diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 3d712d592fff495e6c37152acbaceccf48841e82..bdb092ee9d8df5ec84eb28cd0f70509cc36ccdf3 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -272,6 +272,9 @@ static void cirrus_update_memory_access(CirrusVGAState *s);
 static bool blit_region_is_unsafe(struct CirrusVGAState *s,
                                   int32_t pitch, int32_t addr)
 {
+    if (!pitch) {
+        return true;
+    }
     if (pitch < 0) {
         int64_t min = addr
             + ((int64_t)s->cirrus_blt_height-1) * pitch;
@@ -715,7 +718,7 @@ static int cirrus_bitblt_videotovideo_patterncopy(CirrusVGAState * s)
                                             s->cirrus_addr_mask));
 }
 
-static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
+static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
 {
     int sx = 0, sy = 0;
     int dx = 0, dy = 0;
@@ -729,6 +732,9 @@ static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
         int width, height;
 
         depth = s->vga.get_bpp(&s->vga) / 8;
+        if (!depth) {
+            return 0;
+        }
         s->vga.get_resolution(&s->vga, &width, &height);
 
         /* extra x, y */
@@ -783,6 +789,8 @@ static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
     cirrus_invalidate_region(s, s->cirrus_blt_dstaddr,
 				s->cirrus_blt_dstpitch, s->cirrus_blt_width,
 				s->cirrus_blt_height);
+
+    return 1;
 }
 
 static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
@@ -790,11 +798,9 @@ static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
     if (blit_is_unsafe(s))
         return 0;
 
-    cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
+    return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
             s->cirrus_blt_srcaddr - s->vga.start_addr,
             s->cirrus_blt_width, s->cirrus_blt_height);
-
-    return 1;
 }
 
 /***************************************
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 0e2682d28b2d90d140a3e2a0bd2c870aca8eaf44..62d0c80dcfa7b9ca75965ff43d10039d81f6cb86 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -992,6 +992,34 @@ static uint32_t qxl_crc32(const uint8_t *p, unsigned len)
     return crc32(0xffffffff, p, len) ^ 0xffffffff;
 }
 
+static bool qxl_rom_monitors_config_changed(QXLRom *rom,
+        VDAgentMonitorsConfig *monitors_config,
+        unsigned int max_outputs)
+{
+    int i;
+    unsigned int monitors_count;
+
+    monitors_count = MIN(monitors_config->num_of_monitors, max_outputs);
+
+    if (rom->client_monitors_config.count != monitors_count) {
+        return true;
+    }
+
+    for (i = 0 ; i < rom->client_monitors_config.count ; ++i) {
+        VDAgentMonConfig *monitor = &monitors_config->monitors[i];
+        QXLURect *rect = &rom->client_monitors_config.heads[i];
+        /* monitor->depth ignored */
+        if ((rect->left != monitor->x) ||
+            (rect->top != monitor->y)  ||
+            (rect->right != monitor->x + monitor->width) ||
+            (rect->bottom != monitor->y + monitor->height)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 /* called from main context only */
 static int interface_client_monitors_config(QXLInstance *sin,
                                         VDAgentMonitorsConfig *monitors_config)
@@ -1000,6 +1028,7 @@ static int interface_client_monitors_config(QXLInstance *sin,
     QXLRom *rom = memory_region_get_ram_ptr(&qxl->rom_bar);
     int i;
     unsigned max_outputs = ARRAY_SIZE(rom->client_monitors_config.heads);
+    bool config_changed = false;
 
     if (qxl->revision < 4) {
         trace_qxl_client_monitors_config_unsupported_by_device(qxl->id,
@@ -1030,6 +1059,10 @@ static int interface_client_monitors_config(QXLInstance *sin,
     }
 #endif
 
+    config_changed = qxl_rom_monitors_config_changed(rom,
+                                                     monitors_config,
+                                                     max_outputs);
+
     memset(&rom->client_monitors_config, 0,
            sizeof(rom->client_monitors_config));
     rom->client_monitors_config.count = monitors_config->num_of_monitors;
@@ -1059,7 +1092,9 @@ static int interface_client_monitors_config(QXLInstance *sin,
     trace_qxl_interrupt_client_monitors_config(qxl->id,
                         rom->client_monitors_config.count,
                         rom->client_monitors_config.heads);
-    qxl_send_events(qxl, QXL_INTERRUPT_CLIENT_MONITORS_CONFIG);
+    if (config_changed) {
+        qxl_send_events(qxl, QXL_INTERRUPT_CLIENT_MONITORS_CONFIG);
+    }
     return 1;
 }
 
diff --git a/hw/display/virtio-gpu-3d.c b/hw/display/virtio-gpu-3d.c
index 758d33a09d9dc995b9d28850bdb33bb3870f9f8d..23f39de94d3a4e355673f14cbced5aed7e312e87 100644
--- a/hw/display/virtio-gpu-3d.c
+++ b/hw/display/virtio-gpu-3d.c
@@ -347,6 +347,7 @@ static void virgl_cmd_get_capset_info(VirtIOGPU *g,
 
     VIRTIO_GPU_FILL_CMD(info);
 
+    memset(&resp, 0, sizeof(resp));
     if (info.capset_index == 0) {
         resp.capset_id = VIRTIO_GPU_CAPSET_VIRGL;
         virgl_renderer_get_cap_set(resp.capset_id,
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 60bce94d6b4a7ee5aabcd019f993a328119760de..5f32e1aae9ad5ffb19ea8c4dae2a3daedf43fd19 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -84,6 +84,7 @@ static void update_cursor_data_virgl(VirtIOGPU *g,
 
     if (width != s->current_cursor->width ||
         height != s->current_cursor->height) {
+        free(data);
         return;
     }