freebsd-skq/usr.sbin/bhyve/pci_fbuf.c
John Baldwin 483d953a86 Initial support for bhyve save and restore.
Save and restore (also known as suspend and resume) permits a snapshot
to be taken of a guest's state that can later be resumed.  In the
current implementation, bhyve(8) creates a UNIX domain socket that is
used by bhyvectl(8) to send a request to save a snapshot (and
optionally exit after the snapshot has been taken).  A snapshot
currently consists of two files: the first holds a copy of guest RAM,
and the second file holds other guest state such as vCPU register
values and device model state.

To resume a guest, bhyve(8) must be started with a matching pair of
command line arguments to instantiate the same set of device models as
well as a pointer to the saved snapshot.

While the current implementation is useful for several uses cases, it
has a few limitations.  The file format for saving the guest state is
tied to the ABI of internal bhyve structures and is not
self-describing (in that it does not communicate the set of device
models present in the system).  In addition, the state saved for some
device models closely matches the internal data structures which might
prove a challenge for compatibility of snapshot files across a range
of bhyve versions.  The file format also does not currently support
versioning of individual chunks of state.  As a result, the current
file format is not a fixed binary format and future revisions to save
and restore will break binary compatiblity of snapshot files.  The
goal is to move to a more flexible format that adds versioning,
etc. and at that point to commit to providing a reasonable level of
compatibility.  As a result, the current implementation is not enabled
by default.  It can be enabled via the WITH_BHYVE_SNAPSHOT=yes option
for userland builds, and the kernel option BHYVE_SHAPSHOT.

Submitted by:	Mihai Tiganus, Flavius Anton, Darius Mihai
Submitted by:	Elena Mihailescu, Mihai Carabas, Sergiu Weisz
Relnotes:	yes
Sponsored by:	University Politehnica of Bucharest
Sponsored by:	Matthew Grooms (student scholarships)
Sponsored by:	iXsystems
Differential Revision:	https://reviews.freebsd.org/D19495
2020-05-05 00:02:04 +00:00

467 lines
10 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2015 Nahanni Systems, Inc.
* 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/mman.h>
#include <machine/vmm.h>
#include <machine/vmm_snapshot.h>
#include <vmmapi.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "bhyvegc.h"
#include "bhyverun.h"
#include "debug.h"
#include "console.h"
#include "inout.h"
#include "pci_emul.h"
#include "rfb.h"
#include "vga.h"
/*
* bhyve Framebuffer device emulation.
* BAR0 points to the current mode information.
* BAR1 is the 32-bit framebuffer address.
*
* -s <b>,fbuf,wait,vga=on|io|off,rfb=<ip>:port,w=width,h=height
*/
static int fbuf_debug = 1;
#define DEBUG_INFO 1
#define DEBUG_VERBOSE 4
#define DPRINTF(level, params) if (level <= fbuf_debug) PRINTLN params
#define KB (1024UL)
#define MB (1024 * 1024UL)
#define DMEMSZ 128
#define FB_SIZE (16*MB)
#define COLS_MAX 1920
#define ROWS_MAX 1200
#define COLS_DEFAULT 1024
#define ROWS_DEFAULT 768
#define COLS_MIN 640
#define ROWS_MIN 480
struct pci_fbuf_softc {
struct pci_devinst *fsc_pi;
struct {
uint32_t fbsize;
uint16_t width;
uint16_t height;
uint16_t depth;
uint16_t refreshrate;
uint8_t reserved[116];
} __packed memregs;
/* rfb server */
char *rfb_host;
char *rfb_password;
int rfb_port;
int rfb_wait;
int vga_enabled;
int vga_full;
uint32_t fbaddr;
char *fb_base;
uint16_t gc_width;
uint16_t gc_height;
void *vgasc;
struct bhyvegc_image *gc_image;
};
static struct pci_fbuf_softc *fbuf_sc;
#define PCI_FBUF_MSI_MSGS 4
static void
pci_fbuf_usage(char *opt)
{
EPRINTLN("Invalid fbuf emulation option \"%s\"", opt);
EPRINTLN("fbuf: {wait,}{vga=on|io|off,}rfb=<ip>:port"
"{,w=width}{,h=height}");
}
static void
