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2019-07-02s390/qdio: (re-)initialize tiqdio list entriesJulian Wiedmann2-2/+4
When tiqdio_remove_input_queues() removes a queue from the tiq_list as part of qdio_shutdown(), it doesn't re-initialize the queue's list entry and the prev/next pointers go stale. If a subsequent qdio_establish() fails while sending the ESTABLISH cmd, it calls qdio_shutdown() again in QDIO_IRQ_STATE_ERR state and tiqdio_remove_input_queues() will attempt to remove the queue entry a second time. This dereferences the stale pointers, and bad things ensue. Fix this by re-initializing the list entry after removing it from the list. For good practice also initialize the list entry when the queue is first allocated, and remove the quirky checks that papered over this omission. Note that prior to commit e521813468f7 ("s390/qdio: fix access to uninitialized qdio_q fields"), these checks were bogus anyway. setup_queues_misc() clears the whole queue struct, and thus needs to re-init the prev/next pointers as well. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Cc: <stable@vger.kernel.org> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-02s390/cio: introduce driver_override on the css busCornelia Huck2-0/+54
Sometimes, we want to control which of the matching drivers binds to a subchannel device (e.g. for subchannels we want to handle via vfio-ccw). For pci devices, a mechanism to do so has been introduced in 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override"). It makes sense to introduce the driver_override attribute for subchannel devices as well, so that we can easily extend the 'driverctl' tool (which makes use of the driver_override attribute for pci). Note that unlike pci we still require a driver override to match the subchannel type; matching more than one subchannel type is probably not useful anyway. Signed-off-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-06-26drivers: s390/cio: Fix compilation warning about const qualifiersSuzuki K Poulose2-4/+2
Update __ccwdev_check_busid() and __ccwgroupdev_check_busid() to use "const" qualifiers to fix the compiler warning. Reported-by: kbuild test robot <lkp@intel.com> Cc: gregkh@linuxfoundation.org Cc: devel@driverdev.osuosl.org Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-24vfio-ccw: make convert_ccw0_to_ccw1 staticCornelia Huck1-1/+1
Reported by sparse. Fixes: 7f8e89a8f2fd ("vfio-ccw: Factor out the ccw0-to-ccw1 transition") Signed-off-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190624090721.16241-1-cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-06-24Merge tag 'vfio-ccw-20190621' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into featuresVasily Gorbik3-278/+151
Refactoring of the vfio-ccw cp handling, simplifying the code and avoiding unneeded allocating/copying. * tag 'vfio-ccw-20190621' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw: vfio-ccw: Remove copy_ccw_from_iova() vfio-ccw: Factor out the ccw0-to-ccw1 transition vfio-ccw: Copy CCW data outside length calculation vfio-ccw: Skip second copy of guest cp to host vfio-ccw: Move guest_cp storage into common struct s390/cio: Combine direct and indirect CCW paths vfio-ccw: Rearrange IDAL allocation in direct CCW vfio-ccw: Remove pfn_array_table vfio-ccw: Adjust the first IDAW outside of the nested loops vfio-ccw: Rearrange pfn_array and pfn_array_table arrays s390/cio: Use generalized CCW handler in cp_init() s390/cio: Generalize the TIC handler s390/cio: Refactor the routine that handles TIC CCWs s390/cio: Squash cp_free() and cp_unpin_free() Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-06-24driver_find_device: Unify the match function with class_find_device()Suzuki K Poulose3-4/+4
The driver_find_device() accepts a match function pointer to filter the devices for lookup, similar to bus/class_find_device(). However, there is a minor difference in the prototype for the match parameter for driver_find_device() with the now unified version accepted by {bus/class}_find_device(), where it doesn't accept a "const" qualifier for the data argument. This prevents us from reusing the generic match functions for driver_find_device(). For this reason, change the prototype of the driver_find_device() to make the "match" parameter in line with {bus/class}_find_device() and adjust its callers to use the const qualifier. Also, we could now promote the "data" parameter to const as we pass it down as a const parameter to the match functions. Cc: Corey Minyard <minyard@acm.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Sebastian Ott <sebott@linux.ibm.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Nehal Shah <nehal-bakulchandra.shah@amd.com> Cc: Shyam Sundar S K <shyam-sundar.s-k@amd.com> Cc: Lee Jones <lee.jones@linaro.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-24bus_find_device: Unify the match callback with class_find_deviceSuzuki K Poulose3-6/+6
