Re: [Qemu-devel] [PATCH 1/1] kvm_physical_sync_dirty_bitmap: ignore ENOENT from kvm_vm_ioctl

["Serge E. Hallyn" <serge@hallyn.com>]

D'oh, sorry.  I generated that patch against my qemu tree at the bad_commit^.
That won't apply to the tree...  this should.

>From 0d818e334f6db88b2770e9a1076ae1e68c41e460 Mon Sep 17 00:00:00 2001
From: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Tue, 8 Apr 2014 22:14:20 -0500
Subject: [PATCH 1/1] kvm_physical_sync_dirty_bitmap: ignore ENOENT from
 kvm_vm_ioctl

ENOENT (iiuc) means the kernel has an empty dirty bitmap for this
slot.  Don't abort in that case.  This appears to solve the bug
reported at

https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1303926

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
---
 kvm-all.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Index: qemu-2.0.0~rc1+dfsg/kvm-all.c
===================================================================
--- qemu-2.0.0~rc1+dfsg.orig/kvm-all.c	2014-04-08 22:28:38.000722081 -0500
+++ qemu-2.0.0~rc1+dfsg/kvm-all.c	2014-04-08 22:29:14.644722904 -0500
@@ -441,10 +441,13 @@ static int kvm_physical_sync_dirty_bitma
 
         d.slot = mem->slot;
 
-        if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) < 0) {
+        ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d);
+        if (ret < 0 && ret != -ENOENT) {
             DPRINTF("ioctl failed %d\n", errno);
             ret = -1;
             break;
+        } else if (ret < 0) {
+            ret = 0;
         }
 
         kvm_get_dirty_pages_log_range(section, d.dirty_bitmap);