From: Sebastian Ott <sebott@linux.ibm.com>
To: Halil Pasic <pasic@linux.ibm.com>
Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org,
Cornelia Huck <cohuck@redhat.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
virtualization@lists.linux-foundation.org,
"Michael S. Tsirkin" <mst@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
Thomas Huth <thuth@redhat.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Viktor Mihajlovski <mihajlov@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Farhan Ali <alifm@linux.ibm.com>,
Eric Farman <farman@linux.ibm.com>
Subject: Re: [PATCH 06/10] s390/cio: add basic protected virtualization support
Date: Thu, 9 May 2019 10:52:45 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.21.1905091041130.1779@schleppi> (raw)
In-Reply-To: <20190508230809.6b0faaf7.pasic@linux.ibm.com>
On Wed, 8 May 2019, Halil Pasic wrote:
> On Wed, 8 May 2019 15:46:42 +0200 (CEST)
> Sebastian Ott <sebott@linux.ibm.com> wrote:
> > On Fri, 26 Apr 2019, Halil Pasic wrote:
> > > static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
> > > {
> > [..]
> > > + cdev->private = kzalloc(sizeof(struct ccw_device_private),
> > > + GFP_KERNEL | GFP_DMA);
> >
> > Do we still need GFP_DMA here (since we now have cdev->private->dma_area)?
> >
>
> We probably do not. I kept it GFP_DMA to keep changes to the
> minimum. Should changing this in your opinion be a part of this patch?
This can be changed on top.
> > > @@ -1062,6 +1082,14 @@ static int io_subchannel_probe(struct subchannel *sch)
> > > if (!io_priv)
> > > goto out_schedule;
> > >
> > > + io_priv->dma_area = dma_alloc_coherent(&sch->dev,
> > > + sizeof(*io_priv->dma_area),
> > > + &io_priv->dma_area_dma, GFP_KERNEL);
> >
> > This needs GFP_DMA.
>
> Christoph already answered this one. Thanks Christoph!
Yes, I'm still struggling to grasp the whole channel IO + DMA API +
protected virtualization thing..
>
> > You use a genpool for ccw_private->dma and not for iopriv->dma - looks
> > kinda inconsistent.
> >
>
> Please have a look at patch #9. A virtio-ccw device uses the genpool of
> it's ccw device (the pool from which ccw_private->dma is allicated) for
> the ccw stuff it needs to do. AFAICT for a subchannel device and its API
> all the DMA memory we need is iopriv->dma. So my thought was
> constructing a genpool for that would be an overkill.
>
> Are you comfortable with this answer, or should we change something?
Nope, I'm good with that one - ccw_private->dma has multiple users that
all fit into one page.
WARNING: multiple messages have this Message-ID (diff)
From: Sebastian Ott <sebott@linux.ibm.com>
To: Halil Pasic <pasic@linux.ibm.com>
Cc: Farhan Ali <alifm@linux.ibm.com>,
linux-s390@vger.kernel.org, Thomas Huth <thuth@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Eric Farman <farman@linux.ibm.com>,
virtualization@lists.linux-foundation.org,
Christoph Hellwig <hch@infradead.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Viktor Mihajlovski <mihajlov@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>
Subject: Re: [PATCH 06/10] s390/cio: add basic protected virtualization support
Date: Thu, 9 May 2019 10:52:45 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.21.1905091041130.1779@schleppi> (raw)
In-Reply-To: <20190508230809.6b0faaf7.pasic@linux.ibm.com>
On Wed, 8 May 2019, Halil Pasic wrote:
> On Wed, 8 May 2019 15:46:42 +0200 (CEST)
> Sebastian Ott <sebott@linux.ibm.com> wrote:
> > On Fri, 26 Apr 2019, Halil Pasic wrote:
> > > static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
> > > {
> > [..]
