From: "Michael S. Tsirkin" <mst@redhat.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: Christoph Hellwig <hch@lst.de>, Jason Wang <jasowang@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Jens Axboe <axboe@kernel.dk>,
virtualization@lists.linux-foundation.org,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org, jfehlig@suse.com,
jon.grimm@amd.com, brijesh.singh@amd.com, jroedel@suse.de
Subject: Re: [PATCH 2/5] swiotlb: Add is_swiotlb_active() function
Date: Mon, 28 Jan 2019 12:19:02 -0500 [thread overview]
Message-ID: <20190128121749-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20190124150000.GN32526@8bytes.org>
On Thu, Jan 24, 2019 at 04:00:00PM +0100, Joerg Roedel wrote:
> On Thu, Jan 24, 2019 at 09:41:07AM +0100, Christoph Hellwig wrote:
> > On Thu, Jan 24, 2019 at 09:29:23AM +0100, Joerg Roedel wrote:
> > > > As I've just introduced and fixed a bug in this area in the current
> > > > cycle - I don't think no_iotlb_memory is what your want (and maybe
> > > > not useful at all): if the arch valls swiotlb_exit after previously
> > > > initializing a buffer it won't be set. You probably want to check
> > > > for non-zero io_tlb_start and/or io_tlb_end.
> > >
> > > Okay, but that requires that I also set io_tlb_start and friends back to
> > > zero in the failure path of swiotlb_init(). Otherwise it could be left
> > > non-zero in case swiotlb_init_with_tbl() returns an error.
> >
> > Indeed, and we'll need to do that anyway as otherwise the dma mapping
> > path might cause problems similar to the one when swiotlb_exit is
> > called that I fixed.
>
> Turns out the the error path in swiotlb_init() is redundant because it
> will never be executed. If the function returns it will always return 0
> because in case of failure it will just panic (through memblock_alloc).
>
> I'll clean that up in a separate patch-set. There are more users of that
> function and all of them panic when the function fails.
>
>
> Joerg
OK so are you going to post a new version then? Time's running out for 5.0.
This isn't a regression so maybe we should just defer it all to 5.1.
--
MST
next prev parent reply other threads:[~2019-01-28 17:19 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 16:30 [PATCH 0/5 v3] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-01-23 16:30 ` [PATCH 1/5] swiotlb: Introduce swiotlb_max_mapping_size() Joerg Roedel
2019-01-23 21:28 ` Christoph Hellwig
2019-01-24 8:24 ` Joerg Roedel
2019-01-24 8:47 ` Christoph Hellwig
2019-01-23 16:30 ` [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Joerg Roedel
2019-01-23 21:27 ` Christoph Hellwig
2019-01-24 8:29 ` Joerg Roedel
2019-01-24 8:41 ` Christoph Hellwig
2019-01-24 15:00 ` Joerg Roedel
2019-01-28 17:19 ` Michael S. Tsirkin [this message]
2019-01-23 16:30 ` [PATCH 3/5] dma: Introduce dma_max_mapping_size() Joerg Roedel
2019-01-23 21:29 ` Christoph Hellwig
2019-01-23 16:30 ` [PATCH 4/5] virtio: Introduce virtio_max_dma_size() Joerg Roedel
2019-01-23 16:30 ` [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Joerg Roedel
2019-01-23 21:31 ` Christoph Hellwig
2019-01-23 22:25 ` Michael S. Tsirkin
2019-01-24 8:40 ` Joerg Roedel
2019-01-24 8:42 ` Christoph Hellwig
2019-01-24 9:51 ` Joerg Roedel
2019-01-28 8:05 ` Christoph Hellwig
2019-01-28 17:14 ` Michael S. Tsirkin
2019-01-29 7:38 ` Christoph Hellwig
2019-01-23 17:09 ` [PATCH 0/5 v3] Fix virtio-blk issue with SWIOTLB Konrad Rzeszutek Wilk
2019-01-23 18:51 ` Michael S. Tsirkin
2019-01-23 21:14 ` Konrad Rzeszutek Wilk
2019-01-28 15:20 ` Michael S. Tsirkin
2019-01-28 15:53 ` Konrad Rzeszutek Wilk
2019-01-29 8:43 [PATCH 0/5 v4] " Joerg Roedel
2019-01-29 8:43 ` [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Joerg Roedel
2019-01-29 17:12 ` Christoph Hellwig
2019-01-30 16:40 [PATCH 0/5 v5] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-01-30 16:40 ` [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Joerg Roedel
2019-01-31 16:33 [PATCH 0/5 v6] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-01-31 16:34 ` [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Joerg Roedel
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