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Date: Mon, 8 Dec 2008 13:36:41 +0200 From: Avi Kivity <avi@...hat.com> To: kvm@...r.kernel.org Cc: linux-kernel@...r.kernel.org, Amit Shah <amit.shah@...hat.com> Subject: [PATCH 30/45] KVM: SVM: Set the 'g' bit of the cs selector for cross-vendor migration From: Amit Shah <amit.shah@...hat.com> The hardware does not set the 'g' bit of the cs selector and this breaks migration from amd hosts to intel hosts. Set this bit if the segment limit is beyond 1 MB. Signed-off-by: Amit Shah <amit.shah@...hat.com> Signed-off-by: Avi Kivity <avi@...hat.com> --- arch/x86/kvm/svm.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 05efc4e..665008d 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -772,6 +772,15 @@ static void svm_get_segment(struct kvm_vcpu *vcpu, var->l = (s->attrib >> SVM_SELECTOR_L_SHIFT) & 1; var->db = (s->attrib >> SVM_SELECTOR_DB_SHIFT) & 1; var->g = (s->attrib >> SVM_SELECTOR_G_SHIFT) & 1; + + /* + * SVM always stores 0 for the 'G' bit in the CS selector in + * the VMCB on a VMEXIT. This hurts cross-vendor migration: + * Intel's VMENTRY has a check on the 'G' bit. + */ + if (seg == VCPU_SREG_CS) + var->g = s->limit > 0xfffff; + var->unusable = !var->present; } -- 1.6.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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