[PATCH] qemu vfio-pci: Add extra debugging

[Alex Williamson <alex.williamson@redhat.com>]

Often when debugging it's useful to be able to disable bypass paths
so no interactions with the device are missed.  Add some extra debug
options to do this.  Also add device info on read/write BAR accesses,
which is useful when debugging more than one assigned device.  A
couple DPRINTFs also had redundant "vfio:" prefixes.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio_pci.c |   40 ++++++++++++++++++++++++++++++----------
 1 file changed, 30 insertions(+), 10 deletions(-)

diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
index 769ab05..7aa3d88 100644
--- a/hw/vfio_pci.c
+++ b/hw/vfio_pci.c
@@ -48,6 +48,10 @@
     do { } while (0)
 #endif
 
+/* Extra debugging, trap acceleration paths for more logging */
+#define VFIO_ALLOW_MMAP 1
+#define VFIO_ALLOW_KVM_INTX 1
+
 struct VFIODevice;
 
 typedef struct VFIOQuirk {
@@ -304,7 +308,7 @@ static void vfio_enable_intx_kvm(VFIODevice *vdev)
     int ret, argsz;
     int32_t *pfd;
 
-    if (!kvm_irqfds_enabled() ||
+    if (!VFIO_ALLOW_KVM_INTX || !kvm_irqfds_enabled() ||
         vdev->intx.route.mode != PCI_INTX_ENABLED ||
         !kvm_check_extension(kvm_state, KVM_CAP_IRQFD_RESAMPLE)) {
         return;
@@ -924,8 +928,16 @@ static void vfio_bar_write(void *opaque, hwaddr addr,
                      __func__, addr, data, size);
     }
 
-    DPRINTF("%s(BAR%d+0x%"HWADDR_PRIx", 0x%"PRIx64", %d)\n",
-            __func__, bar->nr, addr, data, size);
+#ifdef DEBUG_VFIO
+    {
+        VFIODevice *vdev = container_of(bar, VFIODevice, bars[bar->nr]);
+
+        DPRINTF("%s(%04x:%02x:%02x.%x:BAR%d+0x%"HWADDR_PRIx", 0x%"PRIx64
+                ", %d)\n", __func__, vdev->host.domain, vdev->host.bus,
+                vdev->host.slot, vdev->host.function, bar->nr, addr,
+                data, size);
+    }
+#endif
 
     /*
      * A read or write to a BAR always signals an INTx EOI.  This will
@@ -971,8 +983,16 @@ static uint64_t vfio_bar_read(void *opaque,
         break;
     }
 
-    DPRINTF("%s(BAR%d+0x%"HWADDR_PRIx", %d) = 0x%"PRIx64"\n",
-            __func__, bar->nr, addr, size, data);
+#ifdef DEBUG_VFIO
+    {
+        VFIODevice *vdev = container_of(bar, VFIODevice, bars[bar->nr]);
+
+        DPRINTF("%s(%04x:%02x:%02x.%x:BAR%d+0x%"HWADDR_PRIx
+                ", %d) = 0x%"PRIx64"\n", __func__, vdev->host.domain,
+                vdev->host.bus, vdev->host.slot, vdev->host.function,
+                bar->nr, addr, size, data);
+    }
+#endif
 
     /* Same as write above */
     vfio_eoi(container_of(bar, VFIODevice, bars[bar->nr]));
@@ -1676,7 +1696,7 @@ static void vfio_listener_region_add(MemoryListener *listener,
     int ret;
 
     if (vfio_listener_skipped_section(section)) {
-        DPRINTF("vfio: SKIPPING region_add %"HWADDR_PRIx" - %"PRIx64"\n",
+        DPRINTF("SKIPPING region_add %"HWADDR_PRIx" - %"PRIx64"\n",
                 section->offset_within_address_space,
                 section->offset_within_address_space + section->size - 1);
         return;
@@ -1700,7 +1720,7 @@ static void vfio_listener_region_add(MemoryListener *listener,
             section->offset_within_region +
             (iova - section->offset_within_address_space);
 
-    DPRINTF("vfio: region_add %"HWADDR_PRIx" - %"HWADDR_PRIx" [%p]\n",
+    DPRINTF("region_add %"HWADDR_PRIx" - %"HWADDR_PRIx" [%p]\n",
             iova, end - 1, vaddr);
 
     ret = vfio_dma_map(container, iova, end - iova, vaddr, section->readonly);
@@ -1720,7 +1740,7 @@ static void vfio_listener_region_del(MemoryListener *listener,
     int ret;
 
     if (vfio_listener_skipped_section(section)) {
-        DPRINTF("vfio: SKIPPING region_del %"HWADDR_PRIx" - %"PRIx64"\n",
+        DPRINTF("SKIPPING region_del %"HWADDR_PRIx" - %"PRIx64"\n",
                 section->offset_within_address_space,
                 section->offset_within_address_space + section->size - 1);
         return;
@@ -1740,7 +1760,7 @@ static void vfio_listener_region_del(MemoryListener *listener,
         return;
     }
 
-    DPRINTF("vfio: region_del %"HWADDR_PRIx" - %"HWADDR_PRIx"\n",
+    DPRINTF("region_del %"HWADDR_PRIx" - %"HWADDR_PRIx"\n",
             iova, end - 1);
 
     ret = vfio_dma_unmap(container, iova, end - iova);
@@ -1943,7 +1963,7 @@ static int vfio_mmap_bar(VFIOBAR *bar, MemoryRegion *mem, MemoryRegion *submem,
 {
     int ret = 0;
 
-    if (size && bar->flags & VFIO_REGION_INFO_FLAG_MMAP) {
+    if (VFIO_ALLOW_MMAP && size && bar->flags & VFIO_REGION_INFO_FLAG_MMAP) {
         int prot = 0;
 
         if (bar->flags & VFIO_REGION_INFO_FLAG_READ) {