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2022-12-05vfio: Move vfio_spapr_iommu_eeh_ioctl into vfio_iommu_spapr_tce.cJason Gunthorpe1-2/+53
As with the previous patch EEH is always enabled if SPAPR_TCE_IOMMU, so move this last bit of code into the main module. Now that this function only processes VFIO_EEH_PE_OP remove a level of indenting as well, it is only called by a case statement that already checked VFIO_EEH_PE_OP. This eliminates an unnecessary module and SPAPR code in a global header. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/3-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-12-05vfio/spapr: Move VFIO_CHECK_EXTENSION into tce_iommu_ioctl()Jason Gunthorpe1-6/+4
The PPC64 kconfig is a bit of a rats nest, but it turns out that if CONFIG_SPAPR_TCE_IOMMU is on then EEH must be too: config SPAPR_TCE_IOMMU bool "sPAPR TCE IOMMU Support" depends on PPC_POWERNV || PPC_PSERIES select IOMMU_API help Enables bits of IOMMU API required by VFIO. The iommu_ops is not implemented as it is not necessary for VFIO. config PPC_POWERNV select FORCE_PCI config PPC_PSERIES select FORCE_PCI config EEH bool depends on (PPC_POWERNV || PPC_PSERIES) && PCI default y So, just open code the call to eeh_enabled() into tce_iommu_ioctl(). Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/2-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-22vfio/spapr_tce: Fix the commentAlexey Kardashevskiy1-1/+4
Grepping for "iommu_ops" finds this spot and gives wrong impression that iommu_ops is used in here, fix the comment. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Link: https://lore.kernel.org/r/20220714080912.3713509-1-aik@ozlabs.ru [aw: convert to multi-line comment] Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-07vfio/spapr_tce: Remove the unused parameters containerDeming Wang1-5/+4
The parameter of container has been unused for tce_iommu_unuse_page. So, we should delete it. Signed-off-by: Deming Wang <wangdeming@inspur.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Link: https://lore.kernel.org/r/20220702064613.5293-1-wangdeming@inspur.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio/spapr_tce: reject mediated devicesChristoph Hellwig1-0/+3
Unlike the the type1 IOMMU backend, the SPAPR one does not contain any support for the magic non-IOMMU backed iommu_group used by mediated devices, so reject them in ->attach_group. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-13-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio: clean up the check for mediated device in vfio_iommu_type1Christoph Hellwig1-1/+1
Pass the group flags to ->attach_group and remove the messy check for the bus type. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-12-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-09-30vfio: move the vfio_iommu_driver_ops interface out of <linux/vfio.h>Christoph Hellwig1-0/+1
Create a new private drivers/vfio/vfio.h header for the interface between the VFIO core and the iommu drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-10-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-07-27vfio/spapr_tce: convert get_user_pages() --> pin_user_pages()John Hubbard1-2/+2
This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: kvm@vger.kernel.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-01-07vfio/spapr_tce: use mmgrabJulia Lawall1-1/+1
Mmgrab was introduced in commit f1f1007644ff ("mm: add new mmgrab() helper") and most of the kernel was updated to use it. Update a remaining file. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) <smpl> @@ expression e; @@ - atomic_inc(&e->mm_count); + mmgrab(e); </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-09-24mm: introduce page_shift()Matthew Wilcox (Oracle)1-4/+4
Replace PAGE_SHIFT + compound_order(page) with the new page_shift() function. Minor improvements in readability. [akpm@linux-foundation.org: fix build in tce_page_is_contained()] Link: http://lkml.kernel.org/r/201907241853.yNQTrJWd%25lkp@intel.com Link: http://lkml.kernel.org/r/20190721104612.19120-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-20Merge tag 'vfio-v5.4-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds1-4/+5
Pull VFIO updates from Alex Williamson: - Fix spapr iommu error case case (Alexey Kardashevskiy) - Consolidate region type definitions (Cornelia Huck) - Restore saved original PCI state on release (hexin) - Simplify mtty sample driver interrupt path (Parav Pandit) - Support for reporting valid IOVA regions to user (Shameer Kolothum) * tag 'vfio-v5.4-rc1' of git://github.com/awilliam/linux-vfio: vfio_pci: Restore original state on release vfio/type1: remove duplicate retrieval of reserved regions vfio/type1: Add IOVA range capability support vfio/type1: check dma map request is within a valid iova range vfio/spapr_tce: Fix incorrect tce_iommu_group memory free vfio-mdev/mtty: Simplify interrupt generation vfio: re-arrange vfio region definitions vfio/type1: Update iova list on detach vfio/type1: Check reserved region conflict and update iova list vfio/type1: Introduce iova list and add iommu aperture validity check
2019-08-30vfio/spapr_tce: Invalidate multiple TCEs at onceAlexey Kardashevskiy1-6/+12
Invalidating a TCE cache entry for each updated TCE is quite expensive. This makes use of the new iommu_table_ops::xchg_no_kill()/tce_kill() callbacks to bring down the time spent in mapping a huge guest DMA window. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190829085252.72370-4-aik@ozlabs.ru
2019-08-19vfio/spapr_tce: Fix incorrect tce_iommu_group memory freeAlexey Kardashevskiy1-4/+5
The @tcegrp variable is used in 1) a loop over attached groups 2) it stores a pointer to a newly allocated tce_iommu_group if 1) found nothing. However the error handler does not distinguish how we got there and incorrectly releases memory for a found+incompatible group. This fixes it by adding another error handling case. Fixes: 0bd971676e68 ("powerpc/powernv/npu: Add compound IOMMU groups") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-07-16mm: add account_locked_vm utility functionDaniel Jordan1-49/+5
