Add legacy debug/test interfaces for kvm unit tests.

Implement the legacy debug/test interfaces expected by KVM-unit-tests'
realmode, emulator, and ioapic tests.

Submitted by:	adam_fenn.io
Reviewed by:	markj, grehan
Approved by:	grehan (bhyve)
MFC after:	3 weeks
Relnotes:	Yes
Differential Revision:	https://reviews.freebsd.org/D27130

5 files changed, 344 insertions, 4 deletions

diff --git a/usr.sbin/bhyve/Makefile b/usr.sbin/bhyve/Makefile
index c1d4d2ee77f6..b884930d5b03 100644
--- a/usr.sbin/bhyve/Makefile
+++ b/usr.sbin/bhyve/Makefile
@@ -56,6 +56,7 @@ SRCS=	\
 	pci_virtio_scsi.c	\
 	pci_uart.c		\
 	pci_xhci.c		\
+	pctestdev.c		\
 	pm.c			\
 	post.c			\
 	ps2kbd.c		\
diff --git a/usr.sbin/bhyve/bhyve.8 b/usr.sbin/bhyve/bhyve.8
index 7bb3bbc9e20a..ce9d8bb0515c 100644
--- a/usr.sbin/bhyve/bhyve.8
+++ b/usr.sbin/bhyve/bhyve.8
@@ -169,9 +169,11 @@ Allow devices behind the LPC PCI-ISA bridge to be configured.
 The only supported devices are the TTY-class devices
 .Ar com1
 and
-.Ar com2
-and the boot ROM device
-.Ar bootrom .
+.Ar com2 ,
+the boot ROM device
+.Ar bootrom ,
+and the debug/test device
+.Ar pc-testdev .
 .Pp
 .Ar help
 print a list of supported LPC devices.
@@ -277,7 +279,8 @@ Intel e82545 network interface.
 .It Li uart
 PCI 16550 serial device.
 .It Li lpc
-LPC PCI-ISA bridge with COM1 and COM2 16550 serial ports and a boot ROM.
+LPC PCI-ISA bridge with COM1 and COM2 16550 serial ports, a boot ROM, and,
+optionally, the debug/test device.
 The LPC bridge emulation can only be configured on bus 0.
 .It Li fbuf
 Raw framebuffer device attached to VNC server.
diff --git a/usr.sbin/bhyve/pci_lpc.c b/usr.sbin/bhyve/pci_lpc.c
index 4ebdd7039cbc..3f7df55b5ffd 100644
--- a/usr.sbin/bhyve/pci_lpc.c
+++ b/usr.sbin/bhyve/pci_lpc.c
@@ -49,6 +49,7 @@ __FBSDID("$FreeBSD$");
 #include "pci_emul.h"
 #include "pci_irq.h"
 #include "pci_lpc.h"
+#include "pctestdev.h"
 #include "uart_emul.h"
 
 #define	IO_ICU1		0x20
@@ -80,6 +81,8 @@ static struct lpc_uart_softc {
 
 static const char *lpc_uart_names[LPC_UART_NUM] = { "COM1", "COM2" };
 
+static bool pctestdev_present;
+
 /*
  * LPC device configuration is in the following form:
  * <lpc_device_name>[,<options>]
@@ -107,6 +110,18 @@ lpc_device_parse(const char *opts)
 				goto done;
 			}
 		}
+		if (strcasecmp(lpcdev, pctestdev_getname()) == 0) {
+			if (pctestdev_present) {
+				EPRINTLN("More than one %s device conf is "
+				    "specified; only one is allowed.",
+				    pctestdev_getname());
+			} else if (pctestdev_parse(str) == 0) {
+				pctestdev_present = true;
+				error = 0;
+				free(cpy);
+				goto done;
+			}
+		}
 	}
 
 done:
@@ -124,6 +139,7 @@ lpc_print_supported_devices()
 	printf("bootrom\n");
 	for (i = 0; i < LPC_UART_NUM; i++)
 		printf("%s\n", lpc_uart_names[i]);
+	printf("%s\n", pctestdev_getname());
 }
 
 const char *
@@ -232,6 +248,13 @@ lpc_init(struct vmctx *ctx)
 		sc->enabled = 1;
 	}
 
