vfio: platform: probe to devices on the platform bus

Driver to bind to Linux platform devices, and callbacks to discover their
resources to be used by the main VFIO PLATFORM code.

Signed-off-by: Antonios Motakis <redacted>
---
 drivers/vfio/platform/vfio_platform.c | 96 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/vfio.h             |  1 +
 2 files changed, 97 insertions(+)
 create mode 100644 drivers/vfio/platform/vfio_platform.c

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
new file mode 100644
index 0000000..024c026
--- /dev/null
+++ b/drivers/vfio/platform/vfio_platform.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/irq.h>
+
+#include "vfio_platform_private.h"
+
+#define DRIVER_VERSION  "0.7"
+#define DRIVER_AUTHOR   "Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>"
+#define DRIVER_DESC     "VFIO for platform devices - User Level meta-driver"
+
+/* probing devices from the linux platform bus */
+
+static struct resource *get_platform_resource(struct vfio_platform_device *vdev,
+						int i)
+{
+	struct platform_device *pdev = (struct platform_device *) vdev->opaque;
+
+	return platform_get_resource(pdev, IORESOURCE_MEM, i);
+}
+
+static int get_platform_irq(struct vfio_platform_device *vdev, int i)
+{
+	struct platform_device *pdev = (struct platform_device *) vdev->opaque;
+
+	return platform_get_irq(pdev, i);
+}
+
+
+static int vfio_platform_probe(struct platform_device *pdev)
+{
+	struct vfio_platform_device *vdev;
+	int ret;
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+
+	vdev->opaque = (void *) pdev;
+	vdev->name = pdev->name;
+	vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
+	vdev->get_resource = get_platform_resource;
+	vdev->get_irq = get_platform_irq;
+
+	ret = vfio_platform_probe_common(vdev, &pdev->dev);
+	if (ret)
+		kfree(vdev);
+
+	return ret;
+}
+
+static int vfio_platform_remove(struct platform_device *pdev)
+{
+	return vfio_platform_remove_common(&pdev->dev);
+}
+
+static struct platform_driver vfio_platform_driver = {
+	.probe		= vfio_platform_probe,
+	.remove		= vfio_platform_remove,
+	.driver	= {
+		.name	= "vfio-platform",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(vfio_platform_driver);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 30f630c..b022a25 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h

@@ -158,6 +158,7 @@ struct vfio_device_info {
 	__u32	flags;
 #define VFIO_DEVICE_FLAGS_RESET	(1 << 0)	/* Device supports reset */
 #define VFIO_DEVICE_FLAGS_PCI	(1 << 1)	/* vfio-pci device */
+#define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2)	/* vfio-platform device */
 	__u32	num_regions;	/* Max region index + 1 */
 	__u32	num_irqs;	/* Max IRQ index + 1 */
 };

-- 
1.8.3.2

On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote:

20 more quoted lines

ARM may only support IORESOURCE_MEM, but I don't think platform devices
are limited to MMIO, right?  vfio-platform shouldn't be either.

24 more quoted lines

On Wed, Sep 24, 2014 at 1:01 AM, Alex Williamson
[off-list ref] wrote:

On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote:

quoted

Driver to bind to Linux platform devices, and callbacks to discover their
resources to be used by the main VFIO PLATFORM code.

Signed-off-by: Antonios Motakis <redacted>
---
 drivers/vfio/platform/vfio_platform.c | 96 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/vfio.h             |  1 +
 2 files changed, 97 insertions(+)
 create mode 100644 drivers/vfio/platform/vfio_platform.c

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
new file mode 100644
index 0000000..024c026
--- /dev/null
+++ b/drivers/vfio/platform/vfio_platform.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/pm_runtime.h>

26 more quoted lines

Indeed. Should we however implement this lacking a target to verify it
is working correctly?

Leaving it out would mean PIO resources for those devices would not be
exposed before an update to VFIO, but we wouldn't have to break
backward compatibility I think.

Would you prefer to have it implemented regardless?

quoted

+}
+
+static int get_platform_irq(struct vfio_platform_device *vdev, int i)
+{
+     struct platform_device *pdev = (struct platform_device *) vdev->opaque;
+
+     return platform_get_irq(pdev, i);
+}
+
+
+static int vfio_platform_probe(struct platform_device *pdev)
+{
+     struct vfio_platform_device *vdev;
+     int ret;
+
+     vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+     if (!vdev)
+             return -ENOMEM;
+
+     vdev->opaque = (void *) pdev;
+     vdev->name = pdev->name;
+     vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
+     vdev->get_resource = get_platform_resource;
+     vdev->get_irq = get_platform_irq;
+
+     ret = vfio_platform_probe_common(vdev, &pdev->dev);
+     if (ret)
+             kfree(vdev);
+
+     return ret;
+}
+
+static int vfio_platform_remove(struct platform_device *pdev)
+{
+     return vfio_platform_remove_common(&pdev->dev);
+}
+
+static struct platform_driver vfio_platform_driver = {
+     .probe          = vfio_platform_probe,
+     .remove         = vfio_platform_remove,

27 more quoted lines

-- 
Antonios Motakis
Virtual Open Systems

On Fri, 2014-09-26 at 17:30 +0200, Antonios Motakis wrote:

On Wed, Sep 24, 2014 at 1:01 AM, Alex Williamson
[off-list ref] wrote:

quoted

On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote:

quoted

Driver to bind to Linux platform devices, and callbacks to discover their
resources to be used by the main VFIO PLATFORM code.

