[Qemu-devel] [PATCH] target-i386: n270 can MOVBE

[Borislav Petkov]

From: Borislav Petkov <address@hidden>

The Atom core (cpu name "n270" in QEMU speak) supports MOVBE. This is
needed when booting 3.8 and later linux kernels built with the MATOM
target because we require MOVBE in order to boot properly now.

Cc: "H. Peter Anvin" <address@hidden>
Cc: Richard Henderson <address@hidden>
Signed-off-by: Borislav Petkov <address@hidden>
---

Right, so I was playing with booting MATOM kernels in QEMU.
As it turns out, QEMU's n270 model doesn't advertize MOVBE
although the real hardware supports it. Quick search pointed me to
http://lists.nongnu.org/archive/html/qemu-devel/2013-01/msg04317.html
which adds that support, among other things. I've merged Richard's
patchset with qemu's current master and after applying this patch below,
I can report success booting an MATOM kernel with QEMU. The same kernel
boots on the real n270 hardware, btw.

 target-i386/cpu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 9f38e4435e53..83816edd8410 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -610,7 +610,8 @@ static x86_def_t builtin_x86_defs[] = {
             CPUID_ACPI | CPUID_SS | CPUID_HT | CPUID_TM | CPUID_PBE,
             /* Some CPUs got no CPUID_SEP */
         .ext_features = CPUID_EXT_SSE3 | CPUID_EXT_MONITOR | CPUID_EXT_SSSE3 |
-            CPUID_EXT_DSCPL | CPUID_EXT_EST | CPUID_EXT_TM2 | CPUID_EXT_XTPR,
+            CPUID_EXT_DSCPL | CPUID_EXT_EST | CPUID_EXT_TM2 | CPUID_EXT_XTPR |
+           CPUID_EXT_MOVBE,
         .ext2_features = (PPRO_FEATURES & CPUID_EXT2_AMD_ALIASES) |
             CPUID_EXT2_NX,
         .ext3_features = CPUID_EXT3_LAHF_LM,
-- 
1.8.1.2.422.g08c0e7f