Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
On 2021/2/26 12:21, Viresh Kumar wrote: On 26-02-21, 10:46, Jie Deng wrote: This v4 was the old version before the specification was acked by the virtio tc. Following is the latest specification. https://raw.githubusercontent.com/oasis-tcs/virtio-spec/master/virtio-i2c.tex I will send the v5 since the host/guest ABI changes. Okay, now it makes some sense :) I am interested in this stuff, if possible please keep me Cc'd for following versions, thanks. Sure. I will add you to the Cc list.
Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
On 26-02-21, 10:46, Jie Deng wrote: > This v4 was the old version before the specification was acked by the virtio > tc. > > Following is the latest specification. > > https://raw.githubusercontent.com/oasis-tcs/virtio-spec/master/virtio-i2c.tex > > I will send the v5 since the host/guest ABI changes. Okay, now it makes some sense :) I am interested in this stuff, if possible please keep me Cc'd for following versions, thanks. -- viresh
Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
On 2021/2/25 15:21, Viresh Kumar wrote:
On 12-10-20, 09:55, Jie Deng wrote:
Add an I2C bus driver for virtio para-virtualization.
The controller can be emulated by the backend driver in
any device model software by following the virtio protocol.
This driver communicates with the backend driver through a
virtio I2C message structure which includes following parts:
- Header: i2c_msg addr, flags, len.
- Data buffer: the pointer to the I2C msg data.
- Status: the processing result from the backend.
People may implement different backend drivers to emulate
different controllers according to their needs. A backend
example can be found in the device model of the open source
project ACRN. For more information, please refer to
https://projectacrn.org.
diff --git a/include/uapi/linux/virtio_i2c.h b/include/uapi/linux/virtio_i2c.h
new file mode 100644
index 000..7413e45
--- /dev/null
+++ b/include/uapi/linux/virtio_i2c.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause */
+/*
+ * Definitions for virtio I2C Adpter
+ *
+ * Copyright (c) 2020 Intel Corporation. All rights reserved.
+ */
+
+#ifndef _UAPI_LINUX_VIRTIO_I2C_H
+#define _UAPI_LINUX_VIRTIO_I2C_H
+
+#include
+#include
+#include
+
+/**
+ * struct virtio_i2c_hdr - the virtio I2C message header structure
+ * @addr: i2c_msg addr, the slave address
+ * @flags: i2c_msg flags
+ * @len: i2c_msg len
+ */
+struct virtio_i2c_hdr {
+ __le16 addr;
+ __le16 flags;
+ __le16 len;
+};
Hi Jie,
I am a bit confused about the header and the format in which data is being
processed here. When I look at the specification present here:
https://lists.oasis-open.org/archives/virtio-comment/202009/msg00021.html
it talks about
struct virtio_i2c_out_hdr {
le16 addr;
le16 padding;
le32 flags;
};
struct virtio_i2c_in_hdr {
u8 status;
};
struct virtio_i2c_req {
struct virtio_i2c_out_hdr out_hdr;
u8 write_buf [];
u8 read_buf [];
struct virtio_i2c_in_hdr in_hdr;
};
while what we have above is completely different. What am I missing ?
This v4 was the old version before the specification was acked by the
virtio tc.
Following is the latest specification.
https://raw.githubusercontent.com/oasis-tcs/virtio-spec/master/virtio-i2c.tex
I will send the v5 since the host/guest ABI changes.
Thanks.
Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
On 12-10-20, 09:55, Jie Deng wrote:
> Add an I2C bus driver for virtio para-virtualization.
>
> The controller can be emulated by the backend driver in
> any device model software by following the virtio protocol.
>
> This driver communicates with the backend driver through a
> virtio I2C message structure which includes following parts:
>
> - Header: i2c_msg addr, flags, len.
> - Data buffer: the pointer to the I2C msg data.
> - Status: the processing result from the backend.
>
> People may implement different backend drivers to emulate
> different controllers according to their needs. A backend
> example can be found in the device model of the open source
> project ACRN. For more information, please refer to
> https://projectacrn.org.
