528 Commits

Author SHA1 Message Date
Harald Freudenberger
b7f6c3630e s390/zcrypt: fix reference counting on zcrypt card objects
[ Upstream commit 50ed48c80fecbe17218afed4f8bed005c802976c ]

Tests with hot-plugging crytpo cards on KVM guests with debug
kernel build revealed an use after free for the load field of
the struct zcrypt_card. The reason was an incorrect reference
handling of the zcrypt card object which could lead to a free
of the zcrypt card object while it was still in use.

This is an example of the slab message:

    kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b
    kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43
    kernel:  kmalloc_trace+0x3f2/0x470
    kernel:  zcrypt_card_alloc+0x36/0x70 [zcrypt]
    kernel:  zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4]
    kernel:  ap_device_probe+0x15c/0x290
    kernel:  really_probe+0xd2/0x468
    kernel:  driver_probe_device+0x40/0xf0
    kernel:  __device_attach_driver+0xc0/0x140
    kernel:  bus_for_each_drv+0x8c/0xd0
    kernel:  __device_attach+0x114/0x198
    kernel:  bus_probe_device+0xb4/0xc8
    kernel:  device_add+0x4d2/0x6e0
    kernel:  ap_scan_adapter+0x3d0/0x7c0
    kernel:  ap_scan_bus+0x5a/0x3b0
    kernel:  ap_scan_bus_wq_callback+0x40/0x60
    kernel:  process_one_work+0x26e/0x620
    kernel:  worker_thread+0x21c/0x440
    kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43
    kernel:  kfree+0x37e/0x418
    kernel:  zcrypt_card_put+0x54/0x80 [zcrypt]
    kernel:  ap_device_remove+0x4c/0xe0
    kernel:  device_release_driver_internal+0x1c4/0x270
    kernel:  bus_remove_device+0x100/0x188
    kernel:  device_del+0x164/0x3c0
    kernel:  device_unregister+0x30/0x90
    kernel:  ap_scan_adapter+0xc8/0x7c0
    kernel:  ap_scan_bus+0x5a/0x3b0
    kernel:  ap_scan_bus_wq_callback+0x40/0x60
    kernel:  process_one_work+0x26e/0x620
    kernel:  worker_thread+0x21c/0x440
    kernel:  kthread+0x150/0x168
    kernel:  __ret_from_fork+0x3c/0x58
    kernel:  ret_from_fork+0xa/0x30
    kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff)
    kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88
    kernel: Redzone  00000000885a74b0: bb bb bb bb bb bb bb bb                          ........
    kernel: Object   00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5  kkkkkkkkkkhKkkk.
    kernel: Redzone  00000000885a7518: bb bb bb bb bb bb bb bb                          ........
    kernel: Padding  00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ
    kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2
    kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux)
    kernel: Call Trace:
    kernel:  [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120
    kernel:  [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140
    kernel:  [<00000000c99d53cc>] check_object+0x334/0x3f8
    kernel:  [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8
    kernel:  [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0
    kernel:  [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8
    kernel:  [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8
    kernel:  [<00000000c99dc8dc>] __kmalloc+0x434/0x590
    kernel:  [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0
    kernel:  [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0
    kernel:  [<00000000c9b919dc>] ext4_htree_fill_tree+0x134/0x400
    kernel:  [<00000000c9b4b3d0>] ext4_dx_readdir+0x160/0x2f0
    kernel:  [<00000000c9b4bedc>] ext4_readdir+0x5f4/0x760
    kernel:  [<00000000c9a7efc4>] iterate_dir+0xb4/0x280
    kernel:  [<00000000c9a7f1ea>] __do_sys_getdents64+0x5a/0x120
    kernel:  [<00000000ca5d6946>] __do_syscall+0x256/0x310
    kernel:  [<00000000ca5eea10>] system_call+0x70/0x98
    kernel: INFO: lockdep is turned off.
    kernel: FIX kmalloc-96: Restoring Poison 0x00000000885a7512-0x00000000885a7513=0x6b
    kernel: FIX kmalloc-96: Marking all objects used

The fix is simple: Before use of the queue not only the queue object
but also the card object needs to increase it's reference count
with a call to zcrypt_card_get(). Similar after use of the queue
not only the queue but also the card object's reference count is
decreased with zcrypt_card_put().

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:36 +02:00
Tony Krowiak
08f65c9067 s390/vfio-ap: fix sysfs status attribute for AP queue devices
[ Upstream commit a0d8f4eeb7c4ffaee21702bcc91a09b3988c5b7a ]

The 'status' attribute for AP queue devices bound to the vfio_ap device
driver displays incorrect status when the mediated device is attached to a
guest, but the queue device is not passed through. In the current
implementation, the status displayed is 'in_use' which is not correct; it
should be 'assigned'. This can happen if one of the queue devices
associated with a given adapter is not bound to the vfio_ap device driver.
For example:

Queues listed in /sys/bus/ap/drivers/vfio_ap:
14.0005
14.0006
14.000d
16.0006
16.000d

Queues listed in /sys/devices/vfio_ap/matrix/$UUID/matrix
14.0005
14.0006
14.000d
16.0005
16.0006
16.000d

Queues listed in /sys/devices/vfio_ap/matrix/$UUID/guest_matrix
14.0005
14.0006
14.000d

The reason no queues for adapter 0x16 are listed in the guest_matrix is
because queue 16.0005 is not bound to the vfio_ap device driver, so no
queue associated with the adapter is passed through to the guest;
therefore, each queue device for adapter 0x16 should display 'assigned'
instead of 'in_use', because those queues are not in use by a guest, but
only assigned to the mediated device.

Let's check the AP configuration for the guest to determine whether a
queue device is passed through before displaying a status of 'in_use'.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Acked-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20231108201135.351419-1-akrowiak@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:49 +00:00
Tony Krowiak
6690a0acbb s390/vfio-ap: let on_scan_complete() callback filter matrix and update guest's APCB
commit 774d10196e648e2c0b78da817f631edfb3dfa557 upstream.

When adapters and/or domains are added to the host's AP configuration, this
may result in multiple queue devices getting created and probed by the
vfio_ap device driver. For each queue device probed, the matrix of adapters
and domains assigned to a matrix mdev will be filtered to update the
guest's APCB. If any adapters or domains get added to or removed from the
APCB, the guest's AP configuration will be dynamically updated (i.e., hot
plug/unplug). To dynamically update the guest's configuration, its VCPUs
must be taken out of SIE for the period of time it takes to make the
update. This is disruptive to the guest's operation and if there are many
queues probed due to a change in the host's AP configuration, this could be
troublesome. The problem is exacerbated by the fact that the
'on_scan_complete' callback also filters the mdev's matrix and updates
the guest's AP configuration.

In order to reduce the potential amount of disruption to the guest that may
result from a change to the host's AP configuration, let's bypass the
filtering of the matrix and updating of the guest's AP configuration in the
probe callback - if due to a host config change - and defer it until the
'on_scan_complete' callback is invoked after the AP bus finishes its device
scan operation. This way the filtering and updating will be performed only
once regardless of the number of queues added.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: 48cae940c31d ("s390/vfio-ap: refresh guest's APCB by filtering AP resources assigned to mdev")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240115185441.31526-4-akrowiak@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:16:59 -08:00
Tony Krowiak
baf3fcb268 s390/vfio-ap: loop over the shadow APCB when filtering guest's AP configuration
commit 16fb78cbf56e42b8efb2682a4444ab59e32e7959 upstream.

