From: Jan Beulich <jbeul...@suse.com>
Before adding a new vCPU operation to register the runstate area by
guest-physical address, add code to actually keep such areas up-to-date.
Note that updating of the area will be done exclusively following the
model enabled by VMASST_TYPE_runstate_update_flag for virtual-address
based registered areas.
Note further that pages aren't marked dirty when written to (matching
the handling of space mapped by map_vcpu_info()), on the basis that the
registrations are lost anyway across migration (or would need re-
populating at the target for transparent migration). Plus the contents
of the areas in question have to be deemed volatile in the first place
(so saving a "most recent" value is pretty meaningless even for e.g.
snapshotting).
Signed-off-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Roger Pau Monné <roger....@citrix.com>
Reviewed-by: Julien Grall <jgr...@amazon.com>
---
xen/common/domain.c | 43 ++++++++++++++++++++++++++++++++++++++---
xen/include/xen/sched.h | 2 ++
2 files changed, 42 insertions(+), 3 deletions(-)
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 76a4c2072e10..d4958ec5e149 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1644,15 +1644,52 @@ bool update_runstate_area(struct vcpu *v)
bool rc;
struct guest_memory_policy policy = { };
void __user *guest_handle = NULL;
- struct vcpu_runstate_info runstate;
+ struct vcpu_runstate_info runstate = v->runstate;
+ struct vcpu_runstate_info *map = v->runstate_guest_area.map;
+
+ if ( map )
+ {
+ uint64_t *pset;
+#ifdef CONFIG_COMPAT
+ struct compat_vcpu_runstate_info *cmap = NULL;
+
+ if ( v->runstate_guest_area_compat )
+ cmap = (void *)map;
+#endif
+
+ /*
+ * NB: No VM_ASSIST(v->domain, runstate_update_flag) check here.
+ * Always using that updating model.
+ */
+#ifdef CONFIG_COMPAT
+ if ( cmap )
+ pset = &cmap->state_entry_time;
+ else
+#endif
+ pset = &map->state_entry_time;
+ runstate.state_entry_time |= XEN_RUNSTATE_UPDATE;
+ write_atomic(pset, runstate.state_entry_time);
+ smp_wmb();
+
+#ifdef CONFIG_COMPAT
+ if ( cmap )
+ XLAT_vcpu_runstate_info(cmap, &runstate);
+ else
+#endif
+ *map = runstate;
+
+ smp_wmb();
+ runstate.state_entry_time &= ~XEN_RUNSTATE_UPDATE;
+ write_atomic(pset, runstate.state_entry_time);
+
+ return true;
+ }
if ( guest_handle_is_null(runstate_guest(v)) )
return true;
update_guest_memory_policy(v, &policy);
- memcpy(&runstate, &v->runstate, sizeof(runstate));
-
if ( VM_ASSIST(v->domain, runstate_update_flag) )
{
#ifdef CONFIG_COMPAT
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index f30f3b0ebeab..6e1028785d8c 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -232,6 +232,8 @@ struct vcpu
#ifdef CONFIG_COMPAT
/* A hypercall is using the compat ABI? */
bool hcall_compat;
+ /* Physical runstate area registered via compat ABI? */
+ bool runstate_guest_area_compat;
#endif
#ifdef CONFIG_IOREQ_SERVER
--
2.42.0
