December 2021 - Linux-kselftest-mirror

[RFC PATCH 00/13] x86 User Interrupts support

by Sohil Mehta

User Interrupts Introduction ============================ User Interrupts (Uintr) is a hardware technology that enables delivering interrupts directly to user space. Today, virtually all communication across privilege boundaries happens by going through the kernel. These include signals, pipes, remote procedure calls and hardware interrupt based notifications. User interrupts provide the foundation for more efficient (low latency and low CPU utilization) versions of these common operations by avoiding transitions through the kernel. In the User Interrupts hardware architecture, a receiver is always expected to be a user space task. However, a user interrupt can be sent by another user space task, kernel or an external source (like a device). In addition to the general infrastructure to receive user interrupts, this series introduces a single source: interrupts from another user task. These are referred to as User IPIs. The first implementation of User IPIs will be in the Intel processor code-named Sapphire Rapids. Refer Chapter 11 of the Intel Architecture instruction set extensions for details of the hardware architecture [1]. Series-reviewed-by: Tony Luck <tony.luck(a)intel.com> Main goals of this RFC ====================== - Introduce this upcoming technology to the community. This cover letter includes a hardware architecture summary along with the software architecture and kernel design choices. This post is a bit long as a result. Hopefully, it helps answer more questions than it creates :) I am also planning to talk about User Interrupts next week at the LPC Kernel summit. - Discuss potential use cases. We are starting to look at actual usages and libraries (like libevent[2] and liburing[3]) that can take advantage of this technology. Unfortunately, we don't have much to share on this right now. We need some help from the community to identify usages that can benefit from this. We would like to make sure the proposed APIs work for the eventual consumers. - Get early feedback on the software architecture. We are hoping to get some feedback on the direction of overall software architecture - starting with User IPI, extending it for kernel-to-user interrupt notifications and external interrupts in the future. - Discuss some of the main architecture opens. There is lot of work that still needs to happen to enable this technology. We are looking for some input on future patches that would be of interest. Here are some of the big opens that we are looking to resolve. * Should Uintr interrupt all blocking system calls like sleep(), read(), poll(), etc? If so, should we implement an SA_RESTART type of mechanism similar to signals? - Refer Blocking for interrupts section below. * Should the User Interrupt Target table (UITT) be shared between threads of a multi-threaded application or maybe even across processes? - Refer Sharing the UITT section below. Why care about this? - Micro benchmark performance ================================================== There is a ~9x or higher performance improvement using User IPI over other IPC mechanisms for event signaling. Below is the average normalized latency for a 1M ping-pong IPC notifications with message size=1. +------------+-------------------------+ | IPC type | Relative Latency | | |(normalized to User IPI) | +------------+-------------------------+ | User IPI | 1.0 | | Signal | 14.8 | | Eventfd | 9.7 | | Pipe | 16.3 | | Domain | 17.3 | +------------+-------------------------+ Results have been estimated based on tests on internal hardware with Linux v5.14 + User IPI patches. Original benchmark: https://github.com/goldsborough/ipc-bench Updated benchmark: https://github.com/intel/uintr-ipc-bench/tree/linux-rfc-v1 *Performance varies by use, configuration and other factors. How it works underneath? - Hardware Summary =========================================== User Interrupts is a posted interrupt delivery mechanism. The interrupts are first posted to a memory location and then delivered to the receiver when they are running with CPL=3. Kernel managed architectural data structures -------------------------------------------- UPID: User Posted Interrupt Descriptor - Holds receiver interrupt vector information and notification state (like an ongoing notification, suppressed notifications). UITT: User Interrupt Target Table - Stores UPID pointer and vector information for interrupt routing on the sender side. Referred by the senduipi instruction. The interrupt state of each task is referenced via MSRs which are saved and restored by the kernel during context switch. Instructions ------------ senduipi <index> - send a user IPI to a target task based on the UITT index. clui - Mask user interrupts by clearing UIF (User Interrupt Flag). stui - Unmask user interrupts by setting UIF. testui - Test current value of UIF. uiret - return from a user interrupt handler. User IPI -------- When a User IPI sender executes 'senduipi <index>', the hardware refers the UITT table entry pointed by the index and posts the interrupt vector (63-0) into the receiver's UPID. If the receiver is running (CPL=3), the sender cpu would send a physical IPI to the receiver's cpu. On the receiver side this IPI is detected as a User Interrupt. The User Interrupt handler for the receiver is invoked and the vector number (63-0) is pushed onto the stack. Upon execution of 'uiret' in the interrupt handler, the control is transferred back to instruction that was interrupted. Refer Chapter 11 of the Intel Architecture instruction set extensions [1] for more details. Application interface - Software Architecture ============================================= User Interrupts (Uintr) is an opt-in feature (unlike signals). Applications wanting to use Uintr are expected to register themselves with the kernel using the Uintr related system calls. A Uintr receiver is always a userspace task. A Uintr sender can be another userspace task, kernel or a device. 1) A receiver can register/unregister an interrupt handler using the Uintr receiver related syscalls. uintr_register_handler(handler, flags) uintr_unregister_handler(flags) 2) A syscall also allows a receiver to register a vector and create a user interrupt file descriptor - uintr_fd. uintr_fd = uintr_create_fd(vector, flags) Uintr can be useful in some of the usages where eventfd or signals are used for frequent userspace event notifications. The semantics of uintr_fd are somewhat similar to an eventfd() or the write end of a pipe. 3) Any sender with access to uintr_fd can use it to deliver events (in this case - interrupts) to a receiver. A sender task can manage its connection with the receiver using the sender related syscalls based on uintr_fd. uipi_index = uintr_register_sender(uintr_fd, flags) Using an FD abstraction provides a secure mechanism to connect with a receiver. The FD sharing and isolation mechanisms put in place by the kernel would extend to Uintr as well. 4a) After the initial setup, a sender task can use the SENDUIPI instruction along with the uipi_index to generate user IPIs without any kernel intervention. SENDUIPI <uipi_index> If the receiver is running (CPL=3), then the user interrupt is delivered directly without a kernel transition. If the receiver isn't running the interrupt is delivered when the receiver gets context switched back. If the receiver is blocked in the kernel, the user interrupt is delivered to the kernel which then unblocks the intended receiver to deliver the interrupt. 4b) If the sender is the kernel or a device, the uintr_fd can be passed onto the related kernel entity to allow them to setup a connection and then generate a user interrupt for event delivery. <The exact details of this API are still being worked upon.> For details of the user interface and associated system calls refer the Uintr man-pages draft: https://github.com/intel/uintr-linux-kernel/tree/rfc-v1/tools/uintr/manpages. We have also included the same content as patch 1 of this series to make it easier to review. Refer the Uintr compiler programming guide [4] for details on Uintr integration with GCC and Binutils. Kernel design choices ===================== Here are some of the reasons and trade-offs for the current design of the APIs. System call interface --------------------- Why a system call interface?: The 2 options we considered are using a char device at /dev or use system calls (current approach). A syscall approach avoids exposing a core cpu feature through a driver model. Also, we want to have a user interrupt FD per vector and share a single common interrupt handler among all vectors. This seems easier for the kernel and userspace to accomplish using a syscall based approach. Data sharing using user interrupts: Uintr doesn't include a mechanism to share/transmit data. The expectation is applications use existing data sharing mechanisms to share data and use Uintr only for signaling. An FD for each vector: A uintr_fd is assigned to each vector to allow fine grained priority and event management by the receiver. The alternative we considered was to allocate an FD to the interrupt handler and having that shared with the sender. However, that approach relies on the sender selecting the vector and moves the vector priority management to the sender. Also, if multiple senders want to send unique user interrupts they would need to coordinate the vector selection amongst them. Extending the APIs: Currently, the system calls are only extendable using the flags argument. We can add a variable size struct to some of the syscalls if needed. Extending existing mechanisms ----------------------------- Uintr can be beneficial in some of the usages where eventfd() or signals are used. Since Uintr is hardware-dependent, thread-specific and bypasses the kernel in the fast path, it makes extending existing mechanisms harder. Main issues with extending signals: Signal handlers are defined significantly differently than a User interrupt handler. An application needs to