There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Corey Minyard <minyard@acm.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Kershner <david.kershner@unisys.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: David Airlie <airlied@linux.ie> Cc: Felipe Balbi <balbi@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Cameron <jic23@kernel.org> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: Len Brown <lenb@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Jamet <michael.jamet@intel.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Sebastian Ott <sebott@linux.ibm.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Cc: rafael@kernel.org Acked-by: Corey Minyard <minyard@acm.org> Acked-by: David Kershner <david.kershner@unisys.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-21vfio-ccw: Remove copy_ccw_from_iova()Eric Farman1-12/+2
Just to keep things tidy. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190618202352.39702-6-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>
2019-06-21vfio-ccw: Factor out the ccw0-to-ccw1 transitionEric Farman1-23/+25
This is a really useful function, but it's buried in the copy_ccw_from_iova() routine so that ccwchain_calc_length() can just work with Format-1 CCWs while doing its counting. But it means we're translating a full 2K of "CCWs" to Format-1, when in reality there's probably far fewer in that space. Let's factor it out, so maybe we can do something with it later. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190618202352.39702-5-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>
2019-06-21vfio-ccw: Copy CCW data outside length calculationEric Farman1-12/+7
It doesn't make much sense to "hide" the copy to the channel_program struct inside a routine that calculates the length of the chain. Let's move it to the calling routine, which will later copy from channel_program to the memory it allocated itself. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190618202352.39702-4-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>
2019-06-21vfio-ccw: Skip second copy of guest cp to hostEric Farman1-7/+3
We already pinned/copied/unpinned 2K (256 CCWs) of guest memory to the host space anchored off vfio_ccw_private. There's no need to do that again once we have the length calculated, when we could just copy the section we need to the "permanent" space for the I/O. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190618202352.39702-3-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>
2019-06-21vfio-ccw: Move guest_cp storage into common structEric Farman3-19/+18
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>
2019-06-19s390/cio: move struct node_descriptor to cio.hJulian Wiedmann1-30/+0
This allows device drivers (eg. qeth) to use the struct when processing information retrieved via RCD. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Acked-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-06-17s390/cio: Combine direct and indirect CCW pathsEric Farman1-76/+39
With both the direct-addressed and indirect-addressed CCW paths simplified to this point, the amount of shared code between them is (hopefully) more easily visible. Move the processing of IDA-specific bits into the direct-addressed path, and add some useful commentary of what the individual pieces are doing. This allows us to remove the entire ccwchain_fetch_idal() routine and maintain a single function for any non-TIC CCW. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-10-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17vfio-ccw: Rearrange IDAL allocation in direct CCWEric Farman1-10/+15
This is purely deck furniture, to help understand the merge of the direct and indirect handlers. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-9-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17vfio-ccw: Remove pfn_array_tableEric Farman1-85/+33
Now that both CCW codepaths build this nested array: ccwchain->pfn_array_table[1]->pfn_array[#idaws/#pages] We can collapse this into simply: ccwchain->pfn_array[#idaws/#pages] Let's do that, so that we don't have to continually navigate two nested arrays when the first array always has a count of one. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-8-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17vfio-ccw: Adjust the first IDAW outside of the nested loopsEric Farman1-2/+3
Now that pfn_array_table[] is always an array of 1, it seems silly to check for the very first entry in an array in the middle of two nested loops, since we know it'll only ever happen once. Let's move this outside the loops to simplify things, even though the "k" variable is still necessary. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-7-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17vfio-ccw: Rearrange pfn_array and pfn_array_table arraysEric Farman1-15/+11
