qemu-xen-trad: fix msi_translate with PV event delivery

When switching from msitranslate to straight msi we need to make sure
that we respect PV event delivery for the msi if the guest asked for it:

- completely disable MSI on the device in pt_disable_msi_translate;
- then enable MSI again (pt_msi_setup), mapping the correct pirq to it.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Rolu <rolu@roce.org>
(cherry picked from commit 3e66da7266c84638c0e22a09c9d2b07529802576)

diff --git a/hw/pass-through.c b/hw/pass-through.c
index 9c5620da2076f32add7356e15ec6021c54d4f049..41926c6efa8644c262d9c13f6132e530e6ef62af 100644 (file)
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -3803,21 +3803,18 @@ static int pt_msgctrl_reg_write(struct pt_dev *ptdev,
                 PT_LOG("guest enabling MSI, disable MSI-INTx translation\n");
                 pt_disable_msi_translate(ptdev);
             }
-            else
+            /* Init physical one */
+            PT_LOG("setup msi for dev %x\n", pd->devfn);
+            if (pt_msi_setup(ptdev))
             {
-                /* Init physical one */
-                PT_LOG("setup msi for dev %x\n", pd->devfn);
-                if (pt_msi_setup(ptdev))
-                {
-                   /* We do not broadcast the error to the framework code, so
-                    * that MSI errors are contained in MSI emulation code and
-                    * QEMU can go on running.
-                    * Guest MSI would be actually not working.
-                    */
-                   *value &= ~PCI_MSI_FLAGS_ENABLE;
-                   PT_LOG("Warning: Can not map MSI for dev %x\n", pd->devfn);
-                   return 0;
-                }
+                /* We do not broadcast the error to the framework code, so
+                 * that MSI errors are contained in MSI emulation code and
+                 * QEMU can go on running.
+                 * Guest MSI would be actually not working.
+                 */
+                *value &= ~PCI_MSI_FLAGS_ENABLE;
+                PT_LOG("Warning: Can not map MSI for dev %x\n", pd->devfn);
+                return 0;
             }
             if (pt_msi_update(ptdev))
             {

diff --git a/hw/pt-msi.c b/hw/pt-msi.c
index 71fa6f00414566bdbd0d0c0cff6fa853275b485e..fcec36a0f27c7c7d85e2a3b7cc11d0290e1481ff 100644 (file)
--- a/hw/pt-msi.c
+++ b/hw/pt-msi.c
@@ -263,16 +263,8 @@ void pt_disable_msi_translate(struct pt_dev *dev)
     uint8_t e_device = 0;
     uint8_t e_intx = 0;
 
-    /* MSI_ENABLE bit should be disabed until the new handler is set */
-    msi_set_enable(dev, 0);
-
-    e_device = PCI_SLOT(dev->dev.devfn);
-    e_intx = pci_intx(dev);
-
-    if (xc_domain_unbind_pt_irq(xc_handle, domid, dev->msi->pirq,
-                                 PT_IRQ_TYPE_MSI_TRANSLATE, 0,
-                                 e_device, e_intx, 0))
-        PT_LOG("Error: Unbinding pt irq for MSI-INTx failed!\n");
+    pt_msi_disable(dev);
+    dev->msi->flags |= MSI_FLAG_UNINIT;
 
     if (dev->machine_irq)
     {
@@ -280,8 +272,6 @@ void pt_disable_msi_translate(struct pt_dev *dev)
                                        0, e_device, e_intx))
             PT_LOG("Error: Rebinding of interrupt failed!\n");
     }
-
-    dev->msi_trans_en = 0;
 }
 
 /* MSI-X virtulization functions */