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/*
* xen/common/monitor.c
*
* Common monitor_op domctl handler.
*
* Copyright (c) 2015 Tamas K Lengyel (tamas@tklengyel.com)
* Copyright (c) 2016, Bitdefender S.R.L.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; If not, see <http://www.gnu.org/licenses/>.
*/
#include <xen/event.h>
#include <xen/monitor.h>
#include <xen/sched.h>
#include <xen/vm_event.h>
#include <xsm/xsm.h>
#include <asm/altp2m.h>
#include <asm/monitor.h>
#include <asm/vm_event.h>
int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
{
int rc;
bool requested_status = false;
if ( unlikely(current->domain == d) ) /* no domain_pause() */
return -EPERM;
rc = xsm_vm_event_control(XSM_PRIV, d, mop->op, mop->event);
if ( unlikely(rc) )
return rc;
switch ( mop->op )
{
case XEN_DOMCTL_MONITOR_OP_ENABLE:
requested_status = true;
/* fallthrough */
case XEN_DOMCTL_MONITOR_OP_DISABLE:
/* sanity check: avoid left-shift undefined behavior */
if ( unlikely(mop->event > 31) )
return -EINVAL;
/* Check if event type is available. */
if ( unlikely(!(arch_monitor_get_capabilities(d) & (1U << mop->event))) )
return -EOPNOTSUPP;
break;
case XEN_DOMCTL_MONITOR_OP_GET_CAPABILITIES:
mop->event = arch_monitor_get_capabilities(d);
return 0;
default:
/* The monitor op is probably handled on the arch-side. */
return arch_monitor_domctl_op(d, mop);
}
switch ( mop->event )
{
case XEN_DOMCTL_MONITOR_EVENT_GUEST_REQUEST:
{
bool old_status = d->monitor.guest_request_enabled;
if ( unlikely(old_status == requested_status) )
return -EEXIST;
domain_pause(d);
d->monitor.guest_request_sync = mop->u.guest_request.sync;
d->monitor.guest_request_enabled = requested_status;
arch_monitor_allow_userspace(d, mop->u.guest_request.allow_userspace);
domain_unpause(d);
break;
}
default:
/* Give arch-side the chance to handle this event */
return arch_monitor_domctl_event(d, mop);
}
return 0;
}
int monitor_traps(struct vcpu *v, bool sync, vm_event_request_t *req)
{
int rc;
struct domain *d = v->domain;
rc = vm_event_claim_slot(d, d->vm_event_monitor);
switch ( rc )
{
case 0:
break;
case -EOPNOTSUPP:
/*
* If there was no ring to handle the event, then
* simply continue executing normally.
*/
return 0;
default:
return rc;
};
req->vcpu_id = v->vcpu_id;
if ( sync )
{
req->flags |= VM_EVENT_FLAG_VCPU_PAUSED;
vm_event_sync_event(v, true);
vm_event_vcpu_pause(v);
rc = 1;
}
if ( altp2m_active(d) )
{
req->flags |= VM_EVENT_FLAG_ALTERNATE_P2M;
req->altp2m_idx = altp2m_vcpu_idx(v);
}
vm_event_fill_regs(req);
vm_event_put_request(d, d->vm_event_monitor, req);
return rc;
}
void monitor_guest_request(void)
{
struct vcpu *curr = current;
struct domain *d = curr->domain;
if ( d->monitor.guest_request_enabled )
{
vm_event_request_t req = {
.reason = VM_EVENT_REASON_GUEST_REQUEST,
.vcpu_id = curr->vcpu_id,
};
monitor_traps(curr, d->monitor.guest_request_sync, &req);
}
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* indent-tabs-mode: nil
* End:
*/
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