pci_fbuf_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
int baridx, uint64_t offset, int size, uint64_t value)
{
struct pci_fbuf_softc *sc;
uint8_t *p;
assert(baridx == 0);
sc = pi->pi_arg;
DPRINTF(DEBUG_VERBOSE,
("fbuf wr: offset 0x%lx, size: %d, value: 0x%lx",
offset, size, value));
if (offset + size > DMEMSZ) {
printf("fbuf: write too large, offset %ld size %d\n",
offset, size);
return;
}
p = (uint8_t *)&sc->memregs + offset;
switch (size) {
case 1:
*p = value;
break;
case 2:
*(uint16_t *)p = value;
break;
case 4:
*(uint32_t *)p = value;
break;
case 8:
*(uint64_t *)p = value;
break;
default:
printf("fbuf: write unknown size %d\n", size);
break;
}
if (!sc->gc_image->vgamode && sc->memregs.width == 0 &&
sc->memregs.height == 0) {
DPRINTF(DEBUG_INFO, ("switching to VGA mode"));
sc->gc_image->vgamode = 1;
sc->gc_width = 0;
sc->gc_height = 0;
} else if (sc->gc_image->vgamode && sc->memregs.width != 0 &&
sc->memregs.height != 0) {
DPRINTF(DEBUG_INFO, ("switching to VESA mode"));
sc->gc_image->vgamode = 0;
}
}
uint64_t
pci_fbuf_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
int baridx, uint64_t offset, int size)
{
struct pci_fbuf_softc *sc;
uint8_t *p;
uint64_t value;
assert(baridx == 0);
sc = pi->pi_arg;
if (offset + size > DMEMSZ) {
printf("fbuf: read too large, offset %ld size %d\n",
offset, size);
return (0);
}
p = (uint8_t *)&sc->memregs + offset;
value = 0;
switch (size) {
case 1:
value = *p;
break;
case 2:
value = *(uint16_t *)p;
break;
case 4:
value = *(uint32_t *)p;
break;
case 8:
value = *(uint64_t *)p;
break;
default:
printf("fbuf: read unknown size %d\n", size);
break;
}
DPRINTF(DEBUG_VERBOSE,
("fbuf rd: offset 0x%lx, size: %d, value: 0x%lx",
offset, size, value));
return (value);
}
static int
pci_fbuf_parse_opts(struct pci_fbuf_softc *sc, char *opts)
{
char *uopts, *uoptsbak, *xopts, *config;
char *tmpstr;
int ret;
ret = 0;
uoptsbak = uopts = strdup(opts);
while ((xopts = strsep(&uopts, ",")) != NULL) {
if (strcmp(xopts, "wait") == 0) {
sc->rfb_wait = 1;
continue;
}
if ((config = strchr(xopts, '=')) == NULL) {
pci_fbuf_usage(xopts);
ret = -1;
goto done;
}
*config++ = '\0';
DPRINTF(DEBUG_VERBOSE, ("pci_fbuf option %s = %s",
xopts, config));
if (!strcmp(xopts, "tcp") || !strcmp(xopts, "rfb")) {
/*
* IPv4 -- host-ip:port
* IPv6 -- [host-ip%zone]:port
* XXX for now port is mandatory.
*/
tmpstr = strsep(&config, "]");
if (config) {
if (tmpstr[0] == '[')
tmpstr++;
sc->rfb_host = strdup(tmpstr);
if (config[0] == ':')
config++;
else {
pci_fbuf_usage(xopts);
ret = -1;
goto done;
}
sc->rfb_port = atoi(config);
} else {
config = tmpstr;
tmpstr = strsep(&config, ":");
if (!config)
sc->rfb_port = atoi(tmpstr);
else {
sc->rfb_port = atoi(config);
sc->rfb_host = strdup(tmpstr);
}
}
} else if (!strcmp(xopts, "vga")) {
if (!strcmp(config, "off")) {
sc->vga_enabled = 0;
} else if (!strcmp(config, "io")) {
sc->vga_enabled = 1;
sc->vga_full = 0;
} else if (!strcmp(config, "on")) {
sc->vga_enabled = 1;
sc->vga_full = 1;
} else {
pci_fbuf_usage(xopts);
ret = -1;
goto done;
}
} else if (!strcmp(xopts, "w")) {
sc->memregs.width = atoi(config);
if (sc->memregs.width > COLS_MAX) {
pci_fbuf_usage(xopts);
ret = -1;
goto done;
} else if (sc->memregs.width == 0)
sc->memregs.width = 1920;
} else if (!strcmp(xopts, "h")) {
sc->memregs.height = atoi(config);
if (sc->memregs.height > ROWS_MAX) {
pci_fbuf_usage(xopts);
ret = -1;
goto done;
} else if (sc->memregs.height == 0)
sc->memregs.height = 1080;
} else if (!strcmp(xopts, "password")) {
sc->rfb_password = strdup(config);
} else {
pci_fbuf_usage(xopts);
ret = -1;
goto done;
}
}
done:
free(uoptsbak);
return (ret);
}
extern void vga_render(struct bhyvegc *gc, void *arg);
void
pci_fbuf_render(struct bhyvegc *gc, void *arg)
{
struct pci_fbuf_softc *sc;
sc = arg;
if (sc->vga_full && sc->gc_image->vgamode) {
/* TODO: mode switching to vga and vesa should use the special
* EFI-bhyve protocol port.
