@@ -69,6 +69,9 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
struct arch_domain *ad = &d->arch;
uint32_t capabilities = get_capabilities(d);
+ if ( current->domain == d ) /* no domain_pause() */
+ return -EPERM;
+
rc = xsm_vm_event_control(XSM_PRIV, d, mop->op, mop->event);
if ( rc )
return rc;
@@ -80,7 +83,9 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
return 0;
case XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP:
- d->arch.mem_access_emulate_each_rep = !!mop->event;
+ domain_pause(d);
+ ad->mem_access_emulate_each_rep = !!mop->event;
+ domain_unpause(d);
return 0;
}
@@ -109,6 +114,8 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
if ( rc )
return rc;
+ domain_pause(d);
+
if ( mop->u.mov_to_cr.sync )
ad->monitor.write_ctrlreg_sync |= ctrlreg_bitmask;
else
@@ -119,20 +126,18 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
else
ad->monitor.write_ctrlreg_onchangeonly &= ~ctrlreg_bitmask;
- domain_pause(d);
-
if ( !status )
ad->monitor.write_ctrlreg_enabled |= ctrlreg_bitmask;
else
ad->monitor.write_ctrlreg_enabled &= ~ctrlreg_bitmask;
- domain_unpause(d);
-
if ( mop->u.mov_to_cr.index == VM_EVENT_X86_CR3 )
/* Latches new CR3 mask through CR0 code */
for_each_vcpu ( d, v )
hvm_update_guest_cr(v, 0);
+ domain_unpause(d);
+
break;
}
@@ -145,16 +150,18 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
return rc;
if ( mop->op == XEN_DOMCTL_MONITOR_OP_ENABLE &&
+ mop->u.mov_to_msr.extended_capture &&
+ !hvm_enable_msr_exit_interception(d) )
+ return -EOPNOTSUPP;
+
+ domain_pause(d);
+
+ if ( mop->op == XEN_DOMCTL_MONITOR_OP_ENABLE &&
mop->u.mov_to_msr.extended_capture )
- {
- if ( hvm_enable_msr_exit_interception(d) )
ad->monitor.mov_to_msr_extended = 1;
- else
- return -EOPNOTSUPP;
- } else
+ else
ad->monitor.mov_to_msr_extended = 0;
- domain_pause(d);
ad->monitor.mov_to_msr_enabled = !status;
domain_unpause(d);
break;
@@ -196,9 +203,8 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
if ( rc )
return rc;
- ad->monitor.guest_request_sync = mop->u.guest_request.sync;
-
domain_pause(d);
+ ad->monitor.guest_request_sync = mop->u.guest_request.sync;
ad->monitor.guest_request_enabled = !status;
domain_unpause(d);
break;
@@ -709,7 +709,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
}
case XEN_DOMCTL_soft_reset:
- if ( d == current->domain )
+ if ( d == current->domain ) /* no domain_pause() */
{
ret = -EINVAL;
break;
@@ -1136,11 +1136,15 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
#ifdef CONFIG_HAS_MEM_ACCESS
case XEN_DOMCTL_set_access_required:
- if ( unlikely(current->domain == d) )
+ if ( unlikely(current->domain == d) ) /* no domain_pause() */
ret = -EPERM;
else
+ {
+ domain_pause(d);
p2m_get_hostp2m(d)->access_required =
op->u.access_required.access_required;
+ domain_unpause(d);
+ }
break;
#endif
@@ -1175,10 +1179,6 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
}
case XEN_DOMCTL_monitor_op:
- ret = -EPERM;
- if ( current->domain == d )
- break;
-
ret = monitor_domctl(d, &op->u.monitor_op);
if ( !ret )
copyback = 1;
@@ -567,7 +567,7 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
if ( rc )
return rc;
- if ( unlikely(d == current->domain) )
+ if ( unlikely(d == current->domain) ) /* no domain_pause() */
{
gdprintk(XENLOG_INFO, "Tried to do a memory event op on itself.\n");
return -EINVAL;
@@ -624,6 +624,7 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
if ( p2m->pod.entry_count )
break;
+ /* domain_pause() not required here, see XSA-99 */
rc = vm_event_enable(d, vec, ved, _VPF_mem_paging,
HVM_PARAM_PAGING_RING_PFN,
mem_paging_notification);
@@ -632,7 +633,11 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
case XEN_VM_EVENT_DISABLE:
if ( ved->ring_page )
+ {
+ domain_pause(d);
rc = vm_event_disable(d, ved);
+ domain_unpause(d);
+ }
break;
case XEN_VM_EVENT_RESUME:
@@ -658,6 +663,7 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
switch( vec->op )
{
case XEN_VM_EVENT_ENABLE:
+ /* domain_pause() not required here, see XSA-99 */
rc = vm_event_enable(d, vec, ved, _VPF_mem_access,
HVM_PARAM_MONITOR_RING_PFN,
monitor_notification);
@@ -665,7 +671,11 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
case XEN_VM_EVENT_DISABLE:
if ( ved->ring_page )
+ {
+ domain_pause(d);
rc = vm_event_disable(d, ved);
+ domain_unpause(d);
+ }
break;
case XEN_VM_EVENT_RESUME:
@@ -701,6 +711,7 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
if ( !hap_enabled(d) )
break;
+ /* domain_pause() not required here, see XSA-99 */
rc = vm_event_enable(d, vec, ved, _VPF_mem_sharing,
HVM_PARAM_SHARING_RING_PFN,
mem_sharing_notification);
@@ -708,7 +719,11 @@ int vm_event_domctl(struct domain *d, xen_domctl_vm_event_op_t *vec,
case XEN_VM_EVENT_DISABLE:
if ( ved->ring_page )
+ {
+ domain_pause(d);
rc = vm_event_disable(d, ved);
+ domain_unpause(d);
+ }
break;
case XEN_VM_EVENT_RESUME:
This patch pauses the domain for all writes through the 'ad' pointer in monitor_domctl(), defers a domain_unpause() call until after the CRs are updated for the MONITOR_EVENT_WRITE_CTRLREG case, and makes sure that the domain is paused for both vm_event enable and disable cases in vm_event_domctl(). Thanks go to Andrew Cooper for his review and suggestions. Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com> --- Changes since V1: - Annotated domctl d != current->domain checks with /* no domain_pause() */. - Moved the XEN_DOMCTL_monitor_op current->domain check into monitor_domctl(). - Reworked the return -EOPNOTSUPP statement to not leave the domain accidentally paused. - Found an additional instance of lacking domain_pause() at XEN_DOMCTL_set_access_required. - Replaced the vm_event_enable() pause_domain() call with a comment pointing to XSA-99, which made sure that the domain is paused in libxc for the enable case (at Tamas K Lengyel's suggestion). --- xen/arch/x86/monitor.c | 32 +++++++++++++++++++------------- xen/common/domctl.c | 12 ++++++------ xen/common/vm_event.c | 17 ++++++++++++++++- 3 files changed, 41 insertions(+), 20 deletions(-)