[PATCH] x86/loader: Don't update kernel header for CoCo VMs

[Xiaoyao Li]

Update the header makes it different from the original kernel that user
provides via "-kernel", which leads to a different hash and breaks the
attestation, e.g., for TDX.

We already skip it for SEV VMs. Instead of adding another check of
is_tdx_vm() to cover the TDX case, check machine->cgs to cover all the
confidential computing case for x86.

Reported-by: Vikrant Garg <vikrant1g...@gmail.com>
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com>
---
 hw/i386/x86-common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
index b1b5f11e7396..7512be64d67b 100644
--- a/hw/i386/x86-common.c
+++ b/hw/i386/x86-common.c
@@ -952,7 +952,7 @@ void x86_load_linux(X86MachineState *x86ms,
      * kernel on the other side of the fw_cfg interface matches the hash of the
      * file the user passed in.
      */
-    if (!sev_enabled() && protocol > 0) {
+    if (!MACHINE(x86ms)->cgs && protocol > 0) {
         memcpy(setup, header, MIN(sizeof(header), setup_size));
     }
 
-- 
2.43.0