[Qemu-devel] [patch] 64 bit truncation in code_gen_buffer_size calculation

[Qemu-devel] [patch] 64 bit truncation in code_gen_buffer_size calculation

[Jes Sorensen]

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Hi,

This one is pretty obvious, don't truncate the result of
code_gen_buffer_size calculation to int when the target is an unsigned
long. Gives funny results when trying to boot something with a lot of
memory on a 64 bit system.

Cheers,
Jes




[-- Attachment #2: 1199-code-gen-64bit.patch --]
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Don't truncate code_gen_buffer_size calculation to int, as it will give
unpredicted results on 64 bit systems when booting large guests.

Signed-off-by: Jes Sorensen <jes@sgi.com>

---
 exec.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: qemu/exec.c
===================================================================
--- qemu.orig/exec.c
+++ qemu/exec.c
@@ -410,7 +410,7 @@ static void code_gen_alloc(unsigned long
         code_gen_buffer_size = DEFAULT_CODE_GEN_BUFFER_SIZE;
 #else
         /* XXX: needs ajustments */
-        code_gen_buffer_size = (int)(phys_ram_size / 4);
+        code_gen_buffer_size = (unsigned long)(phys_ram_size / 4);
 #endif
     }
     if (code_gen_buffer_size < MIN_CODE_GEN_BUFFER_SIZE)

[Qemu-devel] Re: [patch] 64 bit truncation in code_gen_buffer_size calculation

[Anthony Liguori]

Jes Sorensen wrote:
> Hi,
>
> This one is pretty obvious, don't truncate the result of
> code_gen_buffer_size calculation to int when the target is an unsigned
> long. Gives funny results when trying to boot something with a lot of
> memory on a 64 bit system.

Applied.  Thanks.

Regards,

Anthony Liguori

> Cheers,
> Jes
>
>
>