*/
vga_render(gc, sc->vgasc);
return;
}
if (sc->gc_width != sc->memregs.width ||
sc->gc_height != sc->memregs.height) {
bhyvegc_resize(gc, sc->memregs.width, sc->memregs.height);
sc->gc_width = sc->memregs.width;
sc->gc_height = sc->memregs.height;
}
return;
}
static int
pci_fbuf_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
{
int error, prot;
struct pci_fbuf_softc *sc;
if (fbuf_sc != NULL) {
EPRINTLN("Only one frame buffer device is allowed.");
return (-1);
}
sc = calloc(1, sizeof(struct pci_fbuf_softc));
pi->pi_arg = sc;
/* initialize config space */
pci_set_cfgdata16(pi, PCIR_DEVICE, 0x40FB);
pci_set_cfgdata16(pi, PCIR_VENDOR, 0xFB5D);
pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_DISPLAY);
pci_set_cfgdata8(pi, PCIR_SUBCLASS, PCIS_DISPLAY_VGA);
error = pci_emul_alloc_bar(pi, 0, PCIBAR_MEM32, DMEMSZ);
assert(error == 0);
error = pci_emul_alloc_bar(pi, 1, PCIBAR_MEM32, FB_SIZE);
assert(error == 0);
error = pci_emul_add_msicap(pi, PCI_FBUF_MSI_MSGS);
assert(error == 0);
sc->fbaddr = pi->pi_bar[1].addr;
sc->memregs.fbsize = FB_SIZE;
sc->memregs.width = COLS_DEFAULT;
sc->memregs.height = ROWS_DEFAULT;
sc->memregs.depth = 32;
sc->vga_enabled = 1;
sc->vga_full = 0;
sc->fsc_pi = pi;
error = pci_fbuf_parse_opts(sc, opts);
if (error != 0)
goto done;
/* XXX until VGA rendering is enabled */
if (sc->vga_full != 0) {
EPRINTLN("pci_fbuf: VGA rendering not enabled");
goto done;
}
sc->fb_base = vm_create_devmem(ctx, VM_FRAMEBUFFER, "framebuffer", FB_SIZE);
if (sc->fb_base == MAP_FAILED) {
error = -1;
goto done;
}
DPRINTF(DEBUG_INFO, ("fbuf frame buffer base: %p [sz %lu]",
sc->fb_base, FB_SIZE));
/*
* Map the framebuffer into the guest address space.
* XXX This may fail if the BAR is different than a prior
* run. In this case flag the error. This will be fixed
* when a change_memseg api is available.
*/
prot = PROT_READ | PROT_WRITE;
if (vm_mmap_memseg(ctx, sc->fbaddr, VM_FRAMEBUFFER, 0, FB_SIZE, prot) != 0) {
EPRINTLN("pci_fbuf: mapseg failed - try deleting VM and restarting");
error = -1;
goto done;
}
console_init(sc->memregs.width, sc->memregs.height, sc->fb_base);
console_fb_register(pci_fbuf_render, sc);
if (sc->vga_enabled)
sc->vgasc = vga_init(!sc->vga_full);
sc->gc_image = console_get_image();
fbuf_sc = sc;
memset((void *)sc->fb_base, 0, FB_SIZE);
error = rfb_init(sc->rfb_host, sc->rfb_port, sc->rfb_wait, sc->rfb_password);
done:
if (error)
free(sc);
return (error);
}
#ifdef BHYVE_SNAPSHOT
static int
pci_fbuf_snapshot(struct vm_snapshot_meta *meta)
{
int ret;
SNAPSHOT_BUF_OR_LEAVE(fbuf_sc->fb_base, FB_SIZE, meta, ret, err);
err:
return (ret);
}
#endif
struct pci_devemu pci_fbuf = {
.pe_emu = "fbuf",
.pe_init = pci_fbuf_init,
.pe_barwrite = pci_fbuf_write,
.pe_barread = pci_fbuf_read,
#ifdef BHYVE_SNAPSHOT
.pe_snapshot = pci_fbuf_snapshot,
#endif
};
PCI_EMUL_SET(pci_fbuf);