| Message ID | 1360402311-19904-2-git-send-email-avi.kivity@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Feb 09, 2013 at 11:31:44AM +0200, Avi Kivity wrote: > Some instructions write back the source operand, not just the destination. > Add support for doing this via the decode flags. > We cannot really write back to memory operands. I feel it's deceiving to make the code look like we can. > Signed-off-by: Avi Kivity <avi.kivity@gmail.com> > --- > arch/x86/kvm/emulate.c | 47 ++++++++++++++++++++++++++--------------------- > 1 file changed, 26 insertions(+), 21 deletions(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index 2b11318..18c86b5 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -152,6 +152,7 @@ > #define Avx ((u64)1 << 43) /* Advanced Vector Extensions */ > #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ > #define NoWrite ((u64)1 << 45) /* No writeback */ > +#define SrcWrite ((u64)1 << 46) /* Write back src operand */ > > #define X2(x...) x, x > #define X3(x...) X2(x), x > @@ -1708,45 +1709,42 @@ static void write_register_operand(struct operand *op) > } > } > > -static int writeback(struct x86_emulate_ctxt *ctxt) > +static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op) > { > int rc; > > - if (ctxt->d & NoWrite) > - return X86EMUL_CONTINUE; > - > - switch (ctxt->dst.type) { > + switch (op->type) { > case OP_REG: > - write_register_operand(&ctxt->dst); > + write_register_operand(op); > break; > case OP_MEM: > if (ctxt->lock_prefix) > rc = segmented_cmpxchg(ctxt, > - ctxt->dst.addr.mem, > - &ctxt->dst.orig_val, > - &ctxt->dst.val, > - ctxt->dst.bytes); > + op->addr.mem, > + &op->orig_val, > + &op->val, > + op->bytes); > else > rc = segmented_write(ctxt, > - ctxt->dst.addr.mem, > - &ctxt->dst.val, > - ctxt->dst.bytes); > + op->addr.mem, > + &op->val, > + op->bytes); > if (rc != X86EMUL_CONTINUE) > return rc; > break; > case OP_MEM_STR: > rc = segmented_write(ctxt, > - ctxt->dst.addr.mem, > - ctxt->dst.data, > - ctxt->dst.bytes * ctxt->dst.count); > + op->addr.mem, > + op->data, > + op->bytes * op->count); > if (rc != X86EMUL_CONTINUE) > return rc; > break; > case OP_XMM: > - write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm); > + write_sse_reg(ctxt, &op->vec_val, op->addr.xmm); > break; > case OP_MM: > - write_mmx_reg(ctxt, &ctxt->dst.mm_val, ctxt->dst.addr.mm); > + write_mmx_reg(ctxt, &op->mm_val, op->addr.mm); > break; > case OP_NONE: > /* no writeback */ > @@ -4717,9 +4715,16 @@ special_insn: > goto done; > > writeback: > - rc = writeback(ctxt); > - if (rc != X86EMUL_CONTINUE) > - goto done; > + if (!(ctxt->d & NoWrite)) { > + rc = writeback(ctxt, &ctxt->dst); > + if (rc != X86EMUL_CONTINUE) > + goto done; > + } > + if (ctxt->d & SrcWrite) { > + rc = writeback(ctxt, &ctxt->src); > + if (rc != X86EMUL_CONTINUE) > + goto done; > + } > > /* > * restore dst type in case the decoding will be reused > -- > 1.8.1.2 -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 2b11318..18c86b5 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -152,6 +152,7 @@ #define Avx ((u64)1 << 43) /* Advanced Vector Extensions */ #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ #define NoWrite ((u64)1 << 45) /* No writeback */ +#define SrcWrite ((u64)1 << 46) /* Write back src operand */ #define X2(x...) x, x #define X3(x...) X2(x), x @@ -1708,45 +1709,42 @@ static void write_register_operand(struct operand *op) } } -static int writeback(struct x86_emulate_ctxt *ctxt) +static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op) { int rc; - if (ctxt->d & NoWrite) - return X86EMUL_CONTINUE; - - switch (ctxt->dst.type) { + switch (op->type) { case OP_REG: - write_register_operand(&ctxt->dst); + write_register_operand(op); break; case OP_MEM: if (ctxt->lock_prefix) rc = segmented_cmpxchg(ctxt, - ctxt->dst.addr.mem, - &ctxt->dst.orig_val, - &ctxt->dst.val, - ctxt->dst.bytes); + op->addr.mem, + &op->orig_val, + &op->val, + op->bytes); else rc = segmented_write(ctxt, - ctxt->dst.addr.mem, - &ctxt->dst.val, - ctxt->dst.bytes); + op->addr.mem, + &op->val, + op->bytes); if (rc != X86EMUL_CONTINUE) return rc; break; case OP_MEM_STR: rc = segmented_write(ctxt, - ctxt->dst.addr.mem, - ctxt->dst.data, - ctxt->dst.bytes * ctxt->dst.count); + op->addr.mem, + op->data, + op->bytes * op->count); if (rc != X86EMUL_CONTINUE) return rc; break; case OP_XMM: - write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm); + write_sse_reg(ctxt, &op->vec_val, op->addr.xmm); break; case OP_MM: - write_mmx_reg(ctxt, &ctxt->dst.mm_val, ctxt->dst.addr.mm); + write_mmx_reg(ctxt, &op->mm_val, op->addr.mm); break; case OP_NONE: /* no writeback */ @@ -4717,9 +4715,16 @@ special_insn: goto done; writeback: - rc = writeback(ctxt); - if (rc != X86EMUL_CONTINUE) - goto done; + if (!(ctxt->d & NoWrite)) { + rc = writeback(ctxt, &ctxt->dst); + if (rc != X86EMUL_CONTINUE) + goto done; + } + if (ctxt->d & SrcWrite) { + rc = writeback(ctxt, &ctxt->src); + if (rc != X86EMUL_CONTINUE) + goto done; + } /* * restore dst type in case the decoding will be reused
Some instructions write back the source operand, not just the destination. Add support for doing this via the decode flags. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> --- arch/x86/kvm/emulate.c | 47 ++++++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 21 deletions(-)