_cc_platform_has(attr);
> +
>   	return false;
>   }
>   EXPORT_SYMBOL_GPL(cc_platform_has);