diff options
author | Oliver Upton <oliver.upton@linux.dev> | 2023-03-27 19:47:47 +0300 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2023-03-29 16:08:31 +0300 |
commit | f00327731131d1b5aa6a1aa9f50bcf8d620ace4c (patch) | |
tree | 54a48d77f7e49b0e2d4635b664e8a8623cdc6604 /arch/arm64/kvm/vgic/vgic-v4.c | |
parent | 4bba7f7def6f278266dadf845da472cfbfed784e (diff) | |
download | linux-f00327731131d1b5aa6a1aa9f50bcf8d620ace4c.tar.xz |
KVM: arm64: Use config_lock to protect vgic state
Almost all of the vgic state is VM-scoped but accessed from the context
of a vCPU. These accesses were serialized on the kvm->lock which cannot
be nested within a vcpu->mutex critical section.
Move over the vgic state to using the config_lock. Tweak the lock
ordering where necessary to ensure that the config_lock is acquired
after the vcpu->mutex. Acquire the config_lock in kvm_vgic_create() to
avoid a race between the converted flows and GIC creation. Where
necessary, continue to acquire kvm->lock to avoid a race with vCPU
creation (i.e. flows that use lock_all_vcpus()).
Finally, promote the locking expectations in comments to lockdep
assertions and update the locking documentation for the config_lock as
well as vcpu->mutex.
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230327164747.2466958-5-oliver.upton@linux.dev
Diffstat (limited to 'arch/arm64/kvm/vgic/vgic-v4.c')
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-v4.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c index a413718be92b..3bb003478060 100644 --- a/arch/arm64/kvm/vgic/vgic-v4.c +++ b/arch/arm64/kvm/vgic/vgic-v4.c @@ -232,9 +232,8 @@ int vgic_v4_request_vpe_irq(struct kvm_vcpu *vcpu, int irq) * @kvm: Pointer to the VM being initialized * * We may be called each time a vITS is created, or when the - * vgic is initialized. This relies on kvm->lock to be - * held. In both cases, the number of vcpus should now be - * fixed. + * vgic is initialized. In both cases, the number of vcpus + * should now be fixed. */ int vgic_v4_init(struct kvm *kvm) { @@ -243,6 +242,8 @@ int vgic_v4_init(struct kvm *kvm) int nr_vcpus, ret; unsigned long i; + lockdep_assert_held(&kvm->arch.config_lock); + if (!kvm_vgic_global_state.has_gicv4) return 0; /* Nothing to see here... move along. */ @@ -309,14 +310,14 @@ int vgic_v4_init(struct kvm *kvm) /** * vgic_v4_teardown - Free the GICv4 data structures * @kvm: Pointer to the VM being destroyed - * - * Relies on kvm->lock to be held. */ void vgic_v4_teardown(struct kvm *kvm) { struct its_vm *its_vm = &kvm->arch.vgic.its_vm; int i; + lockdep_assert_held(&kvm->arch.config_lock); + if (!its_vm->vpes) return; |