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| author | Oliver Upton <oliver.upton@linux.dev> | 2024-02-21 05:42:53 +0000 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2024-02-23 21:46:02 +0000 |
| commit | e27f2d561fee873d415697e6e5e3ec78efc9c259 (patch) | |
| tree | d5a5a60fa10c354122bc3469c48f9bdfec363d6a /arch/arm64 | |
| parent | 50ac89bb709275731217f74da8ccef8c99def319 (diff) | |
| download | linux-stable-e27f2d561fee873d415697e6e5e3ec78efc9c259.tar.gz linux-stable-e27f2d561fee873d415697e6e5e3ec78efc9c259.tar.bz2 linux-stable-e27f2d561fee873d415697e6e5e3ec78efc9c259.zip | |
KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq()
The LPI xarray's xa_lock is sufficient for synchronizing writers when
freeing a given LPI. Furthermore, readers can only take a new reference
on an IRQ if it was already nonzero.
Stop taking the lpi_list_lock unnecessarily and get rid of
__vgic_put_lpi_locked().
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-11-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic-its.c | 4 | ||||
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic.c | 28 | ||||
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic.h | 1 |
3 files changed, 11 insertions, 22 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index dad6f0ee7c49..f6025886071c 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -649,7 +649,7 @@ static void vgic_its_cache_translation(struct kvm *kvm, struct vgic_its *its, * was in the cache, and increment it on the new interrupt. */ if (cte->irq) - __vgic_put_lpi_locked(kvm, cte->irq); + vgic_put_irq(kvm, cte->irq); /* * The irq refcount is guaranteed to be nonzero while holding the @@ -686,7 +686,7 @@ void vgic_its_invalidate_cache(struct kvm *kvm) if (!cte->irq) break; - __vgic_put_lpi_locked(kvm, cte->irq); + vgic_put_irq(kvm, cte->irq); cte->irq = NULL; } diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index df9e1aa1956c..f963f410788a 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -111,22 +111,6 @@ static void vgic_irq_release(struct kref *ref) { } -/* - * Drop the refcount on the LPI. Must be called with lpi_list_lock held. - */ -void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq) -{ - struct vgic_dist *dist = &kvm->arch.vgic; - - if (!kref_put(&irq->refcount, vgic_irq_release)) - return; - - xa_erase(&dist->lpi_xa, irq->intid); - atomic_dec(&dist->lpi_count); - - kfree_rcu(irq, rcu); -} - void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) { struct vgic_dist *dist = &kvm->arch.vgic; @@ -135,9 +119,15 @@ void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) if (irq->intid < VGIC_MIN_LPI) return; - raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); - __vgic_put_lpi_locked(kvm, irq); - raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); + if (!kref_put(&irq->refcount, vgic_irq_release)) + return; + + xa_lock_irqsave(&dist->lpi_xa, flags); + __xa_erase(&dist->lpi_xa, irq->intid); + xa_unlock_irqrestore(&dist->lpi_xa, flags); + + atomic_dec(&dist->lpi_count); + kfree_rcu(irq, rcu); } void vgic_flush_pending_lpis(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index f874b9932c5a..0c2b82de8fa3 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -180,7 +180,6 @@ vgic_get_mmio_region(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev, gpa_t addr, int len); struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 intid); -void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq); void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq); bool vgic_get_phys_line_level(struct vgic_irq *irq); void vgic_irq_set_phys_pending(struct vgic_irq *irq, bool pending); |