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freebsd/usr.sbin/bhyve/pci_lpc.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

488 lines
10 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2013 Neel Natu <neel@freebsd.org>
* Copyright (c) 2013 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
* 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 NETAPP, INC ``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 NETAPP, INC 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 <machine/vmm.h>
#include <machine/vmm_snapshot.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <vmmapi.h>
#include "acpi.h"
#include "debug.h"
#include "bootrom.h"
#include "inout.h"
#include "pci_emul.h"
#include "pci_irq.h"
#include "pci_lpc.h"
#include "uart_emul.h"
#define IO_ICU1 0x20
#define IO_ICU2 0xA0
SET_DECLARE(lpc_dsdt_set, struct lpc_dsdt);
SET_DECLARE(lpc_sysres_set, struct lpc_sysres);
#define ELCR_PORT 0x4d0
SYSRES_IO(ELCR_PORT, 2);
#define IO_TIMER1_PORT 0x40
#define NMISC_PORT 0x61
SYSRES_IO(NMISC_PORT, 1);
static struct pci_devinst *lpc_bridge;
static const char *romfile;
#define LPC_UART_NUM 2
static struct lpc_uart_softc {
struct uart_softc *uart_softc;
const char *opts;
int iobase;
int irq;
int enabled;
} lpc_uart_softc[LPC_UART_NUM];
static const char *lpc_uart_names[LPC_UART_NUM] = { "COM1", "COM2" };
/*
* LPC device configuration is in the following form:
* <lpc_device_name>[,<options>]
* For e.g. "com1,stdio" or "bootrom,/var/romfile"
*/
int
lpc_device_parse(const char *opts)
{
int unit, error;
char *str, *cpy, *lpcdev;
error = -1;
str = cpy = strdup(opts);
lpcdev = strsep(&str, ",");
if (lpcdev != NULL) {
if (strcasecmp(lpcdev, "bootrom") == 0) {
romfile = str;
error = 0;
goto done;
}
for (unit = 0; unit < LPC_UART_NUM; unit++) {
if (strcasecmp(lpcdev, lpc_uart_names[unit]) == 0) {
lpc_uart_softc[unit].opts = str;
error = 0;
goto done;
}
}
}
done:
if (error)
free(cpy);
return (error);
}
void
lpc_print_supported_devices()
{
size_t i;
printf("bootrom\n");
for (i = 0; i < LPC_UART_NUM; i++)
printf("%s\n", lpc_uart_names[i]);
}
const char *
lpc_bootrom(void)
{
return (romfile);
}
static void
lpc_uart_intr_assert(void *arg)
{
struct lpc_uart_softc *sc = arg;
assert(sc->irq >= 0);
vm_isa_pulse_irq(lpc_bridge->pi_vmctx, sc->irq, sc->irq);
}
static void
lpc_uart_intr_deassert(void *arg)
{
/*
* The COM devices on the LPC bus generate edge triggered interrupts,
* so nothing more to do here.
*/
}
static int
lpc_uart_io_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
uint32_t *eax, void *arg)
{
int offset;
struct lpc_uart_softc *sc = arg;
offset = port - sc->iobase;
switch (bytes) {
case 1:
if (in)
*eax = uart_read(sc->uart_softc, offset);
else
uart_write(sc->uart_softc, offset, *eax);
break;
case 2:
if (in) {
*eax = uart_read(sc->uart_softc, offset);
*eax |= uart_read(sc->uart_softc, offset + 1) << 8;
} else {
uart_write(sc->uart_softc, offset, *eax);
uart_write(sc->uart_softc, offset + 1, *eax >> 8);
}
break;
default:
return (-1);
}
return (0);
