From: Christoph Hellwig <hch@lst.de>
To: David Rientjes <rientjes@google.com>
Cc: Christoph Hellwig <hch@lst.de>,
"Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
"Singh, Brijesh" <brijesh.singh@amd.com>,
Ming Lei <ming.lei@redhat.com>, Peter Gonda <pgonda@google.com>,
Jianxiong Gao <jxgao@google.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Subject: Re: [bug] __blk_mq_run_hw_queue suspicious rcu usage
Date: Thu, 28 Nov 2019 07:40:56 +0100 [thread overview]
Message-ID: <20191128064056.GA19822@lst.de> (raw)
In-Reply-To: <alpine.DEB.2.21.1911271359000.135363@chino.kir.corp.google.com>
On Wed, Nov 27, 2019 at 02:11:28PM -0800, David Rientjes wrote:
> So we're left with making dma_pool_alloc(GFP_ATOMIC) actually be atomic
> even when the DMA needs to be unencrypted for SEV. Christoph's suggestion
> was to wire up dmapool in kernel/dma/remap.c for this. Is that necessary
> to be done for all devices that need to do dma_pool_alloc(GFP_ATOMIC) or
> can we do it within the DMA API itself so it's transparent to the driver?
It needs to be transparent to the driver. Lots of drivers use GFP_ATOMIC
dma allocations, and all of them are broken on SEV setups currently.
next prev parent reply other threads:[~2019-11-28 6:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 21:40 [bug] __blk_mq_run_hw_queue suspicious rcu usage David Rientjes
2019-09-05 6:06 ` Christoph Hellwig
2019-09-05 22:37 ` David Rientjes
2019-09-16 23:45 ` David Rientjes
2019-09-17 18:23 ` David Rientjes
2019-09-17 18:32 ` Jens Axboe
2019-09-17 18:41 ` Lendacky, Thomas
2019-09-18 13:22 ` Christoph Hellwig
2019-11-27 22:11 ` David Rientjes
2019-11-28 6:40 ` Christoph Hellwig [this message]
2019-12-13 0:07 ` David Rientjes
2019-12-13 9:33 ` David Rientjes
2019-12-15 5:38 ` David Rientjes
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