From: John Garry <john.garry@huawei.com>
To: Xie Yongji <xieyongji@bytedance.com>, <mst@redhat.com>,
<jasowang@redhat.com>, <stefanha@redhat.com>,
<sgarzare@redhat.com>, <parav@nvidia.com>, <hch@infradead.org>,
<christian.brauner@canonical.com>, <rdunlap@infradead.org>,
<willy@infradead.org>, <viro@zeniv.linux.org.uk>,
<axboe@kernel.dk>, <bcrl@kvack.org>, <corbet@lwn.net>,
<mika.penttila@nextfour.com>, <dan.carpenter@oracle.com>,
<joro@8bytes.org>, <gregkh@linuxfoundation.org>,
<zhe.he@windriver.com>, <xiaodong.liu@intel.com>,
<joe@perches.com>, <robin.murphy@arm.com>
Cc: <kvm@vger.kernel.org>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<virtualization@lists.linux-foundation.org>,
<iommu@lists.linux-foundation.org>, <songmuchun@bytedance.com>,
<linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v11 10/12] vduse: Implement an MMU-based software IOTLB
Date: Fri, 27 Aug 2021 09:57:42 +0100 [thread overview]
Message-ID: <2d807de3-e245-c2fb-ae5d-7cacbe35dfcb@huawei.com> (raw)
In-Reply-To: <20210818120642.165-11-xieyongji@bytedance.com>
On 18/08/2021 13:06, Xie Yongji wrote:
> +
> +static dma_addr_t
> +vduse_domain_alloc_iova(struct iova_domain *iovad,
> + unsigned long size, unsigned long limit)
> +{
> + unsigned long shift = iova_shift(iovad);
> + unsigned long iova_len = iova_align(iovad, size) >> shift;
> + unsigned long iova_pfn;
> +
> + /*
> + * Freeing non-power-of-two-sized allocations back into the IOVA caches
> + * will come back to bite us badly, so we have to waste a bit of space
> + * rounding up anything cacheable to make sure that can't happen. The
> + * order of the unadjusted size will still match upon freeing.
> + */
> + if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
> + iova_len = roundup_pow_of_two(iova_len);
Whether it's proper to use this "fast" API or not here, this seems to be
copied verbatim from dma-iommu.c, which tells me that something should
be factored out.
Indeed, this rounding up seems a requirement of the rcache, so not sure
why this is not done there.
> + iova_pfn = alloc_iova_fast(iovad, iova_len, limit >> shift, true);
next prev parent reply other threads:[~2021-08-27 8:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-18 12:06 [PATCH v11 00/12] Introduce VDUSE - vDPA Device in Userspace Xie Yongji
2021-08-18 12:06 ` [PATCH v11 01/12] iova: Export alloc_iova_fast() and free_iova_fast() Xie Yongji
2021-08-23 6:24 ` Jason Wang
2021-08-24 18:08 ` Michael S. Tsirkin
2021-08-25 9:55 ` Will Deacon
2021-08-25 10:39 ` John Garry
2021-08-25 12:17 ` Yongji Xie
2021-08-27 9:03 ` John Garry
2021-08-18 12:06 ` [PATCH v11 02/12] file: Export receive_fd() to modules Xie Yongji
2021-08-18 12:06 ` [PATCH v11 03/12] vdpa: Fix some coding style issues Xie Yongji
2021-08-23 6:27 ` Jason Wang
2021-08-24 11:09 ` Stefano Garzarella
2021-08-18 12:06 ` [PATCH v11 04/12] vdpa: Add reset callback in vdpa_config_ops Xie Yongji
2021-08-23 6:31 ` Jason Wang
2021-08-23 7:44 ` Yongji Xie
2021-08-18 12:06 ` [PATCH v11 05/12] vhost-vdpa: Handle the failure of vdpa_reset() Xie Yongji
2021-08-23 6:32 ` Jason Wang
2021-08-24 11:12 ` Stefano Garzarella
2021-08-18 12:06 ` [PATCH v11 06/12] vhost-iotlb: Add an opaque pointer for vhost IOTLB Xie Yongji
2021-08-18 12:06 ` [PATCH v11 07/12] vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() Xie Yongji
2021-08-18 12:06 ` [PATCH v11 08/12] vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() Xie Yongji
2021-08-18 12:06 ` [PATCH v11 09/12] vdpa: Support transferring virtual addressing during DMA mapping Xie Yongji
2021-08-18 12:06 ` [PATCH v11 10/12] vduse: Implement an MMU-based software IOTLB Xie Yongji
2021-08-27 8:57 ` John Garry [this message]
2021-08-27 9:25 ` Yongji Xie
2021-08-18 12:06 ` [PATCH v11 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace Xie Yongji
2021-08-23 6:56 ` Jason Wang
2021-08-24 18:10 ` Michael S. Tsirkin
2021-08-25 5:37 ` Yongji Xie
2021-08-18 12:06 ` [PATCH v11 12/12] Documentation: Add documentation for VDUSE Xie Yongji
2021-08-23 6:57 ` Jason Wang
2021-08-23 7:54 ` Jason Wang
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