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Message-Id: <1198421495-31481-15-git-send-email-avi@qumranet.com>
Date: Sun, 23 Dec 2007 16:50:59 +0200
From: Avi Kivity <avi@...ranet.com>
To: linux-kernel@...r.kernel.org, kvm-devel@...ts.sourceforge.net
Cc: Laurent Vivier <Laurent.Vivier@...l.net>
Subject: [PATCH 14/50] KVM: x86 emulator: Remove no_wb, use dst.type = OP_NONE instead
From: Laurent Vivier <Laurent.Vivier@...l.net>
Remove no_wb, use dst.type = OP_NONE instead, idea stollen from xen-3.1
Signed-off-by: Laurent Vivier <Laurent.Vivier@...l.net>
Signed-off-by: Avi Kivity <avi@...ranet.com>
---
drivers/kvm/x86_emulate.c | 76 ++++++++++++++------------------------------
drivers/kvm/x86_emulate.h | 2 +-
2 files changed, 25 insertions(+), 53 deletions(-)
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 45beeb9..8b0186f 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1016,8 +1016,7 @@ done:
}
static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
- struct x86_emulate_ops *ops,
- int *no_wb)
+ struct x86_emulate_ops *ops)
{
struct decode_cache *c = &ctxt->decode;
int rc;
@@ -1055,7 +1054,7 @@ static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
c->dst.bytes, ctxt->vcpu);
if (rc != 0)
return rc;
- *no_wb = 1;
+ c->dst.type = OP_NONE;
break;
default:
DPRINTF("Cannot emulate %02x\n", c->b);
@@ -1137,6 +1136,10 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
ctxt->vcpu);
if (rc != 0)
return rc;
+ break;
+ case OP_NONE:
+ /* no writeback */
+ break;
default:
break;
}
@@ -1147,7 +1150,6 @@ int
x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
unsigned long cr2 = ctxt->cr2;
- int no_wb = 0;
u64 msr_data;
unsigned long saved_eip = 0;
struct decode_cache *c = &ctxt->decode;
@@ -1344,18 +1346,16 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
goto done;
break;
case 0xfe ... 0xff: /* Grp4/Grp5 */
- rc = emulate_grp45(ctxt, ops, &no_wb);
+ rc = emulate_grp45(ctxt, ops);
if (rc != 0)
goto done;
break;
}
writeback:
- if (!no_wb) {
- rc = writeback(ctxt, ops);
- if (rc != 0)
- goto done;
- }
+ rc = writeback(ctxt, ops);
+ if (rc != 0)
+ goto done;
/* Commit shadow register state. */
memcpy(ctxt->vcpu->regs, c->regs, sizeof c->regs);
@@ -1395,7 +1395,7 @@ special_insn:
register_address_increment(c->regs[VCPU_REGS_RSP],
c->op_bytes);
- no_wb = 1; /* Disable writeback. */
+ c->dst.type = OP_NONE; /* Disable writeback. */
break;
case 0x6a: /* push imm8 */
c->src.val = 0L;
@@ -1538,7 +1538,7 @@ special_insn:
case 0xe9: /* jmp rel */
case 0xeb: /* jmp rel short */
JMP_REL(c->src.val);
- no_wb = 1; /* Disable writeback. */
+ c->dst.type = OP_NONE; /* Disable writeback. */
break;
@@ -1548,8 +1548,6 @@ special_insn:
twobyte_insn:
switch (c->b) {
case 0x01: /* lgdt, lidt, lmsw */
- /* Disable writeback. */
- no_wb = 1;
switch (c->modrm_reg) {
u16 size;
unsigned long address;
@@ -1604,56 +1602,30 @@ twobyte_insn:
default:
goto cannot_emulate;
}
+ /* Disable writeback. */
+ c->dst.type = OP_NONE;
break;
case 0x21: /* mov from dr to reg */
- no_wb = 1;
if (c->modrm_mod != 3)
goto cannot_emulate;
rc = emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]);
+ if (rc)
+ goto cannot_emulate;
+ c->dst.type = OP_NONE; /* no writeback */
break;
case 0x23: /* mov from reg to dr */
- no_wb = 1;
if (c->modrm_mod != 3)
goto cannot_emulate;
rc = emulator_set_dr(ctxt, c->modrm_reg,
c->regs[c->modrm_rm]);
+ if (rc)
+ goto cannot_emulate;
+ c->dst.type = OP_NONE; /* no writeback */
break;
case 0x40 ... 0x4f: /* cmov */
c->dst.val = c->dst.orig_val = c->src.val;
- no_wb = 1;
- /*
- * First, assume we're decoding an even cmov opcode
- * (lsb == 0).
- */
- switch ((c->b & 15) >> 1) {
- case 0: /* cmovo */
- no_wb = (ctxt->eflags & EFLG_OF) ? 0 : 1;
- break;
- case 1: /* cmovb/cmovc/cmovnae */
- no_wb = (ctxt->eflags & EFLG_CF) ? 0 : 1;
- break;
- case 2: /* cmovz/cmove */
- no_wb = (ctxt->eflags & EFLG_ZF) ? 0 : 1;
- break;
- case 3: /* cmovbe/cmovna */
- no_wb = (ctxt->eflags & (EFLG_CF | EFLG_ZF)) ? 0 : 1;
- break;
- case 4: /* cmovs */
- no_wb = (ctxt->eflags & EFLG_SF) ? 0 : 1;
- break;
- case 5: /* cmovp/cmovpe */
- no_wb = (ctxt->eflags & EFLG_PF) ? 0 : 1;
- break;
- case 7: /* cmovle/cmovng */
- no_wb = (ctxt->eflags & EFLG_ZF) ? 0 : 1;
- /* fall through */
- case 6: /* cmovl/cmovnge */
- no_wb &= (!(ctxt->eflags & EFLG_SF) !=
- !(ctxt->eflags & EFLG_OF)) ? 0 : 1;
- break;
- }
- /* Odd cmov opcodes (lsb == 1) have inverted sense. */
- no_wb ^= c->b & 1;
+ if (!test_cc(c->b, ctxt->eflags))
+ c->dst.type = OP_NONE; /* no writeback */
break;
case 0xa3:
bt: /* bt */
@@ -1727,8 +1699,6 @@ twobyte_insn:
goto writeback;
twobyte_special_insn:
- /* Disable writeback. */
- no_wb = 1;
switch (c->b) {
case 0x06:
emulate_clts(ctxt->vcpu);
@@ -1802,6 +1772,8 @@ twobyte_special_insn:
goto done;
break;
}
+ /* Disable writeback. */
+ c->dst.type = OP_NONE;
goto writeback;
cannot_emulate:
diff --git a/drivers/kvm/x86_emulate.h b/drivers/kvm/x86_emulate.h
index 28acad4..f03b128 100644
--- a/drivers/kvm/x86_emulate.h
+++ b/drivers/kvm/x86_emulate.h
@@ -114,7 +114,7 @@ struct x86_emulate_ops {
/* Type, address-of, and value of an instruction's operand. */
struct operand {
- enum { OP_REG, OP_MEM, OP_IMM } type;
+ enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type;
unsigned int bytes;
unsigned long val, orig_val, *ptr;
};
--
1.5.3.7
--
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