[kvm-unit-tests RFC PATCH 3/3] x86 AMD SEV-ES: Setup a new page table and install level 1 PTEs

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

KUT's UEFI tests don't currently have support for page allocation.
SEV-ES/SNP tests will need this later, so the support for page
allocation is provided via setup_vm().

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.

Signed-off-by: Pavan Kumar Paluri <papaluri@amd.com>
---
 lib/x86/vm.c  | 6 ++++++
 x86/amd_sev.c | 7 +++++++
 2 files changed, 13 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);
diff --git a/x86/amd_sev.c b/x86/amd_sev.c
index 7757d4f85b7a..03636e581dfe 100644
--- a/x86/amd_sev.c
+++ b/x86/amd_sev.c
@@ -14,6 +14,8 @@
 #include "x86/processor.h"
 #include "x86/amd_sev.h"
 #include "msr.h"
+#include "x86/vm.h"
+#include "alloc_page.h"
 
 #define EXIT_SUCCESS 0
 #define EXIT_FAILURE 1
@@ -89,9 +91,14 @@ static void test_stringio(void)
 int main(void)
 {
 	int rtn;
+	unsigned long *vaddr;
 	rtn = test_sev_activation();
 	report(rtn == EXIT_SUCCESS, "SEV activation test.");
 	test_sev_es_activation();
 	test_stringio();
+	setup_vm();
+	vaddr = alloc_page();
+	if (!vaddr)
+		assert_msg(vaddr, "Page allocation Failure");
 	return report_summary();
 }
-- 
2.34.1