x86/amd_sev.c

/*
 * AMD SEV test cases
 *
 * Copyright (c) 2021, Google Inc
 *
 * Authors:
 *   Hyunwook (Wooky) Baek <baekhw@google.com>
 *   Zixuan Wang <zixuanwang@google.com>
 *
 * SPDX-License-Identifier: LGPL-2.0-or-later
 */

#include "libcflat.h"
#include "x86/processor.h"
#include "x86/amd_sev.h"
#include "msr.h"

#define TESTDEV_IO_PORT 0xe0

static char st1[] = "abcdefghijklmnop";

static void test_stringio(void)
{
	int st1_len = sizeof(st1) - 1;
	u16 got;

	asm volatile("cld \n\t"
		     "movw %0, %%dx \n\t"
		     "rep outsw \n\t"
		     : : "i"((short)TESTDEV_IO_PORT),
		         "S"(st1), "c"(st1_len / 2));

	asm volatile("inw %1, %0\n\t" : "=a"(got) : "i"((short)TESTDEV_IO_PORT));

	report((got & 0xff) == st1[sizeof(st1) - 3], "outsb nearly up");
	report((got & 0xff00) >> 8 == st1[sizeof(st1) - 2], "outsb up");
}

int main(void)
{
	if (!amd_sev_enabled()) {
		report_skip("AMD SEV not enabled\n");
		goto out;
	}

	printf("SEV-ES is %senabled.\n", amd_sev_es_enabled() ? "" : "not ");

	test_stringio();

out:
	return report_summary();
}