> > > + cdev->private = kzalloc(sizeof(struct ccw_device_private),
> > > + GFP_KERNEL | GFP_DMA);
> >
> > Do we still need GFP_DMA here (since we now have cdev->private->dma_area)?
> >
>
> We probably do not. I kept it GFP_DMA to keep changes to the
> minimum. Should changing this in your opinion be a part of this patch?
This can be changed on top.
> > > @@ -1062,6 +1082,14 @@ static int io_subchannel_probe(struct subchannel *sch)
> > > if (!io_priv)
> > > goto out_schedule;
> > >
> > > + io_priv->dma_area = dma_alloc_coherent(&sch->dev,
> > > + sizeof(*io_priv->dma_area),
> > > + &io_priv->dma_area_dma, GFP_KERNEL);
> >
> > This needs GFP_DMA.
>
> Christoph already answered this one. Thanks Christoph!
Yes, I'm still struggling to grasp the whole channel IO + DMA API +
protected virtualization thing..
>
> > You use a genpool for ccw_private->dma and not for iopriv->dma - looks
> > kinda inconsistent.
> >
>
> Please have a look at patch #9. A virtio-ccw device uses the genpool of
> it's ccw device (the pool from which ccw_private->dma is allicated) for
> the ccw stuff it needs to do. AFAICT for a subchannel device and its API
> all the DMA memory we need is iopriv->dma. So my thought was
> constructing a genpool for that would be an overkill.
>
> Are you comfortable with this answer, or should we change something?
Nope, I'm good with that one - ccw_private->dma has multiple users that
all fit into one page.
next prev parent reply other threads:[~2019-05-09 8:52 UTC|newest]
Thread overview: 182+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-26 18:32 [PATCH 00/10] s390: virtio: support protected virtualization Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-04-26 18:32 ` [PATCH 01/10] virtio/s390: use vring_create_virtqueue Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-03 9:17 ` Cornelia Huck
2019-05-03 20:04 ` Michael S. Tsirkin
2019-05-03 20:04 ` Michael S. Tsirkin
2019-05-04 14:03 ` Halil Pasic
2019-05-04 14:03 ` Halil Pasic
2019-05-05 11:15 ` Cornelia Huck
2019-05-05 11:15 ` Cornelia Huck
2019-05-07 13:58 ` Christian Borntraeger
2019-05-07 13:58 ` Christian Borntraeger
2019-05-08 20:12 ` Halil Pasic
2019-05-08 20:12 ` Halil Pasic
2019-05-10 14:07 ` Cornelia Huck
2019-05-10 14:07 ` Cornelia Huck
2019-05-12 16:47 ` Michael S. Tsirkin
2019-05-12 16:47 ` Michael S. Tsirkin
2019-05-13 9:52 ` Cornelia Huck
2019-05-13 9:52 ` Cornelia Huck
2019-05-13 12:27 ` Michael Mueller
2019-05-13 12:27 ` Michael Mueller
2019-05-13 12:29 ` Cornelia Huck
2019-05-13 12:29 ` Cornelia Huck
2019-04-26 18:32 ` [PATCH 02/10] virtio/s390: DMA support for virtio-ccw Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-03 9:31 ` Cornelia Huck
2019-04-26 18:32 ` [PATCH 03/10] virtio/s390: enable packed ring Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-03 9:44 ` Cornelia Huck
