linux/drivers/vfio, branch v4.3

vfio: Fix lockdep issue

2015-07-24T21:14:04Z

When we open a device file descriptor, we currently have the following: vfio_group_get_device_fd() mutex_lock(&group->device_lock); open() ... if (ret) release() If we hit that error case, we call the backend driver release path, which for vfio-pci looks like this: vfio_pci_release() vfio_pci_disable() vfio_pci_try_bus_reset() vfio_pci_get_devs() vfio_device_get_from_dev() vfio_group_get_device() mutex_lock(&group->device_lock); Whoops, we've stumbled back onto group.device_lock and created a deadlock. There's a low likelihood of ever seeing this play out, but obviously it needs to be fixed. To do that we can use a reference to the vfio_device for vfio_group_get_device_fd() rather than holding the lock. There was a loop in this function, theoretically allowing multiple devices with the same name, but in practice we don't expect such a thing to happen and the code is already aborting from the loop with break on any sort of error rather than continuing and only parsing the first match anyway, so the loop was effectively unused already. Signed-off-by: Alex Williamson Fixes: 20f300175a1e ("vfio/pci: Fix racy vfio_device_get_from_dev() call") Reported-by: Joerg Roedel Tested-by: Joerg Roedel

Merge tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio

2015-06-28T19:32:13Z

Pull VFIO updates from Alex Williamson: - fix race with device reference versus driver release (Alex Williamson) - add reset hooks and Calxeda xgmac reset for vfio-platform (Eric Auger) - enable vfio-platform for ARM64 (Eric Auger) - tag Baptiste Reynal as vfio-platform sub-maintainer (Alex Williamson) * tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio: MAINTAINERS: Add vfio-platform sub-maintainer VFIO: platform: enable ARM64 build VFIO: platform: Calxeda xgmac reset module VFIO: platform: populate the reset function on probe VFIO: platform: add reset callback VFIO: platform: add reset struct and lookup table vfio/pci: Fix racy vfio_device_get_from_dev() call

Merge tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

2015-06-24T15:46:32Z

Pull powerpc updates from Michael Ellerman: - disable the 32-bit vdso when building LE, so we can build with a 64-bit only toolchain. - EEH fixes from Gavin & Richard. - enable the sys_kcmp syscall from Laurent. - sysfs control for fastsleep workaround from Shreyas. - expose OPAL events as an irq chip by Alistair. - MSI ops moved to pci_controller_ops by Daniel. - fix for kernel to userspace backtraces for perf from Anton. - merge pseries and pseries_le defconfigs from Cyril. - CXL in-kernel API from Mikey. - OPAL prd driver from Jeremy. - fix for DSCR handling & tests from Anshuman. - Powernv flash mtd driver from Cyril. - dynamic DMA Window support on powernv from Alexey. - LLVM clang fixes & workarounds from Anton. - reworked version of the patch to abort syscalls when transactional. - fix the swap encoding to support 4TB, from Aneesh. - various fixes as usual. - Freescale updates from Scott: Highlights include more 8xx optimizations, an e6500 hugetlb optimization, QMan device tree nodes, t1024/t1023 support, and various fixes and cleanup. * tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (180 commits) cxl: Fix typo in debug print cxl: Add CXL_KERNEL_API config option powerpc/powernv: Fix wrong IOMMU table in pnv_ioda_setup_bus_dma() powerpc/mm: Change the swap encoding in pte. powerpc/mm: PTE_RPN_MAX is not used, remove the same powerpc/tm: Abort syscalls in active transactions powerpc/iommu/ioda2: Enable compile with IOV=on and IOMMU_API=off powerpc/include: Add opal-prd to installed uapi headers powerpc/powernv: fix construction of opal PRD messages powerpc/powernv: Increase opal-irqchip initcall priority powerpc: Make doorbell check preemption safe powerpc/powernv: pnv_init_idle_states() should only run on powernv macintosh/nvram: Remove as unused powerpc: Don't use gcc specific options on clang powerpc: Don't use -mno-strict-align on clang powerpc: Only use -mtraceback=no, -mno-string and -msoft-float if toolchain supports it powerpc: Only use -mabi=altivec if toolchain supports it powerpc: Fix duplicate const clang warning in user access code vfio: powerpc/spapr: Support Dynamic DMA windows vfio: powerpc/spapr: Register memory and define IOMMU v2 ...

VFIO: platform: enable ARM64 build

2015-06-22T15:35:47Z

This patch enables building VFIO platform and derivatives on ARM64. Signed-off-by: Eric Auger Acked-by: Baptiste Reynal Tested-by: Baptiste Reynal Signed-off-by: Alex Williamson

VFIO: platform: Calxeda xgmac reset module

2015-06-22T15:35:38Z

This patch introduces a module that registers and implements a basic reset function for the Calxeda xgmac device. This latter basically disables interrupts and stops DMA transfers. The reset function code is inherited from the native calxeda xgmac driver. Signed-off-by: Eric Auger Acked-by: Baptiste Reynal Tested-by: Baptiste Reynal Signed-off-by: Alex Williamson

VFIO: platform: populate the reset function on probe

2015-06-22T15:35:30Z

The reset function lookup happens on vfio-platform probe. The reset module load is requested and a reference to the function symbol is hold. The reference is released on vfio-platform remove. Signed-off-by: Eric Auger Acked-by: Baptiste Reynal Tested-by: Baptiste Reynal Signed-off-by: Alex Williamson

VFIO: platform: add reset callback

2015-06-22T15:35:22Z

A new reset callback is introduced. If this callback is populated, the reset is invoked on device first open/last close or upon userspace ioctl. The modality is exposed on VFIO_DEVICE_GET_INFO. Signed-off-by: Eric Auger Acked-by: Baptiste Reynal Tested-by: Baptiste Reynal Signed-off-by: Alex Williamson

VFIO: platform: add reset struct and lookup table

2015-06-17T21:39:09Z

This patch introduces the vfio_platform_reset_combo struct that stores all the information useful to handle the reset modality: compat string, name of the reset function, name of the module that implements the reset function. A lookup table of such structures is added, currently void. Signed-off-by: Eric Auger Acked-by: Baptiste Reynal Tested-by: Baptiste Reynal Signed-off-by: Alex Williamson

vfio: powerpc/spapr: Support Dynamic DMA windows

2015-06-11T05:16:55Z

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 [aw: for the vfio related changes] Acked-by: Alex Williamson Reviewed-by: David Gibson Signed-off-by: Michael Ellerman

vfio: powerpc/spapr: Register memory and define IOMMU v2

2015-06-11T05:16:55Z

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 [aw: for the vfio related changes] Acked-by: Alex Williamson Reviewed-by: David Gibson Signed-off-by: Michael Ellerman