[PATCH v11 for-xen-4.5 13/20] x86/VPMU: Save VPMU state for PV guests during context switch

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

Save VPMU state during context switch for both HVM and PV(H) guests.

A subsequent patch will make it possible for vpmu_switch_to() to call
vmx_vmcs_try_enter()->vcpu_pause() which needs is_running to be correctly
set/cleared. To prepare for that, call context_saved() before vpmu_switch_to()
is executed.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 xen/arch/x86/domain.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 5e492d8..d7fb99d 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1495,16 +1495,13 @@ void context_switch(struct vcpu *prev, struct vcpu *next)
     }
 
     if ( prev != next )
-        _update_runstate_area(prev);
-
-    if ( is_hvm_vcpu(prev) )
     {
-        if (prev != next)
-            vpmu_switch_from(prev, next);
+        _update_runstate_area(prev);
+        vpmu_switch_from(prev, next);
+    }
 
-        if ( !list_empty(&prev->arch.hvm_vcpu.tm_list) )
+    if ( is_hvm_vcpu(prev) && !list_empty(&prev->arch.hvm_vcpu.tm_list) )
             pt_save_timer(prev);
-    }
 
     local_irq_disable();
 
@@ -1543,15 +1540,16 @@ void context_switch(struct vcpu *prev, struct vcpu *next)
                            !is_hardware_domain(next->domain));
     }
 
-    if ( is_hvm_vcpu(prev) && (prev != next) )
-        /* Must be done with interrupts enabled */
-        vpmu_switch_to(prev, next);
-
     context_saved(prev);
 
     if ( prev != next )
+    {
         _update_runstate_area(next);
 
+        /* Must be done with interrupts enabled */
+        vpmu_switch_to(prev, next);
+    }
+
     /* Ensure that the vcpu has an up-to-date time base. */
     update_vcpu_system_time(next);
 
-- 
1.8.1.4