Signed-off-by: Antonios Motakis <redacted>
---
 drivers/vfio/platform/vfio_platform.c | 96 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/vfio.h             |  1 +
 2 files changed, 97 insertions(+)
 create mode 100644 drivers/vfio/platform/vfio_platform.c

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
new file mode 100644
index 0000000..024c026
--- /dev/null
+++ b/drivers/vfio/platform/vfio_platform.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mutex.h>

37 more quoted lines

I think we need to have PIO figured out at least enough to have stubbed
read/write handlers that could be filled in by someone with test
hardware.  I'm not sure I fully understand how a user associates a
region index to a device tree description, whether it's ordering or
something more complicated, so I'm not sure if simply listing all the
PIO resources after the MMIO resources is sufficient and compatible.
Maybe you have some thoughts on that.  Thanks,

Alex

quoted

quoted

+}
+
+static int get_platform_irq(struct vfio_platform_device *vdev, int i)
+{
+     struct platform_device *pdev = (struct platform_device *) vdev->opaque;
+
+     return platform_get_irq(pdev, i);
+}
+
+
+static int vfio_platform_probe(struct platform_device *pdev)
+{
+     struct vfio_platform_device *vdev;
+     int ret;
+
+     vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+     if (!vdev)
+             return -ENOMEM;
+
+     vdev->opaque = (void *) pdev;
+     vdev->name = pdev->name;
+     vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
+     vdev->get_resource = get_platform_resource;
+     vdev->get_irq = get_platform_irq;
+
+     ret = vfio_platform_probe_common(vdev, &pdev->dev);
+     if (ret)
+             kfree(vdev);
+
+     return ret;
+}
+
+static int vfio_platform_remove(struct platform_device *pdev)
+{
+     return vfio_platform_remove_common(&pdev->dev);
+}
+
+static struct platform_driver vfio_platform_driver = {
+     .probe          = vfio_platform_probe,
+     .remove         = vfio_platform_remove,

30 more quoted lines

On Fri, Sep 26, 2014 at 10:18 PM, Alex Williamson
[off-list ref] wrote:

On Fri, 2014-09-26 at 17:30 +0200, Antonios Motakis wrote:

quoted

On Wed, Sep 24, 2014 at 1:01 AM, Alex Williamson
[off-list ref] wrote:

quoted

On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote:

quoted

Driver to bind to Linux platform devices, and callbacks to discover their
resources to be used by the main VFIO PLATFORM code.

Signed-off-by: Antonios Motakis <redacted>
---
 drivers/vfio/platform/vfio_platform.c | 96 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/vfio.h             |  1 +
 2 files changed, 97 insertions(+)
 create mode 100644 drivers/vfio/platform/vfio_platform.c

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
new file mode 100644
index 0000000..024c026
--- /dev/null
+++ b/drivers/vfio/platform/vfio_platform.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/module.h>

46 more quoted lines

You are right. I'm not aware if the Linux calls used are guaranteed to
preserve ordering of PIO/MMIO resources, I will investigate a bit on
that.

Alex

quoted

quoted

quoted

+}
+
+static int get_platform_irq(struct vfio_platform_device *vdev, int i)
+{
+     struct platform_device *pdev = (struct platform_device *) vdev->opaque;
+
+     return platform_get_irq(pdev, i);
+}
+
+
+static int vfio_platform_probe(struct platform_device *pdev)
+{
+     struct vfio_platform_device *vdev;
+     int ret;
+
+     vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+     if (!vdev)
+             return -ENOMEM;
+
+     vdev->opaque = (void *) pdev;
+     vdev->name = pdev->name;
+     vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
+     vdev->get_resource = get_platform_resource;
+     vdev->get_irq = get_platform_irq;
+
+     ret = vfio_platform_probe_common(vdev, &pdev->dev);
+     if (ret)
+             kfree(vdev);
+
+     return ret;
+}
+
+static int vfio_platform_remove(struct platform_device *pdev)
+{
+     return vfio_platform_remove_common(&pdev->dev);
+}
+

36 more quoted lines

-- 
Antonios Motakis
Virtual Open Systems