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* xen: remove redundant initialization of variable retJing Xiangfeng2020-10-051-1/+1
| | | | | | | | | | | After commit 9f51c05dc41a ("pvcalls-front: Avoid get_free_pages(GFP_KERNEL) under spinlock"), the variable ret is being initialized with '-ENOMEM' that is meaningless. So remove it. Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Link: https://lore.kernel.org/r/20200919031702.32192-1-jingxiangfeng@huawei.com Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-241-1/+1
| | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* xen: Use evtchn_type_t as a type for event channelsYan Yankovskyi2020-04-071-6/+9
| | | | | | | | | | Make event channel functions pass event channel port using evtchn_port_t type. It eliminates signed <-> unsigned conversion. Signed-off-by: Yan Yankovskyi <yyankovskyi@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20200323152343.GA28422@kbp1-lhp-F74019 Signed-off-by: Juergen Gross <jgross@suse.com>
* Merge tag 'for-linus-5.2b-rc3-tag' of ↵Linus Torvalds2019-05-311-4/+0
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: "One minor cleanup patch and a fix for handling of live migration when running as Xen guest" * tag 'for-linus-5.2b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xenbus: Avoid deadlock during suspend due to open transactions xen/pvcalls: Remove set but not used variable
| * xen/pvcalls: Remove set but not used variableYueHaibing2019-05-281-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes gcc '-Wunused-but-set-variable' warning: drivers/xen/pvcalls-front.c: In function pvcalls_front_sendmsg: drivers/xen/pvcalls-front.c:543:25: warning: variable bedata set but not used [-Wunused-but-set-variable] drivers/xen/pvcalls-front.c: In function pvcalls_front_recvmsg: drivers/xen/pvcalls-front.c:638:25: warning: variable bedata set but not used [-Wunused-but-set-variable] They are never used since introduction. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157Thomas Gleixner2019-05-301-10/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version 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 this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] 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 this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pvcalls-front: fix potential null dereferenceWen Yang2019-01-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | static checker warning: drivers/xen/pvcalls-front.c:373 alloc_active_ring() error: we previously assumed 'map->active.ring' could be null (see line 357) drivers/xen/pvcalls-front.c 351 static int alloc_active_ring(struct sock_mapping *map) 352 { 353 void *bytes; 354 355 map->active.ring = (struct pvcalls_data_intf *) 356 get_zeroed_page(GFP_KERNEL); 357 if (!map->active.ring) ^^^^^^^^^^^^^^^^^ Check 358 goto out; 359 360 map->active.ring->ring_order = PVCALLS_RING_ORDER; 361 bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 362 PVCALLS_RING_ORDER); 363 if (!bytes) 364 goto out; 365 366 map->active.data.in = bytes; 367 map->active.data.out = bytes + 368 XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); 369 370 return 0; 371 372 out: --> 373 free_active_ring(map); ^^^ Add null check on map->active.ring before dereferencing it to avoid any NULL pointer dereferences. Fixes: 9f51c05dc41a ("pvcalls-front: Avoid get_free_pages(GFP_KERNEL) under spinlock") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Juergen Gross <jgross@suse.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: Dan Carpenter <dan.carpenter@oracle.com> CC: xen-devel@lists.xenproject.org CC: linux-kernel@vger.kernel.org Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* pvcalls-front: Avoid get_free_pages(GFP_KERNEL) under spinlockWen Yang2019-01-101-22/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem is that we call this with a spin lock held. The call tree is: pvcalls_front_accept() holds bedata->socket_lock. -> create_active() -> __get_free_pages() uses GFP_KERNEL The create_active() function is only called from pvcalls_front_accept() with a spin_lock held, The allocation is not allowed to sleep and GFP_KERNEL is not sufficient. This issue was detected by using the Coccinelle software. v2: Add a function doing the allocations which is called outside the lock and passing the allocated data to create_active(). v3: Use the matching deallocators i.e., free_page() and free_pages(), respectively. v4: It would be better to pre-populate map (struct sock_mapping), rather than introducing one more new struct. v5: Since allocating the data outside of this call it should also be freed outside, when create_active() fails. Move kzalloc(sizeof(*map2), GFP_ATOMIC) outside spinlock and use GFP_KERNEL instead. v6: Drop the superfluous calls. Suggested-by: Juergen Gross <jgross@suse.com> Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Suggested-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Acked-by: Stefano Stabellini <sstabellini@kernel.org> CC: Julia Lawall <julia.lawall@lip6.fr> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Juergen Gross <jgross@suse.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: xen-devel@lists.xenproject.org CC: linux-kernel@vger.kernel.org Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* pvcalls-front: don't return error when the ring is fullStefano Stabellini2019-01-021-1/+3
