RISC-V: KVM: Use flexible array for APLIC IRQ state

Store the per-source APLIC IRQ state in the APLIC allocation instead
of allocating it separately.

This ties the IRQ state lifetime directly to the APLIC state, removes a
separate allocation failure path, and lets __counted_by() describe the
array bounds.

Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260511032144.361520-1-rosenp@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/kvm/aia_aplic.c b/arch/riscv/kvm/aia_aplic.c
index 3464f3351df72db225108e0d745ed74574298acd..748107c347d915e4940e2c9a4f25b5b7c99378a6 100644 (file)
--- a/arch/riscv/kvm/aia_aplic.c
+++ b/arch/riscv/kvm/aia_aplic.c
@@ -35,7 +35,7 @@ struct aplic {
 
        u32 nr_irqs;
        u32 nr_words;
-       struct aplic_irq *irqs;
+       struct aplic_irq irqs[] __counted_by(nr_irqs);
 };
 
 static u32 aplic_read_sourcecfg(struct aplic *aplic, u32 irq)
@@ -581,7 +581,7 @@ int kvm_riscv_aia_aplic_init(struct kvm *kvm)
                return 0;
 
        /* Allocate APLIC global state */
-       aplic = kzalloc_obj(*aplic);
+       aplic = kzalloc_flex(*aplic, irqs, kvm->arch.aia.nr_sources + 1);
        if (!aplic)
                return -ENOMEM;
        kvm->arch.aia.aplic_state = aplic;
@@ -589,11 +589,6 @@ int kvm_riscv_aia_aplic_init(struct kvm *kvm)
        /* Setup APLIC IRQs */
        aplic->nr_irqs = kvm->arch.aia.nr_sources + 1;
        aplic->nr_words = DIV_ROUND_UP(aplic->nr_irqs, 32);
-       aplic->irqs = kzalloc_objs(*aplic->irqs, aplic->nr_irqs);
-       if (!aplic->irqs) {
-               ret = -ENOMEM;
-               goto fail_free_aplic;
-       }
        for (i = 0; i < aplic->nr_irqs; i++)
                raw_spin_lock_init(&aplic->irqs[i].lock);
 
@@ -606,7 +601,7 @@ int kvm_riscv_aia_aplic_init(struct kvm *kvm)
                                      &aplic->iodev);
        mutex_unlock(&kvm->slots_lock);
        if (ret)
-               goto fail_free_aplic_irqs;
+               goto fail_free_aplic;
 
        /* Setup default IRQ routing */
        ret = kvm_riscv_setup_default_irq_routing(kvm, aplic->nr_irqs);
@@ -619,8 +614,6 @@ fail_unreg_iodev:
        mutex_lock(&kvm->slots_lock);
        kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &aplic->iodev);
        mutex_unlock(&kvm->slots_lock);
-fail_free_aplic_irqs:
-       kfree(aplic->irqs);
 fail_free_aplic:
        kvm->arch.aia.aplic_state = NULL;
        kfree(aplic);
@@ -638,8 +631,6 @@ void kvm_riscv_aia_aplic_cleanup(struct kvm *kvm)
        kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &aplic->iodev);
        mutex_unlock(&kvm->slots_lock);
 
-       kfree(aplic->irqs);
-
        kvm->arch.aia.aplic_state = NULL;
        kfree(aplic);
 }