diff options
| author | Marc Zyngier <maz@kernel.org> | 2025-09-17 17:30:32 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-09-17 17:30:32 +0100 |
| commit | 295593ab948f76a4e9c5f4579b07cab2a243396d (patch) | |
| tree | ee088a7096e0d663487c46dd54b68ff006c56919 /include | |
| parent | 3064cee8c3f78ac800111e60bd04ddf87e565cfc (diff) | |
| parent | 7d9a0273c45962e9a6bc06f3b87eef7c431c1853 (diff) | |
Merge branch kvm-arm64/mmio-rcu into kvmarm-master/next
* kvm-arm64/mmio-rcu:
: .
: Speed up MMIO registration by avoiding unnecessary RCU synchronisation,
: courtesy of Keir Fraser (20250909100007.3136249-1-keirf@google.com).
: .
KVM: Avoid synchronize_srcu() in kvm_io_bus_register_dev()
KVM: Implement barriers before accessing kvm->buses[] on SRCU read paths
KVM: arm64: vgic: Explicitly implement vgic_dist::ready ordering
KVM: arm64: vgic-init: Remove vgic_ready() macro
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/kvm/arm_vgic.h | 1 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 11 |
2 files changed, 8 insertions, 4 deletions
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 404883c7af6e..e7ffaf4bf2e7 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -406,7 +406,6 @@ u64 vgic_v3_get_misr(struct kvm_vcpu *vcpu); #define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel)) #define vgic_initialized(k) ((k)->arch.vgic.initialized) -#define vgic_ready(k) ((k)->arch.vgic.ready) #define vgic_valid_spi(k, i) (((i) >= VGIC_NR_PRIVATE_IRQS) && \ ((i) < (k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 15656b7fba6c..103be35caf0d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -206,6 +206,7 @@ struct kvm_io_range { struct kvm_io_bus { int dev_count; int ioeventfd_count; + struct rcu_head rcu; struct kvm_io_range range[]; }; @@ -966,11 +967,15 @@ static inline bool kvm_dirty_log_manual_protect_and_init_set(struct kvm *kvm) return !!(kvm->manual_dirty_log_protect & KVM_DIRTY_LOG_INITIALLY_SET); } +/* + * Get a bus reference under the update-side lock. No long-term SRCU reader + * references are permitted, to avoid stale reads vs concurrent IO + * registrations. + */ static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx) { - return srcu_dereference_check(kvm->buses[idx], &kvm->srcu, - lockdep_is_held(&kvm->slots_lock) || - !refcount_read(&kvm->users_count)); + return rcu_dereference_protected(kvm->buses[idx], + lockdep_is_held(&kvm->slots_lock)); } static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i) |