While filtering the mdev matrix, it doesn't make sense - and will have
unexpected results - to filter an APID from the matrix if the APID or one
of the associated APQIs is not in the host's AP configuration. There are
two reasons for this:

1. An adapter or domain that is not in the host's AP configuration can be
   assigned to the matrix; this is known as over-provisioning. Queue
   devices, however, are only created for adapters and domains in the
   host's AP configuration, so there will be no queues associated with an
   over-provisioned adapter or domain to filter.

2. The adapter or domain may have been externally removed from the host's
   configuration via an SE or HMC attached to a DPM enabled LPAR. In this
   case, the vfio_ap device driver would have been notified by the AP bus
   via the on_config_changed callback and the adapter or domain would
   have already been filtered.

Since the matrix_mdev->shadow_apcb.apm and matrix_mdev->shadow_apcb.aqm are
copied from the mdev matrix sans the APIDs and APQIs not in the host's AP
configuration, let's loop over those bitmaps instead of those assigned to
the matrix.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: 48cae940c31d ("s390/vfio-ap: refresh guest's APCB by filtering AP resources assigned to mdev")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240115185441.31526-3-akrowiak@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:16:59 -08:00
Tony Krowiak
d6b8d034b5 s390/vfio-ap: always filter entire AP matrix
commit 850fb7fa8c684a4c6bf0e4b6978f4ddcc5d43d11 upstream.

The vfio_ap_mdev_filter_matrix function is called whenever a new adapter or
domain is assigned to the mdev. The purpose of the function is to update
the guest's AP configuration by filtering the matrix of adapters and
domains assigned to the mdev. When an adapter or domain is assigned, only
the APQNs associated with the APID of the new adapter or APQI of the new
domain are inspected. If an APQN does not reference a queue device bound to
the vfio_ap device driver, then it's APID will be filtered from the mdev's
matrix when updating the guest's AP configuration.

Inspecting only the APID of the new adapter or APQI of the new domain will
result in passing AP queues through to a guest that are not bound to the
vfio_ap device driver under certain circumstances. Consider the following:

guest's AP configuration (all also assigned to the mdev's matrix):
14.0004
14.0005
14.0006
16.0004
16.0005
16.0006

unassign domain 4
unbind queue 16.0005
assign domain 4

When domain 4 is re-assigned, since only domain 4 will be inspected, the
APQNs that will be examined will be:
14.0004
16.0004

Since both of those APQNs reference queue devices that are bound to the
vfio_ap device driver, nothing will get filtered from the mdev's matrix
when updating the guest's AP configuration. Consequently, queue 16.0005
will get passed through despite not being bound to the driver. This
violates the linux device model requirement that a guest shall only be
given access to devices bound to the device driver facilitating their
pass-through.

To resolve this problem, every adapter and domain assigned to the mdev will
be inspected when filtering the mdev's matrix.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: 48cae940c31d ("s390/vfio-ap: refresh guest's APCB by filtering AP resources assigned to mdev")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240115185441.31526-2-akrowiak@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:16:59 -08:00
Anthony Krowiak
f4518de40a s390/vfio-ap: unpin pages on gisc registration failure
commit 7b2d039da622daa9ba259ac6f38701d542b237c3 upstream.

In the vfio_ap_irq_enable function, after the page containing the
notification indicator byte (NIB) is pinned, the function attempts
to register the guest ISC. If registration fails, the function sets the
status response code and returns without unpinning the page containing
the NIB. In order to avoid a memory leak, the NIB should be unpinned before
returning from the vfio_ap_irq_enable function.

Co-developed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Fixes: 783f0a3ccd79 ("s390/vfio-ap: add s390dbf logging to the vfio_ap_irq_enable function")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20231109164427.460493-2-akrowiak@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:16:58 -08:00
Harald Freudenberger
57e35d9229 s390/ap: fix AP bus crash on early config change callback invocation
commit e14aec23025eeb1f2159ba34dbc1458467c4c347 upstream.

Fix kernel crash in AP bus code caused by very early invocation of the
config change callback function via SCLP.

After a fresh IML of the machine the crypto cards are still offline and
will get switched online only with activation of any LPAR which has the
card in it's configuration. A crypto card coming online is reported
to the LPAR via SCLP and the AP bus offers a callback function to get
this kind of information. However, it may happen that the callback is
invoked before the AP bus init function is complete. As the callback
triggers a synchronous AP bus scan, the scan may already run but some
internal states are not initialized by the AP bus init function resulting
in a crash like this:

  [   11.635859] Unable to handle kernel pointer dereference in virtual kernel address space
  [   11.635861] Failing address: 0000000000000000 TEID: 0000000000000887
  [   11.635862] Fault in home space mode while using kernel ASCE.
  [   11.635864] AS:00000000894c4007 R3:00000001fece8007 S:00000001fece7800 P:000000000000013d
  [   11.635879] Oops: 0004 ilc:1 [#1] SMP
  [   11.635882] Modules linked in:
  [   11.635884] CPU: 5 PID: 42 Comm: kworker/5:0 Not tainted 6.6.0-rc3-00003-g4dbf7cdc6b42 #12
  [   11.635886] Hardware name: IBM 3931 A01 751 (LPAR)
  [   11.635887] Workqueue: events_long ap_scan_bus
  [   11.635891] Krnl PSW : 0704c00180000000 0000000000000000 (0x0)
  [   11.635895]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
  [   11.635897] Krnl GPRS: 0000000001000a00 0000000000000000 0000000000000006 0000000089591940
  [   11.635899]            0000000080000000 0000000000000a00 0000000000000000 0000000000000000
  [   11.635901]            0000000081870c00 0000000089591000 000000008834e4e2 0000000002625a00
  [   11.635903]            0000000081734200 0000038000913c18 000000008834c6d6 0000038000913ac8
  [   11.635906] Krnl Code:>0000000000000000: 0000                illegal
  [   11.635906]            0000000000000002: 0000                illegal
  [   11.635906]            0000000000000004: 0000                illegal
  [   11.635906]            0000000000000006: 0000                illegal
  [   11.635906]            0000000000000008: 0000                illegal
  [   11.635906]            000000000000000a: 0000                illegal
  [   11.635906]            000000000000000c: 0000                illegal
  [   11.635906]            000000000000000e: 0000                illegal
  [   11.635915] Call Trace:
  [   11.635916]  [<0000000000000000>] 0x0
  [   11.635918]  [<000000008834e4e2>] ap_queue_init_state+0x82/0xb8
  [   11.635921]  [<000000008834ba1c>] ap_scan_domains+0x6fc/0x740
  [   11.635923]  [<000000008834c092>] ap_scan_adapter+0x632/0x8b0
  [   11.635925]  [<000000008834c3e4>] ap_scan_bus+0xd4/0x288
  [   11.635927]  [<00000000879a33ba>] process_one_work+0x19a/0x410
  [   11.635930] Discipline DIAG cannot be used without z/VM
  [   11.635930]  [<00000000879a3a2c>] worker_thread+0x3fc/0x560
  [   11.635933]  [<00000000879aea60>] kthread+0x120/0x128
  [   11.635936]  [<000000008792afa4>] __ret_from_fork+0x3c/0x58
  [   11.635938]  [<00000000885ebe62>] ret_from_fork+0xa/0x30
  [   11.635942] Last Breaking-Event-Address:
  [   11.635942]  [<000000008834c6d4>] ap_wait+0xcc/0x148

This patch improves the ap_bus_force_rescan() function which is
invoked by the config change callback by checking if a first
initial AP bus scan has been done. If not, the force rescan request
is simple ignored. Anyhow it does not make sense to trigger AP bus
re-scans even before the very first bus scan is complete.