While processing a channel program, we currently have two nested arrays that carry a slightly different structure. The direct CCW path creates this: ccwchain->pfn_array_table[1]->pfn_array[#pages] while an IDA CCW creates: ccwchain->pfn_array_table[#idaws]->pfn_array[1] The distinction appears to state that each pfn_array_table entry points to an array of contiguous pages, represented by a pfn_array, um, array. Since the direct-addressed scenario can ONLY represent contiguous pages, it makes the intermediate array necessary but difficult to recognize. Meanwhile, since an IDAL can contain non-contiguous pages and there is no logic in vfio-ccw to detect adjacent IDAWs, it is the second array that is necessary but appearing to be superfluous. I am not aware of any documentation that states the pfn_array[] needs to be of contiguous pages; it is just what the code does today. I don't see any reason for this either, let's just flip the IDA codepath around so that it generates: ch_pat->pfn_array_table[1]->pfn_array[#idaws] This will bring it in line with the direct-addressed codepath, so that we can understand the behavior of this memory regardless of what type of CCW is being processed. And it means the casual observer does not need to know/care whether the pfn_array[] represents contiguous pages or not. NB: The existing vfio-ccw code only supports 4K-block Format-2 IDAs, so that "#pages" == "#idaws" in this area. This means that we will have difficulty with this overlap in terminology if support for Format-1 or 2K-block Format-2 IDAs is ever added. I don't think that this patch changes our ability to make that distinction. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-6-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17s390/cio: Use generalized CCW handler in cp_init()Eric Farman1-23/+4
It is now pretty apparent that ccwchain_handle_ccw() (nee ccwchain_handle_tic()) does everything that cp_init() wants to do. Let's remove that duplicated code from cp_init() and let ccwchain_handle_ccw() handle it itself. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-5-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17s390/cio: Generalize the TIC handlerEric Farman1-5/+6
Refactor ccwchain_handle_tic() into a routine that handles a channel program address (which itself is a CCW pointer), rather than a CCW pointer that is only a TIC CCW. This will make it easier to reuse this code for other CCW commands. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-4-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17s390/cio: Refactor the routine that handles TIC CCWsEric Farman1-4/+4
Extract the "does the target of this TIC already exist?" check from ccwchain_handle_tic(), so that it's easier to refactor that function into one that cp_init() is able to use. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-3-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-17s390/cio: Squash cp_free() and cp_unpin_free()Eric Farman1-20/+16
The routine cp_free() does nothing but call cp_unpin_free(), and while most places call cp_free() there is one caller of cp_unpin_free() used when the cp is guaranteed to have not been marked initialized. This seems like a dubious way to make a distinction, so let's combine these routines and make cp_free() do all the work. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20190606202831.44135-2-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-15s390/airq: use DMA memory for adapter interruptsHalil Pasic3-14/+26
Protected virtualization guests have to use shared pages for airq notifier bit vectors, because the hypervisor needs to write these bits. Let us make sure we allocate DMA memory for the notifier bit vectors by replacing the kmem_cache with a dma_cache and kalloc() with cio_dma_zalloc(). Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-15s390/cio: add basic protected virtualization supportHalil Pasic8-73/+160
As virtio-ccw devices are channel devices, we need to use the dma area within the common I/O layer for any communication with the hypervisor. Note that we do not need to use that area for control blocks directly referenced by instructions, e.g. the orb. It handles neither QDIO in the common code, nor any device type specific stuff (like channel programs constructed by the DASD driver). An interesting side effect is that virtio structures are now going to get allocated in 31 bit addressable storage. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-15s390/cio: introduce DMA pools to cioHalil Pasic1-4/+129
To support protected virtualization cio will need to make sure the memory used for communication with the hypervisor is DMA memory. Let us introduce one global pool for cio. Our DMA pools are implemented as a gen_pool backed with DMA pages. The idea is to avoid each allocation effectively wasting a page, as we typically allocate much less than PAGE_SIZE. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-13vfio-ccw: Destroy kmem cache region on module exitFarhan Ali1-0/+1
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>
2019-06-07s390/qdio: handle PENDING state for QEBSM devicesJulian Wiedmann1-0/+1
