KVM: nSVM: use svm->nested.save to load vmcb12 registers and avoid TOC/TOU races

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Use the already checked svm->nested.save cached fields
(EFER, CR0, CR4, ...) instead of vmcb12's in
nested_vmcb02_prepare_save().
This prevents from creating TOC/TOU races, since the
guest could modify the vmcb12 fields.

This also avoids the need of force-setting EFER_SVME in
nested_vmcb02_prepare_save.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20211103140527.752797-6-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Emanuele Giuseppe Esposito 2021-11-03 10:05:25 -04:00 • committed by Paolo Bonzini

parent b7a3d8b6f4

commit 355d0473b1

1 changed files with 6 additions and 18 deletions

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arch/x86/kvm/svm/nested.c

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