save/restore registers in a user interrupt handler and call uiret to return from it. Also, signals can be process directed (or thread directed) but user interrupts are always thread directed. Comparison of signals with User Interrupts: +=====================+===========================+===========================+ | | Signals | User Interrupts | +=====================+===========================+===========================+ | Stacks | Has alt stacks | Uses application stack | | | | (alternate stack option | | | | not yet enabled) | +---------------------+---------------------------+---------------------------+ | Registers state | Kernel manages incl. | App responsible (Use GCC | | | FPU/XSTATE area | 'interrupt' attribute for | | | | general purpose registers)| +---------------------+---------------------------+---------------------------+ | Blocking/Masking | sigprocmask(2)/sa_mask | CLUI instruction (No per | | | | vector masking) | +---------------------+---------------------------+---------------------------+ | Direction | Uni-directional | Uni-directional | +---------------------+---------------------------+---------------------------+ | Post event | kill(), signal(), | SENDUIPI <index> - index | | | sigqueue(), etc. | derived from uintr_fd | +---------------------+---------------------------+---------------------------+ | Target | Process-directed or | Thread-directed | | | thread-directed | | +---------------------+---------------------------+---------------------------+ | Fork/inheritance | Empty signal set | Nothing is inherited | +---------------------+---------------------------+---------------------------+ | Execv | Pending signals preserved | Nothing is inherited | +---------------------+---------------------------+---------------------------+ | Order of delivery | Undetermined | High to low vector numbers| | for multiple signals| | | +---------------------+---------------------------+---------------------------+ | Handler re-entry | All signals except the | No interrupts can cause | | | one being handled | handler re-entry. | +---------------------+---------------------------+---------------------------+ | Delivery feedback | 0 or -1 based on whether | No feedback on whether the| | | the signal was sent | interrupt was sent or | | | | received. | +---------------------+---------------------------+---------------------------+ Main issues with extending eventfd(): eventfd() has a counter value that is core to the API. User interrupts can't have an associated counter since the signaling happens at the user level and the hardware doesn't have a memory counter mechanism. Also, eventfd can be used for bi-directional signaling where as uintr_fd is uni-directional. Comparison of eventfd with uintr_fd: +====================+======================+==============================+ | | Eventfd | uintr_fd (User Interrupt FD) | +====================+======================+==============================+ | Object | Counter - uint64 | Receiver vector information | +--------------------+----------------------+------------------------------+ | Post event | write() to eventfd | SENDUIPI <index> - index | | | | derived from uintr_fd | +--------------------+----------------------+------------------------------+ | Receive event | read() on eventfd | Implicit - Handler is | | | | invoked with associated | | | | vector. | +--------------------+----------------------+------------------------------+ | Direction | Bi-directional | Uni-directional | +--------------------+----------------------+------------------------------+ | Data transmitted | Counter - uint64 | None | +--------------------+----------------------+------------------------------+ | Waiting for events | Poll() family of | No per vector wait. | | | syscalls | uintr_wait() allows waiting | | | | for all user interrupts | +--------------------+----------------------+------------------------------+ Security Model ============== User Interrupts is designed as an opt-in feature (unlike signals). The security model for user interrupts is intended to be similar to eventfd(). The general idea is that any sender with access to uintr_fd would be able to generate the associated interrupt vector for the receiver task that created the fd. Untrusted processes ------------------- The current implementation expects only trusted and cooperating processes to communicate using user interrupts. Coordination is expected between processes for a connection teardown. In situations where coordination doesn't happen (say, due to abrupt process exit), the kernel would end up keeping shared resources (like UPID) allocated to avoid faults. Currently, a sender can easily cause a denial of service for the receiver by generating a storm of user interrupts. A user interrupt handler is invoked with interrupts disabled, but upon execution of uiret, interrupts get enabled again by the hardware. This can lead to the handler being invoked again before normal execution can resume. There isn't a hardware mechanism to mask specific interrupt vectors. To