When a CQ-enabled device uses QEBSM for SBAL state inspection, get_buf_states() can return the PENDING state for an Output Queue. get_outbound_buffer_frontier() isn't prepared for this, and any PENDING buffer will permanently stall all further completion processing on this Queue. This isn't a concern for non-QEBSM devices, as get_buf_states() for such devices will manually turn PENDING buffers into EMPTY ones. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-07s390/cio: fix kdoc for tiqdio_thinint_handlerSebastian Ott1-0/+1
Add missing parameter description to fix the following warning: drivers/s390/cio/qdio_thinint.c:183: warning: Function parameter or member 'floating' not described in 'tiqdio_thinint_handler' Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-03s390/cio: Remove vfio-ccw checks of command codesEric Farman1-6/+5
If the CCW being processed is a No-Operation, then by definition no data is being transferred. Let's fold those checks into the normal CCW processors, rather than skipping out early. Likewise, if the CCW being processed is a "test" (a category defined here as an opcode that contains zero in the lowest four bits) then no special processing is necessary as far as vfio-ccw is concerned. These command codes have not been valid since the S/370 days, meaning they are invalid in the same way as one that ends in an eight [1] or an otherwise valid command code that is undefined for the device type in question. Considering that, let's just process "test" CCWs like any other CCW, and send everything to the hardware. [1] POPS states that a x08 is a TIC CCW, and that having any high-order bits enabled is invalid for format-1 CCWs. For format-0 CCWs, the high-order bits are ignored. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190516161403.79053-4-farman@linux.ibm.com> Acked-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-03s390/cio: Allow zero-length CCWs in vfio-ccwEric Farman1-18/+12
It is possible that a guest might issue a CCW with a length of zero, and will expect a particular response. Consider this chain: Address Format-1 CCW -------- ----------------- 0 33110EC0 346022CC 33177468 1 33110EC8 CF200000 3318300C CCW[0] moves a little more than two pages, but also has the Suppress Length Indication (SLI) bit set to handle the expectation that considerably less data will be moved. CCW[1] also has the SLI bit set, and has a length of zero. Once vfio-ccw does its magic, the kernel issues a start subchannel on behalf of the guest with this: Address Format-1 CCW -------- ----------------- 0 021EDED0 346422CC 021F0000 1 021EDED8 CF240000 3318300C Both CCWs were converted to an IDAL and have the corresponding flags set (which is by design), but only the address of the first data address is converted to something the host is aware of. The second CCW still has the address used by the guest, which happens to be (A) (probably) an invalid address for the host, and (B) an invalid IDAW address (doubleword boundary, etc.). While the I/O fails, it doesn't fail correctly. In this example, we would receive a program check for an invalid IDAW address, instead of a unit check for an invalid command. To fix this, revert commit 4cebc5d6a6ff ("vfio: ccw: validate the count field of a ccw before pinning") and allow the individual fetch routines to process them like anything else. We'll make a slight adjustment to our allocation of the pfn_array (for direct CCWs) or IDAL (for IDAL CCWs) memory, so that we have room for at least one address even though no guest memory will be pinned and thus the IDAW will not be populated with a host address. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190516161403.79053-3-farman@linux.ibm.com> Acked-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-03s390/cio: Don't pin vfio pages for empty transfersEric Farman1-5/+50
The skip flag of a CCW offers the possibility of data not being transferred, but is only meaningful for certain commands. Specifically, it is only applicable for a read, read backward, sense, or sense ID CCW and will be ignored for any other command code (SA22-7832-11 page 15-64, and figure 15-30 on page 15-75). (A sense ID is xE4, while a sense is x04 with possible modifiers in the upper four bits. So we will cover the whole "family" of sense CCWs.) For those scenarios, since there is no requirement for the target address to be valid, we should skip the call to vfio_pin_pages() and rely on the IDAL address we have allocated/built for the channel program. The fact that the individual IDAWs within the IDAL are invalid is fine, since they aren't actually checked in these cases. Set pa_nr to zero when skipping the pfn_array_pin() call, since it is defined as the number of pages pinned and is used to determine whether to call vfio_unpin_pages() upon cleanup. The pfn_array_pin() routine returns the number of pages that were pinned, but now might be skipped for some CCWs. Thus we need to calculate the expected number of pages ourselves such that we are guaranteed to allocate a reasonable number of IDAWs, which will provide a valid address in CCW.CDA regardless of whether the IDAWs are filled in with pinned/translated addresses or not. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190516161403.79053-2-farman@linux.ibm.com> Acked-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-03s390/cio: Initialize the host addresses in pfn_arrayEric Farman1-1/+4