| | | | | | | | | When the ring is full, size == array_size. It is not an error condition, so simply return 0 instead of an error. 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>
* pvcalls-front: properly allocate skStefano Stabellini2019-01-021-1/+7
| | | | | | | | | | Don't use kzalloc: it ends up leaving sk->sk_prot not properly initialized. Use sk_alloc instead and define our own trivial struct proto. 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>
* pvcalls-front: don't try to free unallocated ringsStefano Stabellini2019-01-021-2/+2
| | | | | | | | | inflight_req_id is 0 when initialized. If inflight_req_id is 0, there is no accept_map to free. Fix the check in pvcalls_front_release. 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>
* pvcalls-front: read all data before closing the connectionStefano Stabellini2019-01-021-3/+1
| | | | | | | | | | When a connection is closing in_error is set to ENOTCONN. There could still be outstanding data on the ring left by the backend. Before closing the connection on the frontend side, drain the ring. 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>
* pvcalls-front: fixes incorrect error handlingPan Bian2018-11-291-2/+2
| | | | | | | | | | kfree() is incorrectly used to release the pages allocated by __get_free_page() and __get_free_pages(). Use the matching deallocators i.e., free_page() and free_pages(), respectively. Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
* pvcalls-front: 64-bit align flagsStefano Stabellini2018-03-011-3/+8
| | | | | | | | | | | | We are using test_and_* operations on the status and flag fields of struct sock_mapping. However, these functions require the operand to be 64-bit aligned on arm64. Currently, only status is 64-bit aligned. Make status and flags explicitly 64-bit aligned. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* pvcalls-front: wait for other operations to return when release passive socketsStefano Stabellini2018-02-171-0/+6
| | | | | | | | | | | | Passive sockets can have ongoing operations on them, specifically, we have two wait_event_interruptable calls in pvcalls_front_accept. Add two wake_up calls in pvcalls_front_release, then wait for the potential waiters to return and release the sock_mapping refcount. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Acked-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* pvcalls-front: introduce a per sock_mapping refcountStefano Stabellini2018-02-171-112/+79
| | | | | | | | | | | Introduce a per sock_mapping refcount, in addition to the existing global refcount. Thanks to the sock_mapping refcount, we can safely wait for it to be 1 in pvcalls_front_release before freeing an active socket, instead of waiting for the global refcount to be 1. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Acked-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds2018-02-111-7/+7
| | | | | | | | | | | | | | | | | | | | | | | This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'misc.poll' of ↵Linus Torvalds2018-01-311-5/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
| * the rest of drivers/*: annotate ->poll() instancesAl Viro2017-11-281-5/+5
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | xen/pvcalls: use GFP_ATOMIC under spin lockWei Yongjun2018-01-021-1/+1
| | | | | | | | | | | | | | | | | | A spin lock is taken here so we should use GFP_ATOMIC. Fixes: 9774c6cca266 ("xen/pvcalls: implement accept command") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen/pvcalls: Fix a check in pvcalls_front_remove()Dan Carpenter2017-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | bedata->ref can't be less than zero because it's unsigned. This affects certain error paths in probe. We first set ->ref = -1 and then we set it to a valid value later. Fixes: 219681909913 ("xen/pvcalls: connect to the backend") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen/pvcalls: check for xenbus_read() errorsDan Carpenter2017-12-061-0/+2
|/ | | | | | | | | | Smatch complains that "len" is uninitialized if xenbus_read() fails so let's add some error handling. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: fix potential endless loop in pvcalls-front.cStefano Stabellini2017-11-151-6/+5
