qemu-e2k/hw/xen/xen-common.c
Ross Lagerwall 4473348adf xen: Expect xenstore write to fail when restricted
Saving the current state to xenstore may fail when running restricted
(in particular, after a migration). Therefore, don't report the error or
exit when running restricted.  Toolstacks that want to allow running
QEMU restricted should instead make use of QMP events to listen for
state changes.

CC: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2018-04-26 16:29:51 +01:00

205 lines
4.9 KiB
C

/*
* Copyright (C) 2014 Citrix Systems UK Ltd.
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "hw/xen/xen_backend.h"
#include "chardev/char.h"
#include "sysemu/accel.h"
#include "migration/misc.h"
#include "migration/global_state.h"
//#define DEBUG_XEN
#ifdef DEBUG_XEN
#define DPRINTF(fmt, ...) \
do { fprintf(stderr, "xen: " fmt, ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do { } while (0)
#endif
xc_interface *xen_xc;
xenforeignmemory_handle *xen_fmem;
xendevicemodel_handle *xen_dmod;
static int store_dev_info(int domid, Chardev *cs, const char *string)
{
struct xs_handle *xs = NULL;
char *path = NULL;
char *newpath = NULL;
char *pts = NULL;
int ret = -1;
/* Only continue if we're talking to a pty. */
if (!CHARDEV_IS_PTY(cs)) {
return 0;
}
pts = cs->filename + 4;
/* We now have everything we need to set the xenstore entry. */
xs = xs_open(0);
if (xs == NULL) {
fprintf(stderr, "Could not contact XenStore\n");
goto out;
}
path = xs_get_domain_path(xs, domid);
if (path == NULL) {
fprintf(stderr, "xs_get_domain_path() error\n");
goto out;
}
newpath = realloc(path, (strlen(path) + strlen(string) +
strlen("/tty") + 1));
if (newpath == NULL) {
fprintf(stderr, "realloc error\n");
goto out;
}
path = newpath;
strcat(path, string);
strcat(path, "/tty");
if (!xs_write(xs, XBT_NULL, path, pts, strlen(pts))) {
fprintf(stderr, "xs_write for '%s' fail", string);
goto out;
}
ret = 0;
out:
free(path);
xs_close(xs);
return ret;
}
void xenstore_store_pv_console_info(int i, Chardev *chr)
{
if (i == 0) {
store_dev_info(xen_domid, chr, "/console");
} else {
char buf[32];
snprintf(buf, sizeof(buf), "/device/console/%d", i);
store_dev_info(xen_domid, chr, buf);
}
}
static void xenstore_record_dm_state(struct xs_handle *xs, const char *state)
{
char path[50];
if (xs == NULL) {
error_report("xenstore connection not initialized");
exit(1);
}
snprintf(path, sizeof (path), "device-model/%u/state", xen_domid);
/*
* This call may fail when running restricted so don't make it fatal in
* that case. Toolstacks should instead use QMP to listen for state changes.
*/
if (!xs_write(xs, XBT_NULL, path, state, strlen(state)) &&
!xen_domid_restrict) {
error_report("error recording dm state");
exit(1);
}
}
static void xen_change_state_handler(void *opaque, int running,
RunState state)
{
if (running) {
/* record state running */
xenstore_record_dm_state(xenstore, "running");
}
}
static void xen_setup_post(MachineState *ms, AccelState *accel)
{
int rc;
if (xen_domid_restrict) {
rc = xen_restrict(xen_domid);
if (rc < 0) {
perror("xen: failed to restrict");
exit(1);
}
}
}
static int xen_init(MachineState *ms)
{
xen_xc = xc_interface_open(0, 0, 0);
if (xen_xc == NULL) {
xen_pv_printf(NULL, 0, "can't open xen interface\n");
return -1;
}
xen_fmem = xenforeignmemory_open(0, 0);
if (xen_fmem == NULL) {
xen_pv_printf(NULL, 0, "can't open xen fmem interface\n");
xc_interface_close(xen_xc);
return -1;
}
xen_dmod = xendevicemodel_open(0, 0);
if (xen_dmod == NULL) {
xen_pv_printf(NULL, 0, "can't open xen devicemodel interface\n");
xenforeignmemory_close(xen_fmem);
xc_interface_close(xen_xc);
return -1;
}
qemu_add_vm_change_state_handler(xen_change_state_handler, NULL);
return 0;
}
static GlobalProperty xen_compat_props[] = {
{
.driver = "migration",
.property = "store-global-state",
.value = "off",
},
{
.driver = "migration",
.property = "send-configuration",
.value = "off",
},
{
.driver = "migration",
.property = "send-section-footer",
.value = "off",
},
{ /* end of list */ },
};
static void xen_accel_class_init(ObjectClass *oc, void *data)
{
AccelClass *ac = ACCEL_CLASS(oc);
ac->name = "Xen";
ac->init_machine = xen_init;
ac->setup_post = xen_setup_post;
ac->allowed = &xen_allowed;
ac->global_props = xen_compat_props;
}
#define TYPE_XEN_ACCEL ACCEL_CLASS_NAME("xen")
static const TypeInfo xen_accel_type = {
.name = TYPE_XEN_ACCEL,
.parent = TYPE_ACCEL,
.class_init = xen_accel_class_init,
};
static void xen_type_init(void)
{
type_register_static(&xen_accel_type);
}
type_init(xen_type_init);