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Commit 1f3141e8 authored by Gleb Natapov's avatar Gleb Natapov Committed by Marcelo Tosatti
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KVM: VMX: remove special CPL cache access during transition to real mode. 



Since vmx_get_cpl() always returns 0 when VCPU is in real mode it is no
longer needed. Also reset CPL cache to zero during transaction to
protected mode since transaction may happen while CS.selectors & 3 != 0,
but in reality CPL is 0.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 158de57f

arch/x86/kvm/vmx.c

+4 −8
Original line number Diff line number Diff line
@@ -2817,6 +2817,10 @@ static void enter_pmode(struct kvm_vcpu *vcpu) 
	fix_pmode_dataseg(vcpu, VCPU_SREG_DS, &vmx->rmode.segs[VCPU_SREG_DS]);

	fix_pmode_dataseg(vcpu, VCPU_SREG_FS, &vmx->rmode.segs[VCPU_SREG_FS]);

	fix_pmode_dataseg(vcpu, VCPU_SREG_GS, &vmx->rmode.segs[VCPU_SREG_GS]);



	/* CPL is always 0 when CPU enters protected mode */

	__set_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);

	vmx->cpl = 0;

}



static gva_t rmode_tss_base(struct kvm *kvm)
@@ -3229,14 +3233,6 @@ static int vmx_get_cpl(struct kvm_vcpu *vcpu) 
	    && (kvm_get_rflags(vcpu) & X86_EFLAGS_VM)) /* if virtual 8086 */

		return 3;



	/*

	 * If we enter real mode with cs.sel & 3 != 0, the normal CPL calculations

	 * fail; use the cache instead.

	 */

	if (unlikely(vmx->emulation_required && emulate_invalid_guest_state)) {

		return vmx->cpl;

	}



	if (!test_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail)) {

		__set_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);

		vmx->cpl = vmx_read_guest_seg_selector(vmx, VCPU_SREG_CS) & 3;