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2017-10-02vfio/spapr: Add cond_resched() for huge updatesAlexey Kardashevskiy1-0/+2
Clearing very big IOMMU tables can trigger soft lockups. This adds cond_resched() to allow the scheduler to do context switching when it decides to. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-05-05Merge tag 'powerpc-4.12-1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Highlights include: - Larger virtual address space on 64-bit server CPUs. By default we use a 128TB virtual address space, but a process can request access to the full 512TB by passing a hint to mmap(). - Support for the new Power9 "XIVE" interrupt controller. - TLB flushing optimisations for the radix MMU on Power9. - Support for CAPI cards on Power9, using the "Coherent Accelerator Interface Architecture 2.0". - The ability to configure the mmap randomisation limits at build and runtime. - Several small fixes and cleanups to the kprobes code, as well as support for KPROBES_ON_FTRACE. - Major improvements to handling of system reset interrupts, correctly treating them as NMIs, giving them a dedicated stack and using a new hypervisor call to trigger them, all of which should aid debugging and robustness. - Many fixes and other minor enhancements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton Blanchard, Balbir Singh, Ben Hutchings, Benjamin Herrenschmidt, Bhupesh Sharma, Chris Packham, Christian Zigotzky, Christophe Leroy, Christophe Lombard, Daniel Axtens, David Gibson, Gautham R. Shenoy, Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli, Hamish Martin, Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mahesh J Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell Currey, Sukadev Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C. Harding, Tyrel Datwyler, Uma Krishnan, Vaibhav Jain, Vipin K Parashar, Yang Shi" * tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits) powerpc/64s: Power9 has no LPCR[VRMASD] field so don't set it powerpc/powernv: Fix TCE kill on NVLink2 powerpc/mm/radix: Drop support for CPUs without lockless tlbie powerpc/book3s/mce: Move add_taint() later in virtual mode powerpc/sysfs: Move #ifdef CONFIG_HOTPLUG_CPU out of the function body powerpc/smp: Document irq enable/disable after migrating IRQs powerpc/mpc52xx: Don't select user-visible RTAS_PROC powerpc/powernv: Document cxl dependency on special case in pnv_eeh_reset() powerpc/eeh: Clean up and document event handling functions powerpc/eeh: Avoid use after free in eeh_handle_special_event() cxl: Mask slice error interrupts after first occurrence cxl: Route eeh events to all drivers in cxl_pci_error_detected() cxl: Force context lock during EEH flow powerpc/64: Allow CONFIG_RELOCATABLE if COMPILE_TEST powerpc/xmon: Teach xmon oops about radix vectors powerpc/mm/hash: Fix off-by-one in comment about kernel contexts ids powerpc/pseries: Enable VFIO powerpc/powernv: Fix iommu table size calculation hook for small tables powerpc/powernv: Check kzalloc() return value in pnv_pci_table_alloc powerpc: Add arch/powerpc/tools directory ...
