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From: Nikunj A Dadhania <nikunj@amd.com>
To: <linux-kernel@vger.kernel.org>, <thomas.lendacky@amd.com>, <bp@alien8.de>,
	<x86@kernel.org>, <kvm@vger.kernel.org>
CC: <mingo@redhat.com>, <tglx@linutronix.de>, <dave.hansen@linux.intel.com>,
	<pgonda@google.com>, <seanjc@google.com>, <pbonzini@redhat.com>,
	<nikunj@amd.com>
Subject: [PATCH v9 14/24] x86/sev: Handle failures from snp_init()
Date: Fri, 31 May 2024 10:00:28 +0530
Message-ID: <20240531043038.3370793-15-nikunj@amd.com>
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Failures from the snp_init() are currently being ignored by sme_enable().
Add missing error handling for cases where snp_init() fails to retrieve
SEV-SNP CC blob or encounters issues while parsing CC blob. SNP guests will
error out early with this change.

Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
---
 arch/x86/mm/mem_encrypt_identity.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index ac33b2263a43..e83b363c5e68 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -535,6 +535,13 @@ void __head sme_enable(struct boot_params *bp)
 	if (snp && !(msr & MSR_AMD64_SEV_SNP_ENABLED))
 		snp_abort();
 
+	/*
+	 * The SEV-SNP CC blob should be present and parsing CC blob should
+	 * succeed when SEV-SNP is enabled.
+	 */
+	if (!snp && (msr & MSR_AMD64_SEV_SNP_ENABLED))
+		snp_abort();
+
 	/* Check if memory encryption is enabled */
 	if (feature_mask == AMD_SME_BIT) {
 		if (!(bp->hdr.xloadflags & XLF_MEM_ENCRYPTION))
-- 
2.34.1