--- /dev/null
+
+# HG changeset patch
+# User Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+# Date 1321623485 0
+# Node ID 5a00ccfc63915650b8e1a262c2cad8e8d8670612
+# Parent e73ada19a69daf821aa7d80323f1bd76239b9bae
+x86: re-inject emulated level pirqs in PV on HVM guests if still asserted
+
+PV on HVM guests can loose level interrupts coming from emulated
+devices if they have been remapped onto event channels. The reason is
+that we are missing the code to inject a pirq again in the guest when
+the guest EOIs it, if it corresponds to an emulated level interrupt
+and the interrupt is still asserted.
+
+Fix this issue and also return error when the guest tries to get the
+irq_status of a non-existing pirq.
+
+
+Changes in this backport:
+ - move the spinlock afterward to cover the new code only.
+
+Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+Committed-by: Keir Fraser <keir@xen.org>
+xen-unstable changeset: 24007:0526644ad2a6
+xen-unstable date: Thu Oct 27 16:07:18 2011 +0100
+
+diff -r e73ada19a69d -r 5a00ccfc6391 xen/arch/x86/physdev.c
+--- a/xen/arch/x86/physdev.c Thu Nov 17 09:13:25 2011 +0000
++++ b/xen/arch/x86/physdev.c Fri Nov 18 13:38:05 2011 +0000
+@@ -268,6 +268,20 @@
+ ret = pirq_guest_eoi(v->domain, eoi.irq);
+ else
+ ret = 0;
++ spin_lock(&v->domain->event_lock);
++ if ( is_hvm_domain(v->domain) &&
++ domain_pirq_to_emuirq(v->domain, eoi.irq) > 0 )
++ {
++ struct hvm_irq *hvm_irq = &v->domain->arch.hvm_domain.irq;
++ int gsi = domain_pirq_to_emuirq(v->domain, eoi.irq);
++
++ /* if this is a level irq and count > 0, send another
++ * notification */
++ if ( gsi >= NR_ISAIRQS /* ISA irqs are edge triggered */
++ && hvm_irq->gsi_assert_count[gsi] )
++ send_guest_pirq(v->domain, eoi.irq);
++ }
++ spin_unlock(&v->domain->event_lock);
+ break;
+ }
+
+@@ -323,9 +337,10 @@
+ break;
+ irq_status_query.flags = 0;
+ if ( is_hvm_domain(v->domain) &&
+- domain_pirq_to_irq(v->domain, irq) <= 0 )
++ domain_pirq_to_irq(v->domain, irq) <= 0 &&
++ domain_pirq_to_emuirq(v->domain, irq) == IRQ_UNBOUND )
+ {
+- ret = copy_to_guest(arg, &irq_status_query, 1) ? -EFAULT : 0;
++ ret = -EINVAL;
+ break;
+ }
+
+