2017-04-11vfio/spapr_tce: Check kzalloc() return when preregistering memoryAlexey Kardashevskiy1-0/+5
This adds missing checking for kzalloc() return value. Fixes: 4b6fad7097f8 ("powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-04-11vfio/powerpc/spapr_tce: Enforce IOMMU type compatibility checkAlexey Kardashevskiy1-0/+8
The existing SPAPR TCE driver advertises both VFIO_SPAPR_TCE_IOMMU and VFIO_SPAPR_TCE_v2_IOMMU types to the userspace and the userspace usually picks the v2. Normally the userspace would create a container, attach an IOMMU group to it and only then set the IOMMU type (which would normally be v2). However a specific IOMMU group may not support v2, in other words it may not implement set_window/unset_window/take_ownership/ release_ownership and such a group should not be attached to a v2 container. This adds extra checks that a new group can do what the selected IOMMU type suggests. The userspace can then test the return value from ioctl(VFIO_SET_IOMMU, VFIO_SPAPR_TCE_v2_IOMMU) and try VFIO_SPAPR_TCE_IOMMU. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-03-30powerpc/vfio_spapr_tce: Add reference counting to iommu_tableAlexey Kardashevskiy1-1/+1
So far iommu_table obejcts were only used in virtual mode and had a single owner. We are going to change this by implementing in-kernel acceleration of DMA mapping requests. The proposed acceleration will handle requests in real mode and KVM will keep references to tables. This adds a kref to iommu_table and defines new helpers to update it. This replaces iommu_free_table() with iommu_tce_table_put() and makes iommu_free_table() static. iommu_tce_table_get() is not used in this patch but it will be in the following patch. Since this touches prototypes, this also removes @node_name parameter as it has never been really useful on powernv and carrying it for the pseries platform code to iommu_free_table() seems to be quite useless as well. This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-30powerpc/iommu/vfio_spapr_tce: Cleanup iommu_table disposalAlexey Kardashevskiy1-1/+1
At the moment iommu_table can be disposed by either calling iommu_table_free() directly or it_ops::free(); the only implementation of free() is in IODA2 - pnv_ioda2_table_free() - and it calls iommu_table_free() anyway. As we are going to have reference counting on tables, we need an unified way of disposing tables. This moves it_ops::free() call into iommu_free_table() and makes use of the latter. The free() callback now handles only platform-specific data. As from now on the iommu_free_table() calls it_ops->free(), we need to have it_ops initialized before calling iommu_free_table() so this moves this initialization in pnv_pci_ioda2_create_table(). This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+1
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+2
<linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-07vfio/spapr_tce: Set window when adding additional groups to containerAlexey Kardashevskiy1-0/+22
If a container already has a group attached, attaching a new group should just program already created IOMMU tables to the hardware via the iommu_table_group_ops::set_window() callback. However commit 6f01cc692a16 ("vfio/spapr: Add a helper to create default DMA window") did not just simplify the code but also removed the set_window() calls in the case of attaching groups to a container which already has tables so it broke VFIO PCI hotplug. This reverts set_window() bits in tce_iommu_take_ownership_ddw(). Fixes: 6f01cc692a16 ("vfio/spapr: Add a helper to create default DMA window") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-02-01vfio/spapr: Fix missing mutex unlock when creating a windowAlexey Kardashevskiy1-6/+5
Commit d9c728949ddc ("vfio/spapr: Postpone default window creation") added an additional exit to the VFIO_IOMMU_SPAPR_TCE_CREATE case and made it possible to return from tce_iommu_ioctl() without unlocking container->lock; this fixes the issue. Fixes: d9c728949ddc ("vfio/spapr: Postpone default window creation") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-01-24vfio/spapr: fail tce_iommu_attach_group() when iommu_data is nullGreg Kurz1-0/+4
