dm: add io port 0xF4 writing to force DM exit

This patch addes the debugexit function to DM. If it's enabled
by DM cmdline (by add --debugexit), the guest could write a
32bit value to port 0xF4 to trigger guest shutdown.

Tracked-on: #1465
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

devicemodel/Makefile

@@ -78,6 +78,7 @@ SRCS += hw/platform/acpi/acpi.c
 SRCS += hw/platform/acpi/acpi_pm.c
 SRCS += hw/platform/rpmb/rpmb_sim.c
 SRCS += hw/platform/rpmb/rpmb_backend.c
+SRCS += hw/platform/debugexit.c
 SRCS += hw/pci/wdt_i6300esb.c
 SRCS += hw/pci/lpc.c
 SRCS += hw/pci/xhci.c

devicemodel/core/main.c

@@ -84,6 +84,7 @@ bool stdio_in_use;
 
 static int virtio_msix = 1;
 static int x2apic_mode;	/* default is xAPIC */
+static bool debugexit_enabled;
 
 static int strictmsr = 1;
 
@@ -131,7 +132,7 @@ usage(int code)
 		"Usage: %s [-abehuwxACHPSTWY] [-c vcpus] [-g <gdb port>] [-l <lpc>]\n"
 		"       %*s [-m mem] [-p vcpu:hostcpu] [-s <pci>] [-U uuid] \n"
 		"       %*s [--vsbl vsbl_file_name] [--part_info part_info_name]\n"
-		"       %*s [--enable_trusty] <vm>\n"
+		"       %*s [--enable_trusty] [--debugexit] <vm>\n"
 		"       -a: local apic is in xAPIC mode (deprecated)\n"
 		"       -A: create ACPI tables\n"
 		"       -b: enable bvmcons\n"
@@ -160,7 +161,8 @@ usage(int code)
 		"       --vsbl: vsbl file path\n"
 		"       --part_info: guest partition info file path\n"
 		"       --enable_trusty: enable trusty for guest\n"
-		"       --ptdev_no_reset: disable reset check for ptdev\n",
+		"       --ptdev_no_reset: disable reset check for ptdev\n"
+		"	--debugexit: enable debug exit function\n",
 		progname, (int)strlen(progname), "", (int)strlen(progname), "",
 		(int)strlen(progname), "");
 
@@ -439,6 +441,9 @@ vm_init_vdevs(struct vmctx *ctx)
 	sci_init(ctx);
 	init_bvmcons();
 
+	if (debugexit_enabled)
+		init_debugexit();
+
 	ret = monitor_init(ctx);
 	if (ret < 0)
 		goto monitor_fail;
@@ -452,6 +457,9 @@ vm_init_vdevs(struct vmctx *ctx)
 pci_fail:
 	monitor_close();
 monitor_fail:
+	if (debugexit_enabled)
+		deinit_debugexit();
+
 	deinit_bvmcons();
 	vpit_deinit(ctx);
 vpit_fail:
@@ -469,6 +477,10 @@ vm_deinit_vdevs(struct vmctx *ctx)
 {
 	deinit_pci(ctx);
 	monitor_close();
+
+	if (debugexit_enabled)
+		deinit_debugexit();
+
 	deinit_bvmcons();
 	vpit_deinit(ctx);
 	vrtc_deinit(ctx);
@@ -493,6 +505,10 @@ vm_reset_vdevs(struct vmctx *ctx)
 	 * could be assigned with different number after reset.
 	 */
 	atkbdc_deinit(ctx);
+
+	if (debugexit_enabled)
+		deinit_debugexit();
+
 	vpit_deinit(ctx);
 	vrtc_deinit(ctx);
 
@@ -505,6 +521,9 @@ vm_reset_vdevs(struct vmctx *ctx)
 	vrtc_init(ctx);
 	vpit_init(ctx);
 
+	if (debugexit_enabled)
+		init_debugexit();
+
 	ioapic_init(ctx);
 	init_pci(ctx);
 
@@ -684,6 +703,7 @@ enum {
 	CMD_OPT_PART_INFO,
 	CMD_OPT_TRUSTY_ENABLE,
 	CMD_OPT_PTDEV_NO_RESET,
+	CMD_OPT_DEBUGEXIT,
 };
 
 static struct option long_options[] = {
@@ -720,6 +740,7 @@ static struct option long_options[] = {
 					CMD_OPT_TRUSTY_ENABLE},
 	{"ptdev_no_reset",	no_argument,		0,
 		CMD_OPT_PTDEV_NO_RESET},
+	{"debugexit",		no_argument,		0, CMD_OPT_DEBUGEXIT},
 	{0,			0,			0,  0  },
 };
 
@@ -869,6 +890,9 @@ main(int argc, char *argv[])
 		case CMD_OPT_PTDEV_NO_RESET:
 			ptdev_no_reset(true);
 			break;
+		case CMD_OPT_DEBUGEXIT:
+			debugexit_enabled = true;
+			break;
 		case 'h':
 			usage(0);
 		default:

devicemodel/hw/platform/debugexit.c

@@ -0,0 +1,80 @@
+/*-
+ * Copyright (c) 2018 Intel
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "types.h"
+#include "vmmapi.h"
+#include "inout.h"
+#include "mevent.h"
+
+#define DEBUG_IO_BASE	(0xf4)
+#define	DEBUG_IO_SIZE	(1)
+
+static int
+debugexit_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
+	      uint32_t *eax, void *arg)
+{
+	if (in)
+		*eax = 0xFFFF;
+	else {
+		vm_suspend(ctx, VM_SUSPEND_POWEROFF);
+		mevent_notify();
+	}
+	return 0;
+}
+
+void
+init_debugexit(void)
+{
+	struct inout_port iop;
+
+	memset(&iop, 0, sizeof(struct inout_port));
+	iop.name = "debugexit";
+	iop.port = DEBUG_IO_BASE;
+	iop.size = DEBUG_IO_SIZE;
+	iop.flags = IOPORT_F_INOUT;
+	iop.handler = debugexit_handler;
+
+	register_inout(&iop);
+}
+
+void
+deinit_debugexit(void)
+{
+	struct inout_port iop;
+
+	memset(&iop, 0, sizeof(struct inout_port));
+	iop.name = "debugexit";
+	iop.port = DEBUG_IO_BASE;
+	iop.size = DEBUG_IO_SIZE;
+
+	unregister_inout(&iop);
+}

devicemodel/include/dm.h

@@ -49,4 +49,6 @@ void *paddr_guest2host(struct vmctx *ctx, uintptr_t addr, size_t len);
 void *dm_gpa2hva(uint64_t gpa, size_t size);
 int  virtio_uses_msix(void);
 void ptdev_no_reset(bool enable);
+void init_debugexit(void);
+void deinit_debugexit(void);
 #endif