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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Minios-devel] [UNIKRAFT PATCH v2 2/8] lib/uk9p: Add 9P transport registration
Hi Simon,
I applied your suggestions regarding the default transport in v3.
Thanks!
Cristian
On Sat, Jun 29, 2019 at 1:29 PM Simon Kuenzer <simon.kuenzer@xxxxxxxxx> wrote:
>
> Hey,
>
> thanks a lot for this patch. I still have some comments to the default
> transport setting. I commented it inline.
>
> Thanks,
>
> Simon
>
> On 29.06.19 10:56, Cristian Banu wrote:
> > This patch introduces the 9P transport registration and lookup API.
> >
> > Transports are communication channels such as virtio by using the
> > virtio-9p device, or xen rings. Those are the default transports
> > for the KVM and Xen platforms respectively. However, in the future
> > one might have multiple available transports for the same platform
> > by supporting TCP or RDMA.
> >
> > Signed-off-by: Cristian Banu <cristb@xxxxxxxxx>
> > ---
> > lib/uk9p/9pdev_trans.c | 76 +++++++++++++++++++++++++++++++
> > lib/uk9p/Makefile.uk | 2 +
> > lib/uk9p/exportsyms.uk | 3 ++
> > lib/uk9p/include/uk/9pdev_trans.h | 96
> > +++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 177 insertions(+)
> > create mode 100644 lib/uk9p/9pdev_trans.c
> > create mode 100644 lib/uk9p/exportsyms.uk
> > create mode 100644 lib/uk9p/include/uk/9pdev_trans.h
> >
> > diff --git a/lib/uk9p/9pdev_trans.c b/lib/uk9p/9pdev_trans.c
> > new file mode 100644
> > index 000000000000..6372876765b2
> > --- /dev/null
> > +++ b/lib/uk9p/9pdev_trans.c
> > @@ -0,0 +1,76 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause */
> > +/*
> > + * Authors: Cristian Banu <cristb@xxxxxxxxx>
> > + *
> > + * Copyright (c) 2019, University Politehnica of Bucharest. All rights
> > reserved.
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions
> > + * are met:
> > + *
> > + * 1. Redistributions of source code must retain the above copyright
> > + * notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + * notice, this list of conditions and the following disclaimer in the
> > + * documentation and/or other materials provided with the distribution.
> > + * 3. Neither the name of the copyright holder nor the names of its
> > + * contributors may be used to endorse or promote products derived from
> > + * this software without specific prior written permission.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
> > IS"
> > + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> > THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> > PURPOSE
> > + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
> > BE
> > + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> > + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> > + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> > + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> > + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
> > THE
> > + * POSSIBILITY OF SUCH DAMAGE.
> > + *
> > + * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
> > + */
> > +
> > +#include <errno.h>
> > +#include <string.h>
> > +#include <uk/config.h>
> > +#include <uk/list.h>
> > +#include <uk/assert.h>
> > +#include <uk/9pdev_trans.h>
> > +
> > +static UK_LIST_HEAD(uk_9pdev_trans_list);
> > +
> > +static struct uk_9pdev_trans *uk_9pdev_trans_saved_default;
> > +
> > +int uk_9pdev_trans_register(struct uk_9pdev_trans *trans)
> > +{
> > + UK_ASSERT(trans);
> > + UK_ASSERT(trans->name);
> > + UK_ASSERT(trans->a);
> > +
> > + uk_list_add_tail(&trans->_list, &uk_9pdev_trans_list);
> > + if (trans->is_default)
> > + uk_9pdev_trans_saved_default = trans;
>
> Hum. I would prefer providing a setter function for the default
> transport instead of having the 'is_default' boolean in the struct. It
> may get less clear by just seeing the API what is going on if multiple
> transports are setting themselves as default during registration.
>
> I would take just the first registration and then update the
> saved_default with on an default setter function. What do you think?
>
> > +
> > + uk_pr_info("Registered transport %s\n", trans->name);
> > +
> > + return 0;
> > +}
> > +
> > +struct uk_9pdev_trans *uk_9pdev_trans_by_name(const char *name)
> > +{
> > + struct uk_9pdev_trans *t;
> > +
> > + uk_list_for_each_entry(t, &uk_9pdev_trans_list, _list) {
> > + if (!strcmp(t->name, name))
> > + return t;
> > + }
> > +
> > + return NULL;
> > +}
> > +
> > +struct uk_9pdev_trans *uk_9pdev_trans_default(void)
> > +{
> > + return uk_9pdev_trans_saved_default;
> > +}
>
> If you add a uk_9pdev_trans_set_default(), I would prefer calling this
> one then uk_9pdev_trans_get_default().