Cc: stable@vger.kernel.org
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:07:18 +00:00
Holger Dengler
03b808058a s390/pkey: fix PKEY_TYPE_EP11_AES handling in PKEY_CLR2SECK2 IOCTL
[ Upstream commit da2863f15945de100b95c72d5656541d30956c5d ]

Commit 'fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC
private keys")' introduced PKEY_TYPE_EP11_AES for the PKEY_CLR2SECK2
IOCTL to convert an AES clearkey into a securekey of this type.
Unfortunately, all PKEY_CLR2SECK2 IOCTL requests with type
PKEY_TYPE_EP11_AES return with an error (-EINVAL). Fix the handling
for PKEY_TYPE_EP11_AES in PKEY_CLR2SECK2 IOCTL, so that userspace can
convert clearkey blobs into PKEY_TYPE_EP11_AES securekey blobs.

Cc: stable@vger.kernel.org # v5.10+
Fixes: fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC private keys")
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-06 14:56:44 +02:00
Andy Shevchenko
147d8da33a s390/zcrypt: don't leak memory if dev_set_name() fails
[ Upstream commit 6252f47b78031979ad919f971dc8468b893488bd ]

When dev_set_name() fails, zcdn_create() doesn't free the newly
allocated resources. Do it.

Fixes: 00fab2350e6b ("s390/zcrypt: multiple zcrypt device nodes support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230831110000.24279-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:28:03 +02:00
Holger Dengler
f326e37a21 s390/pkey: fix PKEY_TYPE_EP11_AES handling for sysfs attributes
[ Upstream commit b9352e4b9b9eff949bcc6907b8569b3a1d992f1e ]

Commit 'fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC
private keys")' introduced a new PKEY_TYPE_EP11_AES securekey type as
a supplement to the existing PKEY_TYPE_EP11 (which won't work in
environments with session-bound keys). The pkey EP11 securekey
attributes use PKEY_TYPE_EP11_AES (instead of PKEY_TYPE_EP11)
keyblobs, to make the generated keyblobs usable also in environments,
where session-bound keys are required.

There should be no negative impacts to userspace because the internal
structure of the keyblobs is opaque. The increased size of the
generated keyblobs is reflected by the changed size of the attributes.

Fixes: fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC private keys")
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13 09:42:29 +02:00
Holger Dengler
f98ea9abc1 s390/pkey: fix PKEY_TYPE_EP11_AES handling in PKEY_GENSECK2 IOCTL
[ Upstream commit fb249ce7f7bfd8621a38e4ad401ba74b680786d4 ]

Commit 'fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC
private keys")' introduced PKEY_TYPE_EP11_AES for the PKEY_GENSECK2
IOCTL, to enable userspace to generate securekey blobs of this
type. Unfortunately, all PKEY_GENSECK2 IOCTL requests for
PKEY_TYPE_EP11_AES return with an error (-EINVAL). Fix the handling
for PKEY_TYPE_EP11_AES in PKEY_GENSECK2 IOCTL, so that userspace can
generate securekey blobs of this type.

The start of the header and the keyblob, as well as the length need
special handling, depending on the internal keyversion. Add a helper
function that splits an uninitialized buffer into start and size of
the header as well as start and size of the payload, depending on the
requested keyversion.

Do the header-related calculations and the raw genkey request handling
in separate functions. Use the raw genkey request function for
internal purposes.

Fixes: fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC private keys")
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13 09:42:29 +02:00
Holger Dengler
87d452a076 s390/pkey: fix/harmonize internal keyblob headers
[ Upstream commit 37a08f010b7c423b5e4c9ed3b187d21166553007 ]

Commit 'fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC
private keys")' introduced PKEY_TYPE_EP11_AES as a supplement to
PKEY_TYPE_EP11. All pkeys have an internal header/payload structure,
which is opaque to the userspace. The header structures for
PKEY_TYPE_EP11 and PKEY_TYPE_EP11_AES are nearly identical and there
is no reason, why different structures are used. In preparation to fix
the keyversion handling in the broken PKEY IOCTLs, the same header
structure is used for PKEY_TYPE_EP11 and PKEY_TYPE_EP11_AES. This
reduces the number of different code paths and increases the
readability.

Fixes: fa6999e326fe ("s390/pkey: support CCA and EP11 secure ECC private keys")
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13 09:42:29 +02:00
Harald Freudenberger
d4f5dcf68c s390/zcrypt: fix reply buffer calculations for CCA replies
[ Upstream commit 4cfca532ddc3474b3fc42592d0e4237544344b1a ]

The length information for available buffer space for CCA
replies is covered with two fields in the T6 header prepended
on each CCA reply: fromcardlen1 and fromcardlen2. The sum of
these both values must not exceed the AP bus limit for this
card (24KB for CEX8, 12KB CEX7 and older) minus the always
present headers.

The current code adjusted the fromcardlen2 value in case
of exceeding the AP bus limit when there was a non-zero
value given from userspace. Some tests now showed that this
was the wrong assumption. Instead the userspace value given for
this field should always be trusted and if the sum of the
two fields exceeds the AP bus limit for this card the first
field fromcardlen1 should be adjusted instead.

So now the calculation is done with this new insight in mind.
Also some additional checks for overflow have been introduced
and some comments to provide some documentation for future
maintainers of this complicated calculation code.

Furthermore the 128 bytes of fix overhead which is used
in the current code is not correct. Investigations showed
that for a reply always the same two header structs are
prepended before a possible payload. So this is also fixed
with this patch.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 16:10:59 +02:00
Yu Zhe
246d763b79 s390/zcrypt: remove unnecessary (void *) conversions
[ Upstream commit 72c2112ce9d72e6c40dd893f32187a3d34453113 ]

Pointer variables of void * type do not require type cast.

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20230303052155.21072-1-yuzhe@nfschina.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Stable-dep-of: 4cfca532ddc3 ("s390/zcrypt: fix reply buffer calculations for CCA replies")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 16:10:59 +02:00
Harald Freudenberger
25cb64ecc3 s390/zcrypt: do not retry administrative requests
commit af40322e90d4e0093569eceb7d3a28ab635f3e75 upstream.

All kind of administrative requests should not been retried. Some card
firmware detects this and assumes a replay attack. This patch checks
on failure if the low level functions indicate a retry (EAGAIN) and
checks for the ADMIN flag set on the request message.  If this both
are true, the response code for this message is changed to EIO to make
sure the zcrypt API layer does not attempt to retry the request. As of
now the ADMIN flag is set for a request message when
- for EP11 the field 'flags' of the EP11 CPRB struct has the leftmost
  bit set.
- for CCA when the CPRB minor version is 'T3', 'T5', 'T6' or 'T7'.