Let's initialize the host address to something that is invalid, rather than letting it default to zero. This just makes it easier to notice when a pin operation has failed or been skipped. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190514234248.36203-5-farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-03s390/cio: Split pfn_array_alloc_pin into piecesEric Farman1-18/+46
The pfn_array_alloc_pin routine is doing too much. Today, it does the alloc of the pfn_array struct and its member arrays, builds the iova address lists out of a contiguous piece of guest memory, and asks vfio to pin the resulting pages. Let's effectively revert a significant portion of commit 5c1cfb1c3948 ("vfio: ccw: refactor and improve pfn_array_alloc_pin()") such that we break pfn_array_alloc_pin() into its component pieces, and have one routine that allocates/populates the pfn_array structs, and another that actually pins the memory. In the future, we will be able to handle scenarios where pinning memory isn't actually appropriate. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190514234248.36203-4-farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-03s390/cio: Set vfio-ccw FSM state before ioeventfdEric Farman1-3/+3
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>
2019-06-03s390/cio: Update SCSW if it points to the end of the chainEric Farman1-1/+5
Per the POPs [1], when processing an interrupt the SCSW.CPA field of an IRB generally points to 8 bytes after the last CCW that was executed (there are exceptions, but this is the most common behavior). In the case of an error, this points us to the first un-executed CCW in the chain. But in the case of normal I/O, the address points beyond the end of the chain. While the guest generally only cares about this when possibly restarting a channel program after error recovery, we should convert the address even in the good scenario so that we provide a consistent, valid, response upon I/O completion. [1] Figure 16-6 in SA22-7832-11. The footnotes in that table also state that this is true even if the resulting address is invalid or protected, but moving to the end of the guest chain should not be a surprise. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20190514234248.36203-2-farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-05-08s390/qdio: optimize state inspection of HW-owned SBALsJulian Wiedmann1-2/+9
When get_buf_states() gets called with count > 1, it scans the corresponding number of SBAL states until it encounters a mismatch. But when these SBALs are in a HW-owned state, the callers don't actually care _how many_ such SBALs are on the queue. If we can't process the first SBAL, we can't process any of the following SBALs either. So when the first SBAL is HW-owned, skip the scan of the remaining SBALs and thus save some CPU time. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08s390/qdio: use get_buf_state() in debug_get_buf_state()Julian Wiedmann1-1/+1
For a 1-SBAL state inspection, use the corresponding helper. No functional change, just reducing the number of immediate callers to get_buf_states(). Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08s390/qdio: allow to scan all Output SBALs in one goJulian Wiedmann1-5/+1
Old code restricted the number of inspected SBALs to QDIO_MAX_BUFFERS_PER_Q - 1, as otherwise the first_to_check and first_to_kick cursors could overlap. Subsequent code would then assume that there was no progress on the queue, when in fact _all_ SBALs on the queue were ready-to-process. This limitation no longer applies, so allow the queue-scan code to inspect all SBALs on the queue. Note that qeth requires an additional patch ("s390/qeth: stop/wake TX queues based on their fill level"), to avoid potential queue stalls when all 128 SBALs are reported as ready-to-process. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08s390/cio: Remove tracing for rchp instructionFarhan Ali2-24/+0
Since commit d485235b00 "s390: assume diag308 set always works", the kernel does not use the rchp instruction anymore. So let's remove the tracing for it. Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Acked-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390: show statistics for MSI IRQsSebastian Ott1-1/+1
Improve /proc/interrupts on s390 to show statistics for individual MSI interrupts. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/airq: provide cacheline aligned ivsSebastian Ott1-5/+34
Provide the ability to create cachesize aligned interrupt vectors. These will be used for per-CPU interrupt vectors. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/airq: recognize directed interruptsSebastian Ott3-4/+4
