Ben Gardon fb10129335 KVM: x86/mmu: handle cmpxchg failure in kvm_tdp_mmu_get_root
To reduce dependence on the MMU write lock, don't rely on the assumption
that the atomic operation in kvm_tdp_mmu_get_root will always succeed.
By not relying on that assumption, threads do not need to hold the MMU
lock in write mode in order to take a reference on a TDP MMU root.

In the root iterator, this change means that some roots might have to be
skipped if they are found to have a zero refcount. This will still never
happen as of this patch, but a future patch will need that flexibility to
make the root iterator safe under the MMU read lock.

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210401233736.638171-8-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-19 09:05:25 -04:00
..
2021-02-27 08:29:02 -08:00
2021-03-14 13:33:33 -07:00
2021-02-28 12:06:45 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00
2021-02-27 08:29:02 -08:00