+	/* pc-testdev */
+	if (pctestdev_present) {
+		error = pctestdev_init(ctx);
+		if (error)
+			return (error);
+	}
+
 	return (0);
 }
 
diff --git a/usr.sbin/bhyve/pctestdev.c b/usr.sbin/bhyve/pctestdev.c
new file mode 100644
index 000000000000..be445e5c75ae
--- /dev/null
+++ b/usr.sbin/bhyve/pctestdev.c
@@ -0,0 +1,270 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 Adam Fenn <adam@fenn.io>
+ *
+ * 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 AUTHORS AND CONTRIBUTORS ``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 AUTHORS 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.
+ */
+
+/*
+ * Emulation of selected legacy test/debug interfaces expected by KVM-unit-tests
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <machine/vmm.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <vmmapi.h>
+
+#include "debug.h"
+#include "inout.h"
+#include "mem.h"
+#include "pctestdev.h"
+
+#define	DEBUGEXIT_BASE		0xf4
+#define	DEBUGEXIT_LEN		4
+#define	DEBUGEXIT_NAME		"isa-debug-exit"
+
+#define	IOMEM_BASE		0xff000000
+#define	IOMEM_LEN		0x10000
+#define	IOMEM_NAME		"pc-testdev-iomem"
+
+#define	IOPORT_BASE		0xe0
+#define	IOPORT_LEN		4
+#define	IOPORT_NAME		"pc-testdev-ioport"
+
+#define	IRQ_BASE		0x2000
+#define	IRQ_IOAPIC_PINCOUNT_MIN	24
+#define	IRQ_IOAPIC_PINCOUNT_MAX	32
+#define	IRQ_NAME		"pc-testdev-irq-line"
+
+#define	PCTESTDEV_NAME		"pc-testdev"
+
+static bool	pctestdev_inited;
+static uint8_t	pctestdev_iomem_buf[IOMEM_LEN];
+static uint32_t	pctestdev_ioport_data;
+
+static int	pctestdev_debugexit_io(struct vmctx *ctx, int vcpu, int in,
+		    int port, int bytes, uint32_t *eax, void *arg);
+static int	pctestdev_iomem_io(struct vmctx *ctx, int vcpu, int dir,
+		    uint64_t addr, int size, uint64_t *val, void *arg1,
+		    long arg2);
+static int	pctestdev_ioport_io(struct vmctx *ctx, int vcpu, int in,
+		    int port, int bytes, uint32_t *eax, void *arg);
+static int	pctestdev_irq_io(struct vmctx *ctx, int vcpu, int in,
+		    int port, int bytes, uint32_t *eax, void *arg);
+
+const char *
+pctestdev_getname(void)
+{
+	return (PCTESTDEV_NAME);
+}
+
+int
+pctestdev_parse(const char *opts)
+{
+	if (opts != NULL && *opts != '\0')
+		return (-1);
+
+	return (0);
+}
+
+int
+pctestdev_init(struct vmctx *ctx)
+{
+	struct mem_range iomem;
+	struct inout_port debugexit, ioport, irq;
+	int err, pincount;
+
+	if (pctestdev_inited) {
+		EPRINTLN("Only one pc-testdev device is allowed.");
+
+		return (-1);
+	}
+
+	err = vm_ioapic_pincount(ctx, &pincount);
+	if (err != 0) {
+		EPRINTLN("pc-testdev: Failed to obtain IOAPIC pin count.");
+
+		return (-1);
+	}
+	if (pincount < IRQ_IOAPIC_PINCOUNT_MIN ||
+	    pincount > IRQ_IOAPIC_PINCOUNT_MAX) {
+		EPRINTLN("pc-testdev: Unsupported IOAPIC pin count: %d.",
+		    pincount);
+
+		return (-1);
+	}
+
+	debugexit.name = DEBUGEXIT_NAME;
+	debugexit.port = DEBUGEXIT_BASE;
+	debugexit.size = DEBUGEXIT_LEN;
+	debugexit.flags = IOPORT_F_INOUT;
+	debugexit.handler = pctestdev_debugexit_io;
+	debugexit.arg = NULL;
+
+	iomem.name = IOMEM_NAME;
+	iomem.flags = MEM_F_RW | MEM_F_IMMUTABLE;
+	iomem.handler = pctestdev_iomem_io;
+	iomem.arg1 = NULL;
+	iomem.arg2 = 0;
+	iomem.base = IOMEM_BASE;
+	iomem.size = IOMEM_LEN;
+
+	ioport.name = IOPORT_NAME;
