From: Sean Christopherson <seanjc@google.com> mainline inclusion from mainline-v6.17 commit add57f493e0893ac0fb4acbdc441918d3e800f10 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9782 CVE: NA Reference: https://github.com/kvm-x86/linux/commit/add57f493e08 -------------------------------- Explicitly track IRQ bypass producer:consumer bindings. This will allow making removal an O(1) operation; searching through the list to find information that is trivially tracked (and useful for debug) is wasteful. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20250516230734.2564775-5-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Qiqi Li <liqiqi23@huawei.com> --- include/linux/irqbypass.h | 7 +++++++ virt/lib/irqbypass.c | 9 +++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/irqbypass.h b/include/linux/irqbypass.h index 1b57d15ac4cf..b28197c87483 100644 --- a/include/linux/irqbypass.h +++ b/include/linux/irqbypass.h @@ -29,10 +29,13 @@ struct irq_bypass_consumer; * pairings are not supported. */ +struct irq_bypass_consumer; + /** * struct irq_bypass_producer - IRQ bypass producer definition * @node: IRQ bypass manager private list management * @eventfd: eventfd context used to match producers and consumers + * @consumer: The connected consumer (NULL if no connection) * @irq: Linux IRQ number for the producer device * @add_consumer: Connect the IRQ producer to an IRQ consumer (optional) * @del_consumer: Disconnect the IRQ producer from an IRQ consumer (optional) @@ -46,6 +49,7 @@ struct irq_bypass_consumer; struct irq_bypass_producer { struct list_head node; struct eventfd_ctx *eventfd; + struct irq_bypass_consumer *consumer; int irq; int (*add_consumer)(struct irq_bypass_producer *, struct irq_bypass_consumer *); @@ -59,6 +63,7 @@ struct irq_bypass_producer { * struct irq_bypass_consumer - IRQ bypass consumer definition * @node: IRQ bypass manager private list management * @eventfd: eventfd context used to match producers and consumers + * @producer: The connected producer (NULL if no connection) * @add_producer: Connect the IRQ consumer to an IRQ producer * @del_producer: Disconnect the IRQ consumer from an IRQ producer * @stop: Perform any quiesce operations necessary prior to add/del (optional) @@ -72,6 +77,8 @@ struct irq_bypass_producer { struct irq_bypass_consumer { struct list_head node; struct eventfd_ctx *eventfd; + struct irq_bypass_producer *producer; + int (*add_producer)(struct irq_bypass_consumer *, struct irq_bypass_producer *); void (*del_producer)(struct irq_bypass_consumer *, diff --git a/virt/lib/irqbypass.c b/virt/lib/irqbypass.c index e8d7c420db52..fdbf7ecc0c21 100644 --- a/virt/lib/irqbypass.c +++ b/virt/lib/irqbypass.c @@ -51,6 +51,10 @@ static int __connect(struct irq_bypass_producer *prod, if (prod->start) prod->start(prod); + if (!ret) { + prod->consumer = cons; + cons->producer = prod; + } return ret; } @@ -72,6 +76,9 @@ static void __disconnect(struct irq_bypass_producer *prod, cons->start(cons); if (prod->start) prod->start(prod); + + prod->consumer = NULL; + cons->producer = NULL; } /** @@ -145,6 +152,7 @@ void irq_bypass_unregister_producer(struct irq_bypass_producer *producer) list_for_each_entry(consumer, &consumers, node) { if (consumer->eventfd == producer->eventfd) { + WARN_ON_ONCE(producer->consumer != consumer); __disconnect(producer, consumer); break; } @@ -234,6 +242,7 @@ void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer) list_for_each_entry(producer, &producers, node) { if (producer->eventfd == consumer->eventfd) { + WARN_ON_ONCE(consumer->producer != producer); __disconnect(producer, consumer); break; } -- 2.43.0