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vmx realmode: Restructure code for clarity and better treatment of
VM_ENTRY_INTR_INFO. Also add more sanity checking. Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
This commit is contained in:
Keir Fraser committed
1 parent
826202abce
commit
3502a233e0
1 file changed
+111
-67
+111
-67
@@ -41,6 +41,8 @@ struct realmode_emulate_ctxt {
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uint8_t exn_vector;
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uint8_t exn_insn_len;
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uint32_t intr_shadow;
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};
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static void realmode_deliver_exception(
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@@ -502,13 +504,108 @@ static struct x86_emulate_ops realmode_emulator_ops = {
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.load_fpu_ctxt = realmode_load_fpu_ctxt
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};
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static void realmode_emulate_one(struct realmode_emulate_ctxt *rm_ctxt)
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{
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struct cpu_user_regs *regs = rm_ctxt->ctxt.regs;
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struct vcpu *curr = current;
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u32 new_intr_shadow;
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int rc, io_completed;
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rm_ctxt->insn_buf_eip = regs->eip;
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(void)hvm_copy_from_guest_phys(
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rm_ctxt->insn_buf,
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(uint32_t)(rm_ctxt->seg_reg[x86_seg_cs].base + regs->eip),
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sizeof(rm_ctxt->insn_buf));
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rm_ctxt->flag_word = 0;
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io_completed = curr->arch.hvm_vmx.real_mode_io_completed;
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if ( curr->arch.hvm_vmx.real_mode_io_in_progress )
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{
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gdprintk(XENLOG_ERR, "I/O in progress before insn is emulated.\n");
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goto fail;
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}
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rc = x86_emulate(&rm_ctxt->ctxt, &realmode_emulator_ops);
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if ( curr->arch.hvm_vmx.real_mode_io_completed )
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{
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gdprintk(XENLOG_ERR, "I/O completion after insn is emulated.\n");
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goto fail;
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}
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if ( io_completed && curr->arch.hvm_vmx.real_mode_io_in_progress )
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{
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gdprintk(XENLOG_ERR, "Multiple I/O transactions in a single insn.\n");
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goto fail;
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}
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if ( rc == X86EMUL_UNHANDLEABLE )
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{
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gdprintk(XENLOG_ERR, "Failed to emulate insn.\n");
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goto fail;
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}
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if ( rc == X86EMUL_RETRY )
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return;
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if ( curr->arch.hvm_vmx.real_mode_io_in_progress &&
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(get_ioreq(curr)->vp_ioreq.dir == IOREQ_READ) )
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{
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gdprintk(XENLOG_ERR, "I/O read in progress but insn is retired.\n");
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goto fail;
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}
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new_intr_shadow = rm_ctxt->intr_shadow;
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/* MOV-SS instruction toggles MOV-SS shadow, else we just clear it. */
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if ( rm_ctxt->flags.mov_ss )
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new_intr_shadow ^= VMX_INTR_SHADOW_MOV_SS;
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else
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new_intr_shadow &= ~VMX_INTR_SHADOW_MOV_SS;
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/* STI instruction toggles STI shadow, else we just clear it. */
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if ( rm_ctxt->flags.sti )
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new_intr_shadow ^= VMX_INTR_SHADOW_STI;
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else
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new_intr_shadow &= ~VMX_INTR_SHADOW_STI;
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/* Update interrupt shadow information in VMCS only if it changes. */
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if ( rm_ctxt->intr_shadow != new_intr_shadow )
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{
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rm_ctxt->intr_shadow = new_intr_shadow;
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__vmwrite(GUEST_INTERRUPTIBILITY_INFO, rm_ctxt->intr_shadow);
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}
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if ( rc == X86EMUL_EXCEPTION )
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{
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realmode_deliver_exception(
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rm_ctxt->exn_vector, rm_ctxt->exn_insn_len, rm_ctxt);
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}
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else if ( rm_ctxt->flags.hlt && !hvm_local_events_need_delivery(curr) )
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{
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hvm_hlt(regs->eflags);
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}
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return;
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fail:
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gdprintk(XENLOG_ERR,
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"Real-mode emulation failed @ %04x:%08lx: "
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"%02x %02x %02x %02x %02x %02x\n",
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rm_ctxt->seg_reg[x86_seg_cs].sel, rm_ctxt->insn_buf_eip,
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rm_ctxt->insn_buf[0], rm_ctxt->insn_buf[1],
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rm_ctxt->insn_buf[2], rm_ctxt->insn_buf[3],
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rm_ctxt->insn_buf[4], rm_ctxt->insn_buf[5]);
