From: Keir Fraser <keir.fraser@citrix.com>
Date: Tue, 22 Apr 2008 10:46:41 +0000 (+0100)
Subject: x86 iommu: Better synchronisation on dirq_mask.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14215^2~145
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=a8add4da193a45f0486cbe01f0ab2a48938d9d7a;p=xen.git

x86 iommu: Better synchronisation on dirq_mask.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---

diff --git a/xen/arch/x86/hvm/svm/intr.c b/xen/arch/x86/hvm/svm/intr.c
index 4b3dcd33ad..3463ac42a6 100644
--- a/xen/arch/x86/hvm/svm/intr.c
+++ b/xen/arch/x86/hvm/svm/intr.c
@@ -109,8 +109,10 @@ static void svm_dirq_assist(struct vcpu *v)
           irq < NR_IRQS;
           irq = find_next_bit(hvm_irq_dpci->dirq_mask, NR_IRQS, irq + 1) )
     {
+        if ( !test_and_clear_bit(irq, &hvm_irq_dpci->dirq_mask) )
+            continue;
+
         stop_timer(&hvm_irq_dpci->hvm_timer[irq_to_vector(irq)]);
-        clear_bit(irq, &hvm_irq_dpci->dirq_mask);
 
         list_for_each_entry ( digl, &hvm_irq_dpci->mirq[irq].digl_list, list )
         {
diff --git a/xen/arch/x86/hvm/vmx/intr.c b/xen/arch/x86/hvm/vmx/intr.c
index dc47430a63..3fcfc52175 100644
--- a/xen/arch/x86/hvm/vmx/intr.c
+++ b/xen/arch/x86/hvm/vmx/intr.c
@@ -118,8 +118,10 @@ static void vmx_dirq_assist(struct vcpu *v)
           irq < NR_IRQS;
           irq = find_next_bit(hvm_irq_dpci->dirq_mask, NR_IRQS, irq + 1) )
     {
+        if ( !test_and_clear_bit(irq, &hvm_irq_dpci->dirq_mask) )
+            continue;
+
         stop_timer(&hvm_irq_dpci->hvm_timer[irq_to_vector(irq)]);
-        clear_bit(irq, &hvm_irq_dpci->dirq_mask);
 
         list_for_each_entry ( digl, &hvm_irq_dpci->mirq[irq].digl_list, list )
         {