From: Andre Przywara <andre.przywara@amd.com>
Date: Fri, 18 Sep 2009 22:30:47 +0000 (+0200)
Subject: target-i386: add lock mov cr0 = cr8
X-Git-Tag: v0.12.0-rc0~963
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ccd59d09a9d0c75b86185b89d8246e40b5f01168;p=users%2Fdwmw2%2Fqemu.git

target-i386: add lock mov cr0 = cr8

AMD CPUs featuring a shortcut to access CR8 even from 32-bit mode.
If you use the LOCK prefix with "mov CR0", it accesses CR8 instead.
This behavior is guarded by the CR8_LEGACY CPUID bit
(Fn8000_0001:ECX[1]).

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---

diff --git a/target-i386/translate.c b/target-i386/translate.c
index 5b11d7f63e..0f62a97286 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -7351,6 +7351,10 @@ static target_ulong disas_insn(DisasContext *s, target_ulong pc_start)
                 ot = OT_QUAD;
             else
                 ot = OT_LONG;
+            if ((prefixes & PREFIX_LOCK) && (reg == 0) &&
+                (s->cpuid_ext3_features & CPUID_EXT3_CR8LEG)) {
+                reg = 8;
+            }
             switch(reg) {
             case 0:
             case 2: