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>
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>
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>
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>
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>
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>
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>
Pull xen fixes from Juergen Gross:
- a fix for the Xen gntdev device repairing an issue in case of partial
failure of mapping multiple pages of another domain
- a fix of a regression in the Xen balloon driver introduced in 4.13
- a build fix for Xen on ARM which will trigger e.g. for Linux RT
- a maintainers update for pvops (not really Xen, but carrying through
this tree just for convenience)
* tag 'for-linus-4.14c-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
maintainers: drop Chris Wright from pvops
arm/xen: don't inclide rwlock.h directly.
xen: fix booting ballooned down hvm guest
xen/gntdev: avoid out of bounds access in case of partial gntdev_mmap()
Commit 96edd61dcf ("xen/balloon: don't
online new memory initially") introduced a regression when booting a
HVM domain with memory less than mem-max: instead of ballooning down
immediately the system would try to use the memory up to mem-max
resulting in Xen crashing the domain.
For HVM domains the current size will be reflected in Xenstore node
memory/static-max instead of memory/target.
Additionally we have to trigger the ballooning process at once.
Cc: <stable@vger.kernel.org> # 4.13
Fixes: 96edd61dcf ("xen/balloon: don't
online new memory initially")
Reported-by: Simon Gaiser <hw42@ipsumj.de>
Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
In case gntdev_mmap() succeeds only partially in mapping grant pages
it will leave some vital information uninitialized needed later for
cleanup. This will lead to an out of bounds array access when unmapping
the already mapped pages.
So just initialize the data needed for unmapping the pages a little bit
earlier.
Cc: <stable@vger.kernel.org>
Reported-by: Arthur Borsboom <arthurborsboom@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Pull xen fixes from Juergen Gross:
- avoid a warning when compiling with clang
- consider read-only bits in xen-pciback when writing to a BAR
- fix a boot crash of pv-domains
* tag 'for-linus-4.14c-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/mmu: Call xen_cleanhighmap() with 4MB aligned for page tables mapping
xen-pciback: relax BAR sizing write value check
x86/xen: clean up clang build warning
Just like done in d2bd05d88d ("xen-pciback: return proper values during
BAR sizing") for the ROM BAR, ordinary ones also shouldn't compare the
written value directly against ~0, but consider the r/o bits at the
bottom (if any).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Pull xen fixes from Juergen Gross:
"A fix for a missing __init annotation and two cleanup patches"
* tag 'for-linus-4.14b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen, arm64: drop dummy lookup_address()
xen: don't compile pv-specific parts if XEN_PV isn't configured
xen: x86: mark xen_find_pt_base as __init
xenbus_client.c contains some functions specific for pv guests.
Enclose them with #ifdef CONFIG_XEN_PV to avoid compiling them when
they are not needed (e.g. on ARM).
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation. As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.
The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory. So
this is rather misleading and hard to evaluate for any benefits.
I have checked some random users and none of them has added the flag
with a specific justification. I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring. This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.
I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL. Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.
I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.
This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic. It
seems to be a heuristic without any measured advantage for most (if not
all) its current users. The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers. So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.
[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org
[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull xen updates from Juergen Gross:
- the new pvcalls backend for routing socket calls from a guest to dom0
- some cleanups of Xen code
- a fix for wrong usage of {get,put}_cpu()
* tag 'for-linus-4.14b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (27 commits)
xen/mmu: set MMU_NORMAL_PT_UPDATE in remap_area_mfn_pte_fn
xen: Don't try to call xen_alloc_p2m_entry() on autotranslating guests
xen/events: events_fifo: Don't use {get,put}_cpu() in xen_evtchn_fifo_init()
xen/pvcalls: use WARN_ON(1) instead of __WARN()
xen: remove not used trace functions
xen: remove unused function xen_set_domain_pte()
xen: remove tests for pvh mode in pure pv paths
xen-platform: constify pci_device_id.
xen: cleanup xen.h
xen: introduce a Kconfig option to enable the pvcalls backend
xen/pvcalls: implement write
xen/pvcalls: implement read
xen/pvcalls: implement the ioworker functions
xen/pvcalls: disconnect and module_exit
xen/pvcalls: implement release command
xen/pvcalls: implement poll command
xen/pvcalls: implement accept command
xen/pvcalls: implement listen command
xen/pvcalls: implement bind command
xen/pvcalls: implement connect command
...