The recently added mediated VFIO driver doesn't know about powerpc iommu. It thus doesn't register a struct iommu_table_group in the iommu group upon device creation. The iommu_data pointer hence remains null. This causes a kernel oops when userspace tries to set the iommu type of a container associated with a mediated device to VFIO_SPAPR_TCE_v2_IOMMU. [ 82.585440] mtty mtty: MDEV: Registered [ 87.655522] iommu: Adding device 83b8f4f2-509f-382f-3c1e-e6bfe0fa1001 to group 10 [ 87.655527] vfio_mdev 83b8f4f2-509f-382f-3c1e-e6bfe0fa1001: MDEV: group_id = 10 [ 116.297184] Unable to handle kernel paging request for data at address 0x00000030 [ 116.297389] Faulting instruction address: 0xd000000007870524 [ 116.297465] Oops: Kernel access of bad area, sig: 11 [#1] [ 116.297611] SMP NR_CPUS=2048 [ 116.297611] NUMA [ 116.297627] PowerNV ... [ 116.297954] CPU: 33 PID: 7067 Comm: qemu-system-ppc Not tainted 4.10.0-rc5-mdev-test #8 [ 116.297993] task: c000000e7718b680 task.stack: c000000e77214000 [ 116.298025] NIP: d000000007870524 LR: d000000007870518 CTR: 0000000000000000 [ 116.298064] REGS: c000000e77217990 TRAP: 0300 Not tainted (4.10.0-rc5-mdev-test) [ 116.298103] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> [ 116.298107] CR: 84004444 XER: 00000000 [ 116.298154] CFAR: c00000000000888c DAR: 0000000000000030 DSISR: 40000000 SOFTE: 1 GPR00: d000000007870518 c000000e77217c10 d00000000787b0ed c000000eed2103c0 GPR04: 0000000000000000 0000000000000000 c000000eed2103e0 0000000f24320000 GPR08: 0000000000000104 0000000000000001 0000000000000000 d0000000078729b0 GPR12: c00000000025b7e0 c00000000fe08400 0000000000000001 000001002d31d100 GPR16: 000001002c22c850 00003ffff315c750 0000000043145680 0000000043141bc0 GPR20: ffffffffffffffed fffffffffffff000 0000000020003b65 d000000007706018 GPR24: c000000f16cf0d98 d000000007706000 c000000003f42980 c000000003f42980 GPR28: c000000f1575ac00 c000000003f429c8 0000000000000000 c000000eed2103c0 [ 116.298504] NIP [d000000007870524] tce_iommu_attach_group+0x10c/0x360 [vfio_iommu_spapr_tce] [ 116.298555] LR [d000000007870518] tce_iommu_attach_group+0x100/0x360 [vfio_iommu_spapr_tce] [ 116.298601] Call Trace: [ 116.298610] [c000000e77217c10] [d000000007870518] tce_iommu_attach_group+0x100/0x360 [vfio_iommu_spapr_tce] (unreliable) [ 116.298671] [c000000e77217cb0] [d0000000077033a0] vfio_fops_unl_ioctl+0x278/0x3e0 [vfio] [ 116.298713] [c000000e77217d40] [c0000000002a3ebc] do_vfs_ioctl+0xcc/0x8b0 [ 116.298745] [c000000e77217de0] [c0000000002a4700] SyS_ioctl+0x60/0xc0 [ 116.298782] [c000000e77217e30] [c00000000000b220] system_call+0x38/0xfc [ 116.298812] Instruction dump: [ 116.298828] 7d3f4b78 409effc8 3d220000 e9298020 3c800140 38a00018 608480c0 e8690028 [ 116.298869] 4800249d e8410018 7c7f1b79 41820230 <e93e0030> 2fa90000 419e0114 e9090020 [ 116.298914] ---[ end trace 1e10b0ced08b9120 ]--- This patch fixes the oops. Reported-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Greg Kurz <groug@kaod.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-12-02powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdownAlexey Kardashevskiy1-1/+60
At the moment the userspace tool is expected to request pinning of the entire guest RAM when VFIO IOMMU SPAPR v2 driver is present. When the userspace process finishes, all the pinned pages need to be put; this is done as a part of the userspace memory context (MM) destruction which happens on the very last mmdrop(). This approach has a problem that a MM of the userspace process may live longer than the userspace process itself as kernel threads use userspace process MMs which was runnning on a CPU where the kernel thread was scheduled to. If this happened, the MM remains referenced until this exact kernel thread wakes up again and releases the very last reference to the MM, on an idle system this can take even hours. This moves preregistered regions tracking from MM to VFIO; insteads of using mm_iommu_table_group_mem_t::used, tce_container::prereg_list is added so each container releases regions which it has pre-registered. This changes the userspace interface to return EBUSY if a memory region is already registered in a container. However it should not have any practical effect as the only userspace tool available now does register memory region once per container anyway. As tce_iommu_register_pages/tce_iommu_unregister_pages are called under container->lock, this does not need additional locking. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-02vfio/spapr: Reference mm in tce_containerAlexey Kardashevskiy1-60/+100
