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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Improve stop_machine wait logic: replace cpu_relax_yield call in
generic stop_machine function with a weak stop_machine_yield
function. This is overridden on s390, which yields the current cpu to
the neighbouring cpu after a couple of retries, instead of blindly
giving up the cpu to the hipervisor. This significantly improves
stop_machine performance on s390 in overcommitted scenarios.
This includes common code changes which have been Acked by Peter
Zijlstra and Thomas Gleixner.
- Improve jump label transformation speed: transform jump labels
without using stop_machine.
- Refactoring of the vfio-ccw cp handling, simplifying the code and
avoiding unneeded allocating/copying.
- Various vfio-ccw fixes (ccw translation, state machine).
- Add support for vfio-ap queue interrupt control in the guest. This
includes s390 kvm changes which have been Acked by Christian
Borntraeger.
- Add protected virtualization support for virtio-ccw.
- Enforce both CONFIG_SMP and CONFIG_HOTPLUG_CPU, which allows to
remove some code which most likely isn't working at all, besides that
s390 didn't even compile for !CONFIG_SMP.
- Support for special flagged EP11 CPRBs for zcrypt.
- Handle PCI devices with no support for new MIO instructions.
- Avoid KASAN false positives in reworked stack unwinder.
- Couple of fixes for the QDIO layer.
- Convert s390 specific documentation to ReST format.
- Let s390 crypto modules return -ENODEV instead of -EOPNOTSUPP if
hardware is missing. This way our modules behave like most other
modules and which is also what systemd's systemd-modules-load.service
expects.
- Replace defconfig with performance_defconfig, so there is one config
file less to maintain.
- Remove the SCLP call home device driver, which was never useful.
- Cleanups all over the place.
* tag 's390-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (83 commits)
docs: s390: s390dbf: typos and formatting, update crash command
docs: s390: unify and update s390dbf kdocs at debug.c
docs: s390: restore important non-kdoc parts of s390dbf.rst
vfio-ccw: Fix the conversion of Format-0 CCWs to Format-1
s390/pci: correctly handle MIO opt-out
s390/pci: deal with devices that have no support for MIO instructions
s390: ap: kvm: Enable PQAP/AQIC facility for the guest
s390: ap: implement PAPQ AQIC interception in kernel
vfio: ap: register IOMMU VFIO notifier
s390: ap: kvm: add PQAP interception for AQIC
s390/unwind: cleanup unused READ_ONCE_TASK_STACK
s390/kasan: avoid false positives during stack unwind
s390/qdio: don't touch the dsci in tiqdio_add_input_queues()
s390/qdio: (re-)initialize tiqdio list entries
s390/dasd: Fix a precision vs width bug in dasd_feature_list()
s390/cio: introduce driver_override on the css bus
vfio-ccw: make convert_ccw0_to_ccw1 static
vfio-ccw: Remove copy_ccw_from_iova()
vfio-ccw: Factor out the ccw0-to-ccw1 transition
vfio-ccw: Copy CCW data outside length calculation
...
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Rather than allocating/freeing a piece of memory every time
we try to figure out how long a CCW chain is, let's use a piece
of memory allocated for each device.
The io_mutex added with commit 4f76617378ee9 ("vfio-ccw: protect
the I/O region") is held for the duration of the VFIO_CCW_EVENT_IO_REQ
event that accesses/uses this space, so there should be no race
concerns with another CPU attempting an (unexpected) SSCH for the
same device.
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190618202352.39702-2-farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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Free the vfio_ccw_cmd_region on module exit.
Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions")
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <c0f39039d28af39ea2939391bf005e3495d890fd.1559576250.git.alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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Otherwise, the guest can believe it's okay to start another I/O
and bump into the non-idle state. This results in a cc=2 (with
the asynchronous CSCH/HSCH code) returned to the guest, which is
unfortunate since everything is otherwise working normally.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20190514234248.36203-3-farman@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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The quiesce function calls cio_cancel_halt_clear() and if we
get an -EBUSY we go into a loop where we:
- wait for any interrupts
- flush all I/O in the workqueue
- retry cio_cancel_halt_clear
During the period where we are waiting for interrupts or
flushing all I/O, the channel subsystem could have completed
a halt/clear action and turned off the corresponding activity
control bits in the subchannel status word. This means the next
time we call cio_cancel_halt_clear(), we will again start by
calling cancel subchannel and so we can be stuck between calling
cancel and halt forever.