Pull driver core update from Greg KH:
"Here is the "big" driver core update for 4.14-rc1.
It's really not all that big, the largest thing here being some
firmware tests to help ensure that that crazy api is working properly.
There's also a new uevent for when a driver is bound or unbound from a
device, fixing a hole in the driver model that's been there since the
very beginning. Many thanks to Dmitry for being persistent and
pointing out how wrong I was about this all along :)
Patches for the new uevents are already in the systemd tree, if people
want to play around with them.
Otherwise just a number of other small api changes and updates here,
nothing major. All of these patches have been in linux-next for a
while with no reported issues"
* tag 'driver-core-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (28 commits)
driver core: bus: Fix a potential double free
Do not disable driver and bus shutdown hook when class shutdown hook is set.
base: topology: constify attribute_group structures.
base: Convert to using %pOF instead of full_name
kernfs: Clarify lockdep name for kn->count
fbdev: uvesafb: remove DRIVER_ATTR() usage
xen: xen-pciback: remove DRIVER_ATTR() usage
driver core: Document struct device:dma_ops
mod_devicetable: Remove excess description from structured comment
test_firmware: add batched firmware tests
firmware: enable a debug print for batched requests
firmware: define pr_fmt
firmware: send -EINTR on signal abort on fallback mechanism
test_firmware: add test case for SIGCHLD on sync fallback
initcall_debug: add deferred probe times
Input: axp20x-pek - switch to using devm_device_add_group()
Input: synaptics_rmi4 - use devm_device_add_group() for attributes in F01
Input: gpio_keys - use devm_device_add_group() for attributes
driver core: add devm_device_add_group() and friends
driver core: add device_{add|remove}_group() helpers
...
Pull x86 apic updates from Thomas Gleixner:
"This update provides:
- Cleanup of the IDT management including the removal of the extra
tracing IDT. A first step to cleanup the vector management code.
- The removal of the paravirt op adjust_exception_frame. This is a
XEN specific issue, but merged through this branch to avoid nasty
merge collisions
- Prevent dmesg spam about the TSC DEADLINE bug, when the CPU has
disabled the TSC DEADLINE timer in CPUID.
- Adjust a debug message in the ioapic code to print out the
information correctly"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
x86/idt: Fix the X86_TRAP_BP gate
x86/xen: Get rid of paravirt op adjust_exception_frame
x86/eisa: Add missing include
x86/idt: Remove superfluous ALIGNment
x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on CPUs without the feature
x86/idt: Remove the tracing IDT leftovers
x86/idt: Hide set_intr_gate()
x86/idt: Simplify alloc_intr_gate()
x86/idt: Deinline setup functions
x86/idt: Remove unused functions/inlines
x86/idt: Move interrupt gate initialization to IDT code
x86/idt: Move APIC gate initialization to tables
x86/idt: Move regular trap init to tables
x86/idt: Move IST stack based traps to table init
x86/idt: Move debug stack init to table based
x86/idt: Switch early trap init to IDT tables
x86/idt: Prepare for table based init
x86/idt: Move early IDT setup out of 32-bit asm
x86/idt: Move early IDT handler setup to IDT code
x86/idt: Consolidate IDT invalidation
...
Commit aba831a69632 ("xen: remove tests for pvh mode in pure pv paths")
removed XENFEAT_auto_translated_physmap test in xen_alloc_p2m_entry()
since it is assumed that the routine is never called by non-PV guests.
However, alloc_xenballooned_pages() may make this call on a PVH guest.
Prevent this from happening by adding XENFEAT_auto_translated_physmap
check there.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Fixes: aba831a69632 ("xen: remove tests for pvh mode in pure pv paths")
Stefano Stabellini
Linus Torvalds
Juergen Gross
Al Viro
Kees Cook
Jan Beulich
Michal Hocko
Jérôme Glisse
Boris Ostrovsky