Please note that the do-not-retry only applies to a request
which has been sent to the card (= has been successfully enqueued) but
the reply indicates some kind of failure and by default it would be
replied. It is totally fine to retry a request if a previous attempt
to enqueue the msg into the firmware queue had some kind of failure
and thus the card has never seen this request.

Reported-by: Frank Uhlig <Frank.Uhlig1@ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-23 13:49:35 +02:00
Holger Dengler
26cfe2faa8 s390/pkey: zeroize key blobs
[ Upstream commit 844cf829e5f33e00b279230470c8c93b58b8c16f ]

Key blobs for the IOCTLs PKEY_KBLOB2PROTK[23] may contain clear key
material. Zeroize the copies of these keys in kernel memory after
creating the protected key.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09 10:34:13 +02:00
Tony Krowiak
6a40fda14b s390/vfio-ap: fix memory leak in vfio_ap device driver
[ Upstream commit 8f8cf767589f2131ae5d40f3758429095c701c84 ]

The device release callback function invoked to release the matrix device
uses the dev_get_drvdata(device *dev) function to retrieve the
pointer to the vfio_matrix_dev object in order to free its storage. The
problem is, this object is not stored as drvdata with the device; since the
kfree function will accept a NULL pointer, the memory for the
vfio_matrix_dev object is never freed.

Since the device being released is contained within the vfio_matrix_dev
object, the container_of macro will be used to retrieve its pointer.

Fixes: 1fde573413b5 ("s390: vfio-ap: base implementation of VFIO AP device driver")
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20230320150447.34557-1-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-06 12:10:46 +02:00
Halil Pasic
19e29653c8 s390: vfio-ap: tighten the NIB validity check
[ Upstream commit a64a6d23874c574d30a9816124b2dc37467f3811 ]

The NIB is architecturally invalid if the address designates a
storage location that is not installed or if it is zero.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: ec89b55e3bce ("s390: ap: implement PAPQ AQIC interception in kernel")
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10 09:33:02 +01:00
Christophe JAILLET
f61744f7b4 s390/vfio-ap: fix an error handling path in vfio_ap_mdev_probe_queue()
[ Upstream commit 08866d34c7099e981918d34aab5d6a437436628f ]

The commit in Fixes: has switch the order of a sysfs_create_group() and a
kzalloc().

It correctly removed the now useless kfree() but forgot to add a
sysfs_remove_group() in case of (unlikely) memory allocation failure.

Add it now.

Fixes: 260f3ea14138 ("s390/vfio-ap: move probe and remove callbacks to vfio_ap_ops.c")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/d0c0a35eec4fa87cb7f3910d8ac4dc0f7dc9008a.1659283738.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10 09:32:53 +01:00
Wei Yongjun
9ac74f0666 s390/ap: fix memory leak in ap_init_qci_info()
If kzalloc() for 'ap_qci_info_old' failed, 'ap_qci_info' shold be
freed before return. Otherwise it is a memory leak.

Link: https://lore.kernel.org/r/20221114110830.542246-1-weiyongjun@huaweicloud.com
Fixes: 283915850a44 ("s390/ap: notify drivers on config changed and scan complete callbacks")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-11-23 16:26:21 +01:00
Harald Freudenberger
b43088f30d s390/zcrypt: fix warning about field-spanning write
This patch fixes the warning

memcpy: detected field-spanning write (size 60) of single field "to" at drivers/s390/crypto/zcrypt_api.h:173 (size 2)
WARNING: CPU: 1 PID: 2114 at drivers/s390/crypto/zcrypt_api.h:173 prep_ep11_ap_msg+0x2c6/0x2e0 [zcrypt]

The code has been rewritten to use a union in combination
with a flex array to clearly state which part of the buffer
the payload is to be copied in via z_copy_from_user
function (which may call memcpy() in case of in-kernel calls).

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Suggested-by: Jürgen Christ <jchrist@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-11-02 22:15:57 +01:00
Jason J. Herne
e38de48044 s390/vfio-ap: Fix memory allocation for mdev_types array
The vfio-ap crypto driver fails to allocate memory for an array of
pointers used to pass supported mdev types to mdev_register_parent().

Since we only support a single mdev type, the fix is to allocate a
single entry in the ap_matrix_dev->mdev_types array.

Link: https://lore.kernel.org/r/20221021145905.15100-1-jjherne@linux.ibm.com
Fixes: da44c340c4fe ("vfio/mdev: simplify mdev_type handling")
Cc: stable@vger.kernel.org
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-10-26 14:47:31 +02:00
Linus Torvalds
d3cf405133 VFIO updates for v6.1-rc1
- Prune private items from vfio_pci_core.h to a new internal header,
    fix missed function rename, and refactor vfio-pci interrupt defines.
    (Jason Gunthorpe)
 
  - Create consistent naming and handling of ioctls with a function per
    ioctl for vfio-pci and vfio group handling, use proper type args
    where available. (Jason Gunthorpe)
 
  - Implement a set of low power device feature ioctls allowing userspace
    to make use of power states such as D3cold where supported.
    (Abhishek Sahu)
 
  - Remove device counter on vfio groups, which had restricted the page
    pinning interface to singleton groups to account for limitations in
    the type1 IOMMU backend.  Document usage as limited to emulated IOMMU
    devices, ie. traditional mdev devices where this restriction is
    consistent.  (Jason Gunthorpe)
 
  - Correct function prefix in hisi_acc driver incurred during previous
    refactoring. (Shameer Kolothum)
 
  - Correct typo and remove redundant warning triggers in vfio-fsl driver.
    (Christophe JAILLET)
 
  - Introduce device level DMA dirty tracking uAPI and implementation in
    the mlx5 variant driver (Yishai Hadas & Joao Martins)
 
  - Move much of the vfio_device life cycle management into vfio core,
    simplifying and avoiding duplication across drivers.  This also
    facilitates adding a struct device to vfio_device which begins the
    introduction of device rather than group level user support and fills
    a gap allowing userspace identify devices as vfio capable without
    implicit knowledge of the driver. (Kevin Tian & Yi Liu)
 
  - Split vfio container handling to a separate file, creating a more
    well defined API between the core and container code, masking IOMMU
    backend implementation from the core, allowing for an easier future
    transition to an iommufd based implementation of the same.
    (Jason Gunthorpe)
 
  - Attempt to resolve race accessing the iommu_group for a device
    between vfio releasing DMA ownership and removal of the device from
    the IOMMU driver.  Follow-up with support to allow vfio_group to
    exist with NULL iommu_group pointer to support existing userspace
    use cases of holding the group file open.  (Jason Gunthorpe)
 
  - Fix error code and hi/lo register manipulation issues in the hisi_acc
    variant driver, along with various code cleanups. (Longfang Liu)
 
  - Fix a prior regression in GVT-g group teardown, resulting in
    unreleased resources. (Jason Gunthorpe)
 