}
static int
lpc_init(struct vmctx *ctx)
{
struct lpc_uart_softc *sc;
struct inout_port iop;
const char *name;
int unit, error;
if (romfile != NULL) {
error = bootrom_loadrom(ctx, romfile);
if (error)
return (error);
}
/* COM1 and COM2 */
for (unit = 0; unit < LPC_UART_NUM; unit++) {
sc = &lpc_uart_softc[unit];
name = lpc_uart_names[unit];
if (uart_legacy_alloc(unit, &sc->iobase, &sc->irq) != 0) {
EPRINTLN("Unable to allocate resources for "
"LPC device %s", name);
return (-1);
}
pci_irq_reserve(sc->irq);
sc->uart_softc = uart_init(lpc_uart_intr_assert,
lpc_uart_intr_deassert, sc);
if (uart_set_backend(sc->uart_softc, sc->opts) != 0) {
EPRINTLN("Unable to initialize backend '%s' "
"for LPC device %s", sc->opts, name);
return (-1);
}
bzero(&iop, sizeof(struct inout_port));
iop.name = name;
iop.port = sc->iobase;
iop.size = UART_IO_BAR_SIZE;
iop.flags = IOPORT_F_INOUT;
iop.handler = lpc_uart_io_handler;
iop.arg = sc;
error = register_inout(&iop);
assert(error == 0);
sc->enabled = 1;
}
return (0);
}
static void
pci_lpc_write_dsdt(struct pci_devinst *pi)
{
struct lpc_dsdt **ldpp, *ldp;
dsdt_line("");
dsdt_line("Device (ISA)");
dsdt_line("{");
dsdt_line(" Name (_ADR, 0x%04X%04X)", pi->pi_slot, pi->pi_func);
dsdt_line(" OperationRegion (LPCR, PCI_Config, 0x00, 0x100)");
dsdt_line(" Field (LPCR, AnyAcc, NoLock, Preserve)");
dsdt_line(" {");
dsdt_line(" Offset (0x60),");
dsdt_line(" PIRA, 8,");
dsdt_line(" PIRB, 8,");
dsdt_line(" PIRC, 8,");
dsdt_line(" PIRD, 8,");
dsdt_line(" Offset (0x68),");
dsdt_line(" PIRE, 8,");
dsdt_line(" PIRF, 8,");
dsdt_line(" PIRG, 8,");
dsdt_line(" PIRH, 8");
dsdt_line(" }");
dsdt_line("");
dsdt_indent(1);
SET_FOREACH(ldpp, lpc_dsdt_set) {
ldp = *ldpp;
ldp->handler();
}
dsdt_line("");
dsdt_line("Device (PIC)");
dsdt_line("{");
dsdt_line(" Name (_HID, EisaId (\"PNP0000\"))");
dsdt_line(" Name (_CRS, ResourceTemplate ()");
dsdt_line(" {");
dsdt_indent(2);
dsdt_fixed_ioport(IO_ICU1, 2);
dsdt_fixed_ioport(IO_ICU2, 2);
dsdt_fixed_irq(2);
dsdt_unindent(2);
dsdt_line(" })");
dsdt_line("}");
dsdt_line("");
dsdt_line("Device (TIMR)");
dsdt_line("{");
dsdt_line(" Name (_HID, EisaId (\"PNP0100\"))");
dsdt_line(" Name (_CRS, ResourceTemplate ()");
dsdt_line(" {");
dsdt_indent(2);
dsdt_fixed_ioport(IO_TIMER1_PORT, 4);
dsdt_fixed_irq(0);
dsdt_unindent(2);
dsdt_line(" })");
dsdt_line("}");
dsdt_unindent(1);
dsdt_line("}");
}
static void
pci_lpc_sysres_dsdt(void)
{
struct lpc_sysres **lspp, *lsp;
dsdt_line("");
dsdt_line("Device (SIO)");
dsdt_line("{");
dsdt_line(" Name (_HID, EisaId (\"PNP0C02\"))");
dsdt_line(" Name (_CRS, ResourceTemplate ()");
dsdt_line(" {");
dsdt_indent(2);
SET_FOREACH(lspp, lpc_sysres_set) {
lsp = *lspp;
switch (lsp->type) {
case LPC_SYSRES_IO:
dsdt_fixed_ioport(lsp->base, lsp->length);
break;
case LPC_SYSRES_MEM:
dsdt_fixed_mem32(lsp->base, lsp->length);
break;
}
}
dsdt_unindent(2);
dsdt_line(" })");
dsdt_line("}");
}
LPC_DSDT(pci_lpc_sysres_dsdt);
static void
pci_lpc_uart_dsdt(void)
{
struct lpc_uart_softc *sc;
int unit;