locked_vm accounting is done roughly the same way in five places, so unify them in a helper. Include the helper's caller in the debug print to distinguish between callsites. Error codes stay the same, so user-visible behavior does too. The one exception is that the -EPERM case in tce_account_locked_vm is removed because Alexey has never seen it triggered. [daniel.m.jordan@oracle.com: v3] Link: http://lkml.kernel.org/r/20190529205019.20927-1-daniel.m.jordan@oracle.com [sfr@canb.auug.org.au: fix mm/util.c] Link: http://lkml.kernel.org/r/20190524175045.26897-1-daniel.m.jordan@oracle.com Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Cc: Alan Tull <atull@kernel.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Lameter <cl@linux.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Moritz Fischer <mdf@kernel.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Steve Sistare <steven.sistare@oracle.com> Cc: Wu Hao <hao.wu@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny1-1/+2
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-03vfio/spapr_tce: Make symbol 'tce_iommu_driver_ops' staticWang Hai1-1/+1
Fixes the following sparse warning: drivers/vfio/vfio_iommu_spapr_tce.c:1401:36: warning: symbol 'tce_iommu_driver_ops' was not declared. Should it be static? Fixes: 5ffd229c0273 ("powerpc/vfio: Implement IOMMU driver for VFIO") Signed-off-by: Wang Hai <wanghai26@huawei.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-13vfio/spapr_tce: Skip unsetting already unset tableAlexey Kardashevskiy1-1/+2
VFIO TCE IOMMU v2 owns IOMMU tables. When we detach an IOMMU group from a container, we need to unset these tables from the group which we do by calling unset_window(). We also unset tables when removing a DMA window via the VFIO_IOMMU_SPAPR_TCE_REMOVE ioctl. The window removal checks if the table actually exists (hidden inside tce_iommu_find_table()) but the group detaching does not so the user may see duplicating messages: pci 0009:03 : [PE# fd] Removing DMA window #0 pci 0009:03 : [PE# fd] Removing DMA window #1 pci 0009:03 : [PE# fd] Removing DMA window #0 pci 0009:03 : [PE# fd] Removing DMA window #1 At the moment this is not a problem as the second invocation of unset_window() writes zeroes to the HW registers again and exits early as there is no table. 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>
2018-12-21powerpc/vfio/iommu/kvm: Do not pin device memoryAlexey Kardashevskiy1-10/+19
This new memory does not have page structs as it is not plugged to the host so gup() will fail anyway. This adds 2 helpers: - mm_iommu_newdev() to preregister the "memory device" memory so the rest of API can still be used; - mm_iommu_is_devmem() to know if the physical address is one of thise new regions which we must avoid unpinning of. This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test if the memory is device memory to avoid pfn_to_page(). This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which does delayed pages dirtying. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a regionAlexey Kardashevskiy1-12/+23
Normally mm_iommu_get() should add a reference and mm_iommu_put() should remove it. However historically mm_iommu_find() does the referencing and mm_iommu_get() is doing allocation and referencing. We are going to add another helper to preregister device memory so instead of having mm_iommu_new() (which pre-registers the normal memory and references the region), we need separate helpers for pre-registering and referencing. This renames: - mm_iommu_get to mm_iommu_new; - mm_iommu_find to mm_iommu_get. This changes mm_iommu_get() to reference the region so the name now reflects what it does. This removes the check for exact match from mm_iommu_new() as we want it to fail on existing regions; mm_iommu_get() should be used instead. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20vfio/spapr_tce: Get rid of possible infinite loopAlexey Kardashevskiy1-7/+3
As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered memory. If there is a bug in memory release, the loop in tce_iommu_release() becomes infinite; this actually happened to me. This makes the loop finite and prints a warning on every failure to make the code more bug prone. 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>
2018-10-20KVM: PPC: Optimize clearing TCEs for sparse tablesAlexey Kardashevskiy1-2/+21
The powernv platform maintains 2 TCE tables for VFIO - a hardware TCE table and a table with userspace addresses. These tables are radix trees, we allocate indirect levels when they are written to. Since the memory allocation is problematic in real mode, we have 2 accessors to the entries: - for virtual mode: it allocates the memory and it is always expected to return non-NULL; - fr real mode: it does not allocate and can return NULL. Also, DMA windows can span to up to 55 bits of the address space and since we never have this much RAM, such windows are sparse. However currently the SPAPR TCE IOMMU driver walks through all TCEs to unpin DMA memory. Since we maintain a userspace addresses table for VFIO which is a mirror of the hardware table, we can use it to know which parts of the DMA window have not been mapped and skip these so does this patch. The bare metal systems do not have this problem as they use a bypass mode of a PHB which maps RAM directly. This helps a lot with sparse DMA windows, reducing the shutdown time from about 3 minutes per 1 billion TCEs to a few seconds for 32GB sparse guest. Just skipping the last level seems to be good enough. As non-allocating accessor is used now in virtual mode as well, rename it from IOMMU_TABLE_USERSPACE_ENTRY_RM (real mode) to _RO (read only). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-08-13Merge branch 'fixes' into nextMichael Ellerman1-5/+5
Merge our fixes branch from the 4.18 cycle to resolve some minor conflicts.
