2 files changed, 18 insertions, 3 deletions
diff --git a/hw/pci/msi.c b/hw/pci/msi.c
index 8efa23d376..85f21b8c4b 100644
--- a/hw/pci/msi.c
+++ b/hw/pci/msi.c
@@ -20,6 +20,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/pci/msi.h"
+#include "hw/xen/xen.h"
 #include "qemu/range.h"
 
 /* PCI_MSI_ADDRESS_LO */
@@ -254,13 +255,19 @@ void msi_reset(PCIDevice *dev)
 static bool msi_is_masked(const PCIDevice *dev, unsigned int vector)
 {
     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
-    uint32_t mask;
+    uint32_t mask, data;
+    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
     assert(vector < PCI_MSI_VECTORS_MAX);
 
     if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
         return false;
     }
 
+    data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
+    if (xen_is_pirq_msi(data)) {
+        return false;
+    }
+
     mask = pci_get_long(dev->config +
                         msi_mask_off(dev, flags & PCI_MSI_FLAGS_64BIT));
     return mask & (1U << vector);
diff --git a/hw/pci/msix.c b/hw/pci/msix.c
index 4fea7edc89..eb4ef113d1 100644
--- a/hw/pci/msix.c
+++ b/hw/pci/msix.c
@@ -19,6 +19,7 @@
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
 #include "hw/pci/pci.h"
+#include "hw/xen/xen.h"
 #include "qemu/range.h"
 
 #define MSIX_CAP_LENGTH 12
@@ -78,8 +79,15 @@ static void msix_clr_pending(PCIDevice *dev, int vector)
 
 static bool msix_vector_masked(PCIDevice *dev, unsigned int vector, bool fmask)
 {
-    unsigned offset = vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL;
-    return fmask || dev->msix_table[offset] & PCI_MSIX_ENTRY_CTRL_MASKBIT;
+    unsigned offset = vector * PCI_MSIX_ENTRY_SIZE;
+    uint32_t *data = (uint32_t *)&dev->msix_table[offset + PCI_MSIX_ENTRY_DATA];
+    /* MSIs on Xen can be remapped into pirqs. In those cases, masking
+     * and unmasking go through the PV evtchn path. */
+    if (xen_is_pirq_msi(*data)) {
+        return false;
+    }
+    return fmask || dev->msix_table[offset + PCI_MSIX_ENTRY_VECTOR_CTRL] &
+        PCI_MSIX_ENTRY_CTRL_MASKBIT;
 }
 
 bool msix_is_masked(PCIDevice *dev, unsigned int vector)