> -----Original Message----- > From: Halil Pasic [mailto:pasic@xxxxxxxxxxxxx] > Sent: Wednesday, September 27, 2023 12:42 AM > To: Gonglei (Arei) <arei.gonglei@xxxxxxxxxx> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>; linux-crypto@xxxxxxxxxxxxxxx; > Marc Hartmayer <mhartmay@xxxxxxxxxxxxx>; Michael S. Tsirkin > <mst@xxxxxxxxxx>; Jason Wang <jasowang@xxxxxxxxxx>; > virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > pizhenwei@xxxxxxxxxxxxx; Halil Pasic <pasic@xxxxxxxxxxxxx>; Cornelia Huck > <cohuck@xxxxxxxxxx> > Subject: Re: [PATCH] crypto: virtio-crypto: call finalize with bh disabled > > [..] > > --- a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c > > +++ b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c > > @@ -61,8 +61,9 @@ static void virtio_crypto_akcipher_finalize_req( > > vc_akcipher_req->src_buf = NULL; > > vc_akcipher_req->dst_buf = NULL; > > virtcrypto_clear_request(&vc_akcipher_req->base); > > - > > + local_bh_disable(); > > > > crypto_finalize_akcipher_request(vc_akcipher_req->base.dataq->engine, > > req, err); > > + local_bh_enable(); > > Thanks Gonglei! > > I did this a quick spin, and it does not seem to be sufficient on s390x. > Which does not come as a surprise to me, because > > #define lockdep_assert_in_softirq() > \ > do > { > \ > WARN_ON_ONCE(__lockdep_enabled && > \ > (!in_softirq() || in_irq() || in_nmi())); \ > } while (0) > > will still warn because in_irq() still evaluates to true (your patch addresses > the !in_softirq() part). > You are right. So I think the core of this question is: Can we call crypto_finalize_request() in the upper half of the interrupt? If so, maybe we should introduce a new function, such as lockdep_assert_in_interrupt(). #define lockdep_assert_in_interrupt() \ do { \ WARN_ON_ONCE(__lockdep_enabled && !in_interrupt()); \ } while (0) If not, why? Herbert, do you have any suggestions? Thanks. Regards, -Gonglei > I don't have any results on x86 yet. My current understanding is that the > virtio-pci transport code disables interrupts locally somewhere in the call chain > (actually in vp_vring_interrupt() via spin_lock_irqsave()) and then x86 would be > fine. But I will get that verified. > > On the other hand virtio_airq_handler() calls vring_interrupt() with interrupts > enabled. (While vring_interrupt() is called in a (read) critical section in > virtio_airq_handler() we use read_lock() and not read_lock_irqsave() to grab > the lock. Whether that is correct in it self (i.e. disregarding the crypto problem) > or not I'm not sure right now. Will think some more about it tomorrow.) If the > way to go forward is disabling interrupts in virtio-ccw before vring_interrupt() is > called, I would be glad to spin a patch for that. > > Copying Conny, as she may have an opinion on this (if I'm not wrong she > authored that code). > > Regards, > Halil
