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| author | Avi Kivity <avi.kivity@gmail.com> | 2013-02-09 11:31:44 +0200 |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2013-05-21 15:43:14 +0300 |
| commit | fb32b1eda29f2040148b0e172f9cbbd2f07697e4 (patch) | |
| tree | ce1844ae8998f70fa0bae623fd44cd793fdb28c1 /arch/x86 | |
| parent | f8b5ff2cff232df052955ef975f7219e1faa217f (diff) | |
| download | linux-fb32b1eda29f2040148b0e172f9cbbd2f07697e4.tar.gz linux-fb32b1eda29f2040148b0e172f9cbbd2f07697e4.tar.bz2 linux-fb32b1eda29f2040148b0e172f9cbbd2f07697e4.zip | |
KVM: x86 emulator: add support for writing back the source operand
Some instructions write back the source operand, not just the destination.
Add support for doing this via the decode flags.
Gleb: add BUG_ON() to prevent source to be memory operand.
Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 48 |
1 files changed, 27 insertions, 21 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 8db0010ed150..a4c266e99e50 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -155,6 +155,7 @@ #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 @@ -1723,45 +1724,42 @@ 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 */ @@ -4769,9 +4767,17 @@ 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) { + BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR); + rc = writeback(ctxt, &ctxt->src); + if (rc != X86EMUL_CONTINUE) + goto done; + } /* * restore dst type in case the decoding will be reused |