[RFC 12/16] KVM: selftests: add SEV-ES boot tests

[Michael Roth <michael.roth@xxxxxxx>]

Extend the existing SEV boot tests to also cover SEV-ES guests. Also
add some tests for handling #VC exceptions for cpuid instructions using
both MSR-based and GHCB-based vmgexits.

Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
---
 .../selftests/kvm/x86_64/sev_all_boot_test.c  | 63 ++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/x86_64/sev_all_boot_test.c b/tools/testing/selftests/kvm/x86_64/sev_all_boot_test.c
index 8df7143ac17d..58c57c4c0ec1 100644
--- a/tools/testing/selftests/kvm/x86_64/sev_all_boot_test.c
+++ b/tools/testing/selftests/kvm/x86_64/sev_all_boot_test.c
@@ -18,6 +18,7 @@
 #include "svm_util.h"
 #include "linux/psp-sev.h"
 #include "sev.h"
+#include "sev_exitlib.h"
 
 #define VCPU_ID			2
 #define PAGE_SIZE		4096
@@ -31,6 +32,10 @@
 
 #define TOTAL_PAGES		(512 + SHARED_PAGES + PRIVATE_PAGES)
 
+/* Globals for use by #VC handler. */
+static void *ghcb0_gva;
+static vm_paddr_t ghcb0_gpa;
+
 static void fill_buf(uint8_t *buf, size_t pages, size_t stride, uint8_t val)
 {
 	int i, j;
@@ -171,6 +176,47 @@ guest_sev_code(struct sev_sync_data *sync, uint8_t *shared_buf, uint8_t *private
 	guest_test_done(sync);
 }
 
+static void vc_handler(struct ex_regs *regs)
+{
+	sev_es_handle_vc(ghcb0_gva, ghcb0_gpa, regs);
+}
+
+static void __attribute__((__flatten__))
+guest_sev_es_code(struct sev_sync_data *sync, uint8_t *shared_buf,
+		  uint8_t *private_buf, uint64_t ghcb_gpa, void *ghcb_gva)
+{
+	uint32_t eax, ebx, ecx, edx, token = 1;
+	uint64_t sev_status;
+
+	guest_test_start(sync);
+
+again:
+	/* Check CPUID values via GHCB MSR protocol. */
+	eax = 0x8000001f;
+	ecx = 0;
+	cpuid(&eax, &ebx, &ecx, &edx);
+
+	/* Check SEV bit. */
+	SEV_GUEST_ASSERT(sync, token++, eax & (1 << 1));
+	/* Check SEV-ES bit. */
+	SEV_GUEST_ASSERT(sync, token++, eax & (1 << 3));
+
+	if (!ghcb0_gva) {
+		ghcb0_gva = ghcb_gva;
+		ghcb0_gpa = ghcb_gpa;
+		/* Check CPUID bits again using GHCB-based protocol. */
+		goto again;
+	}
+
+	/* Check SEV and SEV-ES enabled bits (bits 0 and 1, respectively). */
+	sev_status = rdmsr(MSR_AMD64_SEV);
+	SEV_GUEST_ASSERT(sync, token++, (sev_status & 0x3) == 3);
+
+	guest_test_common(sync, shared_buf, private_buf);
+
+	guest_test_done(sync);
+}
+
 static void
 setup_test_common(struct sev_vm *sev, void *guest_code, vm_vaddr_t *sync_vaddr,
 		  vm_vaddr_t *shared_vaddr, vm_vaddr_t *private_vaddr)
@@ -216,7 +262,18 @@ static void test_sev(void *guest_code, uint64_t policy)
 	setup_test_common(sev, guest_code, &sync_vaddr, &shared_vaddr, &private_vaddr);
 
 	/* Set up guest params. */
-	vcpu_args_set(vm, VCPU_ID, 4, sync_vaddr, shared_vaddr, private_vaddr);
+	if (policy & SEV_POLICY_ES) {
+		vm_vaddr_t ghcb_vaddr = vm_vaddr_alloc_shared(vm, PAGE_SIZE, 0);
+
+		vcpu_args_set(vm, VCPU_ID, 6, sync_vaddr, shared_vaddr, private_vaddr,
+			      addr_gva2gpa(vm, ghcb_vaddr), ghcb_vaddr);
+		/* Set up VC handler. */
+		vm_init_descriptor_tables(vm);
+		vm_install_exception_handler(vm, 29, vc_handler);
+		vcpu_init_descriptor_tables(vm, VCPU_ID);
+	} else {
+		vcpu_args_set(vm, VCPU_ID, 4, sync_vaddr, shared_vaddr, private_vaddr);
+	}
 
 	sync = addr_gva2hva(vm, sync_vaddr);
 	shared_buf = addr_gva2hva(vm, shared_vaddr);
@@ -248,5 +305,9 @@ int main(int argc, char *argv[])
 	test_sev(guest_sev_code, SEV_POLICY_NO_DBG);
 	test_sev(guest_sev_code, 0);
 
+	/* SEV-ES tests */
+	test_sev(guest_sev_es_code, SEV_POLICY_ES | SEV_POLICY_NO_DBG);
+	test_sev(guest_sev_es_code, SEV_POLICY_ES);
+
 	return 0;
 }
-- 
2.25.1