In some situations the userspace memory context may live longer than the userspace process itself so if we need to do proper memory context cleanup, we better have tce_container take a reference to mm_struct and use it later when the process is gone (@current or @current->mm is NULL). This references mm and stores the pointer in the container; this is done in a new helper - tce_iommu_mm_set() - when one of the following happens: - a container is enabled (IOMMU v1); - a first attempt to pre-register memory is made (IOMMU v2); - a DMA window is created (IOMMU v2). The @mm stays referenced till the container is destroyed. This replaces current->mm with container->mm everywhere except debug prints. This adds a check that current->mm is the same as the one stored in the container to prevent userspace from making changes to a memory context of other processes. DMA map/unmap ioctls() do not check for @mm as they already check for @enabled which is set after tce_iommu_mm_set() is called. This does not reference a task as multiple threads within the same mm are allowed to ioctl() to vfio and supposedly they will have same limits and capabilities and if they do not, we'll just fail with no harm made. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-02vfio/spapr: Postpone default window creationAlexey Kardashevskiy1-15/+25
We are going to allow the userspace to configure container in one memory context and pass container fd to another so we are postponing memory allocations accounted against the locked memory limit. One of previous patches took care of it_userspace. At the moment we create the default DMA window when the first group is attached to a container; this is done for the userspace which is not DDW-aware but familiar with the SPAPR TCE IOMMU v2 in the part of memory pre-registration - such client expects the default DMA window to exist. This postpones the default DMA window allocation till one of the folliwing happens: 1. first map/unmap request arrives; 2. new window is requested; This adds noop for the case when the userspace requested removal of the default window which has not been created yet. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-02vfio/spapr: Add a helper to create default DMA windowAlexey Kardashevskiy1-45/+42
There is already a helper to create a DMA window which does allocate a table and programs it to the IOMMU group. However tce_iommu_take_ownership_ddw() did not use it and did these 2 calls itself to simplify error path. Since we are going to delay the default window creation till the default window is accessed/removed or new window is added, we need a helper to create a default window from all these cases. This adds tce_iommu_create_default_window(). Since it relies on a VFIO container to have at least one IOMMU group (for future use), this changes tce_iommu_attach_group() to add a group to the container first and then call the new helper. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-02vfio/spapr: Postpone allocation of userspace version of TCE tableAlexey Kardashevskiy1-13/+7
The iommu_table struct manages a hardware TCE table and a vmalloc'd table with corresponding userspace addresses. Both are allocated when the default DMA window is created and this happens when the very first group is attached to a container. As we are going to allow the userspace to configure container in one memory context and pas container fd to another, we have to postpones such allocations till a container fd is passed to the destination user process so we would account locked memory limit against the actual container user constrainsts. This postpones the it_userspace array allocation till it is used first time for mapping. The unmapping patch already checks if the array is allocated. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-02powerpc/iommu: Stop using @current in mm_iommu_xxxAlexey Kardashevskiy1-4/+10
This changes mm_iommu_xxx helpers to take mm_struct as a parameter instead of getting it from @current which in some situations may not have a valid reference to mm. This changes helpers to receive @mm and moves all references to @current to the caller, including checks for !current and !current->mm; checks in mm_iommu_preregistered() are removed as there is no caller yet. This moves the mm_iommu_adjust_locked_vm() call to the caller as it receives mm_iommu_table_group_mem_t but it needs mm. This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-25Merge tag 'vfio-v4.7-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds1-2/+0
Pull VFIO updates from Alex Williamson: - Hide INTx on certain known broken devices (Alex Williamson) - Additional backdoor reset detection (Alex Williamson) - Remove unused iommudata reference (Alexey Kardashevskiy) - Use cfg_size to avoid probing extended config space (Alexey Kardashevskiy) * tag 'vfio-v4.7-rc1' of git://github.com/awilliam/linux-vfio: vfio_pci: Test for extended capabilities if config space > 256 bytes vfio_iommu_spapr_tce: Remove unneeded iommu_group_get_iommudata vfio/pci: Add test for BAR restore vfio/pci: Hide broken INTx support from user
