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authorJakub Kicinski <kuba@kernel.org>2023-08-18 12:44:22 -0700
committerJakub Kicinski <kuba@kernel.org>2023-08-18 12:44:56 -0700
commit7ff57803d24e0cb326251489d70f60462e3e6c04 (patch)
tree4ff813109291e5d2c7745619d490af3cce481674 /arch/x86/boot/compressed/sev.c
parentc2e5f4fd1148727801a63d938cec210f16b48864 (diff)
parent0e8860d2125f51ba9bca67a520d826cb8f66cf42 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/sfc/tc.c fa165e194997 ("sfc: don't unregister flow_indr if it was never registered") 3bf969e88ada ("sfc: add MAE table machinery for conntrack table") https://lore.kernel.org/all/20230818112159.7430e9b4@canb.auug.org.au/ No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86/boot/compressed/sev.c')
-rw-r--r--arch/x86/boot/compressed/sev.c37
1 files changed, 35 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 09dc8c187b3c..c3e343bd4760 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -405,12 +405,45 @@ void sev_enable(struct boot_params *bp)
bp->cc_blob_address = 0;
/*
+ * Do an initial SEV capability check before snp_init() which
+ * loads the CPUID page and the same checks afterwards are done
+ * without the hypervisor and are trustworthy.
+ *
+ * If the HV fakes SEV support, the guest will crash'n'burn
+ * which is good enough.
+ */
+
+ /* Check for the SME/SEV support leaf */
+ eax = 0x80000000;
+ ecx = 0;
+ native_cpuid(&eax, &ebx, &ecx, &edx);
+ if (eax < 0x8000001f)
+ return;
+
+ /*
+ * Check for the SME/SEV feature:
+ * CPUID Fn8000_001F[EAX]
+ * - Bit 0 - Secure Memory Encryption support
+ * - Bit 1 - Secure Encrypted Virtualization support
+ * CPUID Fn8000_001F[EBX]
+ * - Bits 5:0 - Pagetable bit position used to indicate encryption
+ */
+ eax = 0x8000001f;
+ ecx = 0;
+ native_cpuid(&eax, &ebx, &ecx, &edx);
+ /* Check whether SEV is supported */
+ if (!(eax & BIT(1)))
+ return;
+
+ /*
* Setup/preliminary detection of SNP. This will be sanity-checked
* against CPUID/MSR values later.
*/
snp = snp_init(bp);
- /* Check for the SME/SEV support leaf */
+ /* Now repeat the checks with the SNP CPUID table. */
+
+ /* Recheck the SME/SEV support leaf */
eax = 0x80000000;
ecx = 0;
native_cpuid(&eax, &ebx, &ecx, &edx);
@@ -418,7 +451,7 @@ void sev_enable(struct boot_params *bp)
return;
/*
- * Check for the SME/SEV feature:
+ * Recheck for the SME/SEV feature:
* CPUID Fn8000_001F[EAX]
* - Bit 0 - Secure Memory Encryption support
* - Bit 1 - Secure Encrypted Virtualization support