Re: [dpdk-dev] [PATCH v2 05/11] bus/vmbus: open subchannels

[Long Li <longli@microsoft.com>]

> Subject: [PATCH v2 05/11] bus/vmbus: open subchannels
> 
> In FreeBSD, unlike Linux there is no sub-channel open callback that could be
> called by HV_UIO driver, upon their grant by the hypervisor.
> Thus, the PMD makes an IOCTL to the HV_UIO to open the granted sub-channels
> 
> v2 - Added comment in linux/vmbus_uio.c
> 
> Signed-off-by: Srikanth Kaka <srikanth.k@oneconvergence.com>
> Signed-off-by: Vag Singh <vag.singh@oneconvergence.com>
> Signed-off-by: Anand Thulasiram <avelu@juniper.net>

Reviewed-by: Long Li <longli@microsoft.com>
> ---
>  drivers/bus/vmbus/freebsd/vmbus_uio.c | 31 +++++++++++++++++++++++++++
>  drivers/bus/vmbus/linux/vmbus_uio.c   | 12 +++++++++++
>  drivers/bus/vmbus/private.h           |  1 +
>  drivers/bus/vmbus/rte_bus_vmbus.h     | 10 +++++++++
>  drivers/bus/vmbus/version.map         |  1 +
>  drivers/bus/vmbus/vmbus_channel.c     |  5 +++++
>  6 files changed, 60 insertions(+)
> 
> diff --git a/drivers/bus/vmbus/freebsd/vmbus_uio.c
> b/drivers/bus/vmbus/freebsd/vmbus_uio.c
> index fdd37dac3a..022ac85302 100644
> --- a/drivers/bus/vmbus/freebsd/vmbus_uio.c
> +++ b/drivers/bus/vmbus/freebsd/vmbus_uio.c
> @@ -12,6 +12,7 @@
>  #include <sys/mman.h>
>  #include <sys/types.h>
>  #include <sys/sysctl.h>
> +#include <sys/ioctl.h>
> 
>  #include <rte_log.h>
>  #include <rte_bus.h>
> @@ -26,6 +27,9 @@
>  /** Pathname of VMBUS devices directory. */  #define SYSFS_VMBUS_DEVICES
> "/sys/bus/vmbus/devices"
> 
> +/* ioctl */
> +#define HVIOOPENSUBCHAN     _IOW('h', 14, uint32_t)
> +
>  const char *driver_name = "hv_uio";
>  static void *vmbus_map_addr;
> 
> @@ -515,3 +519,30 @@ int vmbus_uio_get_subchan(struct vmbus_channel
> *primary,
>  	closedir(chan_dir);
>  	return err;
>  }
> +
> +int vmbus_uio_subchan_open(struct rte_vmbus_device *dev, uint32_t
> +subchan) {
> +	struct mapped_vmbus_resource *uio_res;
> +	int fd, err = 0;
> +
> +	uio_res = vmbus_uio_find_resource(dev);
> +	if (!uio_res) {
> +		VMBUS_LOG(ERR, "cannot find uio resource");
> +		return -EINVAL;
> +	}
> +
> +	fd = open(uio_res->path, O_RDWR);
> +	if (fd < 0) {
> +		VMBUS_LOG(ERR, "Cannot open %s: %s",
> +				uio_res->path, strerror(errno));
> +		return -1;
> +	}
> +
> +	if (ioctl(fd, HVIOOPENSUBCHAN, &subchan)) {
> +		VMBUS_LOG(ERR, "open subchan ioctl failed %s: %s",
> +				uio_res->path, strerror(errno));
> +		err = -1;
> +	}
> +	close(fd);
> +	return err;
> +}
> diff --git a/drivers/bus/vmbus/linux/vmbus_uio.c
> b/drivers/bus/vmbus/linux/vmbus_uio.c
> index b52ca5bf1d..29e889347a 100644
> --- a/drivers/bus/vmbus/linux/vmbus_uio.c
> +++ b/drivers/bus/vmbus/linux/vmbus_uio.c
> @@ -451,3 +451,15 @@ int vmbus_uio_get_subchan(struct vmbus_channel