  - A significant cleanup and simplification of the mdev interface,
    consolidating much of the open coded per driver sysfs interface
    support into the mdev core. (Christoph Hellwig)
 
  - Simplification of tracking and locking around vfio_groups that
    fall out from previous refactoring. (Jason Gunthorpe)
 
  - Replace trivial open coded f_ops tests with new helper.
    (Alex Williamson)
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Merge tag 'vfio-v6.1-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Prune private items from vfio_pci_core.h to a new internal header,
   fix missed function rename, and refactor vfio-pci interrupt defines
   (Jason Gunthorpe)

 - Create consistent naming and handling of ioctls with a function per
   ioctl for vfio-pci and vfio group handling, use proper type args
   where available (Jason Gunthorpe)

 - Implement a set of low power device feature ioctls allowing userspace
   to make use of power states such as D3cold where supported (Abhishek
   Sahu)

 - Remove device counter on vfio groups, which had restricted the page
   pinning interface to singleton groups to account for limitations in
   the type1 IOMMU backend. Document usage as limited to emulated IOMMU
   devices, ie. traditional mdev devices where this restriction is
   consistent (Jason Gunthorpe)

 - Correct function prefix in hisi_acc driver incurred during previous
   refactoring (Shameer Kolothum)

 - Correct typo and remove redundant warning triggers in vfio-fsl driver
   (Christophe JAILLET)

 - Introduce device level DMA dirty tracking uAPI and implementation in
   the mlx5 variant driver (Yishai Hadas & Joao Martins)

 - Move much of the vfio_device life cycle management into vfio core,
   simplifying and avoiding duplication across drivers. This also
   facilitates adding a struct device to vfio_device which begins the
   introduction of device rather than group level user support and fills
   a gap allowing userspace identify devices as vfio capable without
   implicit knowledge of the driver (Kevin Tian & Yi Liu)

 - Split vfio container handling to a separate file, creating a more
   well defined API between the core and container code, masking IOMMU
   backend implementation from the core, allowing for an easier future
   transition to an iommufd based implementation of the same (Jason
   Gunthorpe)

 - Attempt to resolve race accessing the iommu_group for a device
   between vfio releasing DMA ownership and removal of the device from
   the IOMMU driver. Follow-up with support to allow vfio_group to exist
   with NULL iommu_group pointer to support existing userspace use cases
   of holding the group file open (Jason Gunthorpe)

 - Fix error code and hi/lo register manipulation issues in the hisi_acc
   variant driver, along with various code cleanups (Longfang Liu)

 - Fix a prior regression in GVT-g group teardown, resulting in
   unreleased resources (Jason Gunthorpe)

 - A significant cleanup and simplification of the mdev interface,
   consolidating much of the open coded per driver sysfs interface
   support into the mdev core (Christoph Hellwig)

 - Simplification of tracking and locking around vfio_groups that fall
   out from previous refactoring (Jason Gunthorpe)

 - Replace trivial open coded f_ops tests with new helper (Alex
   Williamson)

* tag 'vfio-v6.1-rc1' of https://github.com/awilliam/linux-vfio: (77 commits)
  vfio: More vfio_file_is_group() use cases
  vfio: Make the group FD disassociate from the iommu_group
  vfio: Hold a reference to the iommu_group in kvm for SPAPR
  vfio: Add vfio_file_is_group()
  vfio: Change vfio_group->group_rwsem to a mutex
  vfio: Remove the vfio_group->users and users_comp
  vfio/mdev: add mdev available instance checking to the core
  vfio/mdev: consolidate all the description sysfs into the core code
  vfio/mdev: consolidate all the available_instance sysfs into the core code
  vfio/mdev: consolidate all the name sysfs into the core code
  vfio/mdev: consolidate all the device_api sysfs into the core code
  vfio/mdev: remove mtype_get_parent_dev
  vfio/mdev: remove mdev_parent_dev
  vfio/mdev: unexport mdev_bus_type
  vfio/mdev: remove mdev_from_dev
  vfio/mdev: simplify mdev_type handling
  vfio/mdev: embedd struct mdev_parent in the parent data structure
  vfio/mdev: make mdev.h standalone includable
  drm/i915/gvt: simplify vgpu configuration management
  drm/i915/gvt: fix a memory leak in intel_gvt_init_vgpu_types
  ...
2022-10-12 14:46:48 -07:00
Jason Gunthorpe
9c799c224d vfio/mdev: add mdev available instance checking to the core
Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the counter
in the mdev_parent. Implement it using correct locking, fixing mdpy.

Drivers just provide the value in the mdev_driver at registration time
and the core code takes care of maintaining it and exposing the value in
sysfs.

[hch: count instances per-parent instead of per-type, use an atomic_t
 to avoid taking mdev_list_lock in the show method]

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Christoph Hellwig
f2fbc72e6d vfio/mdev: consolidate all the available_instance sysfs into the core code
Every driver just print a number, simply add a method to the mdev_driver
to return it and provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-13-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Christoph Hellwig
0bc79069cc vfio/mdev: consolidate all the name sysfs into the core code
Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name and
provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Jason Gunthorpe
290aac5df8 vfio/mdev: consolidate all the device_api sysfs into the core code
Every driver just emits a static string, simply feed it through the ops
and provide a standard sysfs show function.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-11-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Christoph Hellwig
da44c340c4 vfio/mdev: simplify mdev_type handling
Instead of abusing struct attribute_group to control initialization of
struct mdev_type, just define the actual attributes in the mdev_driver,
allocate the mdev_type structures in the caller and pass them to
mdev_register_parent.

This allows the caller to use container_of to get at the containing
structure and thus significantly simplify the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Christoph Hellwig
89345d5177 vfio/mdev: embedd struct mdev_parent in the parent data structure
Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure.  This
removes the need for a list of parents and the separate mdev_parent
refcount as we can simplify rely on the reference to the parent device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Christoph Hellwig
bdef2b7896 vfio/mdev: make mdev.h standalone includable
Include <linux/device.h> and <linux/uuid.h> so that users of this headers
don't need to do that and remove those includes that aren't needed
any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-4-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-10-04 12:06:58 -06:00
Tony Krowiak
1918f2b20c s390/vfio-ap: bypass unnecessary processing of AP resources
It is not necessary to go through the process of validation, linking of
queues to mdev and vice versa and filtering the APQNs assigned to the
matrix mdev to build an AP configuration for a guest if an adapter or
domain being assigned is already assigned to the matrix mdev. Likewise, it
is not necessary to proceed through the process the unassignment of an
adapter, domain or control domain if it is not assigned to the matrix mdev.

Since it is not necessary to process assignment of a resource already
assigned or process unassignment of a resource that is been assigned,
this patch will bypass all assignment/unassignment operations for an
adapter, domain or control domain under these circumstances.

Not only is assignment of a duplicate adapter or domain unnecessary, it
will also cause a hang situation when removing the matrix mdev to which it is
assigned. The reason is because the same vfio_ap_queue objects with an
APQN containing the APID of the adapter or APQI of the domain being
assigned will get added multiple times to the hashtable that holds them.
This results in the pprev and next pointers of the hlist_node (mdev_qnode
field in the vfio_ap_queue object) pointing to the queue object itself
resulting in an interminable loop when the mdev is removed and the queue
table is iterated to reset the queues.