> diff --git a/include/uapi/linux/virtio_i2c.h b/include/uapi/linux/virtio_i2c.h
> new file mode 100644
> index 000..7413e45
> --- /dev/null
> +++ b/include/uapi/linux/virtio_i2c.h
> @@ -0,0 +1,31 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause */
> +/*
> + * Definitions for virtio I2C Adpter
> + *
> + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef _UAPI_LINUX_VIRTIO_I2C_H
> +#define _UAPI_LINUX_VIRTIO_I2C_H
> +
> +#include
> +#include
> +#include
> +
> +/**
> + * struct virtio_i2c_hdr - the virtio I2C message header structure
> + * @addr: i2c_msg addr, the slave address
> + * @flags: i2c_msg flags
> + * @len: i2c_msg len
> + */
> +struct virtio_i2c_hdr {
> + __le16 addr;
> + __le16 flags;
> + __le16 len;
> +};
Hi Jie,
I am a bit confused about the header and the format in which data is being
processed here. When I look at the specification present here:
https://lists.oasis-open.org/archives/virtio-comment/202009/msg00021.html
it talks about
struct virtio_i2c_out_hdr {
le16 addr;
le16 padding;
le32 flags;
};
struct virtio_i2c_in_hdr {
u8 status;
};
struct virtio_i2c_req {
struct virtio_i2c_out_hdr out_hdr;
u8 write_buf [];
u8 read_buf [];
struct virtio_i2c_in_hdr in_hdr;
};
while what we have above is completely different. What am I missing ?
--
viresh
Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
On 2020/11/25 17:35, Michael S. Tsirkin wrote: On Mon, Oct 12, 2020 at 09:55:55AM +0800, Jie Deng wrote: Add an I2C bus driver for virtio para-virtualization. The controller can be emulated by the backend driver in any device model software by following the virtio protocol. This driver communicates with the backend driver through a virtio I2C message structure which includes following parts: - Header: i2c_msg addr, flags, len. - Data buffer: the pointer to the I2C msg data. - Status: the processing result from the backend. People may implement different backend drivers to emulate different controllers according to their needs. A backend example can be found in the device model of the open source project ACRN. For more information, please refer to https://projectacrn.org. The virtio device ID 34 is used for this I2C adpter since IDs before 34 have been reserved by other virtio devices. Co-developed-by: Conghui Chen Signed-off-by: Conghui Chen Signed-off-by: Jie Deng Reviewed-by: Shuo Liu Reviewed-by: Andy Shevchenko I assume this will be updated once the specification is acked by the virtio tc. Holding off on this one for now since we know there will be host/guest ABI changes. Yeah. I will update this driver once the specification is acked by the virtio tc. Thanks.
Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
On Mon, Oct 12, 2020 at 09:55:55AM +0800, Jie Deng wrote:
> Add an I2C bus driver for virtio para-virtualization.
>
> The controller can be emulated by the backend driver in
> any device model software by following the virtio protocol.
>
> This driver communicates with the backend driver through a
> virtio I2C message structure which includes following parts:
>
> - Header: i2c_msg addr, flags, len.
> - Data buffer: the pointer to the I2C msg data.
> - Status: the processing result from the backend.
>
> People may implement different backend drivers to emulate
> different controllers according to their needs. A backend
> example can be found in the device model of the open source
> project ACRN. For more information, please refer to
> https://projectacrn.org.
>
> The virtio device ID 34 is used for this I2C adpter since IDs
> before 34 have been reserved by other virtio devices.
>
> Co-developed-by: Conghui Chen
> Signed-off-by: Conghui Chen
> Signed-off-by: Jie Deng
> Reviewed-by: Shuo Liu
> Reviewed-by: Andy Shevchenko
I assume this will be updated once the specification is acked
by the virtio tc. Holding off on this one for now since
we know there will be host/guest ABI changes.
> ---
> The device ID request:
> https://github.com/oasis-tcs/virtio-spec/issues/85
>
> The specification:
>
> https://lists.oasis-open.org/archives/virtio-comment/202009/msg00021.html
>
> Changes in v4:
> - Use (!(vmsg && vmsg == >vmsg)) instead of ((!vmsg) || (vmsg !=
> >vmsg))
>
> Changes in v3:
> - Move the interface into uAPI according to Jason.
> - Fix issues reported by Dan Carpenter.
> - Fix typo reported by Randy.
>
> Changes in v2:
> - Addressed comments received from Michael, Andy and Jason.