enable untrusted processes to communicate, we need to add a per-vector masking option through another syscall (or maybe IOCTL). However, this can add some complexity to the kernel code. A vector can only be masked by modifying the UITT entries at the source. We need to be careful about races while removing and restoring the UPID from the UITT. Resource limits --------------- The maximum number of receiver-sender connections would be limited by the maximum number of open file descriptors and the size of the UITT. The UITT size is chosen as 4kB fixed size arbitrarily right now. We plan to make it dynamic and configurable in size. RLIMIT_MEMLOCK or ENOMEM should be triggered when the size limits have been hit. Main Opens ========== Blocking for interrupts ----------------------- User interrupts are delivered to applications immediately if they are running in userspace. If a receiver task has blocked in the kernel using the placeholder uintr_wait() syscall, the task would be woken up to deliver the user interrupt. However, if the task is blocked due to any other blocking calls like read(), sleep(), etc; the interrupt will only get delivered when the application gets scheduled again. We need to consider if applications need to receive User Interrupts as soon as they are posted (similar to signals) when they are blocked due to some other reason. Adding this capability would likely make the kernel implementation more complex. Interrupting system calls using User Interrupts would also mean we need to consider an SA_RESTART type of mechanism. We also need to evaluate if some of the signal handler related semantics in the kernel can be reused for User Interrupts. Sharing the User Interrupt Target Table (UITT) ---------------------------------------------- The current implementation assigns a unique UITT to each task. This assumes that User interrupts are used for point-to-point communication between 2 tasks. Also, this keeps the kernel implementation relatively simple. However, there are of benefits to sharing the UITT between threads of a multi-threaded application. One, they would see a consistent view of the UITT. i.e. SENDUIPI <index> would mean the same on all threads of the application. Also, each thread doesn't have to register itself using the common uintr_fd. This would simplify the userspace setup and make efficient use of kernel memory. The potential downside is that the kernel implementation to allocate, modify, expand and free the UITT would be more complex. A similar argument can be made for a set of processes that do a lot of IPC amongst them. They would prefer to have a shared UITT that lets them target any process from any process. With the current file descriptor based approach, the connection setup can be time consuming and somewhat cumbersome. We need to evaluate if this can be made simpler as well. Kernel page table isolation (KPTI) ---------------------------------- SENDUIPI is a special ring-3 instruction that makes a supervisor mode memory access to the UPID and UITT memory. The current patches need KPTI to be disabled for User IPIs to work. To make User IPI work with KPTI, we need to allocate these structures from a special memory region that has supervisor access but it is mapped into userspace. The plan is to implement a mechanism similar to LDT. Processors that support user interrupts are not affected by Meltdown so the auto mode of KPTI will default to off. Users who want to force enable KPTI will need to wait for a later version of this patch series to use user interrupts. Please let us know if you want the development of these patches to be prioritized (or deprioritized). FAQs ==== Q: What happens if a process is "surprised" by a user interrupt? A: For tasks that haven't registered with the kernel and requested for user interrupts aren't expected or able to receive to user interrupts. Q: Do user interrupts affect kernel scheduling? A: No. If a task is blocked waiting for user interrupts, when the kernel receives a notification on behalf of that task we only put it back on the runqueue. Delivery of a user interrupt in no way changes the scheduling priorities of a task. Q: Does the sender get to know if the interrupt was delivered? A: No. User interrupts only provides a posted interrupt delivery mechanism. If applications need to rely on whether the interrupt was delivered they should consider a userspace mechanism for feedback (like a shared memory counter or a user interrupt back to the sender). Q: Why is there no feedback on interrupt delivery? A: Being a posted interrupt delivery mechanism, the interrupt delivery happens in 2 steps: 1) The interrupt information is stored in a memory location (UPID). 