2016-05-11vfio/spapr: Relax the IOMMU compatibility checkAlexey Kardashevskiy1-1/+2
We are going to have multiple different types of PHB on the same system with POWER8 + NVLink and PHBs will have different IOMMU ops. However we only really care about one callback - create_table - so we can relax the compatibility check here. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-28vfio_iommu_spapr_tce: Remove unneeded iommu_group_get_iommudataAlexey Kardashevskiy1-2/+0
This removes iommu_group_get_iommudata() as the result is never used. As this is a minor cleanup, no change in behavior is expected. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-11vfio: powerpc/spapr: Support Dynamic DMA windowsAlexey Kardashevskiy1-1/+195
This adds create/remove window ioctls to create and remove DMA windows. sPAPR defines a Dynamic DMA windows capability which allows para-virtualized guests to create additional DMA windows on a PCI bus. The existing linux kernels use this new window to map the entire guest memory and switch to the direct DMA operations saving time on map/unmap requests which would normally happen in a big amounts. This adds 2 ioctl handlers - VFIO_IOMMU_SPAPR_TCE_CREATE and VFIO_IOMMU_SPAPR_TCE_REMOVE - to create and remove windows. Up to 2 windows are supported now by the hardware and by this driver. This changes VFIO_IOMMU_SPAPR_TCE_GET_INFO handler to return additional information such as a number of supported windows and maximum number levels of TCE tables. DDW is added as a capability, not as a SPAPR TCE IOMMU v2 unique feature as we still want to support v2 on platforms which cannot do DDW for the sake of TCE acceleration in KVM (coming soon). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Register memory and define IOMMU v2Alexey Kardashevskiy1-80/+421
The existing implementation accounts the whole DMA window in the locked_vm counter. This is going to be worse with multiple containers and huge DMA windows. Also, real-time accounting would requite additional tracking of accounted pages due to the page size difference - IOMMU uses 4K pages and system uses 4K or 64K pages. Another issue is that actual pages pinning/unpinning happens on every DMA map/unmap request. This does not affect the performance much now as we spend way too much time now on switching context between guest/userspace/host but this will start to matter when we add in-kernel DMA map/unmap acceleration. This introduces a new IOMMU type for SPAPR - VFIO_SPAPR_TCE_v2_IOMMU. New IOMMU deprecates VFIO_IOMMU_ENABLE/VFIO_IOMMU_DISABLE and introduces 2 new ioctls to register/unregister DMA memory - VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY - which receive user space address and size of a memory region which needs to be pinned/unpinned and counted in locked_vm. New IOMMU splits physical pages pinning and TCE table update into 2 different operations. It requires: 1) guest pages to be registered first 2) consequent map/unmap requests to work only with pre-registered memory. For the default single window case this means that the entire guest (instead of 2GB) needs to be pinned before using VFIO. When a huge DMA window is added, no additional pinning will be required, otherwise it would be guest RAM + 2GB. The new memory registration ioctls are not supported by VFIO_SPAPR_TCE_IOMMU. Dynamic DMA window and in-kernel acceleration will require memory to be preregistered in order to work. The accounting is done per the user process. This advertises v2 SPAPR TCE IOMMU and restricts what the userspace can do with v1 or v2 IOMMUs. In order to support memory pre-registration, we need a way to track the use of every registered memory region and only allow unregistration if a region is not in use anymore. So we need a way to tell from what region the just cleared TCE was from. This adds a userspace view of the TCE table into iommu_table struct. It contains userspace address, one per TCE entry. The table is only allocated when the ownership over an IOMMU group is taken which means it is only used from outside of the powernv code (such as VFIO). As v2 IOMMU supports IODA2 and pre-IODA2 IOMMUs (which do not support DDW API), this creates a default DMA window for IODA2 for consistency. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: powerpc/powernv/ioda2: Use DMA windows API in ownership ↵Alexey Kardashevskiy1-1/+87