>
> drivers/i2c/busses/Kconfig | 11 ++
> drivers/i2c/busses/Makefile | 3 +
> drivers/i2c/busses/i2c-virtio.c | 256
>
> include/uapi/linux/virtio_i2c.h | 31 +
> include/uapi/linux/virtio_ids.h | 1 +
> 5 files changed, 302 insertions(+)
> create mode 100644 drivers/i2c/busses/i2c-virtio.c
> create mode 100644 include/uapi/linux/virtio_i2c.h
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 293e7a0..f2f6543 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -21,6 +21,17 @@ config I2C_ALI1535
> This driver can also be built as a module. If so, the module
> will be called i2c-ali1535.
>
> +config I2C_VIRTIO
> + tristate "Virtio I2C Adapter"
> + depends on VIRTIO
> + help
> + If you say yes to this option, support will be included for the virtio
> + I2C adapter driver. The hardware can be emulated by any device model
> + software according to the virtio protocol.
> +
> + This driver can also be built as a module. If so, the module
> + will be called i2c-virtio.
> +
> config I2C_ALI1563
> tristate "ALI 1563"
> depends on PCI
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 19aff0e..821acfa 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -6,6 +6,9 @@
> # ACPI drivers
> obj-$(CONFIG_I2C_SCMI) += i2c-scmi.o
>
> +# VIRTIO I2C host controller driver
> +obj-$(CONFIG_I2C_VIRTIO) += i2c-virtio.o
> +
> # PC SMBus host controller drivers
> obj-$(CONFIG_I2C_ALI1535)+= i2c-ali1535.o
> obj-$(CONFIG_I2C_ALI1563)+= i2c-ali1563.o
> diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c
> new file mode 100644
> index 000..36d8c68
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-virtio.c
> @@ -0,0 +1,256 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Virtio I2C Bus Driver
> + *
> + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> + */
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +#include
> +#include
> +
> +/**
> + * struct virtio_i2c_msg - the virtio I2C message structure
> + * @hdr: the virtio I2C message header
> + * @buf: virtio I2C message data buffer
> + * @status: the processing result from the backend
> + */
> +struct virtio_i2c_msg {
> + struct virtio_i2c_hdr hdr;
> + u8 *buf;
> + u8 status;
> +};
> +
> +/**
> + * struct virtio_i2c - virtio I2C data
> + * @vdev: virtio device for this controller
> + * @completion: completion of virtio I2C message
> + * @vmsg: the virtio I2C message for communication
> + * @adap: I2C adapter for this controller
> + * @i2c_lock: lock for virtqueue processing
> + * @vq: the virtio virtqueue for communication
> + */
> +struct virtio_i2c {
> + struct virtio_device *vdev;
> + struct completion completion;
> + struct virtio_i2c_msg vmsg;
> + struct i2c_adapter adap;
> + struct mutex i2c_lock;
> + struct virtqueue *vq;
> +};
> +
> +static void
Re: [PATCH v4] i2c: virtio: add a virtio i2c frontend driver
Hi Jie, Thank you for the patch! Yet something to improve: [auto build test ERROR on wsa/i2c/for-next] [also build test ERROR on vhost/linux-next linus/master linux/master v5.9 next-20201009] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Jie-Deng/i2c-virtio-add-a-virtio-i2c-frontend-driver/20201012-095821 base: https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next config: x86_64-randconfig-a004-20201012 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 9e72d3eaf38f217698f72cb8fdc969a6e72dad3a) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/152ef3f6057acca49f276933274b09df8880243d git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jie-Deng/i2c-virtio-add-a-virtio-i2c-frontend-driver/20201012-095821 git checkout 152ef3f6057acca49f276933274b09df8880243d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): >> error: include/uapi/linux/virtio_i2c.h: missing "WITH Linux-syscall-note" >> for SPDX-License-Identifier make[2]: *** [scripts/Makefile.headersinst:63: usr/include/linux/virtio_i2c.h] Error 1 make[2]: Target '__headers' not remade because of errors. make[1]: *** [Makefile:1286: headers] Error 2 make[1]: Target 'prepare' not remade because of errors. make: *** [Makefile:185: __sub-make] Error 2 make: Target 'prepare' not remade because of errors. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org .config.gz Description: application/gzip
[PATCH v4] i2c: virtio: add a virtio i2c frontend driver
Add an I2C bus driver for virtio para-virtualization.
The controller can be emulated by the backend driver in
any device model software by following the virtio protocol.
This driver communicates with the backend driver through a
virtio I2C message structure which includes following parts:
- Header: i2c_msg addr, flags, len.
- Data buffer: the pointer to the I2C msg data.
