[PATCH 1/3] qemu-xen-trad/pt_msi_disable: do not clear all MSI flags

[Rui Guo <firemeteor@users.sourceforge.net>]

"qemu-xen-trad: fix msi_translate with PV event delivery" added a
pt_msi_disable() call into pt_msgctrl_reg_write, clearing the MSI flags as a
consequence. MSIs get enabled again soon after by calling pt_msi_setup.

However the MSI flags are only setup once in the pt_msgctrl_reg_init function,
so from the QEMU point of view the device has lost some important properties,
like for example PCI_MSI_FLAGS_64BIT.

This patch fixes the bug by clearing only the MSI enabled/mapped/initialized
flags in pt_msi_disable.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: G.R. <firemeteor@users.sourceforge.net>
Xen-devel: http://marc.info/?l=xen-devel&m=135489879503075
---
 hw/pt-msi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/pt-msi.c b/hw/pt-msi.c
index 73f737d..b03b989 100644
--- a/hw/pt-msi.c
+++ b/hw/pt-msi.c
@@ -213,7 +213,7 @@ void pt_msi_disable(struct pt_dev *dev)
 
 out:
     /* clear msi info */
-    dev->msi->flags = 0;
+    dev->msi->flags &= ~(MSI_FLAG_UNINIT | PT_MSI_MAPPED | PCI_MSI_FLAGS_ENABLE);
     dev->msi->pirq = -1;
     dev->msi_trans_en = 0;
 }
-- 
1.7.10.4