Rather than calling cio_cancel_halt_clear() immediately after
waiting, let's try to disable the subchannel. If we succeed in
disabling the subchannel then we know nothing else can happen
with the device.
Suggested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <4d5a4b98ab1b41ac6131b5c36de18b76c5d66898.1555449329.git.alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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Currently we call flush_workqueue while holding the subchannel
spinlock. But flush_workqueue function can go to sleep, so
do not call the function while holding the spinlock.
Fixes the following bug:
[ 285.203430] BUG: scheduling while atomic: bash/14193/0x00000002
[ 285.203434] INFO: lockdep is turned off.
....
[ 285.203485] Preemption disabled at:
[ 285.203488] [<000003ff80243e5c>] vfio_ccw_sch_quiesce+0xbc/0x120 [vfio_ccw]
[ 285.203496] CPU: 7 PID: 14193 Comm: bash Tainted: G W
....
[ 285.203504] Call Trace:
[ 285.203510] ([<0000000000113772>] show_stack+0x82/0xd0)
[ 285.203514] [<0000000000b7a102>] dump_stack+0x92/0xd0
[ 285.203518] [<000000000017b8be>] __schedule_bug+0xde/0xf8
[ 285.203524] [<0000000000b95b5a>] __schedule+0x7a/0xc38
[ 285.203528] [<0000000000b9678a>] schedule+0x72/0xb0
[ 285.203533] [<0000000000b9bfbc>] schedule_timeout+0x34/0x528
[ 285.203538] [<0000000000b97608>] wait_for_common+0x118/0x1b0
[ 285.203544] [<0000000000166d6a>] flush_workqueue+0x182/0x548
[ 285.203550] [<000003ff80243e6e>] vfio_ccw_sch_quiesce+0xce/0x120 [vfio_ccw]
[ 285.203556] [<000003ff80245278>] vfio_ccw_mdev_reset+0x38/0x70 [vfio_ccw]
[ 285.203562] [<000003ff802458b0>] vfio_ccw_mdev_remove+0x40/0x78 [vfio_ccw]
[ 285.203567] [<000003ff801a499c>] mdev_device_remove_ops+0x3c/0x80 [mdev]
[ 285.203573] [<000003ff801a4d5c>] mdev_device_remove+0xc4/0x130 [mdev]
[ 285.203578] [<000003ff801a5074>] remove_store+0x6c/0xa8 [mdev]
[ 285.203582] [<000000000046f494>] kernfs_fop_write+0x14c/0x1f8
[ 285.203588] [<00000000003c1530>] __vfs_write+0x38/0x1a8
[ 285.203593] [<00000000003c187c>] vfs_write+0xb4/0x198
[ 285.203597] [<00000000003c1af2>] ksys_write+0x5a/0xb0
[ 285.203601] [<0000000000b9e270>] system_call+0xdc/0x2d8
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <626bab8bb2958ae132452e1ddaf1b20882ad5a9d.1554756534.git.alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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Add a region to the vfio-ccw device that can be used to submit
asynchronous I/O instructions. ssch continues to be handled by the
existing I/O region; the new region handles hsch and csch.
Interrupt status continues to be reported through the same channels
as for ssch.
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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Introduce a mutex to disallow concurrent reads or writes to the
I/O region. This makes sure that the data the kernel or user
space see is always consistent.
The same mutex will be used to protect the async region as well.
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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When we get an interrupt for a channel program, it is not
necessarily the final interrupt; for example, the issuing
guest may request an intermediate interrupt by specifying
the program-controlled-interrupt flag on a ccw.
We must not switch the state to idle if the interrupt is not
yet final; even more importantly, we must not free the translated
channel program if the interrupt is not yet final, or the host
can crash during cp rewind.
Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously")
Cc: stable@vger.kernel.org # v4.12+
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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Let's register the mediated device when all the data structures
which could be used are initialized.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <1540487720-11634-3-git-send-email-pmorel@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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Fix the following sparse warning:
drivers/s390/cio/vfio_ccw_drv.c:25:19: warning: symbol 'vfio_ccw_io_region'
was not declared. Should it be static?
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Message-Id: <alpine.LFD.2.21.1810151328570.1636@schleppi.aag-de.ibmmobiledemo.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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If I attach a vfio-ccw device to my guest, I get the following warning
on the host when the host kernel is CONFIG_HARDENED_USERCOPY=y
[250757.595325] Bad or missing usercopy whitelist? Kernel memory overwrite attempt detected to SLUB object 'dma-kmalloc-512' (offset 64, size 124)!