| | | | | | | | | | | | | | | mutex_trylock() returns 1 if you take the lock and 0 if not. Assume you take in_mutex on the first try, but you can't take out_mutex. Next times you call mutex_trylock() in_mutex is going to fail. It's an endless loop. Solve the problem by waiting until the global refcount is 1 instead (the refcount is 1 when the only active pvcalls frontend function is pvcalls_front_release). Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: Add MODULE_LICENSE()Boris Ostrovsky2017-11-151-0/+4
| | | | | | | | | | | | | 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>
* xen/pvcalls: remove redundant check for irq >= 0Colin Ian King2017-11-031-3/+1
| | | | | | | | | | | | This is a moot point, but irq is always less than zero at the label out_error, so the check for irq >= 0 is redundant and can be removed. Detected by CoverityScan, CID#1460371 ("Logically dead code") Fixes: cb1c7d9bbc87 ("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: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: fix unsigned less than zero error checkColin Ian King2017-11-031-4/+3
| | | | | | | | | | | | | The check on bedata->ref is never true because ref is an unsigned integer. Fix this by assigning signed int ret to the return of the call to gnttab_claim_grant_reference so the -ve return can be checked. Detected by CoverityScan, CID#1460358 ("Unsigned compared against 0") Fixes: 219681909913 ("xen/pvcalls: connect to the backend") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls-front: mark expected switch fall-throughGustavo A. R. Silva2017-11-031-1/+2
| | | | | | | | | | | | In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Notice that in this particular case I placed the "fall through" comment on its own line, which is what GCC is expecting to find. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement release commandStefano Stabellini2017-10-311-0/+98
| | | | | | | | | | | | | | | | Send PVCALLS_RELEASE to the backend and wait for a reply. Take both in_mutex and out_mutex to avoid concurrent accesses. Then, free the socket. For passive sockets, check whether we have already pre-allocated an active socket for the purpose of being accepted. If so, free that as well. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement poll commandStefano Stabellini2017-10-311-9/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | | For active sockets, check the indexes and use the inflight_conn_req waitqueue to wait. For passive sockets if an accept is outstanding (PVCALLS_FLAG_ACCEPT_INFLIGHT), check if it has been answered by looking at bedata->rsp[req_id]. If so, return POLLIN. Otherwise use the inflight_accept_req waitqueue. If no accepts are inflight, send PVCALLS_POLL to the backend. If we have outstanding POLL requests awaiting for a response use the inflight_req waitqueue: inflight_req is awaken when a new response is received; on wakeup we check whether the POLL response is arrived by looking at the PVCALLS_FLAG_POLL_RET flag. We set the flag from pvcalls_front_event_handler, if the response was for a POLL command. In pvcalls_front_event_handler, get the struct sock_mapping from the poll id (we previously converted struct sock_mapping* to uintptr_t and used it as id). Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement recvmsgStefano Stabellini2017-10-311-0/+111
| | | | | | | | | | | | | Implement recvmsg by copying data from the "in" ring. If not enough data is available and the recvmsg call is blocking, then wait on the inflight_conn_req waitqueue. Take the active socket in_mutex so that only one function can access the ring at any given time. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement sendmsgStefano Stabellini2017-10-311-0/+121
| | | | | | | | | | | | | | | | Send data to an active socket by copying data to the "out" ring. Take the active socket out_mutex so that only one function can access the ring at any given time. If not enough room is available on the ring, rather than returning immediately or sleep-waiting, spin for up to 5000 cycles. This small optimization turns out to improve performance significantly. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement accept commandStefano Stabellini2017-10-311-0/+145
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a waitqueue to allow only one outstanding accept command at any given time and to implement polling on the passive socket. Introduce a flags field to keep track of in-flight accept and poll commands. Send PVCALLS_ACCEPT to the backend. Allocate a new active socket. Make sure that only one accept command is executed at any given time by setting PVCALLS_FLAG_ACCEPT_INFLIGHT and waiting on the inflight_accept_req waitqueue. Convert the new struct sock_mapping pointer into an uintptr_t and use it as id for the new socket to pass to the backend. Check if the accept call is non-blocking: in that case after sending the ACCEPT command to the backend store the sock_mapping pointer of the new struct and the inflight req_id then return -EAGAIN (which will respond only when there is something to accept). Next time accept is called, we'll check if the ACCEPT command has been answered, if so we'll pick up where we left off, otherwise we return -EAGAIN again. Note that, differently from the other commands, we can use wait_event_interruptible (instead of wait_event) in the case of accept as we are able to track the req_id of the ACCEPT response that we are waiting. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement listen commandStefano Stabellini2017-10-311-0/+57
