From: Srivatsa Vaddagiri <vatsa@codeaurora.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: tsoni@codeaurora.org, virtio-dev@lists.oasis-open.org,
konrad.wilk@oracle.com, jan.kiszka@siemens.com,
jasowang@redhat.com, christoffer.dall@arm.com,
virtualization@lists.linux-foundation.org,
alex.bennee@linaro.org, iommu@lists.linux-foundation.org,
stefano.stabellini@xilinx.com, will@kernel.org,
linux-kernel@vger.kernel.org, pratikp@codeaurora.org
Subject: Re: [PATCH 5/5] virtio: Add bounce DMA ops
Date: Wed, 29 Apr 2020 09:05:39 +0530 [thread overview]
Message-ID: <20200429033539.GB5097@quicinc.com> (raw)
In-Reply-To: <20200428163448-mutt-send-email-mst@kernel.org>
* Michael S. Tsirkin <mst@redhat.com> [2020-04-28 16:41:04]:
> > Won't we still need some changes to virtio to make use of its own pool (to
> > bounce buffers)? Something similar to its own DMA ops proposed in this patch?
>
> If you are doing this for all devices, you need to either find a way
> to do this without chaning DMA ops, or by doing some automatic change
> to all drivers.
Ok thanks for this input. I will see how we can obfuscate this in DMA APIs
itself.
Can you also comment on the virtio transport problem I cited? The hypervisor we
are dealing with does not support MMIO transport. It supports message queue
send/recv and also doorbell, which I think can be used if we can make some
change like this to virtio_mmio.c:
+static inline u32
+virtio_readl(struct virtio_mmio_device *vm_dev, u32 reg_offset)
+{
+ return vm_dev->mmio_ops->readl(vm_dev, reg_offset);
+}
+
+static inline void
+virtio_writel(struct virtio_mmio_device *vm_dev, u32 reg_offset, u32 data)
+{
+ vm_dev->mmio_ops->writel(vm_dev, reg_offset, data);
+}
/* Check magic value */
- magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
+ magic = vrito_readl(vm_dev, VIRTIO_MMIO_MAGIC_VALUE);
mmio_ops->readl on most platforms can default to readl itself, while on a
platform like us, it can boil down to message_queue send/recv. Would such a
change be acceptable?
--
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of Code Aurora Forum, hosted by The Linux Foundation
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next prev parent reply other threads:[~2020-04-29 3:35 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 11:39 [PATCH 0/5] virtio on Type-1 hypervisor Srivatsa Vaddagiri
2020-04-28 11:39 ` [PATCH 1/5] swiotlb: Introduce concept of swiotlb_pool Srivatsa Vaddagiri
2020-04-29 0:31 ` kbuild test robot
2020-04-28 11:39 ` [PATCH 2/5] swiotlb: Allow for non-linear mapping between paddr and vaddr Srivatsa Vaddagiri
2020-04-28 11:39 ` [PATCH 3/5] swiotlb: Add alloc and free APIs Srivatsa Vaddagiri
2020-04-30 4:18 ` kbuild test robot
2020-04-28 11:39 ` [PATCH 4/5] swiotlb: Add API to register new pool Srivatsa Vaddagiri
2020-04-28 11:39 ` [PATCH 5/5] virtio: Add bounce DMA ops Srivatsa Vaddagiri
2020-04-28 16:17 ` Michael S. Tsirkin
2020-04-28 17:49 ` Srivatsa Vaddagiri
2020-04-28 20:41 ` Michael S. Tsirkin
2020-04-28 23:04 ` Stefano Stabellini
2020-04-29 4:09 ` Srivatsa Vaddagiri
2020-04-29 2:22 ` Lu Baolu
2020-04-29 4:57 ` Michael S. Tsirkin
2020-04-29 5:42 ` Lu Baolu
2020-04-29 6:50 ` Michael S. Tsirkin
2020-04-29 7:01 ` Lu Baolu
2020-04-29 9:44 ` Srivatsa Vaddagiri
2020-04-29 9:52 ` Michael S. Tsirkin
2020-04-29 10:09 ` Srivatsa Vaddagiri
2020-04-29 10:20 ` Michael S. Tsirkin
2020-04-29 10:26 ` Jan Kiszka
2020-04-29 10:45 ` Michael S. Tsirkin
2020-04-29 10:55 ` [virtio-dev] " Jan Kiszka
2020-04-29 10:34 ` Srivatsa Vaddagiri
2020-04-30 15:20 ` Konrad Rzeszutek Wilk
2020-04-29 3:35 ` Srivatsa Vaddagiri [this message]
2020-04-28 21:35 ` kbuild test robot
2020-04-28 22:18 ` kbuild test robot
2020-04-28 22:53 ` Stefano Stabellini
2020-04-29 21:06 ` kbuild test robot
2020-04-29 21:06 ` [RFC PATCH] virtio: virtio_pool can be static kbuild test robot
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