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path: root/drivers/xen/pvcalls-back.c
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2019-01-04xen/pvcalls: remove set but not used variable 'intf'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/xen/pvcalls-back.c: In function 'pvcalls_sk_state_change': drivers/xen/pvcalls-back.c:286:28: warning: variable 'intf' set but not used [-Wunused-but-set-variable] It not used since e6587cdbd732 ("pvcalls-back: set -ENOTCONN in pvcalls_conn_back_read") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-01-02pvcalls-back: set -ENOTCONN in pvcalls_conn_back_readStefano Stabellini
When a connection is closing we receive on pvcalls_sk_state_change notification. Instead of setting the connection as closed immediately (-ENOTCONN), let's read one more time from it: pvcalls_conn_back_read will set the connection as closed when necessary. That way, we avoid races between pvcalls_sk_state_change and pvcalls_back_ioworker. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-10-24iov_iter: Separate type from direction and use accessor functionsDavid Howells
In the iov_iter struct, separate the iterator type from the iterator direction and use accessor functions to access them in most places. Convert a bunch of places to use switch-statements to access them rather then chains of bitwise-AND statements. This makes it easier to add further iterator types. Also, this can be more efficient as to implement a switch of small contiguous integers, the compiler can use ~50% fewer compare instructions than it has to use bitwise-and instructions. Further, cease passing the iterator type into the iterator setup function. The iterator function can set that itself. Only the direction is required. Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-26xen/pvcalls: fix null pointer dereference on map->sockColin Ian King
Currently if map is null then a potential null pointer deference occurs when calling sock_release on map->sock. I believe the actual intention was to call sock_release on sock instead. Fix this. Fixes: 5db4d286a8ef ("xen/pvcalls: implement connect command") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2018-02-06pvcalls-back: do not return error on inet_accept EAGAINStefano Stabellini
When the client sends a regular blocking accept request, the backend is expected to return only when the accept is completed, simulating a blocking behavior, or return an error. Specifically, on EAGAIN from inet_accept, the backend shouldn't return "EAGAIN" to the client. Instead, it should simply continue the wait. Otherwise, the client will send another accept request, which will cause another EAGAIN to be sent back, which is a waste of resources and not conforming to the expected behavior. Change the behavior by turning the "goto error" into a return. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-11-17Merge branch 'work.iov_iter' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull iov_iter updates from Al Viro: - bio_{map,copy}_user_iov() series; those are cleanups - fixes from the same pile went into mainline (and stable) in late September. - fs/iomap.c iov_iter-related fixes - new primitive - iov_iter_for_each_range(), which applies a function to kernel-mapped segments of an iov_iter. Usable for kvec and bvec ones, the latter does kmap()/kunmap() around the callback. _Not_ usable for iovec- or pipe-backed iov_iter; the latter is not hard to fix if the need ever appears, the former is by design. Another related primitive will have to wait for the next cycle - it passes page + offset + size instead of pointer + size, and that one will be usable for everything _except_ kvec. Unfortunately, that one didn't get exposure in -next yet, so... - a bit more lustre iov_iter work, including a use case for iov_iter_for_each_range() (checksum calculation) - vhost/scsi leak fix in failure exit - misc cleanups and detritectomy... * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (21 commits) iomap_dio_actor(): fix iov_iter bugs switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range() lustre: switch struct ksock_conn to iov_iter vhost/scsi: switch to iov_iter_get_pages() fix a page leak in vhost_scsi_iov_to_sgl() error recovery new primitive: iov_iter_for_each_range() lnet_return_rx_credits_locked: don't abuse list_entry xen: don't open-code iov_iter_kvec() orangefs: remove detritus from struct orangefs_kiocb_s kill iov_shorten() bio_alloc_map_data(): do bmd->iter setup right there bio_copy_user_iov(): saner bio size calculation bio_map_user_iov(): get rid of copying iov_iter bio_copy_from_iter(): get rid of copying iov_iter move more stuff down into bio_copy_user_iov() blk_rq_map_user_iov(): move iov_iter_advance() down bio_map_user_iov(): get rid of the iov_for_each() bio_map_user_iov(): move alignment check into the main loop don't rely upon subsequent bio_add_pc_page() calls failing ... and with iov_iter_get_pages_alloc() it becomes even simpler ...
