> -----Original Message----- > From: Michael S. Tsirkin [mailto:mst@xxxxxxxxxx] > Sent: Wednesday, September 27, 2023 1:14 AM > To: Halil Pasic <pasic@xxxxxxxxxxxxx> > Cc: Gonglei (Arei) <arei.gonglei@xxxxxxxxxx>; Herbert Xu > <herbert@xxxxxxxxxxxxxxxxxxx>; linux-crypto@xxxxxxxxxxxxxxx; Marc > Hartmayer <mhartmay@xxxxxxxxxxxxx>; Jason Wang > <jasowang@xxxxxxxxxx>; virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; pizhenwei@xxxxxxxxxxxxx; Cornelia Huck > <cohuck@xxxxxxxxxx> > Subject: Re: [PATCH] crypto: virtio-crypto: call finalize with bh disabled > > On Tue, Sep 26, 2023 at 06:41:58PM +0200, Halil Pasic wrote: > > [..] > > > --- 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). > > > > 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 > > On a related note, config change callback is also handled incorrectly in this > driver, it takes a mutex from interrupt context. Good catch. Will fix it. Thanks. -Gonglei
