[Xen-changelog] [xen master] x86/svm: Don't unconditionally use a new ASID in svm_invlpg_intercept()

[patchbot@xxxxxxx]

commit eee511dec9d1f7e2bdfb4aebfe5ffbd70cdf6f51
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon May 9 18:09:38 2016 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue May 10 18:08:58 2016 +0100

    x86/svm: Don't unconditionally use a new ASID in svm_invlpg_intercept()
    
    paging_invlpg() already returns a boolean indicating whether an invalidation
    is necessary or not.  A return value of 0 indicates that the specified 
virtual
    address wasn't shadowed (or has already been flushed), cannot currently be
    cached in the TLB.
    
    This is a performance optimisation.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
    Reviewed-by: Tim Deegan <tim@xxxxxxx>
    Release-acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 xen/arch/x86/hvm/svm/svm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 7634c3f..081a5d8 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2224,8 +2224,8 @@ static void svm_invlpg_intercept(unsigned long vaddr)
 {
     struct vcpu *curr = current;
     HVMTRACE_LONG_2D(INVLPG, 0, TRC_PAR_LONG(vaddr));
-    paging_invlpg(curr, vaddr);
-    svm_asid_g_invlpg(curr, vaddr);
+    if ( paging_invlpg(curr, vaddr) )
+        svm_asid_g_invlpg(curr, vaddr);
 }
 
 static struct hvm_function_table __initdata svm_function_table = {
--
generated by git-patchbot for /home/xen/git/xen.git#master

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