From: Bjorn Helgaas <helgaas@kernel.org>
To: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: kevin.tian@intel.com, mst@redhat.com, linux-pci@vger.kernel.org,
jasowang@redhat.com, virtualization@lists.linux-foundation.org,
iommu@lists.linux-foundation.org, sebastien.boeuf@intel.com,
jacob.jun.pan@intel.com, robin.murphy@arm.com
Subject: Re: [PATCH v2 2/3] PCI: Add DMA configuration for virtual platforms
Date: Wed, 18 Mar 2020 16:10:02 -0500 [thread overview]
Message-ID: <20200318211002.GA237687@google.com> (raw)
In-Reply-To: <20200228172537.377327-3-jean-philippe@linaro.org>
On Fri, Feb 28, 2020 at 06:25:37PM +0100, Jean-Philippe Brucker wrote:
> Hardware platforms usually describe the IOMMU topology using either
> device-tree pointers or vendor-specific ACPI tables. For virtual
> platforms that don't provide a device-tree, the virtio-iommu device
> contains a description of the endpoints it manages. That information
> allows us to probe endpoints after the IOMMU is probed (possibly as late
> as userspace modprobe), provided it is discovered early enough.
>
> Add a hook to pci_dma_configure(), which returns -EPROBE_DEFER if the
> endpoint is managed by a vIOMMU that will be loaded later, or 0 in any
> other case to avoid disturbing the normal DMA configuration methods.
> When CONFIG_VIRTIO_IOMMU_TOPOLOGY isn't selected, the call to
> virt_dma_configure() is compiled out.
>
> As long as the information is consistent, platforms can provide both a
> device-tree and a built-in topology, and the IOMMU infrastructure is
> able to deal with multiple DMA configuration methods.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
> drivers/pci/pci-driver.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 0454ca0e4e3f..69303a814f21 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -18,6 +18,7 @@
> #include <linux/kexec.h>
> #include <linux/of_device.h>
> #include <linux/acpi.h>
> +#include <linux/virt_iommu.h>
> #include "pci.h"
> #include "pcie/portdrv.h"
>
> @@ -1602,6 +1603,10 @@ static int pci_dma_configure(struct device *dev)
> struct device *bridge;
> int ret = 0;
>
> + ret = virt_dma_configure(dev);
> + if (ret)
> + return ret;
> +
> bridge = pci_get_host_bridge_device(to_pci_dev(dev));
>
> if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
> --
> 2.25.0
>
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next prev parent reply other threads:[~2020-03-18 21:10 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-28 17:25 [PATCH v2 0/3] virtio-iommu on x86 and non-devicetree platforms Jean-Philippe Brucker
2020-02-28 17:25 ` [PATCH v2 1/3] iommu/virtio: Add topology description to virtio-iommu config space Jean-Philippe Brucker
2020-03-01 11:17 ` Michael S. Tsirkin
2020-03-02 16:16 ` Joerg Roedel
2020-03-03 10:19 ` Auger Eric
2020-03-03 13:01 ` Joerg Roedel
2020-03-03 14:00 ` Michael S. Tsirkin
2020-03-03 15:53 ` Joerg Roedel
2020-03-03 16:09 ` Michael S. Tsirkin
2020-03-03 16:21 ` Auger Eric
2020-03-04 13:37 ` Joerg Roedel
2020-03-04 15:38 ` Jean-Philippe Brucker
2020-03-04 17:40 ` Joerg Roedel
2020-03-04 21:37 ` Jacob Pan (Jun)
2020-03-04 21:54 ` Joerg Roedel
2020-03-05 15:42 ` Michael S. Tsirkin
2020-03-04 15:48 ` Jacob Pan
2020-03-04 17:34 ` Joerg Roedel
2020-03-04 19:34 ` Michael S. Tsirkin
2020-03-04 21:50 ` Joerg Roedel
2020-03-05 15:39 ` Michael S. Tsirkin
2020-03-03 14:02 ` Michael S. Tsirkin
2020-03-05 8:07 ` Tian, Kevin
2020-03-11 17:48 ` Jean-Philippe Brucker
2020-03-11 21:48 ` Michael S. Tsirkin
2020-04-13 13:22 ` Michael S. Tsirkin
2020-04-21 7:31 ` Tian, Kevin
2020-08-21 8:39 ` Jean-Philippe Brucker
2020-02-28 17:25 ` [PATCH v2 2/3] PCI: Add DMA configuration for virtual platforms Jean-Philippe Brucker
2020-03-18 21:10 ` Bjorn Helgaas [this message]
2020-02-28 17:25 ` [PATCH v2 3/3] iommu/virtio: Enable x86 support Jean-Philippe Brucker
2020-02-29 14:23 ` kbuild test robot
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