>From 659e9f7657e9c6e2944f4eecb1381c940a6cc51e Mon Sep 17 00:00:00 2001
From: Uri Lublin <uril@redhat.com>
Date: Sun, 13 Mar 2011 19:45:46 +0200
Subject: [PATCH 2/3] qxl: read_pipe: keep reading as long as there are things in the queue

---
 hw/qxl.c |   39 ++++++++++++++++++++++++---------------
 1 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/hw/qxl.c b/hw/qxl.c
index 927a625..1ea66a2 100644
--- a/hw/qxl.c
+++ b/hw/qxl.c
@@ -1104,24 +1104,33 @@ static void pipe_read(void *opaque)
 {
     PCIQXLDevice *d = opaque;
     unsigned char cmd;
-    int len;
+    int len, again = 1, set_irq_done = 0;
 
     do {
+        cmd = 0;
         len = read(d->pipe[0], &cmd, sizeof(cmd));
-    } while (len == sizeof(cmd));
-    switch (cmd) {
-    case QXL_SERVER_SET_IRQ:
-        qxl_set_irq(d);
-        break;
-    case QXL_SERVER_CREATE_UPDATE:
-        d->ssd.update = qemu_spice_create_update(&d->ssd);
-        len = write(d->pipe_out[1], &cmd, 1);
-        ASSERT(len == 1);
-        break;
-    default:
-        fprintf(stderr, "%s: unknown cmd %u\n", __FUNCTION__, cmd);
-        abort();
-    }
+        if ((len < 0) && (errno == EINTR)) {
+            continue;
+        }
+        switch (cmd) {
+        case QXL_SERVER_SET_IRQ:
+            if (set_irq_done == 0) {
+                 /* no need to do it more than once */
+                 set_irq_done = 1;
+                 qxl_set_irq(d);
+            }
+            break;
+        case QXL_SERVER_CREATE_UPDATE:
+            again = 0;
+            d->ssd.update = qemu_spice_create_update(&d->ssd);
+            len = write(d->pipe_out[1], &cmd, 1);
+            ASSERT(len == 1);
+            break;
+        default:
+            fprintf(stderr, "%s: unknown cmd %u\n", __FUNCTION__, cmd);
+            abort();
+        }
+    } while (again);
 }
 
 static void qxl_send_events(PCIQXLDevice *d, uint32_t events)
-- 
1.7.4.1