Add an extra parameter for airq handlers to recognize floating vs. directed interrupts. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-24vfio-ccw: Prevent quiesce function going into an infinite loopFarhan Ali1-14/+18
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>
2019-04-24vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdevFarhan Ali1-1/+10
When releasing the vfio-ccw mdev, we currently do not release any existing channel program and its pinned pages. This can lead to the following warning: [1038876.561565] WARNING: CPU: 2 PID: 144727 at drivers/vfio/vfio_iommu_type1.c:1494 vfio_sanity_check_pfn_list+0x40/0x70 [vfio_iommu_type1] .... 1038876.561921] Call Trace: [1038876.561935] ([<00000009897fb870>] 0x9897fb870) [1038876.561949] [<000003ff8013bf62>] vfio_iommu_type1_detach_group+0xda/0x2f0 [vfio_iommu_type1] [1038876.561965] [<000003ff8007b634>] __vfio_group_unset_container+0x64/0x190 [vfio] [1038876.561978] [<000003ff8007b87e>] vfio_group_put_external_user+0x26/0x38 [vfio] [1038876.562024] [<000003ff806fc608>] kvm_vfio_group_put_external_user+0x40/0x60 [kvm] [1038876.562045] [<000003ff806fcb9e>] kvm_vfio_destroy+0x5e/0xd0 [kvm] [1038876.562065] [<000003ff806f63fc>] kvm_put_kvm+0x2a4/0x3d0 [kvm] [1038876.562083] [<000003ff806f655e>] kvm_vm_release+0x36/0x48 [kvm] [1038876.562098] [<00000000003c2dc4>] __fput+0x144/0x228 [1038876.562113] [<000000000016ee82>] task_work_run+0x8a/0xd8 [1038876.562125] [<000000000014c7a8>] do_exit+0x5d8/0xd90 [1038876.562140] [<000000000014d084>] do_group_exit+0xc4/0xc8 [1038876.562155] [<000000000015c046>] get_signal+0x9ae/0xa68 [1038876.562169] [<0000000000108d66>] do_signal+0x66/0x768 [1038876.562185] [<0000000000b9e37e>] system_call+0x1ea/0x2d8 [1038876.562195] 2 locks held by qemu-system-s39/144727: [1038876.562205] #0: 00000000537abaf9 (&container->group_lock){++++}, at: __vfio_group_unset_container+0x3c/0x190 [vfio] [1038876.562230] #1: 00000000670008b5 (&iommu->lock){+.+.}, at: vfio_iommu_type1_detach_group+0x36/0x2f0 [vfio_iommu_type1] [1038876.562250] Last Breaking-Event-Address: [1038876.562262] [<000003ff8013aa24>] vfio_sanity_check_pfn_list+0x3c/0x70 [vfio_iommu_type1] [1038876.562272] irq event stamp: 4236481 [1038876.562287] hardirqs last enabled at (4236489): [<00000000001cee7a>] console_unlock+0x6d2/0x740 [1038876.562299] hardirqs last disabled at (4236496): [<00000000001ce87e>] console_unlock+0xd6/0x740 [1038876.562311] softirqs last enabled at (4234162): [<0000000000b9fa1e>] __do_softirq+0x556/0x598 [1038876.562325] softirqs last disabled at (4234153): [<000000000014e4cc>] irq_exit+0xac/0x108 [1038876.562337] ---[ end trace 6c96d467b1c3ca06 ]--- Similarly we do not free the channel program when we are removing the vfio-ccw device. Let's fix this by resetting the device and freeing the channel program and pinned pages in the release path. For the remove path we can just quiesce the device, since in the remove path the mediated device is going away for good and so we don't need to do a full reset. Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Message-Id: <ae9f20dc8873f2027f7b3c5d2aaa0bdfe06850b8.1554756534.git.alifm@linux.ibm.com> Acked-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: Do not call flush_workqueue while holding the spinlockFarhan Ali1-1/+1
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>
2019-04-24vfio-ccw: add handling for async channel instructionsCornelia Huck6-18/+256
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>
2019-04-24s390/cio: export hsch to modulesCornelia Huck1-0/+1
The vfio-ccw code will need this, and it matches treatment of ssch and csch. Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: add capabilities chainCornelia Huck2-26/+199
Allow to extend the regions used by vfio-ccw. The first user will be handling of halt and clear subchannel. Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: protect the I/O regionCornelia Huck3-9/+24
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>
2019-04-24vfio-ccw: rework ssch state handlingCornelia Huck3-8/+16
The flow for processing ssch requests can be improved by splitting the BUSY state: - CP_PROCESSING: We reject any user space requests while we are in the process of translating a channel program and submitting it to the hardware. Use -EAGAIN to signal user space that it should retry the request. - CP_PENDING: We have successfully submitted a request with ssch and are now expecting an interrupt. As we can't handle more than one channel program being processed, reject any further requests with -EBUSY. A final interrupt will move us out of this state. By making this a separate state, we make it possible to issue a halt or a clear while we're still waiting for the final interrupt for the ssch (in a follow-on patch). It also makes a lot of sense not to preemptively filter out writes to the io_region if we're in an incorrect state: the state machine will handle this correctly. Reviewed-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>