[PATCH v2 4/4] sev/i386: Enable an SEV-ES guest based on SEV policy

[Tom Lendacky]

From: Tom Lendacky <thomas.lendacky@amd.com>

Update the sev_es_enabled() function return value to be based on the SEV
policy that has been specified. SEV-ES is enabled if SEV is enabled and
the SEV-ES policy bit is set in the policy object.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 target/i386/sev.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/i386/sev.c b/target/i386/sev.c
index 0bc497379b..0fd142abe9 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -70,6 +70,8 @@ struct SevGuestState {
 #define DEFAULT_GUEST_POLICY    0x1 /* disable debug */
 #define DEFAULT_SEV_DEVICE      "/dev/sev"
 
+#define GUEST_POLICY_SEV_ES_BIT (1 << 2)
+
 /* SEV Information Block GUID = 00f771de-1a7e-4fcb-890e-68c77e2fb44e */
 #define SEV_INFO_BLOCK_GUID \
     "\xde\x71\xf7\x00\x7e\x1a\xcb\x4f\x89\x0e\x68\xc7\x7e\x2f\xb4\x4e"
@@ -375,7 +377,7 @@ sev_enabled(void)
 bool
 sev_es_enabled(void)
 {
-    return false;
+    return sev_enabled() && (sev_guest->policy & GUEST_POLICY_SEV_ES_BIT);
 }
 
 uint64_t
-- 
2.28.0