From: Avi Kivity <avi@qumranet.com>
To: kvm-devel@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, akpm@osdl.org
Subject: [PATCH] KVM: Fix mov to/from control register emulation, with r8-r15 as gpr
Date: Thu, 30 Nov 2006 10:56:38 -0000 [thread overview]
Message-ID: <20061130105638.7EADB25017B@cleopatra.q> (raw)
Use the standrd modrm decoder instead of special casing these instructions.
This fixes mov %rX, %crY with X >= 8 or Y >= 8.
The fix only applies to AMD SVM, as Intel vmx decodes the instruction for us.
It cures the FC5 installer crashing when loading the xor module.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Index: linux-2.6/drivers/kvm/x86_emulate.c
===================================================================
--- linux-2.6.orig/drivers/kvm/x86_emulate.c
+++ linux-2.6/drivers/kvm/x86_emulate.c
@@ -155,7 +155,8 @@ static u8 twobyte_table[256] = {
/* 0x10 - 0x1F */
0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0,
/* 0x20 - 0x2F */
- ImplicitOps, ModRM, ImplicitOps, ModRM, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
/* 0x30 - 0x3F */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 0x40 - 0x47 */
@@ -1295,17 +1296,14 @@ twobyte_special_insn:
emulate_clts(ctxt->vcpu);
break;
case 0x20: /* mov cr, reg */
- b = insn_fetch(u8, 1, _eip);
- if ((b & 0xc0) != 0xc0)
+ if (modrm_mod != 3)
goto cannot_emulate;
- _regs[b & 7] = realmode_get_cr(ctxt->vcpu, (b >> 3) & 7);
+ _regs[modrm_rm] = realmode_get_cr(ctxt->vcpu, modrm_reg);
break;
case 0x22: /* mov reg, cr */
- b = insn_fetch(u8, 1, _eip);
- if ((b & 0xc0) != 0xc0)
+ if (modrm_mod != 3)
goto cannot_emulate;
- realmode_set_cr(ctxt->vcpu, (b >> 3) & 7, _regs[b & 7] & -1u,
- &_eflags);
+ realmode_set_cr(ctxt->vcpu, modrm_reg, modrm_val, &_eflags);
break;
case 0xc7: /* Grp9 (cmpxchg8b) */
#if defined(__i386__)
reply other threads:[~2006-11-30 10:56 UTC|newest]
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