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authorAvi Kivity <avi@qumranet.com>2007-08-05 10:16:11 +0300
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-08-06 17:54:41 -0700
commitbac27d35cbbf7c641efcc75b5330df8717d6db65 (patch)
tree2c4d7ec9c63c9bf8d1cd251b16da07f91c50c7da
parent9e865f58da5ff0a9c19669a49ac984117711757a (diff)
downloadop-kernel-dev-bac27d35cbbf7c641efcc75b5330df8717d6db65.zip
op-kernel-dev-bac27d35cbbf7c641efcc75b5330df8717d6db65.tar.gz
KVM: x86 emulator: fix debug reg mov instructions
More fallout from the writeback fixes: debug register transfer instructions do their own writeback and thus need to disable the general writeback mechanism. This fixes oopses and some guest failures on AMD machines (the Intel variant decodes the instruction in hardware and thus does not need emulation). Cc: Alistair John Strachan <alistair@devzero.co.uk> Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/kvm/x86_emulate.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 1f979cb..4b8a0cc 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1217,11 +1217,13 @@ twobyte_insn:
}
break;
case 0x21: /* mov from dr to reg */
+ no_wb = 1;
if (modrm_mod != 3)
goto cannot_emulate;
rc = emulator_get_dr(ctxt, modrm_reg, &_regs[modrm_rm]);
break;
case 0x23: /* mov from reg to dr */
+ no_wb = 1;
if (modrm_mod != 3)
goto cannot_emulate;
rc = emulator_set_dr(ctxt, modrm_reg, _regs[modrm_rm]);
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