From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Date: Tue, 8 Apr 2014 16:50:06 +0000 (+0000)
Subject: qemu-xen-trad: free all the pirqs for msi/msix when driver unloads
X-Git-Tag: xen-4.4.1-rc2^0
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=6ae4e588081620b141071eb010ec40aca7e12876;p=qemu-xen-4.4-testing.git

qemu-xen-trad: free all the pirqs for msi/msix when driver unloads

Pirqs are not freed when driver unloads, then new pirqs are allocated when
driver reloads. 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>

[ This is the qemu-xen-trad version of qemu-xen-upstream
  1d4fd4f0e2fc5dcae0c60e00cc9af95f52988050 -iwj ]
(cherry picked from commit d0395cc49b2ec6d1723c01f1daf2394b9264ca29)
---

diff --git a/hw/pass-through.c b/hw/pass-through.c
index 304c438e8..482118225 100644
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -3866,7 +3866,11 @@ static int pt_msgctrl_reg_write(struct pt_dev *ptdev,
         ptdev->msi->flags |= PCI_MSI_FLAGS_ENABLE;
     }
     else
-        ptdev->msi->flags &= ~PCI_MSI_FLAGS_ENABLE;
+    {
+        if (ptdev->msi->flags & PT_MSI_MAPPED) {
+            pt_msi_disable(ptdev);
+        }
+    }
 
     /* pass through MSI_ENABLE bit when no MSI-INTx translation */
     if (!ptdev->msi_trans_en) {
@@ -4013,6 +4017,8 @@ static int pt_msixctrl_reg_write(struct pt_dev *ptdev,
             pt_disable_msi_translate(ptdev);
         }
         pt_msix_update(ptdev);
+    } else if (!(*value & PCI_MSIX_ENABLE) && ptdev->msix->enabled) {
+        pt_msix_disable(ptdev);
     }
 
     ptdev->msix->enabled = !!(*value & PCI_MSIX_ENABLE);
diff --git a/hw/pt-msi.c b/hw/pt-msi.c
index b03b9890e..3f5f94b13 100644
--- a/hw/pt-msi.c
+++ b/hw/pt-msi.c
@@ -213,7 +213,8 @@ void pt_msi_disable(struct pt_dev *dev)
 
 out:
     /* clear msi info */
-    dev->msi->flags &= ~(MSI_FLAG_UNINIT | PT_MSI_MAPPED | PCI_MSI_FLAGS_ENABLE);
+    dev->msi->flags &= ~(PT_MSI_MAPPED | PCI_MSI_FLAGS_ENABLE);
+    dev->msi->flags |= MSI_FLAG_UNINIT;
     dev->msi->pirq = -1;
     dev->msi_trans_en = 0;
 }
@@ -447,7 +448,7 @@ static void pci_msix_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
     {
         const volatile uint32_t *vec_ctrl;
 
-        if ( entry->io_mem[offset] == val )
+        if ( entry->io_mem[offset] == val && entry->pirq != -1)
             return;
 
         /*