diff options
author | Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net> | 2007-11-26 13:49:09 +0100 |
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committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 17:53:15 +0200 |
commit | d7e5117a2568f7407e98ca85155511ecfe4f0631 (patch) | |
tree | 7f9bcd5b42d4ef8f40b396ac3c979399a41dcfab /drivers | |
parent | e8d8d7fe8877c594c08f40cc7c013626cfe3e9cc (diff) |
KVM: x86 emulator: cmps instruction
Add emulation for the cmps instruction. This lets OpenBSD boot on kvm.
Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/kvm/x86_emulate.c | 58 |
1 files changed, 56 insertions, 2 deletions
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c index 22fdf0ac6615..84e536603f5a 100644 --- a/drivers/kvm/x86_emulate.c +++ b/drivers/kvm/x86_emulate.c @@ -1535,10 +1535,31 @@ special_insn: break; } if (c->rep_prefix) { + /* All REP prefixes have the same first termination condition */ if (c->regs[VCPU_REGS_RCX] == 0) { ctxt->vcpu->rip = c->eip; goto done; } + /* The second termination condition only applies for REPE + * and REPNE. Test if the repeat string operation prefix is + * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the + * corresponding termination condition according to: + * - if REPE/REPZ and ZF = 0 then done + * - if REPNE/REPNZ and ZF = 1 then done + */ + if ((c->b == 0xa6) || (c->b == 0xa7) || + (c->b == 0xae) || (c->b == 0xaf)) { + if ((c->rep_prefix == REPE_PREFIX) && + ((ctxt->eflags & EFLG_ZF) == 0)) { + ctxt->vcpu->rip = c->eip; + goto done; + } + if ((c->rep_prefix == REPNE_PREFIX) && + ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) { + ctxt->vcpu->rip = c->eip; + goto done; + } + } c->regs[VCPU_REGS_RCX]--; c->eip = ctxt->vcpu->rip; } @@ -1564,8 +1585,41 @@ special_insn: : c->dst.bytes); break; case 0xa6 ... 0xa7: /* cmps */ - DPRINTF("Urk! I don't handle CMPS.\n"); - goto cannot_emulate; + c->src.type = OP_NONE; /* Disable writeback. */ + c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->src.ptr = (unsigned long *)register_address( + c->override_base ? *c->override_base : + ctxt->ds_base, + c->regs[VCPU_REGS_RSI]); + if ((rc = ops->read_emulated((unsigned long)c->src.ptr, + &c->src.val, + c->src.bytes, + ctxt->vcpu)) != 0) + goto done; + + c->dst.type = OP_NONE; /* Disable writeback. */ + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.ptr = (unsigned long *)register_address( + ctxt->es_base, + c->regs[VCPU_REGS_RDI]); + if ((rc = ops->read_emulated((unsigned long)c->dst.ptr, + &c->dst.val, + c->dst.bytes, + ctxt->vcpu)) != 0) + goto done; + + DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr); + + emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); + + register_address_increment(c->regs[VCPU_REGS_RSI], + (ctxt->eflags & EFLG_DF) ? -c->src.bytes + : c->src.bytes); + register_address_increment(c->regs[VCPU_REGS_RDI], + (ctxt->eflags & EFLG_DF) ? -c->dst.bytes + : c->dst.bytes); + + break; case 0xaa ... 0xab: /* stos */ c->dst.type = OP_MEM; c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; |