2019-05-05 15:13 ` Thomas Huth
2019-05-05 15:13 ` Thomas Huth
2019-04-26 18:32 ` [PATCH 04/10] s390/mm: force swiotlb for protected virtualization Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-04-26 19:27 ` Christoph Hellwig
2019-04-26 19:27 ` Christoph Hellwig
2019-04-29 13:59 ` Halil Pasic
2019-04-29 13:59 ` Halil Pasic
2019-04-29 14:05 ` Christian Borntraeger
2019-04-29 14:05 ` Christian Borntraeger
2019-05-13 12:50 ` Michael Mueller
2019-05-13 12:50 ` Michael Mueller
2019-05-08 13:15 ` Claudio Imbrenda
2019-05-08 13:15 ` Claudio Imbrenda
2019-05-09 22:34 ` Halil Pasic
2019-05-09 22:34 ` Halil Pasic
2019-05-15 14:15 ` Michael Mueller
2019-05-15 14:15 ` Michael Mueller
[not found] ` <ad23f5e7-dc78-04af-c892-47bbc65134c6@linux.ibm.com>
2019-05-09 18:05 ` Jason J. Herne
2019-05-09 18:05 ` Jason J. Herne
2019-05-09 18:05 ` Jason J. Herne
2019-05-10 7:49 ` Claudio Imbrenda
2019-05-10 7:49 ` Claudio Imbrenda
2019-04-26 18:32 ` [PATCH 05/10] s390/cio: introduce DMA pools to cio Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-08 13:18 ` Sebastian Ott
2019-05-08 13:18 ` Sebastian Ott
2019-05-08 21:22 ` Halil Pasic
2019-05-08 21:22 ` Halil Pasic
2019-05-09 8:40 ` Sebastian Ott
2019-05-09 8:40 ` Sebastian Ott
2019-05-09 10:11 ` Cornelia Huck
2019-05-09 10:11 ` Cornelia Huck
2019-05-09 22:11 ` Halil Pasic
2019-05-09 22:11 ` Halil Pasic
2019-05-10 14:10 ` Cornelia Huck
2019-05-10 14:10 ` Cornelia Huck
2019-05-12 18:22 ` Halil Pasic
2019-05-12 18:22 ` Halil Pasic
2019-05-13 13:29 ` Cornelia Huck
2019-05-13 13:29 ` Cornelia Huck
2019-05-15 17:12 ` Halil Pasic
2019-05-15 17:12 ` Halil Pasic
2019-05-16 6:13 ` Cornelia Huck
2019-05-16 6:13 ` Cornelia Huck
2019-05-16 13:59 ` Sebastian Ott
2019-05-16 13:59 ` Sebastian Ott
2019-05-20 12:13 ` Halil Pasic
2019-05-20 12:13 ` Halil Pasic
2019-05-21 8:46 ` Michael Mueller
2019-05-21 8:46 ` Michael Mueller
2019-05-22 12:07 ` Sebastian Ott
2019-05-22 12:07 ` Sebastian Ott
2019-05-22 22:12 ` Halil Pasic
2019-05-22 22:12 ` Halil Pasic
2019-05-23 15:17 ` Halil Pasic
2019-05-23 15:17 ` Halil Pasic
2019-04-26 18:32 ` [PATCH 06/10] s390/cio: add basic protected virtualization support Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-08 13:46 ` Sebastian Ott
2019-05-08 13:46 ` Sebastian Ott
2019-05-08 13:54 ` Christoph Hellwig
2019-05-08 13:54 ` Christoph Hellwig
2019-05-08 21:08 ` Halil Pasic
2019-05-08 21:08 ` Halil Pasic
2019-05-09 8:52 ` Sebastian Ott [this message]
2019-05-09 8:52 ` Sebastian Ott
2019-05-08 14:23 ` Pierre Morel
2019-05-08 14:23 ` Pierre Morel
2019-05-13 9:41 ` Cornelia Huck
2019-05-13 9:41 ` Cornelia Huck
2019-05-14 14:47 ` Jason J. Herne
2019-05-14 14:47 ` Jason J. Herne
2019-05-15 21:08 ` Halil Pasic
2019-05-15 21:08 ` Halil Pasic
2019-05-16 6:32 ` Cornelia Huck
