Commit f742b90e authored by Brijesh Singh's avatar Brijesh Singh Committed by Borislav Petkov
Browse files

x86/mm: Extend cc_attr to include AMD SEV-SNP 



The CC_ATTR_GUEST_SEV_SNP can be used by the guest to query whether the
SNP (Secure Nested Paging) feature is active.

Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-10-brijesh.singh@amd.com
parent bcce8290

arch/x86/coco/core.c

+3 −0
Original line number Diff line number Diff line
@@ -57,6 +57,9 @@ static bool amd_cc_platform_has(enum cc_attr attr) 
		return (sev_status & MSR_AMD64_SEV_ENABLED) &&

			!(sev_status & MSR_AMD64_SEV_ES_ENABLED);



	case CC_ATTR_GUEST_SEV_SNP:

		return sev_status & MSR_AMD64_SEV_SNP_ENABLED;



	default:

		return false;

	}

arch/x86/include/asm/msr-index.h

+2 −0
Original line number Diff line number Diff line
@@ -502,8 +502,10 @@ 
#define MSR_AMD64_SEV			0xc0010131

#define MSR_AMD64_SEV_ENABLED_BIT	0

#define MSR_AMD64_SEV_ES_ENABLED_BIT	1

#define MSR_AMD64_SEV_SNP_ENABLED_BIT	2

#define MSR_AMD64_SEV_ENABLED		BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT)

#define MSR_AMD64_SEV_ES_ENABLED	BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT)

#define MSR_AMD64_SEV_SNP_ENABLED	BIT_ULL(MSR_AMD64_SEV_SNP_ENABLED_BIT)



#define MSR_AMD64_VIRT_SPEC_CTRL	0xc001011f

arch/x86/mm/mem_encrypt.c

+4 −0
Original line number Diff line number Diff line
@@ -62,6 +62,10 @@ static void print_mem_encrypt_feature_info(void) 
	if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))

		pr_cont(" SEV-ES");



	/* Secure Nested Paging */

	if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))

		pr_cont(" SEV-SNP");



	pr_cont("\n");

}

include/linux/cc_platform.h

+8 −0
Original line number Diff line number Diff line
@@ -72,6 +72,14 @@ enum cc_attr { 
	 * Examples include TDX guest & SEV.

	 */

	CC_ATTR_GUEST_UNROLL_STRING_IO,



	/**

	 * @CC_ATTR_SEV_SNP: Guest SNP is active.

	 *

	 * The platform/OS is running as a guest/virtual machine and actively

	 * using AMD SEV-SNP features.

	 */

	CC_ATTR_GUEST_SEV_SNP,

};



#ifdef CONFIG_ARCH_HAS_CC_PLATFORM