[patch 26/60] KVM: VMX: Reset mmu context when entering real mode

From: Greg KH
Date: Thu Dec 13 2007 - 02:06:57 EST



2.6.23-stable review patch. If anyone has any objections, please let us
know.

------------------
From: Eddie Dong <eddie.dong@xxxxxxxxx>

patch 8668a3c468ed55d19514117a5a959d91d3d03823 in mainline.

Resetting an SMP guest will force AP enter real mode (RESET) with
paging enabled in protected mode. While current enter_rmode() can
only handle mode switch from nonpaging mode to real mode which leads
to SMP reboot failure.

Fix by reloading the mmu context on entering real mode.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@xxxxxxxxx>
Signed-off-by: Qing He <qing.he@xxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/kvm/mmu.c | 1 +
drivers/kvm/vmx.c | 1 +
2 files changed, 2 insertions(+)

--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -1066,6 +1066,7 @@ int kvm_mmu_reset_context(struct kvm_vcp
destroy_kvm_mmu(vcpu);
return init_kvm_mmu(vcpu);
}
+EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);

int kvm_mmu_load(struct kvm_vcpu *vcpu)
{
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -957,6 +957,7 @@ static void enter_rmode(struct kvm_vcpu
fix_rmode_seg(VCPU_SREG_GS, &vcpu->rmode.gs);
fix_rmode_seg(VCPU_SREG_FS, &vcpu->rmode.fs);

+ kvm_mmu_reset_context(vcpu);
init_rmode_tss(vcpu->kvm);
}


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