2017-11-15xen/pvcalls: Add MODULE_LICENSE()Boris Ostrovsky
Since commit ba1029c9cbc5 ("modpost: detect modules without a MODULE_LICENSE") modules without said macro will generate WARNING: modpost: missing MODULE_LICENSE() in <filename> While at it, also add module description and attribution. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2017-10-11xen: don't open-code iov_iter_kvec()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-08-31xen/pvcalls: use WARN_ON(1) instead of __WARN()Arnd Bergmann
__WARN() is an internal helper that is only available on some architectures, but causes a build error e.g. on ARM64 in some configurations: drivers/xen/pvcalls-back.c: In function 'set_backend_state': drivers/xen/pvcalls-back.c:1097:5: error: implicit declaration of function '__WARN' [-Werror=implicit-function-declaration] Unfortunately, there is no equivalent of BUG() that takes no arguments, but WARN_ON(1) is commonly used in other drivers and works on all configurations. Fixes: 7160378206b2 ("xen/pvcalls: xenbus state handling") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement writeStefano Stabellini
When the other end notifies us that there is data to be written (pvcalls_back_conn_event), increment the io and write counters, and schedule the ioworker. Implement the write function called by ioworker by reading the data from the data ring, writing it to the socket by calling inet_sendmsg. Set out_error on error. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement readStefano Stabellini
When an active socket has data available, increment the io and read counters, and schedule the ioworker. Implement the read function by reading from the socket, writing the data to the data ring. Set in_error on error. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement the ioworker functionsStefano Stabellini
We have one ioworker per socket. Each ioworker goes through the list of outstanding read/write requests. Once all requests have been dealt with, it returns. We use one atomic counter per socket for "read" operations and one for "write" operations to keep track of the reads/writes to do. We also use one atomic counter ("io") per ioworker to keep track of how many outstanding requests we have in total assigned to the ioworker. The ioworker finishes when there are none. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: disconnect and module_exitStefano Stabellini
Implement backend_disconnect. Call pvcalls_back_release_active on active sockets and pvcalls_back_release_passive on passive sockets. Implement module_exit by calling backend_disconnect on frontend connections. [ boris: fixed long lines ] Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement release commandStefano Stabellini
Release both active and passive sockets. For active sockets, make sure to avoid possible conflicts with the ioworker reading/writing to those sockets concurrently. Set map->release to let the ioworker know atomically that the socket will be released soon, then wait until the ioworker finishes (flush_work). Unmap indexes pages and data rings. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement poll commandStefano Stabellini
Implement poll on passive sockets by requesting a delayed response with mappass->reqcopy, and reply back when there is data on the passive socket. Poll on active socket is unimplemented as by the spec, as the frontend should just wait for events and check the indexes on the indexes page. Only support one outstanding poll (or accept) request for every passive socket at any given time. [ boris: fixed long lines ] Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement accept commandStefano Stabellini
Implement the accept command by calling inet_accept. To avoid blocking in the kernel, call inet_accept(O_NONBLOCK) from a workqueue, which get scheduled on sk_data_ready (for a passive socket, it means that there are connections to accept). Use the reqcopy field to store the request. Accept the new socket from the delayed work function, create a new sock_mapping for it, map the indexes page and data ring, and reply to the other end. Allocate an ioworker for the socket. Only support one outstanding blocking accept request for every socket at any time. Add a field to sock_mapping to remember the passive socket from which an active socket was created. [ boris: fixed whitespaces ] Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement listen commandStefano Stabellini
Call inet_listen to implement the listen command. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement bind commandStefano Stabellini
Allocate a socket. Track the allocated passive sockets with a new data structure named sockpass_mapping. It contains an unbound workqueue to schedule delayed work for the accept and poll commands. It also has a reqcopy field to be used to store a copy of a request for delayed work. Reads/writes to it are protected by a lock (the "copy_lock" spinlock). Initialize the workqueue in pvcalls_back_bind. Implement the bind command with inet_bind. The pass_sk_data_ready event handler will be added later. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement connect commandStefano Stabellini
Allocate a socket. Keep track of socket <-> ring mappings with a new data structure, called sock_mapping. Implement the connect command by calling inet_stream_connect, and mapping the new indexes page and data ring. Allocate a workqueue and a work_struct, called ioworker, to perform reads and writes to the socket. When an active socket is closed (sk_state_change), set in_error to -ENOTCONN and notify the other end, as specified by the protocol. sk_data_ready and pvcalls_back_ioworker will be implemented later. [ boris: fixed whitespaces ] Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: implement socket commandStefano Stabellini
Just reply with success to the other end for now. Delay the allocation of the actual socket to bind and/or connect. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: handle commands from the frontendStefano Stabellini
When the other end notifies us that there are commands to be read (pvcalls_back_event), wake up the backend thread to parse the command. The command ring works like most other Xen rings, so use the usual ring macros to read and write to it. The functions implementing the commands are empty stubs for now. [ boris: fixed whitespaces ] Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: connect to a frontendStefano Stabellini
Introduce a per-frontend data structure named pvcalls_fedata. It contains pointers to the command ring, its event channel, a list of active sockets and a tree of passive sockets (passing sockets need to be looked up from the id on listen, accept and poll commands, while active sockets only on release). It also has an unbound workqueue to schedule the work of parsing and executing commands on the command ring. socket_lock protects the two lists. In pvcalls_back_global, keep a list of connected frontends. [ boris: fixed whitespaces/long lines ] Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: xenbus state handlingStefano Stabellini
Introduce the code to handle xenbus state changes. Implement the probe function for the pvcalls backend. Write the supported versions, max-page-order and function-calls nodes to xenstore, as required by the protocol. Introduce stub functions for disconnecting/connecting to a frontend. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: initialize the module and register the xenbus backendStefano Stabellini
Keep a list of connected frontends. Use a semaphore to protect list accesses. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-08-31xen/pvcalls: introduce the pvcalls xenbus backendStefano Stabellini
Introduce a xenbus backend for the pvcalls protocol, as defined by https://xenbits.xen.org/docs/unstable/misc/pvcalls.html. This patch only adds the stubs, the code will be added by the following patches. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>