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KVM: x86: reset pdptrs_from_userspace when exiting smm

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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>
This commit is contained in:
Maxim Levitsky 2021-09-13 17:09:50 +03:00 committed by Paolo Bonzini
parent e2e6e449d6
commit 37687c403a
1 changed files with 7 additions and 0 deletions

7
arch/x86/kvm/x86.c
View File

@ -7658,6 +7658,13 @@ 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);