On Tue, Sep 01, 2009 at 03:26:30AM +0200, Mohammed Gamal wrote: > This adds pusha and popa instructions (opcodes 0x60-0x61), this enables > booting > MINIX with invalid guest state emulation on. > > Signed-off-by: Mohammed Gamal <[email protected]> > --- > arch/x86/kvm/emulate.c | 52 > +++++++++++++++++++++++++++++++++++++++++++++++- > 1 files changed, 51 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index db0820d..9be2e6e 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -139,7 +139,8 @@ static u32 opcode_table[256] = { > DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, > DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, > /* 0x60 - 0x67 */ > - 0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ , > + ImplicitOps | Stack | No64, ImplicitOps | Stack | No64, > + 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ , > 0, 0, 0, 0, > /* 0x68 - 0x6F */ > SrcImm | Mov | Stack, 0, SrcImmByte | Mov | Stack, 0, > @@ -1225,6 +1226,47 @@ static int emulate_pop_sreg(struct x86_emulate_ctxt > *ctxt, > return rc; > } > > +static void emulate_pusha(struct x86_emulate_ctxt *ctxt) > +{ > + struct decode_cache *c = &ctxt->decode; > + unsigned long old_esp = c->regs[VCPU_REGS_RSP]; > + int reg = VCPU_REGS_RAX; > + > + while (reg <= VCPU_REGS_RDI) { > + (reg == VCPU_REGS_RSP) ? > + (c->src.val = old_esp) : (c->src.val = c->regs[reg]); > + > + emulate_push(ctxt); > + ++reg; > + } > +} > + > +static int emulate_popa(struct x86_emulate_ctxt *ctxt, > + struct x86_emulate_ops *ops) > +{ > + struct decode_cache *c = &ctxt->decode; > + unsigned long old_esp = c->regs[VCPU_REGS_RSP]; > + int rc = 0; > + int reg = VCPU_REGS_RDI; > + > + while (reg >= VCPU_REGS_RAX) { > + if (reg == VCPU_REGS_RSP) { > + register_address_increment(c, &c->regs[VCPU_REGS_RSP], > + c->op_bytes); > + --reg; > + } > + > + rc = emulate_pop(ctxt, ops, &c->regs[reg], c->op_bytes); > + if (rc != 0) { > + c->regs[VCPU_REGS_RSP] = old_esp;
Why is it necessary to restore the local VCPU_REGS_RSP copy on failure? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