>
> > diff --git a/lib/uk9p/Makefile.uk b/lib/uk9p/Makefile.uk
> > index fa754440598c..b1071a0e7d3c 100644
> > --- a/lib/uk9p/Makefile.uk
> > +++ b/lib/uk9p/Makefile.uk
> > @@ -2,3 +2,5 @@ $(eval $(call addlib_s,libuk9p,$(CONFIG_LIBUK9P)))
> >
> > CINCLUDES-$(CONFIG_LIBUK9P) += -I$(LIBUK9P_BASE)/include
> > CXXINCLUDES-$(CONFIG_LIBUK9P) += -I$(LIBUK9P_BASE)/include
> > +
> > +LIBUK9P_SRCS-y += $(LIBUK9P_BASE)/9pdev_trans.c
> > diff --git a/lib/uk9p/exportsyms.uk b/lib/uk9p/exportsyms.uk
> > new file mode 100644
> > index 000000000000..45f487da2fff
> > --- /dev/null
> > +++ b/lib/uk9p/exportsyms.uk
> > @@ -0,0 +1,3 @@
> > +uk_9pdev_trans_register
> > +uk_9pdev_trans_by_name
> > +uk_9pdev_trans_default
> > diff --git a/lib/uk9p/include/uk/9pdev_trans.h
> > b/lib/uk9p/include/uk/9pdev_trans.h
> > new file mode 100644
> > index 000000000000..7b6645fb5e84
> > --- /dev/null
> > +++ b/lib/uk9p/include/uk/9pdev_trans.h
> > @@ -0,0 +1,96 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause */
> > +/*
> > + * Authors: Cristian Banu <cristb@xxxxxxxxx>
> > + *
> > + * Copyright (c) 2019, University Politehnica of Bucharest. All rights
> > reserved.
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions
> > + * are met:
> > + *
> > + * 1. Redistributions of source code must retain the above copyright
> > + * notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + * notice, this list of conditions and the following disclaimer in the
> > + * documentation and/or other materials provided with the distribution.
> > + * 3. Neither the name of the copyright holder nor the names of its
> > + * contributors may be used to endorse or promote products derived from
> > + * this software without specific prior written permission.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
> > IS"
> > + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> > THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> > PURPOSE
> > + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
> > BE
> > + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> > + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> > + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> > + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> > + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
> > THE
> > + * POSSIBILITY OF SUCH DAMAGE.
> > + *
> > + * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
> > + */
> > +
> > +#ifndef __UK_9PDEV_TRANS__
> > +#define __UK_9PDEV_TRANS__
> > +
> > +#include <stdbool.h>
> > +#include <uk/config.h>
> > +
> > +#ifdef __cplusplus
> > +extern "C" {
> > +#endif
> > +
> > +/** A structure used to describe a transport. */
> > +struct uk_9pdev_trans {
> > + /*
> > + * Transport name (e.g. "virtio", "xen"). This field is reserved for
> > + * future use, when multiple transport options are available on the
> > + * same platform, such as RDMA or TCP, in addition to the platform
> > + * specific transport.
> > + */
> > + const char *name;
> > + /* Can the transport be used as a default one? */
> > + bool is_default
>
> See my comments ahead regarding this boolean. I would like to have a
> more explicit control over setting a default transport rather then the
> library deciding what to do.
>
> > + /* Allocator used for devices which use this transport layer. */
> > + struct uk_alloc *a;
> > + /* @internal Entry in the list of available transports. */
> > + struct uk_list_head _list;
> > +};
> > +
> > +/**
> > + * Adds a transport to the available transports list for Unikraft 9P
> > Devices.
> > + * This should be called once per driver (once for virtio, once for xen,
> > etc.).
> > + *
> > + * @param trans
> > + * Pointer to the transport structure.
> > + * @return
> > + * - (0): Successful.
> > + * - (< 0): Failed to register the transport layer.
> > + */
> > +int uk_9pdev_trans_register(struct uk_9pdev_trans *trans);
> > +
> > +/**
> > + * Looks up a transport layer by its name.
> > + *
> > + * @param name
> > + * The transport layer name.
> > + * @return
> > + * The 9P transport with the given name, or NULL if missing.
> > + */
> > +struct uk_9pdev_trans *uk_9pdev_trans_by_name(const char *name);
> > +
> > +/**
> > + * Gets the default transport layer.
> > + *
> > + * @return
> > + * The default 9P transport, or NULL if missing.
> > + */
> > +struct uk_9pdev_trans *uk_9pdev_trans_default(void);
> > +
> > +#ifdef __cplusplus
> > +}
> > +#endif
> > +
> > +#endif /* __UK_9PDEV_TRANS__ */
> >
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