> *primary,
>  	closedir(chan_dir);
>  	return err;
>  }
> +
> +/*
> + * This is a stub function and it should always succeed.
> + * The Linux UIO kernel driver opens the subchannels implicitly.
> + */
> +int vmbus_uio_subchan_open(struct rte_vmbus_device *dev,
> +			   uint32_t subchan)
> +{
> +	RTE_SET_USED(dev);
> +	RTE_SET_USED(subchan);
> +	return 0;
> +}
> diff --git a/drivers/bus/vmbus/private.h b/drivers/bus/vmbus/private.h index
> 528d60a42f..968f0b6f23 100644
> --- a/drivers/bus/vmbus/private.h
> +++ b/drivers/bus/vmbus/private.h
> @@ -107,6 +107,7 @@ int vmbus_uio_get_subchan(struct vmbus_channel
> *primary,  int vmbus_uio_map_rings(struct vmbus_channel *chan);  int
> vmbus_uio_map_secondary_subchan(const struct rte_vmbus_device *dev,
>  				    const struct vmbus_channel *chan);
> +int vmbus_uio_subchan_open(struct rte_vmbus_device *device, uint32_t
> +subchan);
> 
>  void vmbus_br_setup(struct vmbus_br *br, void *buf, unsigned int blen);
> 
> diff --git a/drivers/bus/vmbus/rte_bus_vmbus.h
> b/drivers/bus/vmbus/rte_bus_vmbus.h
> index 6bcff66468..60c5812706 100644
> --- a/drivers/bus/vmbus/rte_bus_vmbus.h
> +++ b/drivers/bus/vmbus/rte_bus_vmbus.h
> @@ -404,6 +404,16 @@ void rte_vmbus_chan_dump(FILE *f, const struct
> vmbus_channel *chan);
>   */
>  void rte_vmbus_unregister(struct rte_vmbus_driver *driver);
> 
> +/**
> + * Perform IOCTL to VMBUS device
> + *
> + * @param device
> + *	A pointer to a rte_vmbus_device structure
> + * @param subchan
> + *	Count of subchannels to open
> + */
> +int rte_vmbus_ioctl(struct rte_vmbus_device *device, uint32_t subchan);
> +
>  /** Helper for VMBUS device registration from driver instance */
>  #define RTE_PMD_REGISTER_VMBUS(nm, vmbus_drv)		\
>  	RTE_INIT(vmbusinitfn_ ##nm)			\
> diff --git a/drivers/bus/vmbus/version.map b/drivers/bus/vmbus/version.map
> index 3cadec7fae..3509d4fc14 100644
> --- a/drivers/bus/vmbus/version.map
> +++ b/drivers/bus/vmbus/version.map
> @@ -23,6 +23,7 @@ DPDK_22 {
>  	rte_vmbus_subchan_open;
>  	rte_vmbus_unmap_device;
>  	rte_vmbus_unregister;
> +	rte_vmbus_ioctl;
> 
>  	local: *;
>  };
> diff --git a/drivers/bus/vmbus/vmbus_channel.c
> b/drivers/bus/vmbus/vmbus_channel.c
> index f67f1c438a..f53a1b6511 100644
> --- a/drivers/bus/vmbus/vmbus_channel.c
> +++ b/drivers/bus/vmbus/vmbus_channel.c
> @@ -367,6 +367,11 @@ int rte_vmbus_max_channels(const struct
> rte_vmbus_device *device)
>  		return 1;
>  }
> 
> +int rte_vmbus_ioctl(struct rte_vmbus_device *device, uint32_t subchan)
> +{
> +	return vmbus_uio_subchan_open(device, subchan); }
> +
>  /* Setup secondary channel */
>  int rte_vmbus_subchan_open(struct vmbus_channel *primary,
>  			   struct vmbus_channel **new_chan)
> --
> 2.30.1