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Subject[PATCH v3 3/7] KVM: x86: reset pdptrs_from_userspace when exiting smm
Date
When exiting SMM, pdpts are loaded again from the guest memory.

This fixes a theoretical bug, when exit from SMM triggers entry to the
nested guest which re-uses some of the migration
code which uses this flag as a workaround for a legacy userspace.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/x86.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 86539c1686fa..3a61f19455cb 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7654,6 +7654,13 @@ static void kvm_smm_changed(struct kvm_vcpu *vcpu, bool entering_smm)

/* Process a latched INIT or SMI, if any. */
kvm_make_request(KVM_REQ_EVENT, vcpu);
+
+ /*
+ * Even if KVM_SET_SREGS2 loaded PDPTRs out of band,
+ * on SMM exit we still need to reload them from
+ * guest memory
+ */
+ vcpu->arch.pdptrs_from_userspace = false;
}

kvm_mmu_reset_context(vcpu);
--
2.26.3
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