[kvm-unit-tests PATCH v3 3/4] x86 AMD SEV-ES: Set GHCB page attributes for a new page table

[Pavan Kumar Paluri <papaluri@amd.com>]

SEV-ES/SNP guest uses GHCB page to communicate with the host. Such a
page should remain unencrypted (its c-bit should be unset). Therefore,
call setup_ghcb_pte() in the path of setup_vm() to make sure c-bit of
GHCB's pte is unset, for a new page table that will be setup as a part
of page allocation for SEV-ES/SNP tests later on.

Signed-off-by: Pavan Kumar Paluri <papaluri@amd.com>
---
 lib/x86/vm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/x86/vm.c b/lib/x86/vm.c
index 90f73fbb2dfd..ce2063aee75d 100644
--- a/lib/x86/vm.c
+++ b/lib/x86/vm.c
@@ -3,6 +3,7 @@
 #include "vmalloc.h"
 #include "alloc_page.h"
 #include "smp.h"
+#include "amd_sev.h"
 
 static pteval_t pte_opt_mask;
 
@@ -197,6 +198,11 @@ void *setup_mmu(phys_addr_t end_of_memory, void *opt_mask)
     init_alloc_vpage((void*)(3ul << 30));
 #endif
 
+#ifdef CONFIG_EFI
+	if (amd_sev_es_enabled())
+		setup_ghcb_pte(cr3);
+#endif
+
     write_cr3(virt_to_phys(cr3));
 #ifndef __x86_64__
     write_cr4(X86_CR4_PSE);
-- 
2.34.1