[250757.595365] WARNING: CPU: 2 PID: 10958 at mm/usercopy.c:81 usercopy_warn+0xac/0xd8
[250757.595369] Modules linked in: kvm vhost_net vhost tap xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c devlink tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables sunrpc dm_multipath s390_trng crc32_vx_s390 ghash_s390 prng aes_s390 des_s390 des_generic sha512_s390 sha1_s390 eadm_sch tape_3590 tape tape_class qeth_l2 qeth ccwgroup vfio_ccw vfio_mdev zcrypt_cex4 mdev vfio_iommu_type1 zcrypt vfio sha256_s390 sha_common zfcp scsi_transport_fc qdio dasd_eckd_mod dasd_mod
[250757.595424] CPU: 2 PID: 10958 Comm: CPU 2/KVM Not tainted 4.18.0-derp #2
[250757.595426] Hardware name: IBM 3906 M05 780 (LPAR)
...snip regs...
[250757.595523] Call Trace:
[250757.595529] ([<0000000000349210>] usercopy_warn+0xa8/0xd8)
[250757.595535] [<000000000032daaa>] __check_heap_object+0xfa/0x160
[250757.595540] [<0000000000349396>] __check_object_size+0x156/0x1d0
[250757.595547] [<000003ff80332d04>] vfio_ccw_mdev_write+0x74/0x148 [vfio_ccw]
[250757.595552] [<000000000034ed12>] __vfs_write+0x3a/0x188
[250757.595556] [<000000000034f040>] vfs_write+0xa8/0x1b8
[250757.595559] [<000000000034f4e6>] ksys_pwrite64+0x86/0xc0
[250757.595568] [<00000000008959a0>] system_call+0xdc/0x2b0
[250757.595570] Last Breaking-Event-Address:
[250757.595573] [<0000000000349210>] usercopy_warn+0xa8/0xd8
While vfio_ccw_mdev_{write|read} validates that the input position/count
does not run over the ccw_io_region struct, the usercopy code that does
copy_{to|from}_user doesn't necessarily know this. It sees the variable
length and gets worried that it's affecting a normal kmalloc'd struct,
and generates the above warning.
Adjust how the ccw_io_region is alloc'd with a whitelist to remove this
warning. The boundary checking will continue to do its thing.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20180921204013.95804-3-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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In the event that we want to change the layout of the ccw_io_region in the
future[1], it might be easier to work with it as a pointer within the
vfio_ccw_private struct rather than an embedded struct.
[1] https://patchwork.kernel.org/comment/22228541/
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20180921204013.95804-2-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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If the device has not been registered, or there is work pending,
we should reschedule a sch_event call again.
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20180502072559.50691-1-bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Update the drivers/s390/cio/ files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Fix this set but not used warning:
drivers/s390/cio/vfio_ccw_drv.c: In function 'vfio_ccw_sch_io_todo':
drivers/s390/cio/vfio_ccw_drv.c:72:21: warning: variable 'sch' set but not used [-Wunused-but-set-variable]
struct subchannel *sch;
^
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The sysfs attributes implemented by the vfio_ccw driver are also implemented by
the io_subchannel driver. Move these into a device_type which is set by the
css bus.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The current implementation doesn't check if the subchannel is in a
proper device state when handling an event. Let's introduce
a finite state machine to manage the state/event change.
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-14-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
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Introduce a singlethreaded workqueue to handle the I/O interrupts.
With the work added to this queue, we store the I/O results to the
io_region of the subchannel, then signal the userspace program to
handle the results.
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-13-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
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We implement the basic ccw command handling infrastructure
here:
1. Translate the ccw commands.
2. Issue the translated ccw commands to the device.
3. Once we get the execution result, update the guest SCSW
with it.
Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-9-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
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To make vfio support subchannel devices, we need to leverage the
mediated device framework to create a mediated device for the
subchannel device.
This registers the subchannel device to the mediated device
framework during probe to enable mediated device creation.
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-7-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
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To make vfio support subchannel devices, we need a css driver for
the vfio subchannels. This patch adds a basic vfio-ccw subchannel
driver for this purpose.
To enable VFIO for vfio-ccw, enable S390_CCW_IOMMU config option
and configure VFIO as required.
Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-5-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
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