xen: temporary workaround for MSI S3

(this patch is intended to provide people with a temporary
solution to S3 of MSI dom0, before a more formal solution
based on trap and emulation.)

This patch adds a temporary workaround to enable S3 resume
with MSI devices.

Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 362773247fbfc3586e0025d84e006165c14613e0..e1051ca335cf649131169756a6a6db1a3e1db106 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -20,6 +20,8 @@
 #include <asm/errno.h>
 #include <asm/io.h>
 
+#include <asm/xen/hypervisor.h>
+
 #include "pci.h"
 #include "msi.h"
 
@@ -267,7 +269,8 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg)
 {
        struct irq_desc *desc = irq_to_desc(irq);
 
-       write_msi_msg_desc(desc, msg);
+       if (!xen_initial_domain())
+               write_msi_msg_desc(desc, msg);
 }
 
 static int msi_free_irqs(struct pci_dev* dev);