control Before the IOMMU user (VFIO) would take control over the IOMMU table belonging to a specific IOMMU group. This approach did not allow sharing tables between IOMMU groups attached to the same container. This introduces a new IOMMU ownership flavour when the user can not just control the existing IOMMU table but remove/create tables on demand. If an IOMMU implements take/release_ownership() callbacks, this lets the user have full control over the IOMMU group. When the ownership is taken, the platform code removes all the windows so the caller must create them. Before returning the ownership back to the platform code, VFIO unprograms and removes all the tables it created. This changes IODA2's onwership handler to remove the existing table rather than manipulating with the existing one. From now on, iommu_take_ownership() and iommu_release_ownership() are only called from the vfio_iommu_spapr_tce driver. Old-style ownership is still supported allowing VFIO to run on older P5IOC2 and IODA IO controllers. No change in userspace-visible behaviour is expected. Since it recreates TCE tables on each ownership change, related kernel traces will appear more often. This adds a pnv_pci_ioda2_setup_default_config() which is called when PE is being configured at boot time and when the ownership is passed from VFIO to the platform code. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: powerpc/powernv/ioda: Define and implement DMA windows APIAlexey Kardashevskiy1-8/+11
This extends iommu_table_group_ops by a set of callbacks to support dynamic DMA windows management. create_table() creates a TCE table with specific parameters. it receives iommu_table_group to know nodeid in order to allocate TCE table memory closer to the PHB. The exact format of allocated multi-level table might be also specific to the PHB model (not the case now though). This callback calculated the DMA window offset on a PCI bus from @num and stores it in a just created table. set_window() sets the window at specified TVT index + @num on PHB. unset_window() unsets the window from specified TVT. This adds a free() callback to iommu_table_ops to free the memory (potentially a tree of tables) allocated for the TCE table. create_table() and free() are supposed to be called once per VFIO container and set_window()/unset_window() are supposed to be called for every group in a container. This adds IOMMU capabilities to iommu_table_group such as default 32bit window parameters and others. This makes use of new values in vfio_iommu_spapr_tce. IODA1/P5IOC2 do not support DDW so they do not advertise pagemasks to the userspace. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11powerpc/iommu/powernv: Release replaced TCEAlexey Kardashevskiy1-25/+38
At the moment writing new TCE value to the IOMMU table fails with EBUSY if there is a valid entry already. However PAPR specification allows the guest to write new TCE value without clearing it first. Another problem this patch is addressing is the use of pool locks for external IOMMU users such as VFIO. The pool locks are to protect DMA page allocator rather than entries and since the host kernel does not control what pages are in use, there is no point in pool locks and exchange()+put_page(oldtce) is sufficient to avoid possible races. This adds an exchange() callback to iommu_table_ops which does the same thing as set() plus it returns replaced TCE and DMA direction so the caller can release the pages afterwards. The exchange() receives a physical address unlike set() which receives linear mapping address; and returns a physical address as the clear() does. This implements exchange() for P5IOC2/IODA/IODA2. This adds a requirement for a platform to have exchange() implemented in order to support VFIO. This replaces iommu_tce_build() and iommu_clear_tce() with a single iommu_tce_xchg(). This makes sure that TCE permission bits are not set in TCE passed to IOMMU API as those are to be calculated by platform code from DMA direction. This moves SetPageDirty() to the IOMMU code to make it work for both VFIO ioctl interface in in-kernel TCE acceleration (when it becomes available later). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership controlAlexey Kardashevskiy1-5/+65