+	ioport.port = IOPORT_BASE;
+	ioport.size = IOPORT_LEN;
+	ioport.flags = IOPORT_F_INOUT;
+	ioport.handler = pctestdev_ioport_io;
+	ioport.arg = NULL;
+
+	irq.name = IRQ_NAME;
+	irq.port = IRQ_BASE;
+	irq.size = pincount;
+	irq.flags = IOPORT_F_INOUT;
+	irq.handler = pctestdev_irq_io;
+	irq.arg = NULL;
+
+	err = register_inout(&debugexit);
+	if (err != 0)
+		goto fail;
+
+	err = register_inout(&ioport);
+	if (err != 0)
+		goto fail_after_debugexit_reg;
+
+	err = register_inout(&irq);
+	if (err != 0)
+		goto fail_after_ioport_reg;
+
+	err = register_mem(&iomem);
+	if (err != 0)
+		goto fail_after_irq_reg;
+
+	pctestdev_inited = true;
+
+	return (0);
+
+fail_after_irq_reg:
+	(void)unregister_inout(&irq);
+
+fail_after_ioport_reg:
+	(void)unregister_inout(&ioport);
+
+fail_after_debugexit_reg:
+	(void)unregister_inout(&debugexit);
+
+fail:
+	return (err);
+}
+
+static int
+pctestdev_debugexit_io(struct vmctx *ctx, int vcpu, int in, int port,
+    int bytes, uint32_t *eax, void *arg)
+{
+	if (in)
+		*eax = 0;
+	else
+		exit((*eax << 1) | 1);
+
+	return (0);
+}
+
+static int
+pctestdev_iomem_io(struct vmctx *ctx, int vcpu, int dir, uint64_t addr,
+    int size, uint64_t *val, void *arg1, long arg2)
+{
+	uint64_t offset;
+
+	if (addr + size > IOMEM_BASE + IOMEM_LEN)
+		return (-1);
+
+	offset = addr - IOMEM_BASE;
+	if (dir == MEM_F_READ) {
+		(void)memcpy(val, pctestdev_iomem_buf + offset, size);
+	} else {
+		assert(dir == MEM_F_WRITE);
+		(void)memcpy(pctestdev_iomem_buf + offset, val, size);
+	}
+
+	return (0);
+}
+
+static int
+pctestdev_ioport_io(struct vmctx *ctx, int vcpu, int in, int port,
+    int bytes, uint32_t *eax, void *arg)
+{
+	uint32_t mask;
+	int lsb;
+
+	if (port + bytes > IOPORT_BASE + IOPORT_LEN)
+		return (-1);
+
+	lsb = (port & 0x3) * 8;
+	mask = (-1UL >> (32 - (bytes * 8))) << lsb;
+
+	if (in)
+		*eax = (pctestdev_ioport_data & mask) >> lsb;
+	else {
+		pctestdev_ioport_data &= ~mask;
+		pctestdev_ioport_data |= *eax << lsb;
+	}
+
+	return (0);
+}
+
+static int
+pctestdev_irq_io(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
+    uint32_t *eax, void *arg)
+{
+	int irq;
+
+	if (bytes != 1)
+		return (-1);
+
+	if (in) {
+		*eax = 0;
+		return (0);
+	} else {
+		irq = port - IRQ_BASE;
+		if (irq < 16) {
+			if (*eax)
+				return (vm_isa_assert_irq(ctx, irq, irq));
+			else
+				return (vm_isa_deassert_irq(ctx, irq, irq));
+		} else {
+			if (*eax)
+				return (vm_ioapic_assert_irq(ctx, irq));
+			else
+				return (vm_ioapic_deassert_irq(ctx, irq));
+		}
+	}
+}
diff --git a/usr.sbin/bhyve/pctestdev.h b/usr.sbin/bhyve/pctestdev.h
new file mode 100644
index 000000000000..c1c940146e05
--- /dev/null
+++ b/usr.sbin/bhyve/pctestdev.h
@@ -0,0 +1,43 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 Adam Fenn <adam@fenn.io>
+ *
+ * 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 AUTHORS AND CONTRIBUTORS ``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 AUTHORS 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Emulation of selected legacy test/debug interfaces expected by KVM-unit-tests
+ */
+
+#ifndef	_PCTESTDEV_H_
+#define	_PCTESTDEV_H_
+
+struct vmctx;
+
+const char	*pctestdev_getname(void);
+int		 pctestdev_init(struct vmctx *ctx);
+int		 pctestdev_parse(const char *opts);
+
+#endif