[PATCH v3 2/9] pci-host: add pcie-msi read method

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

Add pcie-msi mmio read method to avoid NULL pointer dereference
issue.

Reported-by: Lei Sun <slei.casper@gmail.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/pci-host/designware.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Update v3: Add Reviewed-by: ...
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg09400.html

diff --git a/hw/pci-host/designware.c b/hw/pci-host/designware.c
index 8492c18991..82262bdfdf 100644
--- a/hw/pci-host/designware.c
+++ b/hw/pci-host/designware.c
@@ -21,6 +21,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu/module.h"
+#include "qemu/log.h"
 #include "hw/pci/msi.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_host.h"
@@ -63,6 +64,13 @@ designware_pcie_root_to_host(DesignwarePCIERoot *root)
     return DESIGNWARE_PCIE_HOST(bus->parent);
 }
 
+static uint64_t designware_pcie_root_msi_read(void *opaque, hwaddr addr,
+                                              unsigned size)
+{
+    qemu_log_mask(LOG_UNIMP, "%s not implemented\n", __func__);
+    return 0;
+}
+
 static void designware_pcie_root_msi_write(void *opaque, hwaddr addr,
                                            uint64_t val, unsigned len)
 {
@@ -77,6 +85,7 @@ static void designware_pcie_root_msi_write(void *opaque, hwaddr addr,
 }
 
 static const MemoryRegionOps designware_pci_host_msi_ops = {
+    .read = designware_pcie_root_msi_read,
     .write = designware_pcie_root_msi_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
     .valid = {
-- 
2.26.2