Ping for this one.

On 30. Dec 2024, at 16:08, Tomas Krcka krckatom@amazon.de wrote:

The following call-chain leads to misuse of spinlock_irq when spinlock_irqsave was hold.

irq_set_vcpu_affinity -> irq_get_desc_lock (spinlock_irqsave) -> its_irq_set_vcpu_affinity -> guard(raw_spin_lock_irq) <--- this enables interrupts -> irq_put_desc_unlock // <--- WARN IRQs enabled

Fix the issue by using guard(raw_spinlock), since the function is already called with irqsave and raw_spin_lock was used before the commit b97e8a2f7130 ("irqchip/gic-v3-its: Fix potential race condition in its_vlpi_prop_update()") introducing the guard as well.

This was discovered through the lock debugging, and the corresponding log is as follows:

raw_local_irq_restore() called with IRQs enabled WARNING: CPU: 38 PID: 444 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x2c/0x38 Call trace: warn_bogus_irq_restore+0x2c/0x38 _raw_spin_unlock_irqrestore+0x68/0x88 __irq_put_desc_unlock+0x1c/0x48 irq_set_vcpu_affinity+0x74/0xc0 its_map_vlpi+0x44/0x88 kvm_vgic_v4_set_forwarding+0x148/0x230 kvm_arch_irq_bypass_add_producer+0x20/0x28 __connect+0x98/0xb8 irq_bypass_register_consumer+0x150/0x178 kvm_irqfd+0x6dc/0x744 kvm_vm_ioctl+0xe44/0x16b0

Fixes: b97e8a2f7130 ("irqchip/gic-v3-its: Fix potential race condition in its_vlpi_prop_update()") Signed-off-by: Tomas Krcka krckatom@amazon.de Reviewed-by: Marc Zyngier maz@kernel.org Cc: stable@vger.kernel.org

---

drivers/irqchip/irq-gic-v3-its.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 92244cfa0464..8c3ec5734f1e 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -2045,7 +2045,7 @@ static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info) if (!is_v4(its_dev->its)) return -EINVAL;

• guard(raw_spinlock_irq)(&its_dev->event_map.vlpi_lock);

• guard(raw_spinlock)(&its_dev->event_map.vlpi_lock);

/* Unmap request? */ if (!info) -- 2.40.1