2019-05-16 6:32 ` Cornelia Huck
2019-05-16 13:42 ` Halil Pasic
2019-05-16 13:42 ` Halil Pasic
2019-05-16 13:54 ` Cornelia Huck
2019-05-16 13:54 ` Cornelia Huck
2019-05-15 20:51 ` Halil Pasic
2019-05-15 20:51 ` Halil Pasic
2019-05-16 6:29 ` Cornelia Huck
2019-05-16 6:29 ` Cornelia Huck
2019-05-18 18:11 ` Halil Pasic
2019-05-18 18:11 ` Halil Pasic
2019-05-20 10:21 ` Cornelia Huck
2019-05-20 10:21 ` Cornelia Huck
2019-05-20 12:34 ` Halil Pasic
2019-05-20 12:34 ` Halil Pasic
2019-05-20 13:43 ` Cornelia Huck
2019-05-20 13:43 ` Cornelia Huck
2019-04-26 18:32 ` [PATCH 07/10] s390/airq: use DMA memory for adapter interrupts Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-08 13:58 ` Sebastian Ott
2019-05-08 13:58 ` Sebastian Ott
2019-05-09 11:37 ` Cornelia Huck
2019-05-09 11:37 ` Cornelia Huck
2019-05-13 12:59 ` Cornelia Huck
2019-05-13 12:59 ` Cornelia Huck
2019-04-26 18:32 ` [PATCH 08/10] virtio/s390: add indirection to indicators access Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-08 14:31 ` Pierre Morel
2019-05-08 14:31 ` Pierre Morel
2019-05-09 12:01 ` Pierre Morel
2019-05-09 12:01 ` Pierre Morel
2019-05-09 18:26 ` Halil Pasic
2019-05-09 18:26 ` Halil Pasic
2019-05-10 7:43 ` Pierre Morel
2019-05-10 7:43 ` Pierre Morel
2019-05-10 11:54 ` Halil Pasic
2019-05-10 11:54 ` Halil Pasic
2019-05-10 15:36 ` Pierre Morel
2019-05-10 15:36 ` Pierre Morel
2019-05-13 10:15 ` Cornelia Huck
2019-05-13 10:15 ` Cornelia Huck
2019-05-16 15:24 ` Pierre Morel
2019-05-16 15:24 ` Pierre Morel
2019-04-26 18:32 ` [PATCH 09/10] virtio/s390: use DMA memory for ccw I/O and classic notifiers Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-08 14:46 ` Pierre Morel
2019-05-08 14:46 ` Pierre Morel
2019-05-09 13:30 ` Pierre Morel
2019-05-09 13:30 ` Pierre Morel
2019-05-09 18:30 ` Halil Pasic
2019-05-09 18:30 ` Halil Pasic
2019-05-13 13:54 ` Cornelia Huck
2019-05-13 13:54 ` Cornelia Huck
2019-04-26 18:32 ` [PATCH 10/10] virtio/s390: make airq summary indicators DMA Halil Pasic
2019-04-26 18:32 ` Halil Pasic
2019-05-08 15:11 ` Pierre Morel
2019-05-08 15:11 ` Pierre Morel
2019-05-15 13:33 ` Michael Mueller
2019-05-15 13:33 ` Michael Mueller
2019-05-15 17:23 ` Halil Pasic
2019-05-15 17:23 ` Halil Pasic
2019-05-13 12:20 ` Cornelia Huck
2019-05-13 12:20 ` Cornelia Huck
2019-05-15 13:43 ` Michael Mueller
2019-05-15 13:43 ` Michael Mueller
2019-05-15 13:50 ` Cornelia Huck
2019-05-15 13:50 ` Cornelia Huck
2019-05-15 17:18 ` Halil Pasic
2019-05-15 17:18 ` Halil Pasic
2019-05-03 9:55 ` [PATCH 00/10] s390: virtio: support protected virtualization Cornelia Huck
2019-05-03 10:03 ` Juergen Gross
2019-05-03 13:33 ` Cornelia Huck
2019-05-03 13:33 ` Cornelia Huck
2019-05-04 13:58 ` Halil Pasic
2019-05-04 13:58 ` Halil Pasic
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