Cc: stable@vger.kernel.org
Fixes: 11cb2419fafe ("s390/vfio-ap: manage link between queue struct and matrix mdev")
Reported-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-21 22:33:16 +02:00
Yi Liu
7cb5a82eb1 vfio/ap: Use the new device life cycle helpers
and manage available_instances inside @init/@release.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220921104401.38898-10-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-21 14:15:11 -06:00
Harald Freudenberger
0fef40be5d s390/ap: fix crash on older machines based on QCI info missing
On older z series machines (z12 and older) there is no QCI info
available. The AP code took care of this and the AP bus scan then
switched to simple probing via TAPQ.

With commit
283915850a44 ("s390/ap: notify drivers on config changed and scan complete callbacks")
some code was introduced which silently assumed that the QCI info is
always available. However, with KVM simulating an older machine (z12)
the result was a kernel crash. Funnily the same crash does not happen
on LPAR - maybe because NULL is a valid pointer and reading some data
from address 0 also works fine.

This fix now improves the code to be aware that the QCI instruction
may not be available on older machines and thus the two pointers to
QCI info structs may simple be NULL.

However, on a machine not providing the QCI info the two callbacks to
the zcrypt device drivers on_config_changed() and on_scan_complete()
provide parameters which are pointers to a QCI info struct.
These both callbacks are NOT served if there is no QCI info available.
The only consumer of these callbacks is the vfio device driver. This
driver only supports CEX4 and higher. All physical machines which are
able to provide CEX4 cards have QCI support available. So there is
no sense in for example fill the QCI info struct by hand with looping
over cards and queues and TAPQ each APQN.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 283915850a44 ("s390/ap: notify drivers on config changed and scan complete callbacks")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-08-15 17:19:52 +02:00
Linus Torvalds
24cb958695 s390 updates for 5.20 merge window
- Rework copy_oldmem_page() callback to take an iov_iter.
   This includes few prerequisite updates and fixes to the
   oldmem reading code.
 
 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities,
   but also allows CPU facilities.
 
 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.
 
 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.
 
 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto test.
 
 - Fix incorrect recovery of kretprobe modified return address in stacktrace.
 
 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.
 
 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as well
   as to implement more of the AP architecture.
 
 - Minor boot code cleanups.
 
 - Grammar and typo fixes to hmcdrv and tape drivers.
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Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Rework copy_oldmem_page() callback to take an iov_iter.

   This includes a few prerequisite updates and fixes to the oldmem
   reading code.

 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities, but
   also allows CPU facilities.

 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.

 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.

 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto
   test.

 - Fix incorrect recovery of kretprobe modified return address in
   stacktrace.

 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.

 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as
   well as to implement more of the AP architecture.

 - Minor boot code cleanups.

 - Grammar and typo fixes to hmcdrv and tape drivers.

* tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
  Revert "s390/smp: enforce lowcore protection on CPU restart"
  Revert "s390/smp: rework absolute lowcore access"
  Revert "s390/smp,ptdump: add absolute lowcore markers"
  s390/unwind: fix fgraph return address recovery
  s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit()
  s390: add ELF note type for encrypted CPU state of a PV VCPU
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/setup: rearrange absolute lowcore initialization
  s390/boot: cleanup adjust_to_uv_max() function
  s390/smp: enforce lowcore protection on CPU restart
  s390/tape: fix comment typo
  s390/hmcdrv: fix Kconfig "its" grammar
  s390/docs: fix warnings for vfio_ap driver doc
  s390/docs: fix warnings for vfio_ap driver lock usage doc
  s390/crash: support multi-segment iterators
  s390/crash: use static swap buffer for copy_to_user_real()
  s390/crash: move copy_to_user_real() to crash_dump.c
  s390/zcore: fix race when reading from hardware system area
  s390/crash: fix incorrect number of bytes to copy to user space
  ...
2022-08-06 17:05:21 -07:00
Linus Torvalds
a9cf69d0e7 VFIO updates for v6.0-rc1
- Cleanup use of extern in function prototypes (Alex Williamson)
 
  - Simplify bus_type usage and convert to device IOMMU interfaces
    (Robin Murphy)
 
  - Check missed return value and fix comment typos (Bo Liu)
 
  - Split migration ops from device ops and fix races in mlx5 migration
    support (Yishai Hadas)
 
  - Fix missed return value check in noiommu support (Liam Ni)
 
  - Hardening to clear buffer pointer to avoid use-after-free (Schspa Shi)
 
  - Remove requirement that only the same mm can unmap a previously
    mapped range (Li Zhe)
 
  - Adjust semaphore release vs device open counter (Yi Liu)
 
  - Remove unused arg from SPAPR support code (Deming Wang)
 
  - Rework vfio-ccw driver to better fit new mdev framework (Eric Farman,
    Michael Kawano)
 
  - Replace DMA unmap notifier with callbacks (Jason Gunthorpe)
 
  - Clarify SPAPR support comment relative to iommu_ops (Alexey Kardashevskiy)
 
  - Revise page pinning API towards compatibility with future iommufd support
    (Nicolin Chen)
 
  - Resolve issues in vfio-ccw, including use of DMA unmap callback
    (Eric Farman)
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Merge tag 'vfio-v6.0-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Cleanup use of extern in function prototypes (Alex Williamson)

 - Simplify bus_type usage and convert to device IOMMU interfaces (Robin
   Murphy)

 - Check missed return value and fix comment typos (Bo Liu)

 - Split migration ops from device ops and fix races in mlx5 migration
   support (Yishai Hadas)

 - Fix missed return value check in noiommu support (Liam Ni)

 - Hardening to clear buffer pointer to avoid use-after-free (Schspa
   Shi)

 - Remove requirement that only the same mm can unmap a previously
   mapped range (Li Zhe)

 - Adjust semaphore release vs device open counter (Yi Liu)

 - Remove unused arg from SPAPR support code (Deming Wang)

 - Rework vfio-ccw driver to better fit new mdev framework (Eric Farman,
   Michael Kawano)

 - Replace DMA unmap notifier with callbacks (Jason Gunthorpe)

 - Clarify SPAPR support comment relative to iommu_ops (Alexey
   Kardashevskiy)

 - Revise page pinning API towards compatibility with future iommufd
   support (Nicolin Chen)

 - Resolve issues in vfio-ccw, including use of DMA unmap callback (Eric
   Farman)

* tag 'vfio-v6.0-rc1' of https://github.com/awilliam/linux-vfio: (40 commits)
  vfio/pci: fix the wrong word
  vfio/ccw: Check return code from subchannel quiesce
  vfio/ccw: Remove FSM Close from remove handlers
  vfio/ccw: Add length to DMA_UNMAP checks
  vfio: Replace phys_pfn with pages for vfio_pin_pages()
  vfio/ccw: Add kmap_local_page() for memcpy
  vfio: Rename user_iova of vfio_dma_rw()
  vfio/ccw: Change pa_pfn list to pa_iova list
  vfio/ap: Change saved_pfn to saved_iova
  vfio: Pass in starting IOVA to vfio_pin/unpin_pages API
  vfio/ccw: Only pass in contiguous pages
  vfio/ap: Pass in physical address of ind to ap_aqic()
  drm/i915/gvt: Replace roundup with DIV_ROUND_UP
  vfio: Make vfio_unpin_pages() return void
  vfio/spapr_tce: Fix the comment
  vfio: Replace the iommu notifier with a device list
  vfio: Replace the DMA unmapping notifier with a callback
  vfio/ccw: Move FSM open/close to MDEV open/close
  vfio/ccw: Refactor vfio_ccw_mdev_reset
  vfio/ccw: Create a CLOSE FSM event
  ...
2022-08-06 08:59:35 -07:00
Paolo Bonzini
63f4b21041 Merge remote-tracking branch 'kvm/next' into kvm-next-5.20
KVM/s390, KVM/x86 and common infrastructure changes for 5.20

x86:

