On Tue, Sep 1, 2009 at 2:57 PM, Marcelo Tosatti<mtosatti@xxxxxxxxxx> wrote: > 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 <m.gamal005@xxxxxxxxx> >> --- >> 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? Right. Perhaps this is a little too paranoid since we'll fail anyway -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html