2) The physical interrupt is delivered to the interrupt receiver. The 2nd step could happen immediately, after an extended period, or it might never happen based on the state of the receiver after step 1. (The receiver could have disabled interrupts, have been context switched out or it might have crashed during that time.) This makes it very hard for the hardware to reliably provide feedback upon execution of SENDUIPI. Q: Can user interrupts be nested? A: Yes. Using STUI instruction in the interrupt handler would allow new user interrupts to be delivered. However, there no TPR(thread priority register) like mechanism to allow only higher priority interrupts. Any user interrupt can be taken when nesting is enabled. Q: Can a task receive all pending user interrupts in one go? A: No. The hardware allows only one vector to be processed at a time. If a task is interested in knowing all the interrupts that are pending then we could add a syscall that provides the pending interrupts information. Q: Do the processes need to be pinned to a cpu? A: No. User interrupts will be routed correctly to whichever cpu the receiver is running on. The kernel updates the cpu information in the UPID during context switch. Q: Why are UPID and UITT allocated by the kernel? A: If allocated by user space, applications could misuse the UPID and UITT to write to unauthorized memory and generate interrupts on any cpu. The UPID and UITT are allocated by the kernel and accessed by the hardware with supervisor privilege. Patch structure for this series =============================== - Man-pages and Kernel documentation (patch 1,2) - Hardware enumeration (patch 3, 4) - User IPI kernel vector reservation (patch 5) - Syscall interface for interrupt receiver, sender and vector management(uintr_fd) (patch 6-12) - Basic selftests (patch 13) Along with the patches in this RFC, there are additional tests and samples that are available at: https://github.com/intel/uintr-linux-kernel/tree/rfc-v1 Links ===== [1]: https://software.intel.com/content/www/us/en/develop/download/intel-archite… [2]: https://libevent.org/ [3]: https://github.com/axboe/liburing [4]: https://github.com/intel/uintr-compiler-guide/blob/uintr-gcc-11.1/UINTR-com… Sohil Mehta (13): x86/uintr/man-page: Include man pages draft for reference Documentation/x86: Add documentation for User Interrupts x86/cpu: Enumerate User Interrupts support x86/fpu/xstate: Enumerate User Interrupts supervisor state x86/irq: Reserve a user IPI notification vector x86/uintr: Introduce uintr receiver syscalls x86/process/64: Add uintr task context switch support x86/process/64: Clean up uintr task fork and exit paths x86/uintr: Introduce vector registration and uintr_fd syscall x86/uintr: Introduce user IPI sender syscalls x86/uintr: Introduce uintr_wait() syscall x86/uintr: Wire up the user interrupt syscalls selftests/x86: Add basic tests for User IPI .../admin-guide/kernel-parameters.txt | 2 + Documentation/x86/index.rst | 1 + Documentation/x86/user-interrupts.rst | 107 +++ arch/x86/Kconfig | 12 + arch/x86/entry/syscalls/syscall_32.tbl | 6 + arch/x86/entry/syscalls/syscall_64.tbl | 6 + arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/disabled-features.h | 8 +- arch/x86/include/asm/entry-common.h | 4 + arch/x86/include/asm/fpu/types.h | 20 +- arch/x86/include/asm/fpu/xstate.h | 3 +- arch/x86/include/asm/hardirq.h | 4 + arch/x86/include/asm/idtentry.h | 5 + arch/x86/include/asm/irq_vectors.h | 6 +- arch/x86/include/asm/msr-index.h | 8 + arch/x86/include/asm/processor.h | 8 + arch/x86/include/asm/uintr.h | 76 ++ arch/x86/include/uapi/asm/processor-flags.h | 2 + arch/x86/kernel/Makefile | 1 + arch/x86/kernel/cpu/common.c | 61 ++ arch/x86/kernel/cpu/cpuid-deps.c | 1 + arch/x86/kernel/fpu/core.c | 17 + arch/x86/kernel/fpu/xstate.c | 20 +- arch/x86/kernel/idt.c | 4 + arch/x86/kernel/irq.c | 51 + arch/x86/kernel/process.c | 10 + arch/x86/kernel/process_64.c | 4 + arch/x86/kernel/uintr_core.c | 880 ++++++++++++++++++ arch/x86/kernel/uintr_fd.c | 300 ++++++ include/linux/syscalls.h | 8 + include/uapi/asm-generic/unistd.h | 15 +- kernel/sys_ni.c | 8 + scripts/checksyscalls.sh | 6 + tools/testing/selftests/x86/Makefile | 10 + tools/testing/selftests/x86/uintr.c | 147 +++ tools/uintr/manpages/0_overview.txt | 265 ++++++ tools/uintr/manpages/1_register_receiver.txt | 122 +++ .../uintr/manpages/2_unregister_receiver.txt | 62 ++ tools/uintr/manpages/3_create_fd.txt | 104 +++ tools/uintr/manpages/4_register_sender.txt | 121 +++ tools/uintr/manpages/5_unregister_sender.txt | 79 ++ tools/uintr/manpages/6_wait.txt | 59 ++ 42 files changed, 2626 insertions(+), 8 deletions(-) create mode 100644 Documentation/x86/user-interrupts.rst create mode 100644 arch/x86/include/asm/uintr.h create mode 100644 arch/x86/kernel/uintr_core.c create mode 100644 arch/x86/kernel/uintr_fd.c create mode 100644 tools/testing/selftests/x86/uintr.c create mode 100644 tools/uintr/manpages/0_overview.txt create mode 100644 tools/uintr/manpages/1_register_receiver.txt create mode 100644 tools/uintr/manpages/2_unregister_receiver.txt create mode 100644 tools/uintr/manpages/3_create_fd.txt create mode 100644 tools/uintr/manpages/4_register_sender.txt create mode 100644 tools/uintr/manpages/5_unregister_sender.txt create mode 100644 tools/uintr/manpages/6_wait.txt base-commit: 6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f -- 2.33.0