* Permit guests to ignore single-bit ECC errors

* Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache

* Intel IPI virtualization

* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS

* PEBS virtualization

* Simplify PMU emulation by just using PERF_TYPE_RAW events

* More accurate event reinjection on SVM (avoid retrying instructions)

* Allow getting/setting the state of the speaker port data bit

* Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent

* "Notify" VM exit (detect microarchitectural hangs) for Intel

* Cleanups for MCE MSR emulation

s390:

* add an interface to provide a hypervisor dump for secure guests

* improve selftests to use TAP interface

* enable interpretive execution of zPCI instructions (for PCI passthrough)

* First part of deferred teardown

* CPU Topology

* PV attestation

* Minor fixes

Generic:

* new selftests API using struct kvm_vcpu instead of a (vm, id) tuple

x86:

* Use try_cmpxchg64 instead of cmpxchg64

* Bugfixes

* Ignore benign host accesses to PMU MSRs when PMU is disabled

* Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior

* x86/MMU: Allow NX huge pages to be disabled on a per-vm basis

* Port eager page splitting to shadow MMU as well

* Enable CMCI capability by default and handle injected UCNA errors

* Expose pid of vcpu threads in debugfs

* x2AVIC support for AMD

* cleanup PIO emulation

* Fixes for LLDT/LTR emulation

* Don't require refcounted "struct page" to create huge SPTEs

x86 cleanups:

* Use separate namespaces for guest PTEs and shadow PTEs bitmasks

* PIO emulation

* Reorganize rmap API, mostly around rmap destruction

* Do not workaround very old KVM bugs for L0 that runs with nesting enabled

* new selftests API for CPUID
2022-08-01 03:21:00 -04:00
Nicolin Chen
34a255e676 vfio: Replace phys_pfn with pages for vfio_pin_pages()
Most of the callers of vfio_pin_pages() want "struct page *" and the
low-level mm code to pin pages returns a list of "struct page *" too.
So there's no gain in converting "struct page *" to PFN in between.

Replace the output parameter "phys_pfn" list with a "pages" list, to
simplify callers. This also allows us to replace the vfio_iommu_type1
implementation with a more efficient one.

And drop the pfn_valid check in the gvt code, as there is no need to
do such a check at a page-backed struct page pointer.

For now, also update vfio_iommu_type1 to fit this new parameter too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25 13:41:22 -06:00
Nicolin Chen
3fad3a2613 vfio/ap: Change saved_pfn to saved_iova
The vfio_ap_ops code maintains both nib address and its PFN, which
is redundant, merely because vfio_pin/unpin_pages API wanted pfn.
Since vfio_pin/unpin_pages() now accept "iova", change "saved_pfn"
to "saved_iova" and remove pfn in the vfio_ap_validate_nib().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-7-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25 13:41:22 -06:00
Nicolin Chen
44abdd1646 vfio: Pass in starting IOVA to vfio_pin/unpin_pages API
The vfio_pin/unpin_pages() so far accepted arrays of PFNs of user IOVA.
Among all three callers, there was only one caller possibly passing in
a non-contiguous PFN list, which is now ensured to have contiguous PFN
inputs too.

Pass in the starting address with "iova" alone to simplify things, so
callers no longer need to maintain a PFN list or to pin/unpin one page
at a time. This also allows VFIO to use more efficient implementations
of pin/unpin_pages.

For now, also update vfio_iommu_type1 to fit this new parameter too,
while keeping its input intact (being user_iova) since we don't want
to spend too much effort swapping its parameters and local variables
at that level.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-6-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-25 13:41:22 -06:00
Nicolin Chen
10e19d492a vfio/ap: Pass in physical address of ind to ap_aqic()
The ap_aqic() is called by vfio_ap_irq_enable() where it passes in a
virt value that's casted from a physical address "h_nib". Inside the
ap_aqic(), it does virt_to_phys() again.

Since ap_aqic() needs a physical address, let's just pass in a pa of
ind directly. So change the "ind" to "pa_ind".

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-4-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-23 07:29:10 -06:00
Jason Gunthorpe
ce4b4657ff vfio: Replace the DMA unmapping notifier with a callback
Instead of having drivers register the notifier with explicit code just
have them provide a dma_unmap callback op in their driver ops and rely on
the core code to wire it up.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-20 11:57:59 -06:00
Heiko Carstens
0a5f9b382c s390/cpufeature: rework to allow more than only hwcap bits
Rework cpufeature implementation to allow for various cpu feature
indications, which is not only limited to hwcap bits. This is achieved
by adding a sequential list of cpu feature numbers, where each of them
is mapped to an entry which indicates what this number is about.

Each entry contains a type member, which indicates what feature
name space to look into (e.g. hwcap, or cpu facility). If wanted this
allows also to automatically load modules only in e.g. z/VM
configurations.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713125644.16121-2-seiden@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:49 +02:00
Tony Krowiak
eeb386aeb5 s390/vfio-ap: handle config changed and scan complete notification
This patch implements two new AP driver callbacks:

void (*on_config_changed)(struct ap_config_info *new_config_info,
                  struct ap_config_info *old_config_info);

void (*on_scan_complete)(struct ap_config_info *new_config_info,
                 struct ap_config_info *old_config_info);

The on_config_changed callback is invoked at the start of the AP bus scan
function when it determines that the host AP configuration information
has changed since the previous scan.

The vfio_ap device driver registers a callback function for this callback
that performs the following operations:

1. Unplugs the adapters, domains and control domains removed from the
host's AP configuration from the guests to which they are
assigned in a single operation.

2. Stores bitmaps identifying the adapters, domains and control domains
added to the host's AP configuration with the structure representing
the mediated device. When the vfio_ap device driver's probe callback is
subsequently invoked, the probe function will recognize that the
queue is being probed due to a change in the host's AP configuration
and the plugging of the queue into the guest will be bypassed.

