[PATCH v5 22/24] x86/hvm: domctl_lock synchronization only when MGMT_HYPERCALLS=y

[Penny Zheng <Penny.Zheng@xxxxxxx>]

Helper domctl_lock_{acquire,release}() is domctl_lock, which HVM_PARAM_IDENT_PT
uses to ensure synchronization on potential domctl-op altering guest state.
So it is only needed when MGMT_HYPERCALLS=y.

Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
v3 -> v4:
- new commit
---
v4 -> v5:
- refine title and commit message
---
 xen/arch/x86/hvm/hvm.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ce75fb7839..b52dd8f1c4 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4272,7 +4272,7 @@ static int hvm_set_param(struct domain *d, uint32_t 
index, uint64_t value)
          * the domctl_lock.
          */
         rc = -ERESTART;
-        if ( !domctl_lock_acquire() )
+        if ( IS_ENABLED(CONFIG_MGMT_HYPERCALLS) && !domctl_lock_acquire() )
             break;
 
         rc = 0;
@@ -4282,7 +4282,8 @@ static int hvm_set_param(struct domain *d, uint32_t 
index, uint64_t value)
             paging_update_cr3(v, false);
         domain_unpause(d);
 
-        domctl_lock_release();
+        if ( IS_ENABLED(CONFIG_MGMT_HYPERCALLS) )
+            domctl_lock_release();
         break;
     case HVM_PARAM_DM_DOMAIN:
         /* The only value this should ever be set to is DOMID_SELF */
-- 
2.34.1