| | | | | | | | | | Send PVCALLS_LISTEN to the backend. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement bind commandStefano Stabellini2017-10-311-0/+66
| | | | | | | | | | | | | | Send PVCALLS_BIND to the backend. Introduce a new structure, part of struct sock_mapping, to store information specific to passive sockets. Introduce a status field to keep track of the status of the passive socket. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement connect commandStefano Stabellini2017-10-311-0/+158
| | | | | | | | | | | | | | | | | | Send PVCALLS_CONNECT to the backend. Allocate a new ring and evtchn for the active socket. Introduce fields in struct sock_mapping to keep track of active sockets. Introduce a waitqueue to allow the frontend to wait on data coming from the backend on the active socket (recvmsg command). Two mutexes (one of reads and one for writes) will be used to protect the active socket in and out rings from concurrent accesses. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement socket command and handle eventsStefano Stabellini2017-10-311-0/+131
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Send a PVCALLS_SOCKET command to the backend, use the masked req_prod_pvt as req_id. This way, req_id is guaranteed to be between 0 and PVCALLS_NR_REQ_PER_RING. We already have a slot in the rsp array ready for the response, and there cannot be two outstanding responses with the same req_id. Wait for the response by waiting on the inflight_req waitqueue and check for the req_id field in rsp[req_id]. Use atomic accesses and barriers to read the field. Note that the barriers are simple smp barriers (as opposed to virt barriers) because they are for internal frontend synchronization, not frontend<->backend communication. Once a response is received, clear the corresponding rsp slot by setting req_id to PVCALLS_INVALID_ID. Note that PVCALLS_INVALID_ID is invalid only from the frontend point of view. It is not part of the PVCalls protocol. pvcalls_front_event_handler is in charge of copying responses from the ring to the appropriate rsp slot. It is done by copying the body of the response first, then by copying req_id atomically. After the copies, wake up anybody waiting on waitqueue. socket_lock protects accesses to the ring. Convert the pointer to sock_mapping into an uintptr_t and use it as id for the new socket to pass to the backend. The struct will be fully initialized later on connect or bind. sock->sk->sk_send_head is not used for ip sockets: reuse the field to store a pointer to the struct sock_mapping corresponding to the socket. This way, we can easily get the struct sock_mapping from the struct socket. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: connect to the backendStefano Stabellini2017-10-311-0/+132
| | | | | | | | | | | | | | | | | Implement the probe function for the pvcalls frontend. Read the supported versions, max-page-order and function-calls nodes from xenstore. Only one frontend<->backend connection is supported at any given time for a guest. Store the active frontend device to a static pointer. Introduce a stub functions for the event handler. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: implement frontend disconnectStefano Stabellini2017-10-311-0/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a data structure named pvcalls_bedata. It contains pointers to the command ring, the event channel, a list of active sockets and a list of passive sockets. Lists accesses are protected by a spin_lock. Introduce a waitqueue to allow waiting for a response on commands sent to the backend. Introduce an array of struct xen_pvcalls_response to store commands responses. Introduce a new struct sock_mapping to keep track of sockets. In this patch the struct sock_mapping is minimal, the fields will be added by the next patches. pvcalls_refcount is used to keep count of the outstanding pvcalls users. Only remove connections once the refcount is zero. Implement pvcalls frontend removal function. Go through the list of active and passive sockets and free them all, one at a time. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/pvcalls: introduce the pvcalls xenbus frontendStefano Stabellini2017-10-311-0/+61
Introduce a xenbus frontend 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> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 22:25:25 +0100