2018-07-18KVM: PPC: Check if IOMMU page is contained in the pinned physical pageAlexey Kardashevskiy1-1/+1
A VM which has: - a DMA capable device passed through to it (eg. network card); - running a malicious kernel that ignores H_PUT_TCE failure; - capability of using IOMMU pages bigger that physical pages can create an IOMMU mapping that exposes (for example) 16MB of the host physical memory to the device when only 64K was allocated to the VM. The remaining 16MB - 64K will be some other content of host memory, possibly including pages of the VM, but also pages of host kernel memory, host programs or other VMs. The attacking VM does not control the location of the page it can map, and is only allowed to map as many pages as it has pages of RAM. We already have a check in drivers/vfio/vfio_iommu_spapr_tce.c that an IOMMU page is contained in the physical page so the PCI hardware won't get access to unassigned host memory; however this check is missing in the KVM fastpath (H_PUT_TCE accelerated code). We were lucky so far and did not hit this yet as the very first time when the mapping happens we do not have tbl::it_userspace allocated yet and fall back to the userspace which in turn calls VFIO IOMMU driver, this fails and the guest does not retry, This stores the smallest preregistered page size in the preregistered region descriptor and changes the mm_iommu_xxx API to check this against the IOMMU page size. This calculates maximum page size as a minimum of the natural region alignment and compound page size. For the page shift this uses the shift returned by find_linux_pte() which indicates how the page is mapped to the current userspace - if the page is huge and this is not a zero, then it is a leaf pte and the page is mapped within the range. Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-18vfio/spapr: Use IOMMU pageshift rather than pagesizeAlexey Kardashevskiy1-4/+4
The size is always equal to 1 page so let's use this. Later on this will be used for other checks which use page shifts to check the granularity of access. This should cause no behavioral change. Cc: stable@vger.kernel.org # v4.12+ Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-16powerpc/powernv/ioda: Allocate indirect TCE levels on demandAlexey Kardashevskiy1-1/+1
At the moment we allocate the entire TCE table, twice (hardware part and userspace translation cache). This normally works as we normally have contigous memory and the guest will map entire RAM for 64bit DMA. However if we have sparse RAM (one example is a memory device), then we will allocate TCEs which will never be used as the guest only maps actual memory for DMA. If it is a single level TCE table, there is nothing we can really do but if it a multilevel table, we can skip allocating TCEs we know we won't need. This adds ability to allocate only first level, saving memory. This changes iommu_table::free() to avoid allocating of an extra level; iommu_table::set() will do this when needed. This adds @alloc parameter to iommu_table::exchange() to tell the callback if it can allocate an extra level; the flag is set to "false" for the realmode KVM handlers of H_PUT_TCE hcalls and the callback returns H_TOO_HARD. This still requires the entire table to be counted in mm::locked_vm. To be conservative, this only does on-demand allocation when the usespace cache table is requested which is the case of VFIO. The example math for a system replicating a powernv setup with NVLink2 in a guest: 16GB RAM mapped at 0x0 128GB GPU RAM window (16GB of actual RAM) mapped at 0x244000000000 the table to cover that all with 64K pages takes: (((0x244000000000 + 0x2000000000) >> 16)*8)>>20 = 4556MB If we allocate only necessary TCE levels, we will only need: (((0x400000000 + 0x400000000) >> 16)*8)>>20 = 4MB (plus some for indirect levels). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-16powerpc/powernv: Add indirect levels to it_userspaceAlexey Kardashevskiy1-46/+0
We want to support sparse memory and therefore huge chunks of DMA windows do not need to be mapped. If a DMA window big enough to require 2 or more indirect levels, and a DMA window is used to map all RAM (which is a default case for 64bit window), we can actually save some memory by not allocation TCE for regions which we are not going to map anyway. The hardware tables alreary support indirect levels but we also keep host-physical-to-userspace translation array which is allocated by vmalloc() and is a flat array which might use quite some memory. This converts it_userspace from vmalloc'ed array to a multi level table. As the format becomes platform dependend, this replaces the direct access to it_usespace with a iommu_table_ops::useraddrptr hook which returns a pointer to the userspace copy of a TCE; future extension will return NULL if the level was not allocated. This should not change non-KVM handling of TCE tables and it_userspace will not be allocated for non-KVM tables. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-16KVM: PPC: Make iommu_table::it_userspace big endianAlexey Kardashevskiy1-10/+9
We are going to reuse multilevel TCE code for the userspace copy of the TCE table and since it is big endian, let's make the copy big endian too. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
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