for (unit = 0; unit < LPC_UART_NUM; unit++) {
sc = &lpc_uart_softc[unit];
if (!sc->enabled)
continue;
dsdt_line("");
dsdt_line("Device (%s)", lpc_uart_names[unit]);
dsdt_line("{");
dsdt_line(" Name (_HID, EisaId (\"PNP0501\"))");
dsdt_line(" Name (_UID, %d)", unit + 1);
dsdt_line(" Name (_CRS, ResourceTemplate ()");
dsdt_line(" {");
dsdt_indent(2);
dsdt_fixed_ioport(sc->iobase, UART_IO_BAR_SIZE);
dsdt_fixed_irq(sc->irq);
dsdt_unindent(2);
dsdt_line(" })");
dsdt_line("}");
}
}
LPC_DSDT(pci_lpc_uart_dsdt);
static int
pci_lpc_cfgwrite(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
int coff, int bytes, uint32_t val)
{
int pirq_pin;
if (bytes == 1) {
pirq_pin = 0;
if (coff >= 0x60 && coff <= 0x63)
pirq_pin = coff - 0x60 + 1;
if (coff >= 0x68 && coff <= 0x6b)
pirq_pin = coff - 0x68 + 5;
if (pirq_pin != 0) {
pirq_write(ctx, pirq_pin, val);
pci_set_cfgdata8(pi, coff, pirq_read(pirq_pin));
return (0);
}
}
return (-1);
}
static void
pci_lpc_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
int baridx, uint64_t offset, int size, uint64_t value)
{
}
static uint64_t
pci_lpc_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
int baridx, uint64_t offset, int size)
{
return (0);
}
#define LPC_DEV 0x7000
#define LPC_VENDOR 0x8086
static int
pci_lpc_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
{
/*
* Do not allow more than one LPC bridge to be configured.
*/
if (lpc_bridge != NULL) {
EPRINTLN("Only one LPC bridge is allowed.");
return (-1);
}
/*
* Enforce that the LPC can only be configured on bus 0. This
* simplifies the ACPI DSDT because it can provide a decode for
* all legacy i/o ports behind bus 0.
*/
if (pi->pi_bus != 0) {
EPRINTLN("LPC bridge can be present only on bus 0.");
return (-1);
}
if (lpc_init(ctx) != 0)
return (-1);
/* initialize config space */
pci_set_cfgdata16(pi, PCIR_DEVICE, LPC_DEV);
pci_set_cfgdata16(pi, PCIR_VENDOR, LPC_VENDOR);
pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_BRIDGE);
pci_set_cfgdata8(pi, PCIR_SUBCLASS, PCIS_BRIDGE_ISA);
lpc_bridge = pi;
return (0);
}
char *
lpc_pirq_name(int pin)
{
char *name;
if (lpc_bridge == NULL)
return (NULL);
asprintf(&name, "\\_SB.PC00.ISA.LNK%c,", 'A' + pin - 1);
return (name);
}
void
lpc_pirq_routed(void)
{
int pin;
if (lpc_bridge == NULL)
return;
for (pin = 0; pin < 4; pin++)
pci_set_cfgdata8(lpc_bridge, 0x60 + pin, pirq_read(pin + 1));
for (pin = 0; pin < 4; pin++)
pci_set_cfgdata8(lpc_bridge, 0x68 + pin, pirq_read(pin + 5));
}
#ifdef BHYVE_SNAPSHOT
static int
pci_lpc_snapshot(struct vm_snapshot_meta *meta)
{
int unit, ret;
struct uart_softc *sc;
for (unit = 0; unit < LPC_UART_NUM; unit++) {
sc = lpc_uart_softc[unit].uart_softc;
ret = uart_snapshot(sc, meta);
if (ret != 0)
goto done;
}
done:
return (ret);
}
#endif
struct pci_devemu pci_de_lpc = {
.pe_emu = "lpc",
.pe_init = pci_lpc_init,
.pe_write_dsdt = pci_lpc_write_dsdt,
.pe_cfgwrite = pci_lpc_cfgwrite,
.pe_barwrite = pci_lpc_write,
.pe_barread = pci_lpc_read,
#ifdef BHYVE_SNAPSHOT
.pe_snapshot = pci_lpc_snapshot,
#endif
};
PCI_EMUL_SET(pci_de_lpc);