From 25022acc3dd5f0b54071c7ba7c371860f2971b52 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Mon, 27 Oct 2008 09:04:17 +0000 Subject: [PATCH] KVM: SVM: Set the 'g' bit of the cs selector for cross-vendor migration 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 Signed-off-by: Avi Kivity --- arch/x86/kvm/svm.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 05efc4ef75a6..665008d97856 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; } -- 2.20.1