From 35d3d4a1dd2c1ffd6f2481f6d8ad6c358bb22f07 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 22 Nov 2010 17:53:25 +0200 Subject: [PATCH] KVM: x86 emulator: simplify exception generation Immediately after we generate an exception, we want a X86EMUL_PROPAGATE_FAULT constant, so return it from the generation functions. Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 140 ++++++++++++++++++------------------------------- 1 file changed, 50 insertions(+), 90 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 223c536b7f71..36534ecaf596 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -466,33 +466,33 @@ static ulong linear(struct x86_emulate_ctxt *ctxt, return la; } -static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, - u32 error, bool valid) +static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, + u32 error, bool valid) { ctxt->exception.vector = vec; ctxt->exception.error_code = error; ctxt->exception.error_code_valid = valid; + return X86EMUL_PROPAGATE_FAULT; } -static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err) +static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) { - emulate_exception(ctxt, GP_VECTOR, err, true); + return emulate_exception(ctxt, GP_VECTOR, err, true); } -static void emulate_ud(struct x86_emulate_ctxt *ctxt) +static int emulate_ud(struct x86_emulate_ctxt *ctxt) { - emulate_exception(ctxt, UD_VECTOR, 0, false); + return emulate_exception(ctxt, UD_VECTOR, 0, false); } -static void emulate_ts(struct x86_emulate_ctxt *ctxt, int err) +static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err) { - emulate_exception(ctxt, TS_VECTOR, err, true); + return emulate_exception(ctxt, TS_VECTOR, err, true); } static int emulate_de(struct x86_emulate_ctxt *ctxt) { - emulate_exception(ctxt, DE_VECTOR, 0, false); - return X86EMUL_PROPAGATE_FAULT; + return emulate_exception(ctxt, DE_VECTOR, 0, false); } static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt, @@ -898,10 +898,8 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, get_descriptor_table_ptr(ctxt, ops, selector, &dt); - if (dt.size < index * 8 + 7) { - emulate_gp(ctxt, selector & 0xfffc); - return X86EMUL_PROPAGATE_FAULT; - } + if (dt.size < index * 8 + 7) + return emulate_gp(ctxt, selector & 0xfffc); addr = dt.address + index * 8; ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu, &ctxt->exception); @@ -921,10 +919,8 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, get_descriptor_table_ptr(ctxt, ops, selector, &dt); - if (dt.size < index * 8 + 7) { - emulate_gp(ctxt, selector & 0xfffc); - return X86EMUL_PROPAGATE_FAULT; - } + if (dt.size < index * 8 + 7) + return emulate_gp(ctxt, selector & 0xfffc); addr = dt.address + index * 8; ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu, @@ -1165,10 +1161,8 @@ static int emulate_popf(struct x86_emulate_ctxt *ctxt, change_mask |= EFLG_IF; break; case X86EMUL_MODE_VM86: - if (iopl < 3) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (iopl < 3) + return emulate_gp(ctxt, 0); change_mask |= EFLG_IF; break; default: /* real mode */ @@ -1347,10 +1341,8 @@ static int emulate_iret_real(struct x86_emulate_ctxt *ctxt, if (rc != X86EMUL_CONTINUE) return rc; - if (temp_eip & ~0xffff) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (temp_eip & ~0xffff) + return emulate_gp(ctxt, 0); rc = emulate_pop(ctxt, ops, &cs, c->op_bytes); @@ -1601,10 +1593,8 @@ emulate_syscall(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) /* syscall is not available in real mode */ if (ctxt->mode == X86EMUL_MODE_REAL || - ctxt->mode == X86EMUL_MODE_VM86) { - emulate_ud(ctxt); - return X86EMUL_PROPAGATE_FAULT; - } + ctxt->mode == X86EMUL_MODE_VM86) + return emulate_ud(ctxt); setup_syscalls_segments(ctxt, ops, &cs, &ss); @@ -1655,34 +1645,26 @@ emulate_sysenter(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) u16 cs_sel, ss_sel; /* inject #GP if in real mode */ - if (ctxt->mode == X86EMUL_MODE_REAL) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (ctxt->mode == X86EMUL_MODE_REAL) + return emulate_gp(ctxt, 0); /* XXX sysenter/sysexit have not been tested in 64bit mode. * Therefore, we inject an #UD. */ - if (ctxt->mode == X86EMUL_MODE_PROT64) { - emulate_ud(ctxt); - return X86EMUL_PROPAGATE_FAULT; - } + if (ctxt->mode == X86EMUL_MODE_PROT64) + return emulate_ud(ctxt); setup_syscalls_segments(ctxt, ops, &cs, &ss); ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data); switch (ctxt->mode) { case X86EMUL_MODE_PROT32: - if ((msr_data & 0xfffc) == 0x0) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if ((msr_data & 0xfffc) == 0x0) + return emulate_gp(ctxt, 0); break; case X86EMUL_MODE_PROT64: - if (msr_data == 0x0) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (msr_data == 0x0) + return emulate_gp(ctxt, 0); break; } @@ -1722,10 +1704,8 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) /* inject #GP if in real mode or Virtual 8086 mode */ if (ctxt->mode == X86EMUL_MODE_REAL || - ctxt->mode == X86EMUL_MODE_VM86) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + ctxt->mode == X86EMUL_MODE_VM86) + return emulate_gp(ctxt, 0); setup_syscalls_segments(ctxt, ops, &cs, &ss); @@ -1740,18 +1720,14 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) switch (usermode) { case X86EMUL_MODE_PROT32: cs_sel = (u16)(msr_data + 16); - if ((msr_data & 0xfffc) == 0x0) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if ((msr_data & 0xfffc) == 0x0) + return emulate_gp(ctxt, 0); ss_sel = (u16)(msr_data + 24); break; case X86EMUL_MODE_PROT64: cs_sel = (u16)(msr_data + 32); - if (msr_data == 0x0) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (msr_data == 0x0) + return emulate_gp(ctxt, 0); ss_sel = cs_sel + 8; cs.d = 0; cs.l = 1; @@ -1982,10 +1958,8 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, struct decode_cache *c = &ctxt->decode; int ret; - if (ops->set_cr(3, tss->cr3, ctxt->vcpu)) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (ops->set_cr(3, tss->cr3, ctxt->vcpu)) + return emulate_gp(ctxt, 0); c->eip = tss->eip; ctxt->eflags = tss->eflags | 2; c->regs[VCPU_REGS_RAX] = tss->eax; @@ -2107,10 +2081,8 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, if (reason != TASK_SWITCH_IRET) { if ((tss_selector & 3) > next_tss_desc.dpl || - ops->cpl(ctxt->vcpu) > next_tss_desc.dpl) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + ops->cpl(ctxt->vcpu) > next_tss_desc.dpl) + return emulate_gp(ctxt, 0); } desc_limit = desc_limit_scaled(&next_tss_desc); @@ -2331,10 +2303,8 @@ static int em_rdtsc(struct x86_emulate_ctxt *ctxt) struct decode_cache *c = &ctxt->decode; u64 tsc = 0; - if (cpl > 0 && (ctxt->ops->get_cr(4, ctxt->vcpu) & X86_CR4_TSD)) { - emulate_gp(ctxt, 0); - return X86EMUL_PROPAGATE_FAULT; - } + if (cpl > 0 && (ctxt->ops->get_cr(4, ctxt->vcpu) & X86_CR4_TSD)) + return emulate_gp(ctxt, 0); ctxt->ops->get_msr(ctxt->vcpu, MSR_IA32_TSC, &tsc); c->regs[VCPU_REGS_RAX] = (u32)tsc; c->regs[VCPU_REGS_RDX] = tsc >> 32; @@ -2979,28 +2949,24 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) ctxt->decode.mem_read.pos = 0; if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_ud(ctxt); goto done; } /* LOCK prefix is allowed only with some instructions */ if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_ud(ctxt); goto done; } if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_ud(ctxt); goto done; } /* Privileged instruction can be executed only in CPL=0 */ if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) { - emulate_gp(ctxt, 0); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_gp(ctxt, 0); goto done; } @@ -3178,8 +3144,7 @@ special_insn: break; case 0x8c: /* mov r/m, sreg */ if (c->modrm_reg > VCPU_SREG_GS) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_ud(ctxt); goto done; } c->dst.val = ops->get_segment_selector(c->modrm_reg, ctxt->vcpu); @@ -3194,8 +3159,7 @@ special_insn: if (c->modrm_reg == VCPU_SREG_CS || c->modrm_reg > VCPU_SREG_GS) { - emulate_ud(ctxt); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_ud(ctxt); goto done; } @@ -3327,8 +3291,7 @@ special_insn: do_io_in: c->dst.bytes = min(c->dst.bytes, 4u); if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) { - emulate_gp(ctxt, 0); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_gp(ctxt, 0); goto done; } if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val, @@ -3342,8 +3305,7 @@ special_insn: c->src.bytes = min(c->src.bytes, 4u); if (!emulator_io_permited(ctxt, ops, c->dst.val, c->src.bytes)) { - emulate_gp(ctxt, 0); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_gp(ctxt, 0); goto done; } ops->pio_out_emulated(c->src.bytes, c->dst.val, @@ -3368,16 +3330,14 @@ special_insn: break; case 0xfa: /* cli */ if (emulator_bad_iopl(ctxt, ops)) { - emulate_gp(ctxt, 0); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_gp(ctxt, 0); goto done; } else ctxt->eflags &= ~X86_EFLAGS_IF; break; case 0xfb: /* sti */ if (emulator_bad_iopl(ctxt, ops)) { - emulate_gp(ctxt, 0); - rc = X86EMUL_PROPAGATE_FAULT; + rc = emulate_gp(ctxt, 0); goto done; } else { ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; -- 2.11.0