[PATCH 2/3] KVM: x86 emulator: add macros for executing instructions that may trap

From: Avi Kivity
Date: Tue Aug 24 2010 - 08:48:05 EST


Like DIV and IDIV.

Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 43 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 808934c..f82e43a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -331,6 +331,27 @@ struct group_dual {
"a" (_rax), "d" (_rdx)); \
} while (0)

+#define __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, _eflags, _suffix, _ex) \
+ do { \
+ unsigned long _tmp; \
+ \
+ __asm__ __volatile__ ( \
+ _PRE_EFLAGS("0", "5", "1") \
+ "1: \n\t" \
+ _op _suffix " %6; " \
+ "2: \n\t" \
+ _POST_EFLAGS("0", "5", "1") \
+ ".pushsection .fixup,\"ax\" \n\t" \
+ "3: movb $1, %4 \n\t" \
+ "jmp 2b \n\t" \
+ ".popsection \n\t" \
+ _ASM_EXTABLE(1b, 3b) \
+ : "=m" (_eflags), "=&r" (_tmp), \
+ "+a" (_rax), "+d" (_rdx), "+qm"(_ex) \
+ : "i" (EFLAGS_MASK), "m" ((_src).val), \
+ "a" (_rax), "d" (_rdx)); \
+ } while (0)
+
/* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */
#define emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags) \
do { \
@@ -342,6 +363,28 @@ struct group_dual {
} \
} while (0)

+#define emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, _eflags, _ex) \
+ do { \
+ switch((_src).bytes) { \
+ case 1: \
+ __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
+ _eflags, "b", _ex); \
+ break; \
+ case 2: \
+ __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
+ _eflags, "w", _ex); \
+ break; \
+ case 4: \
+ __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
+ _eflags, "l", _ex); \
+ break; \
+ case 8: ON64( \
+ __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
+ _eflags, "q", _ex)); \
+ break; \
+ } \
+ } while (0)
+
/* Fetch next part of the instruction being emulated. */
#define insn_fetch(_type, _size, _eip) \
({ unsigned long _x; \
--
1.7.1

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