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Date: Thu, 09 May 2013 13:40:12 +0200 From: Paolo Bonzini <pbonzini@...hat.com> To: Gleb Natapov <gleb@...hat.com> CC: linux-kernel@...r.kernel.org, kvm@...r.kernel.org, j-nomura@...jp.nec.com, stable@...r.kernel.org.#.3.9 Subject: Re: [PATCH v2 2/3] KVM: emulator: emulate XLAT Il 09/05/2013 12:03, Gleb Natapov ha scritto: > On Thu, May 09, 2013 at 11:32:50AM +0200, Paolo Bonzini wrote: >> This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1. >> It is just a MOV in disguise, with a funny source address. >> >> Reported-by: Jun'ichi Nomura <j-nomura@...jp.nec.com> >> Cc: stable@...r.kernel.org # 3.9 >> Signed-off-by: Paolo Bonzini <pbonzini@...hat.com> >> --- >> arch/x86/kvm/emulate.c | 16 +++++++++++++++- >> 1 file changed, 15 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c >> index 709ba03..210bb4e 100644 >> --- a/arch/x86/kvm/emulate.c >> +++ b/arch/x86/kvm/emulate.c >> @@ -60,6 +60,7 @@ >> #define OpGS 25ull /* GS */ >> #define OpMem8 26ull /* 8-bit zero extended memory operand */ >> #define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */ >> +#define OpXLat 28ull /* memory at BX/EBX/RBX + zero-extended AL */ >> >> #define OpBits 5 /* Width of operand field */ >> #define OpMask ((1ull << OpBits) - 1) >> @@ -99,6 +100,7 @@ >> #define SrcImmUByte (OpImmUByte << SrcShift) >> #define SrcImmU (OpImmU << SrcShift) >> #define SrcSI (OpSI << SrcShift) >> +#define SrcXLat (OpXLat << SrcShift) >> #define SrcImmFAddr (OpImmFAddr << SrcShift) >> #define SrcMemFAddr (OpMemFAddr << SrcShift) >> #define SrcAcc (OpAcc << SrcShift) >> @@ -3949,7 +3951,8 @@ static const struct opcode opcode_table[256] = { >> G(Src2One | ByteOp, group2), G(Src2One, group2), >> G(Src2CL | ByteOp, group2), G(Src2CL, group2), >> I(DstAcc | SrcImmUByte | No64, em_aam), >> - I(DstAcc | SrcImmUByte | No64, em_aad), N, N, >> + I(DstAcc | SrcImmUByte | No64, em_aad), N, >> + I(DstAcc | SrcXLat | ByteOp, em_mov), >> /* 0xD8 - 0xDF */ >> N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, >> /* 0xE0 - 0xE7 */ >> @@ -4207,6 +4210,17 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, >> op->val = 0; >> op->count = 1; >> break; >> + case OpXLat: > Sigh, obviously this is not reusable by any other instruction. So many > waisted transistor :( And a precious op value too, we only have 3 left. :/ >> + op->type = OP_MEM; >> + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; >> + op->addr.mem.ea = >> + register_address(ctxt, >> + reg_read(ctxt, VCPU_REGS_RBX) + >> + (reg_read(ctxt, VCPU_REGS_RAX) & 0xff)); >> + op->addr.mem.seg = seg_override(ctxt); >> + op->val = 0; >> + op->count = 1; > The count is set only for decoding that is used by string instructions. > I can drop it while applying. Thanks! Paolo >> + break; >> case OpImmFAddr: >> op->type = OP_IMM; >> op->addr.mem.ea = ctxt->_eip; >> -- >> 1.8.1.4 >> > > -- > Gleb. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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