The on_scan_complete callback is invoked after the ap bus scan is
completed if the host AP configuration data has changed. The vfio_ap
device driver registers a callback function for this callback that hot
plugs each queue and control domain added to the AP configuration for each
guest using them in a single hot plug operation.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:12 +02:00
Tony Krowiak
f7f795c54d s390/vfio-ap: sysfs attribute to display the guest's matrix
The matrix of adapters and domains configured in a guest's APCB may
differ from the matrix of adapters and domains assigned to the matrix mdev,
so this patch introduces a sysfs attribute to display the matrix of
adapters and domains that are or will be assigned to the APCB of a guest
that is or will be using the matrix mdev. For a matrix mdev denoted by
$uuid, the guest matrix can be displayed as follows:

   cat /sys/devices/vfio_ap/matrix/$uuid/guest_matrix

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
3f85d1df26 s390/vfio-ap: implement in-use callback for vfio_ap driver
Let's implement the callback to indicate when an APQN
is in use by the vfio_ap device driver. The callback is
invoked whenever a change to the apmask or aqmask would
result in one or more queue devices being removed from the driver. The
vfio_ap device driver will indicate a resource is in use
if the APQN of any of the queue devices to be removed are assigned to
any of the matrix mdevs under the driver's control.

There is potential for a deadlock condition between the
matrix_dev->guests_lock used to lock the guest during assignment of
adapters and domains and the ap_perms_mutex locked by the AP bus when
changes are made to the sysfs apmask/aqmask attributes.

The AP Perms lock controls access to the objects that store the adapter
numbers (ap_perms) and domain numbers (aq_perms) for the sysfs
/sys/bus/ap/apmask and /sys/bus/ap/aqmask attributes. These attributes
identify which queues are reserved for the zcrypt default device drivers.
Before allowing a bit to be removed from either mask, the AP bus must check
with the vfio_ap device driver to verify that none of the queues are
assigned to any of its mediated devices.

The apmask/aqmask attributes can be written or read at any time from
userspace, so care must be taken to prevent a deadlock with asynchronous
operations that might be taking place in the vfio_ap device driver. For
example, consider the following:

1. A system administrator assigns an adapter to a mediated device under the
   control of the vfio_ap device driver. The driver will need to first take
   the matrix_dev->guests_lock to potentially hot plug the adapter into
   the KVM guest.
2. At the same time, a system administrator sets a bit in the sysfs
   /sys/bus/ap/ap_mask attribute. To complete the operation, the AP bus
   must:
   a. Take the ap_perms_mutex lock to update the object storing the values
      for the /sys/bus/ap/ap_mask attribute.
   b. Call the vfio_ap device driver's in-use callback to verify that the
      queues now being reserved for the default zcrypt drivers are not
      assigned to a mediated device owned by the vfio_ap device driver. To
      do the verification, the in-use callback function takes the
      matrix_dev->guests_lock, but has to wait because it is already held
      by the operation in 1 above.
3. The vfio_ap device driver calls an AP bus function to verify that the
   new queues resulting from the assignment of the adapter in step 1 are
   not reserved for the default zcrypt device driver. This AP bus function
   tries to take the ap_perms_mutex lock but gets stuck waiting for the
   waiting for the lock due to step 2a above.

Consequently, we have the following deadlock situation:

matrix_dev->guests_lock locked (1)
ap_perms_mutex lock locked (2a)
Waiting for matrix_dev->gusts_lock (2b) which is currently held (1)
Waiting for ap_perms_mutex lock (3) which is currently held (2a)

To prevent this deadlock scenario, the function called in step 3 will no
longer take the ap_perms_mutex lock and require the caller to take the
lock. The lock will be the first taken by the adapter/domain assignment
functions in the vfio_ap device driver to maintain the proper locking
order.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
70aeefe574 s390/vfio-ap: reset queues after adapter/domain unassignment
When an adapter or domain is unassigned from an mdev attached to a KVM
guest, one or more of the guest's queues may get dynamically removed. Since
the removed queues could get re-assigned to another mdev, they need to be
reset. So, when an adapter or domain is unassigned from the mdev, the
queues that are removed from the guest's AP configuration (APCB) will be
reset.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
09d31ff787 s390/vfio-ap: hot plug/unplug of AP devices when probed/removed
When an AP queue device is probed or removed, if the mediated device is
attached to a KVM guest, the mediated device's adapter, domain and
control domain bitmaps must be filtered to update the guest's APCB and if
any changes are detected, the guest's APCB must then be hot plugged into
the guest to reflect those changes to the guest.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
51dc562af0 s390/vfio-ap: allow hot plug/unplug of AP devices when assigned/unassigned
Let's hot plug an adapter, domain or control domain into the guest when it
is assigned to a matrix mdev that is attached to a KVM guest. Likewise,
let's hot unplug an adapter, domain or control domain from the guest when
it is unassigned from a matrix_mdev that is attached to a KVM guest.

Whenever an assignment or unassignment of an adapter, domain or control
domain is performed, the APQNs and control domains assigned to the matrix
mdev will be filtered and assigned to the AP control block
(APCB) that supplies the AP configuration to the guest so that no
adapter, domain or control domain that is not in the host's AP
configuration nor any APQN that does not reference a queue device bound
to the vfio_ap device driver is assigned.

After updating the APCB, if the mdev is in use by a KVM guest, it is
hot plugged into the guest to dynamically provide access to the adapters,
domains and control domains provided via the newly refreshed APCB.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
2c1ee8983a s390/vfio-ap: prepare for dynamic update of guest's APCB on queue probe/remove
The callback functions for probing and removing a queue device must take
and release the locks required to perform a dynamic update of a guest's
APCB in the proper order.

The proper order for taking the locks is:

        matrix_dev->guests_lock => kvm->lock => matrix_dev->mdevs_lock

The proper order for releasing the locks is:

        matrix_dev->mdevs_lock => kvm->lock => matrix_dev->guests_lock

A new helper function is introduced to be used by the probe callback to
acquire the required locks. Since the probe callback only has
access to a queue device when it is called, the helper function will find
the ap_matrix_mdev object to which the queue device's APQN is assigned and
return it so the KVM guest to which the mdev is attached can be dynamically
updated.

Note that in order to find the ap_matrix_mdev (matrix_mdev) object, it is
necessary to search the matrix_dev->mdev_list. This presents a
locking order dilemma because the matrix_dev->mdevs_lock can't be taken to
protect against changes to the list while searching for the matrix_mdev to
which a queue device's APQN is assigned. This is due to the fact that the
proper locking order requires that the matrix_dev->mdevs_lock be taken
after both the matrix_mdev->kvm->lock and the matrix_dev->mdevs_lock.
Consequently, the matrix_dev->guests_lock will be used to protect against
removal of a matrix_mdev object from the list while a queue device is
being probed. This necessitates changes to the mdev probe/remove
callback functions to take the matrix_dev->guests_lock prior to removing
a matrix_mdev object from the list.

A new macro is also introduced to acquire the locks required to dynamically
update the guest's APCB in the proper order when a queue device is
removed.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
8ee13ad993 s390/vfio-ap: prepare for dynamic update of guest's APCB on assign/unassign
The functions backing the matrix mdev's sysfs attribute interfaces to
assign/unassign adapters, domains and control domains must take and
release the locks required to perform a dynamic update of a guest's APCB
in the proper order.

The proper order for taking the locks is:

matrix_dev->guests_lock => kvm->lock => matrix_dev->mdevs_lock

The proper order for releasing the locks is:

matrix_dev->mdevs_lock => kvm->lock => matrix_dev->guests_lock

Two new macros are introduced for this purpose: One to take the locks and
the other to release the locks. These macros will be used by the
assignment/unassignment functions to prepare for dynamic update of
the KVM guest's APCB.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00