From 2a36b539c652f5753855eb0651bcd7ea3d50b04b Mon Sep 17 00:00:00 2001
From: James Mckenzie <jamesmck@taoand.(none)>
Date: Thu, 20 Aug 2009 08:28:35 +0100
Subject: [PATCH] Ugly hack to fix SATA - Send EOI for MSI immediately.

Xen tends to allocate MSI with high vector numbers (priority)
it leaves them pending until the guest sends EOI. However
if you have an MSI pending per CPU you lose.
---
 master/series                |  1 +
 master/ugly-hack-to-fix-sata | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 master/ugly-hack-to-fix-sata

diff --git a/master/series b/master/series
index c027f7b..31c3a33 100644
--- a/master/series
+++ b/master/series
@@ -18,3 +18,4 @@ tools-hvm-info
 default-iommu-inclusive-mapping
 igd-cmd-reg-change-for-reboot
 xblanker
+ugly-hack-to-fix-sata
diff --git a/master/ugly-hack-to-fix-sata b/master/ugly-hack-to-fix-sata
new file mode 100644
index 0000000..8b5c645
--- /dev/null
+++ b/master/ugly-hack-to-fix-sata
@@ -0,0 +1,29 @@
+diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
+index e2202ba..eee9dd1 100644
+--- a/xen/arch/x86/irq.c
++++ b/xen/arch/x86/irq.c
+@@ -318,13 +318,17 @@ static void __do_IRQ_guest(int vector)
+ 
+     if ( action->ack_type == ACKTYPE_EOI )
+     {
+-        sp = pending_eoi_sp(peoi);
+-        ASSERT((sp == 0) || (peoi[sp-1].vector < vector));
+-        ASSERT(sp < (NR_VECTORS-1));
+-        peoi[sp].vector = vector;
+-        peoi[sp].ready = 0;
+-        pending_eoi_sp(peoi) = sp+1;
+-        cpu_set(smp_processor_id(), action->cpu_eoi_map);
++        if ( desc->handler == &pci_msi_type ) { //FIXME I'M UGLY
++            desc->handler->end(vector);
++        } else {
++            sp = pending_eoi_sp(peoi);
++            ASSERT((sp == 0) || (peoi[sp-1].vector < vector));
++            ASSERT(sp < (NR_VECTORS-1));
++            peoi[sp].vector = vector;
++            peoi[sp].ready = 0;
++            pending_eoi_sp(peoi) = sp+1;
++            cpu_set(smp_processor_id(), action->cpu_eoi_map);
++        }
+     }
+ 
+     for ( i = 0; i < action->nr_guests; i++ )
-- 
2.39.5