From: Maxim Levitsky mlevitsk@redhat.com
[ 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@redhat.com Message-Id: 20210913140954.165665-4-mlevitsk@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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);