From 04b66839d312d3bdaff77f265eb7305347fa1fb7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 19 Mar 2013 16:30:26 +0100 Subject: [PATCH] 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: Gleb Natapov Signed-off-by: Paolo Bonzini Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/svm.c | 8 +------- arch/x86/kvm/vmx.c | 1 + 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 7219a40..7a46c1f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -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; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ad978a6..03f5746 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -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); -- 2.7.4