qemu/accel/xen/xen-all.c
David Woodhouse f75e4f2234 accel/xen: Fix DM state change notification in dm_restrict mode
When dm_restrict is set, QEMU isn't permitted to update the XenStore node
to indicate its running status. Previously, the xs_write() call would fail
but the failure was ignored.

However, in refactoring to allow for emulated XenStore operations, a new
call to xs_open() was added. That one didn't fail gracefully, causing a
fatal error when running in dm_restrict mode.

Partially revert the offending patch, removing the additional call to
xs_open() because the global 'xenstore' variable is still available; it
just needs to be used with qemu_xen_xs_write() now instead of directly
with the xs_write() libxenstore function.

Also make the whole thing conditional on !xen_domid_restrict. There's no
point even registering the state change handler to attempt to update the
XenStore node when we know it's destined to fail.

Fixes: ba2a92db1f ("hw/xen: Add xenstore operations to allow redirection to internal emulation")
Reported-by: Jason Andryuk <jandryuk@gmail.com>
Co-developed-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Message-Id: <1f141995bb61af32c2867ef5559e253f39b0949c.camel@infradead.org>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
2023-03-23 09:56:54 +00:00

169 lines
4.4 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 "qemu/module.h"
#include "qapi/error.h"
#include "hw/xen/xen_native.h"
#include "hw/xen/xen-legacy-backend.h"
#include "hw/xen/xen_pt.h"
#include "chardev/char.h"
#include "qemu/accel.h"
#include "sysemu/cpus.h"
#include "sysemu/xen.h"
#include "sysemu/runstate.h"
#include "migration/misc.h"
#include "migration/global_state.h"
#include "hw/boards.h"
bool xen_allowed;
xc_interface *xen_xc;
xenforeignmemory_handle *xen_fmem;
xendevicemodel_handle *xen_dmod;
static void xenstore_record_dm_state(const char *state)
{
char path[50];
snprintf(path, sizeof (path), "device-model/%u/state", xen_domid);
if (!qemu_xen_xs_write(xenstore, XBT_NULL, path, state, strlen(state))) {
error_report("error recording dm state");
exit(1);
}
}
static void xen_change_state_handler(void *opaque, bool running,
RunState state)
{
if (running) {
/* record state running */
xenstore_record_dm_state("running");
}
}
static bool xen_get_igd_gfx_passthru(Object *obj, Error **errp)
{
return xen_igd_gfx_pt_enabled();
}
static void xen_set_igd_gfx_passthru(Object *obj, bool value, Error **errp)
{
xen_igd_gfx_pt_set(value, errp);
}
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)
{
MachineClass *mc = MACHINE_GET_CLASS(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;
}
/*
* The XenStore write would fail when running restricted so don't attempt
* it in that case. Toolstacks should instead use QMP to listen for state
* changes.
*/
if (!xen_domid_restrict) {
qemu_add_vm_change_state_handler(xen_change_state_handler, NULL);
}
/*
* opt out of system RAM being allocated by generic code
*/
mc->default_ram_id = NULL;
xen_mode = XEN_ATTACH;
return 0;
}
static void xen_accel_class_init(ObjectClass *oc, void *data)
{
AccelClass *ac = ACCEL_CLASS(oc);
static GlobalProperty compat[] = {
{ "migration", "store-global-state", "off" },
{ "migration", "send-configuration", "off" },
{ "migration", "send-section-footer", "off" },
};
ac->name = "Xen";
ac->init_machine = xen_init;
ac->setup_post = xen_setup_post;
ac->allowed = &xen_allowed;
ac->compat_props = g_ptr_array_new();
compat_props_add(ac->compat_props, compat, G_N_ELEMENTS(compat));
object_class_property_add_bool(oc, "igd-passthru",
xen_get_igd_gfx_passthru, xen_set_igd_gfx_passthru);
object_class_property_set_description(oc, "igd-passthru",
"Set on/off to enable/disable igd passthrou");
}
#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_accel_ops_class_init(ObjectClass *oc, void *data)
{
AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
ops->create_vcpu_thread = dummy_start_vcpu_thread;
}
static const TypeInfo xen_accel_ops_type = {
.name = ACCEL_OPS_NAME("xen"),
.parent = TYPE_ACCEL_OPS,
.class_init = xen_accel_ops_class_init,
.abstract = true,
};
static void xen_type_init(void)
{
type_register_static(&xen_accel_type);
type_register_static(&xen_accel_ops_type);
}
type_init(xen_type_init);