This adds tce_iommu_take_ownership() and tce_iommu_release_ownership which call in a loop iommu_take_ownership()/iommu_release_ownership() for every table on the group. As there is just one now, no change in behaviour is expected. At the moment the iommu_table struct has a set_bypass() which enables/ disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code which calls this callback when external IOMMU users such as VFIO are about to get over a PHB. The set_bypass() callback is not really an iommu_table function but IOMMU/PE function. This introduces a iommu_table_group_ops struct and adds take_ownership()/release_ownership() callbacks to it which are called when an external user takes/releases control over the IOMMU. This replaces set_bypass() with ownership callbacks as it is not necessarily just bypass enabling, it can be something else/more so let's give it more generic name. The callbacks is implemented for IODA2 only. Other platforms (P5IOC2, IODA1) will use the old iommu_take_ownership/iommu_release_ownership API. The following patches will replace iommu_take_ownership/ iommu_release_ownership calls in IODA2 with full IOMMU table release/ create. As we here and touching bypass control, this removes pnv_pci_ioda2_setup_bypass_pe() as it does not do much more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base initialization to pnv_pci_ioda2_setup_dma_pe. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_groupAlexey Kardashevskiy1-36/+86
So far one TCE table could only be used by one IOMMU group. However IODA2 hardware allows programming the same TCE table address to multiple PE allowing sharing tables. This replaces a single pointer to a group in a iommu_table struct with a linked list of groups which provides the way of invalidating TCE cache for every PE when an actual TCE table is updated. This adds pnv_pci_link_table_and_group() and pnv_pci_unlink_table_and_group() helpers to manage the list. However without VFIO, it is still going to be a single IOMMU group per iommu_table. This changes iommu_add_device() to add a device to a first group from the group list of a table as it is only called from the platform init code or PCI bus notifier and at these moments there is only one group per table. This does not change TCE invalidation code to loop through all attached groups in order to simplify this patch and because it is not really needed in most cases. IODA2 is fixed in a later patch. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11powerpc/spapr: vfio: Replace iommu_table with iommu_table_groupAlexey Kardashevskiy1-10/+13
Modern IBM POWERPC systems support multiple (currently two) TCE tables per IOMMU group (a.k.a. PE). This adds a iommu_table_group container for TCE tables. Right now just one table is supported. This defines iommu_table_group struct which stores pointers to iommu_group and iommu_table(s). This replaces iommu_table with iommu_table_group where iommu_table was used to identify a group: - iommu_register_group(); - iommudata of generic iommu_group; This removes @data from iommu_table as it_table_group provides same access to pnv_ioda_pe. For IODA, instead of embedding iommu_table, the new iommu_table_group keeps pointers to those. The iommu_table structs are allocated dynamically. For P5IOC2, both iommu_table_group and iommu_table are embedded into PE struct. As there is no EEH and SRIOV support for P5IOC2, iommu_free_table() should not be called on iommu_table struct pointers so we can keep it embedded in pnv_phb::p5ioc2. For pSeries, this replaces multiple calls of kzalloc_node() with a new iommu_pseries_alloc_group() helper and stores the table group struct pointer into the pci_dn struct. For release, a iommu_table_free_group() helper is added. This moves iommu_table struct allocation from SR-IOV code to the generic DMA initialization code in pnv_pci_ioda_setup_dma_pe and pnv_pci_ioda2_setup_dma_pe as this is where DMA is actually initialized. This change is here because those lines had to be changed anyway. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Rework groups attachingAlexey Kardashevskiy1-16/+24
This is to make extended ownership and multiple groups support patches simpler for review. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Moving pinning/unpinning to helpersAlexey Kardashevskiy1-20/+41
