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Commit 04b66839 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Marcelo Tosatti
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KVM: x86: correctly initialize the CS base on reset 



The CS base was initialized to 0 on VMX (wrong, but usually overridden
by userspace before starting) or 0xf0000 on SVM.  The correct value is
0xffff0000, and VMX is able to emulate it now, so use it.

Reviewed-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 4918c6ca

arch/x86/kvm/svm.c

+1 −7
Original line number Diff line number Diff line
@@ -1131,17 +1131,11 @@ static void init_vmcb(struct vcpu_svm *svm) 
	init_seg(&save->gs);



	save->cs.selector = 0xf000;

	save->cs.base = 0xffff0000;

	/* Executable/Readable Code Segment */

	save->cs.attrib = SVM_SELECTOR_READ_MASK | SVM_SELECTOR_P_MASK |

		SVM_SELECTOR_S_MASK | SVM_SELECTOR_CODE_MASK;

	save->cs.limit = 0xffff;

	/*

	 * cs.base should really be 0xffff0000, but vmx can't handle that, so

	 * be consistent with it.

	 *

	 * Replace when we have real mode working for vmx.

	 */

	save->cs.base = 0xf0000;



	save->gdtr.limit = 0xffff;

	save->idtr.limit = 0xffff;

arch/x86/kvm/vmx.c

+1 −0
Original line number Diff line number Diff line
@@ -4113,6 +4113,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu) 


	seg_setup(VCPU_SREG_CS);

	vmcs_write16(GUEST_CS_SELECTOR, 0xf000);

	vmcs_write32(GUEST_CS_BASE, 0xffff0000);



	seg_setup(VCPU_SREG_DS);

	seg_setup(VCPU_SREG_ES);