On 06/10/21 15:30, Sasha Levin wrote:
From: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
[ Upstream commit 37687c403a641f251cb2ef2e7830b88aa0647ba9 ]
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@xxxxxxxxxx>
Message-Id: <20210913140954.165665-4-mlevitsk@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 b3f855d48f72..1e7d629bbf36 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7659,6 +7659,13 @@ 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);
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