This is a pretty mechanical patch to make next patches simpler. New tce_iommu_unuse_page() helper does put_page() now but it might skip that after the memory registering patch applied. As we are here, this removes unnecessary checks for a value returned by pfn_to_page() as it cannot possibly return NULL. This moves tce_iommu_disable() later to let tce_iommu_clear() know if the container has been enabled because if it has not been, then put_page() must not be called on TCEs from the TCE table. This situation is not yet possible but it will after KVM acceleration patchset is applied. This changes code to work with physical addresses rather than linear mapping addresses for better code readability. Following patches will add an xchg() callback for an IOMMU table which will accept/return physical addresses (unlike current tce_build()) which will eliminate redundant conversions. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Disable DMA mappings on disabled containerAlexey Kardashevskiy1-0/+6
At the moment DMA map/unmap requests are handled irrespective to the container's state. This allows the user space to pin memory which it might not be allowed to pin. This adds checks to MAP/UNMAP that the container is enabled, otherwise -EPERM is returned. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Move locked_vm accounting to helpersAlexey Kardashevskiy1-19/+63
There moves locked pages accounting to helpers. Later they will be reused for Dynamic DMA windows (DDW). This reworks debug messages to show the current value and the limit. This stores the locked pages number in the container so when unlocking the iommu table pointer won't be needed. This does not have an effect now but it will with the multiple tables per container as then we will allow attaching/detaching groups on fly and we may end up having a container with no group attached but with the counter incremented. While we are here, update the comment explaining why RLIMIT_MEMLOCK might be required to be bigger than the guest RAM. This also prints pid of the current process in pr_warn/pr_debug. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Use it_page_sizeAlexey Kardashevskiy1-13/+13
This makes use of the it_page_size from the iommu_table struct as page size can differ. This replaces missing IOMMU_PAGE_SHIFT macro in commented debug code as recently introduced IOMMU_PAGE_XXX macros do not include IOMMU_PAGE_SHIFT. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Check that IOMMU page is fully contained by system pageAlexey Kardashevskiy1-0/+16
This checks that the TCE table page size is not bigger that the size of a page we just pinned and going to put its physical address to the table. Otherwise the hardware gets unwanted access to physical memory between the end of the actual page and the end of the aligned up TCE page. Since compound_order() and compound_head() work correctly on non-huge pages, there is no need for additional check whether the page is huge. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11vfio: powerpc/spapr: Move page pinning from arch code to VFIO IOMMU driverAlexey Kardashevskiy1-13/+67
This moves page pinning (get_user_pages_fast()/put_page()) code out of the platform IOMMU code and puts it to VFIO IOMMU driver where it belongs to as the platform code does not deal with page pinning. This makes iommu_take_ownership()/iommu_release_ownership() deal with the IOMMU table bitmap only. This removes page unpinning from iommu_take_ownership() as the actual TCE table might contain garbage and doing put_page() on it is undefined behaviour. Besides the last part, the rest of the patch is mechanical. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-08-05drivers/vfio: EEH support for VFIO PCI deviceGavin Shan1-1/+16
The patch adds new IOCTL commands for sPAPR VFIO container device to support EEH functionality for PCI devices, which have been passed through from host to somebody else via VFIO. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Acked-by: Alexander Graf <agraf@suse.de> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30powerpc/iommu: Update constant names to reflect their hardcoded page sizeAlistair Popple1-14/+14
The powerpc iommu uses a hardcoded page size of 4K. This patch changes the name of the IOMMU_PAGE_* macros to reflect the hardcoded values. A future patch will use the existing names to support dynamic page sizes. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-20powerpc/vfio: Implement IOMMU driver for VFIOAlexey Kardashevskiy1-0/+377
VFIO implements platform independent stuff such as a PCI driver, BAR access (via read/write on a file descriptor or direct mapping when possible) and IRQ signaling. The platform dependent part includes IOMMU initialization and handling. This implements an IOMMU driver for VFIO which does mapping/unmapping pages for the guest IO and provides information about DMA window (required by a POWER guest). Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>