- Status: the processing result from the backend.
People may implement different backend drivers to emulate
different controllers according to their needs. A backend
example can be found in the device model of the open source
project ACRN. For more information, please refer to
https://projectacrn.org.
The virtio device ID 34 is used for this I2C adpter since IDs
before 34 have been reserved by other virtio devices.
Co-developed-by: Conghui Chen
Signed-off-by: Conghui Chen
Signed-off-by: Jie Deng
Reviewed-by: Shuo Liu
Reviewed-by: Andy Shevchenko
---
The device ID request:
https://github.com/oasis-tcs/virtio-spec/issues/85
The specification:
https://lists.oasis-open.org/archives/virtio-comment/202009/msg00021.html
Changes in v4:
- Use (!(vmsg && vmsg == >vmsg)) instead of ((!vmsg) || (vmsg !=
>vmsg))
Changes in v3:
- Move the interface into uAPI according to Jason.
- Fix issues reported by Dan Carpenter.
- Fix typo reported by Randy.
Changes in v2:
- Addressed comments received from Michael, Andy and Jason.
drivers/i2c/busses/Kconfig | 11 ++
drivers/i2c/busses/Makefile | 3 +
drivers/i2c/busses/i2c-virtio.c | 256
include/uapi/linux/virtio_i2c.h | 31 +
include/uapi/linux/virtio_ids.h | 1 +
5 files changed, 302 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-virtio.c
create mode 100644 include/uapi/linux/virtio_i2c.h
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 293e7a0..f2f6543 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -21,6 +21,17 @@ config I2C_ALI1535
This driver can also be built as a module. If so, the module
will be called i2c-ali1535.
+config I2C_VIRTIO
+ tristate "Virtio I2C Adapter"
+ depends on VIRTIO
+ help
+ If you say yes to this option, support will be included for the virtio
+ I2C adapter driver. The hardware can be emulated by any device model
+ software according to the virtio protocol.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-virtio.
+
config I2C_ALI1563
tristate "ALI 1563"
depends on PCI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 19aff0e..821acfa 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -6,6 +6,9 @@
# ACPI drivers
obj-$(CONFIG_I2C_SCMI) += i2c-scmi.o
+# VIRTIO I2C host controller driver
+obj-$(CONFIG_I2C_VIRTIO) += i2c-virtio.o
+
# PC SMBus host controller drivers
obj-$(CONFIG_I2C_ALI1535) += i2c-ali1535.o
obj-$(CONFIG_I2C_ALI1563) += i2c-ali1563.o
diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c
new file mode 100644
index 000..36d8c68
--- /dev/null
+++ b/drivers/i2c/busses/i2c-virtio.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtio I2C Bus Driver
+ *
+ * Copyright (c) 2020 Intel Corporation. All rights reserved.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+#include
+
+/**
+ * struct virtio_i2c_msg - the virtio I2C message structure
+ * @hdr: the virtio I2C message header
+ * @buf: virtio I2C message data buffer
+ * @status: the processing result from the backend
+ */
+struct virtio_i2c_msg {
+ struct virtio_i2c_hdr hdr;
+ u8 *buf;
+ u8 status;
+};
+
+/**
+ * struct virtio_i2c - virtio I2C data
+ * @vdev: virtio device for this controller
+ * @completion: completion of virtio I2C message
+ * @vmsg: the virtio I2C message for communication
+ * @adap: I2C adapter for this controller
+ * @i2c_lock: lock for virtqueue processing
+ * @vq: the virtio virtqueue for communication
+ */
+struct virtio_i2c {
+ struct virtio_device *vdev;
+ struct completion completion;
+ struct virtio_i2c_msg vmsg;
+ struct i2c_adapter adap;
+ struct mutex i2c_lock;
+ struct virtqueue *vq;
+};
+
+static void virtio_i2c_msg_done(struct virtqueue *vq)
+{
+ struct virtio_i2c *vi = vq->vdev->priv;
+
+ complete(>completion);
+}
+
+static int virtio_i2c_add_msg(struct virtqueue *vq,
+ struct virtio_i2c_msg *vmsg,
+ struct i2c_msg *msg)
+{
+ struct scatterlist *sgs[3], hdr, bout, bin, status;
+ int outcnt = 0, incnt = 0;
+
+ if (!msg->len)
+ return -EINVAL;
+
+ vmsg->hdr.addr = cpu_to_le16(msg->addr);