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domain_crash_synchronous();
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}
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void vmx_realmode(struct cpu_user_regs *regs)
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{
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struct vcpu *curr = current;
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struct realmode_emulate_ctxt rm_ctxt;
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unsigned long intr_info;
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int i, rc;
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u32 intr_shadow, new_intr_shadow;
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int i;
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rm_ctxt.ctxt.regs = regs;
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@@ -520,77 +617,24 @@ void vmx_realmode(struct cpu_user_regs *regs)
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rm_ctxt.ctxt.sp_size =
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rm_ctxt.seg_reg[x86_seg_ss].attr.fields.db ? 32 : 16;
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rm_ctxt.intr_shadow = __vmread(GUEST_INTERRUPTIBILITY_INFO);
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if ( curr->arch.hvm_vmx.real_mode_io_in_progress ||
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curr->arch.hvm_vmx.real_mode_io_completed )
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realmode_emulate_one(&rm_ctxt);
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intr_info = __vmread(VM_ENTRY_INTR_INFO);
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intr_shadow = __vmread(GUEST_INTERRUPTIBILITY_INFO);
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new_intr_shadow = intr_shadow;
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if ( intr_info & INTR_INFO_VALID_MASK )
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{
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realmode_deliver_exception((uint8_t)intr_info, 0, &rm_ctxt);
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__vmwrite(VM_ENTRY_INTR_INFO, 0);
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}
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while ( !(curr->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PE) &&
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!softirq_pending(smp_processor_id()) &&
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!hvm_local_events_need_delivery(curr) &&
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!curr->arch.hvm_vmx.real_mode_io_in_progress )
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{
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if ( (intr_info & INTR_INFO_VALID_MASK) &&
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!curr->arch.hvm_vmx.real_mode_io_completed )
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{
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realmode_deliver_exception((uint8_t)intr_info, 0, &rm_ctxt);
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__vmwrite(VM_ENTRY_INTR_INFO, 0);
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intr_info = 0;
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}
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rm_ctxt.insn_buf_eip = regs->eip;
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(void)hvm_copy_from_guest_phys(
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rm_ctxt.insn_buf,
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(uint32_t)(rm_ctxt.seg_reg[x86_seg_cs].base + regs->eip),
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sizeof(rm_ctxt.insn_buf));
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rm_ctxt.flag_word = 0;
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rc = x86_emulate(&rm_ctxt.ctxt, &realmode_emulator_ops);
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if ( rc == X86EMUL_RETRY )
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continue;
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if ( rc == X86EMUL_UNHANDLEABLE )
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{
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gdprintk(XENLOG_ERR,
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"Real-mode emulation failed @ %04x:%08lx: "
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"%02x %02x %02x %02x %02x %02x\n",
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rm_ctxt.seg_reg[x86_seg_cs].sel, rm_ctxt.insn_buf_eip,
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rm_ctxt.insn_buf[0], rm_ctxt.insn_buf[1],
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rm_ctxt.insn_buf[2], rm_ctxt.insn_buf[3],
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rm_ctxt.insn_buf[4], rm_ctxt.insn_buf[5]);
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domain_crash_synchronous();
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}
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/* MOV-SS instruction toggles MOV-SS shadow, else we just clear it. */
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if ( rm_ctxt.flags.mov_ss )
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new_intr_shadow ^= VMX_INTR_SHADOW_MOV_SS;
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else
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new_intr_shadow &= ~VMX_INTR_SHADOW_MOV_SS;
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/* STI instruction toggles STI shadow, else we just clear it. */
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if ( rm_ctxt.flags.sti )
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new_intr_shadow ^= VMX_INTR_SHADOW_STI;
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else
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new_intr_shadow &= ~VMX_INTR_SHADOW_STI;
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/* Update interrupt shadow information in VMCS only if it changes. */
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if ( intr_shadow != new_intr_shadow )
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{
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intr_shadow = new_intr_shadow;
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__vmwrite(GUEST_INTERRUPTIBILITY_INFO, intr_shadow);
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}
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if ( rc == X86EMUL_EXCEPTION )
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{
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realmode_deliver_exception(
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rm_ctxt.exn_vector, rm_ctxt.exn_insn_len, &rm_ctxt);
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}
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else if ( rm_ctxt.flags.hlt && !hvm_local_events_need_delivery(curr) )
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{
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hvm_hlt(regs->eflags);
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}
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}
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realmode_emulate_one(&rm_ctxt);
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/*
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* Cannot enter protected mode with bogus selector RPLs and DPLs. Hence we
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