From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 13 May 2019 14:59:03 +0200 From: Cornelia Huck Subject: Re: [PATCH 07/10] s390/airq: use DMA memory for adapter interrupts Message-ID: <20190513145903.47446b4d.cohuck@redhat.com> In-Reply-To: <20190426183245.37939-8-pasic@linux.ibm.com> References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-8-pasic@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Halil Pasic Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, Martin Schwidefsky , Sebastian Ott , virtualization@lists.linux-foundation.org, "Michael S. Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman List-ID: On Fri, 26 Apr 2019 20:32:42 +0200 Halil Pasic wrote: > Protected virtualization guests have to use shared pages for airq > notifier bit vectors, because hypervisor needs to write these bits. > > Let us make sure we allocate DMA memory for the notifier bit vectors. [Looking at this first, before I can think about your update in patch 5.] > > Signed-off-by: Halil Pasic > --- > arch/s390/include/asm/airq.h | 2 ++ > drivers/s390/cio/airq.c | 18 ++++++++++++++---- > 2 files changed, 16 insertions(+), 4 deletions(-) (...) > diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c > index a45011e4529e..7a5c0a08ee09 100644 > --- a/drivers/s390/cio/airq.c > +++ b/drivers/s390/cio/airq.c > @@ -19,6 +19,7 @@ > > #include > #include > +#include > > #include "cio.h" > #include "cio_debug.h" > @@ -113,6 +114,11 @@ void __init init_airq_interrupts(void) > setup_irq(THIN_INTERRUPT, &airq_interrupt); > } > > +static inline unsigned long iv_size(unsigned long bits) > +{ > + return BITS_TO_LONGS(bits) * sizeof(unsigned long); > +} > + > /** > * airq_iv_create - create an interrupt vector > * @bits: number of bits in the interrupt vector > @@ -123,14 +129,15 @@ void __init init_airq_interrupts(void) > struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) > { > struct airq_iv *iv; > - unsigned long size; > + unsigned long size = 0; Why do you need to init this to 0? > > iv = kzalloc(sizeof(*iv), GFP_KERNEL); > if (!iv) > goto out; > iv->bits = bits; > - size = BITS_TO_LONGS(bits) * sizeof(unsigned long); > - iv->vector = kzalloc(size, GFP_KERNEL); > + size = iv_size(bits); > + iv->vector = dma_alloc_coherent(cio_get_dma_css_dev(), size, > + &iv->vector_dma, GFP_KERNEL); Indent is a bit off. But more importantly, I'm also a bit vary about ap and pci. IIRC, css support is mandatory, so that should not be a problem; and unless I remember incorrectly, ap only uses summary indicators. How does this interact with pci devices? I suppose any of their dma properties do not come into play with the interrupt code here? (Just want to be sure.) > if (!iv->vector) > goto out_free; > if (flags & AIRQ_IV_ALLOC) { > @@ -165,7 +172,8 @@ struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) > kfree(iv->ptr); > kfree(iv->bitlock); > kfree(iv->avail); > - kfree(iv->vector); > + dma_free_coherent(cio_get_dma_css_dev(), size, iv->vector, > + iv->vector_dma); > kfree(iv); > out: > return NULL; > @@ -182,6 +190,8 @@ void airq_iv_release(struct airq_iv *iv) > kfree(iv->ptr); > kfree(iv->bitlock); > kfree(iv->vector); > + dma_free_coherent(cio_get_dma_css_dev(), iv_size(iv->bits), > + iv->vector, iv->vector_dma); > kfree(iv->avail); > kfree(iv); > } From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: Re: [PATCH 07/10] s390/airq: use DMA memory for adapter interrupts Date: Mon, 13 May 2019 14:59:03 +0200 Message-ID: <20190513145903.47446b4d.cohuck@redhat.com> References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-8-pasic@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190426183245.37939-8-pasic@linux.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Halil Pasic Cc: Vasily Gorbik , linux-s390@vger.kernel.org, Thomas Huth , Claudio Imbrenda , kvm@vger.kernel.org, Sebastian Ott , "Michael S. Tsirkin" , Farhan Ali , Eric Farman , virtualization@lists.linux-foundation.org, Christoph Hellwig , Martin Schwidefsky , Viktor Mihajlovski , Janosch Frank List-Id: virtualization@lists.linuxfoundation.org On Fri, 26 Apr 2019 20:32:42 +0200 Halil Pasic wrote: > Protected virtualization guests have to use shared pages for airq > notifier bit vectors, because hypervisor needs to write these bits. > > Let us make sure we allocate DMA memory for the notifier bit vectors. [Looking at this first, before I can think about your update in patch 5.] > > Signed-off-by: Halil Pasic > --- > arch/s390/include/asm/airq.h | 2 ++ > drivers/s390/cio/airq.c | 18 ++++++++++++++---- > 2 files changed, 16 insertions(+), 4 deletions(-) (...) > diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c > index a45011e4529e..7a5c0a08ee09 100644 > --- a/drivers/s390/cio/airq.c > +++ b/drivers/s390/cio/airq.c > @@ -19,6 +19,7 @@ > > #include > #include > +#include > > #include "cio.h" > #include "cio_debug.h" > @@ -113,6 +114,11 @@ void __init init_airq_interrupts(void) > setup_irq(THIN_INTERRUPT, &airq_interrupt); > } > > +static inline unsigned long iv_size(unsigned long bits) > +{ > + return BITS_TO_LONGS(bits) * sizeof(unsigned long); > +} > + > /** > * airq_iv_create - create an interrupt vector > * @bits: number of bits in the interrupt vector > @@ -123,14 +129,15 @@ void __init init_airq_interrupts(void) > struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) > { > struct airq_iv *iv; > - unsigned long size; > + unsigned long size = 0; Why do you need to init this to 0? > > iv = kzalloc(sizeof(*iv), GFP_KERNEL); > if (!iv) > goto out; > iv->bits = bits; > - size = BITS_TO_LONGS(bits) * sizeof(unsigned long); > - iv->vector = kzalloc(size, GFP_KERNEL); > + size = iv_size(bits); > + iv->vector = dma_alloc_coherent(cio_get_dma_css_dev(), size, > + &iv->vector_dma, GFP_KERNEL); Indent is a bit off. But more importantly, I'm also a bit vary about ap and pci. IIRC, css support is mandatory, so that should not be a problem; and unless I remember incorrectly, ap only uses summary indicators. How does this interact with pci devices? I suppose any of their dma properties do not come into play with the interrupt code here? (Just want to be sure.) > if (!iv->vector) > goto out_free; > if (flags & AIRQ_IV_ALLOC) { > @@ -165,7 +172,8 @@ struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) > kfree(iv->ptr); > kfree(iv->bitlock); > kfree(iv->avail); > - kfree(iv->vector); > + dma_free_coherent(cio_get_dma_css_dev(), size, iv->vector, > + iv->vector_dma); > kfree(iv); > out: > return NULL; > @@ -182,6 +190,8 @@ void airq_iv_release(struct airq_iv *iv) > kfree(iv->ptr); > kfree(iv->bitlock); > kfree(iv->vector); > + dma_free_coherent(cio_get_dma_css_dev(), iv_size(iv->bits), > + iv->vector, iv->vector_dma); > kfree(iv->avail); > kfree(iv); > }