[Xen-changelog] [xen master] x86/hvm: fix non-onchangeonly CR write events logic

[patchbot@xxxxxxx]

commit 421850a06d54dbe48f8e5979d3453428071db4fd
Author:     Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
AuthorDate: Thu Aug 13 14:46:25 2015 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Aug 13 14:46:25 2015 +0200

    x86/hvm: fix non-onchangeonly CR write events logic
    
    hvm_event_crX() already returns a bool_t to tell us whether an
    event will be sent out or not, so the extra check that value != old
    is not only useless, but also prevents non-onchangeonly events from
    being sent.
    
    Signed-off-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Release-acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index c957610..707ad86 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3368,8 +3368,7 @@ int hvm_set_cr0(unsigned long value, bool_t may_defer)
     }
 
     if ( may_defer && unlikely(currad->monitor.write_ctrlreg_enabled &
-                               monitor_ctrlreg_bitmask(VM_EVENT_X86_CR0)) &&
-         value != old_value )
+                               monitor_ctrlreg_bitmask(VM_EVENT_X86_CR0)) )
     {
         ASSERT(currad->event_write_data != NULL);
 
@@ -3472,8 +3471,7 @@ int hvm_set_cr3(unsigned long value, bool_t may_defer)
     struct arch_domain *currad = &v->domain->arch;
 
     if ( may_defer && unlikely(currad->monitor.write_ctrlreg_enabled &
-                               monitor_ctrlreg_bitmask(VM_EVENT_X86_CR3)) &&
-         value != old )
+                               monitor_ctrlreg_bitmask(VM_EVENT_X86_CR3)) )
     {
         ASSERT(currad->event_write_data != NULL);
 
@@ -3546,8 +3544,7 @@ int hvm_set_cr4(unsigned long value, bool_t may_defer)
     }
 
     if ( may_defer && unlikely(currad->monitor.write_ctrlreg_enabled &
-                               monitor_ctrlreg_bitmask(VM_EVENT_X86_CR4)) &&
-         value != old_cr )
+                               monitor_ctrlreg_bitmask(VM_EVENT_X86_CR4)) )
     {
         ASSERT(currad->event_write_data != NULL);
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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