[Qemu-devel] [PATCH] Fix segfault with ram_size > 4095M without kvm

[Luiz Capitulino <lcapitulino@redhat.com>]

Currently, x86_64-softmmu qemu segfaults when trying to use > 4095M memsize.
This patch adds a simple check and error message (much like the 2047 limit on
32-bit hosts) on ram_size in the control path after we determine we're
not using kvm

Upstream qemu-kvm is affected if using the -no-kvm option; this patch address
the segfault there as well.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
NOTE: this patch was applied in the v0.12.x branch, but it seems it got
      lost for master

 vl.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/vl.c b/vl.c
index 2dbb6db..bb9c21c 100644
--- a/vl.c
+++ b/vl.c
@@ -5792,6 +5792,12 @@ int main(int argc, char **argv, char **envp)
             fprintf(stderr, "failed to initialize KVM\n");
             exit(1);
         }
+    } else {
+        /* without kvm enabled, we can only support 4095 MB RAM */
+        if (ram_size > (4095UL << 20)) {
+            fprintf(stderr, "qemu: without kvm support at most 4095 MB RAM can be simulated\n");
+            exit(1);
+        }
     }
 
     if (qemu_init_main_loop()) {
-- 
1.7.3.3.402.ga48aa