File qemu-xen-upstream-free-all-pirqs-for-msi_msix-when-driver-unload.patch of Package xen.7317

References: bsc#1032598

Subject: qemu-xen: free all the pirqs for msi/msix when driver unload
From: Zhenzhong Duan zhenzhong.duan@oracle.com Wed May 7 13:41:48 2014 +0000
Date: Wed May 7 16:14:41 2014 +0000:
Git: c976437c7dba9c7444fb41df45468968aaa326ad

Pirqs are not freed when driver unload, then new pirqs are allocated when
driver reload. This could exhaust pirqs if do it in a loop.

This patch fixes the bug by freeing pirqs when ENABLE bit is cleared in
msi/msix control reg.

There is also other way of fixing it such as reuse pirqs between driver reload,
but this way is better.
Xen-devel: http://marc.info/?l=xen-devel&m=136800120304275&w=2

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Index: xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/xen/xen_pt_config_init.c
===================================================================
--- xen-4.4.4-testing.orig/tools/qemu-xen-dir-remote/hw/xen/xen_pt_config_init.c
+++ xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/xen/xen_pt_config_init.c
@@ -1109,8 +1109,8 @@ static int xen_pt_msgctrl_reg_write(XenP
             msi->mapped = true;
         }
         msi->flags |= PCI_MSI_FLAGS_ENABLE;
-    } else {
-        msi->flags &= ~PCI_MSI_FLAGS_ENABLE;
+    } else if (msi->mapped) {
+        xen_pt_msi_disable(s);
     }
 
     return 0;
@@ -1451,6 +1451,8 @@ static int xen_pt_msixctrl_reg_write(Xen
     if ((*val & PCI_MSIX_FLAGS_ENABLE)
         && !(*val & PCI_MSIX_FLAGS_MASKALL)) {
         xen_pt_msix_update(s);
+    } else if (!(*val & PCI_MSIX_FLAGS_ENABLE) && s->msix->enabled) {
+        xen_pt_msix_disable(s);
     }
 
     debug_msix_enabled_old = s->msix->enabled;
Index: xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/xen/xen_pt_msi.c
===================================================================
--- xen-4.4.4-testing.orig/tools/qemu-xen-dir-remote/hw/xen/xen_pt_msi.c
+++ xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/xen/xen_pt_msi.c
@@ -282,7 +282,8 @@ void xen_pt_msi_disable(XenPCIPassthroug
                      msi->initialized);
 
     /* clear msi info */
-    msi->flags = 0;
+    msi->flags &= ~PCI_MSI_FLAGS_ENABLE;
+    msi->initialized = false;
     msi->mapped = false;
     msi->pirq = XEN_PT_UNASSIGNED_PIRQ;
 }
@@ -445,7 +446,8 @@ static void pci_msix_write(void *opaque,
     if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) {
         const volatile uint32_t *vec_ctrl;
 
-        if (get_entry_value(entry, offset) == val) {
+        if (get_entry_value(entry, offset) == val
+            && entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
             return;
         }