Searched hist:fb10129335ca6cc7a229226b03f54394757d773d (Results 1 – 2 of 2) sorted by relevance
| /linux/arch/x86/kvm/mmu/ |
| H A D | tdp_mmu.h | diff fb10129335ca6cc7a229226b03f54394757d773d Fri Apr 02 01:37:30 CEST 2021 Ben Gardon <bgardon@google.com> 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>
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| H A D | tdp_mmu.c | diff fb10129335ca6cc7a229226b03f54394757d773d Fri Apr 02 01:37:30 CEST 2021 Ben Gardon <bgardon@google.com> 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>
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