2 years, 6 months

13
86
0 0

[PATCH v4 0/2] selftests: tpm2: Determine available PCR bank

by Stefan Berger

From: Stefan Berger <stefanb(a)linux.ibm.com> This series of patches fixes two issues with TPM2 selftest. - Determines available PCR banks for use by test cases - Resets DA lock on TPM2 to avoid subsequent test failures Stefan v4: - Switch to query TPM2_GET_CAP to determine the available PCR banks - Moved call to reset DA lock into finally branch at end of test - Dropped patch 3 v3: - Mention SHA-256 PCR bank as alternative in patch 1 description v2: - Clarified patch 1 description - Added patch 3 with support for SHA-384 and SHA-512 Stefan Berger (2): selftests: tpm2: Determine available PCR bank selftests: tpm2: Reset the dictionary attack lock tools/testing/selftests/tpm2/tpm2.py | 31 ++++++++++++++++++++++ tools/testing/selftests/tpm2/tpm2_tests.py | 31 ++++++++++++++++------ 2 files changed, 54 insertions(+), 8 deletions(-) -- 2.31.1

2 years, 6 months

3
12
0 0

[PATCH v2 1/2] selftests: net: remove meaningless help option

by Li Zhijian

$ ./fcnal-test.sh -t help Test names: help Looks it intent to list the available tests but it didn't do the right thing. I will add another option the do that in the later patch. Signed-off-by: Li Zhijian <lizhijian(a)cn.fujitsu.com> --- tools/testing/selftests/net/fcnal-test.sh | 2 -- 1 file changed, 2 deletions(-) diff --git a/tools/testing/selftests/net/fcnal-test.sh b/tools/testing/selftests/net/fcnal-test.sh index 7f5b265fcb90..5cb59947eed2 100755 --- a/tools/testing/selftests/net/fcnal-test.sh +++ b/tools/testing/selftests/net/fcnal-test.sh @@ -4068,8 +4068,6 @@ do # setup namespaces and config, but do not run any tests setup) setup; exit 0;; vrf_setup) setup "yes"; exit 0;; - - help) echo "Test names: $TESTS"; exit 0;; esac done -- 2.33.0

2 years, 6 months

3
4
0 0

[PATCH v2] ksefltest: pidfd: Fix wait_states: Test terminated by timeout

by Li Zhijian

0Day/LKP observed that the kselftest blocks foever since one of the pidfd_wait doesn't terminate in 1 of 30 runs. After digging into the source, we found that it blocks at: ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); we can reproduce it by: $ while true; do make run_tests -C pidfd; done Introduce a blocking read in child process to make sure the parent can check its WCONTINUED. CC: Philip Li <philip.li(a)intel.com> Reported-by: kernel test robot <lkp(a)intel.com> Signed-off-by: Li Zhijian <lizhijian(a)cn.fujitsu.com> --- V2: rewrite with pipe to avoid usleep --- tools/testing/selftests/pidfd/pidfd_wait.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c index be2943f072f6..d5c0ffa26c32 100644 --- a/tools/testing/selftests/pidfd/pidfd_wait.c +++ b/tools/testing/selftests/pidfd/pidfd_wait.c @@ -96,21 +96,26 @@ TEST(wait_states) .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, .exit_signal = SIGCHLD, }; - int ret; + int ret, pfd[2]; pid_t pid; siginfo_t info = { .si_signo = 0, }; - + ASSERT_EQ(pipe(pfd), 0); pid = sys_clone3(&args); ASSERT_GE(pid, 0); if (pid == 0) { + char buf[2]; + close(pfd[1]); kill(getpid(), SIGSTOP); + ASSERT_EQ(read(pfd[0], buf, 1), 1); + close(pfd[0]); kill(getpid(), SIGSTOP); exit(EXIT_SUCCESS); } + close(pfd[0]); ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0); ASSERT_EQ(info.si_signo, SIGCHLD); ASSERT_EQ(info.si_code, CLD_STOPPED); @@ -119,6 +124,8 @@ TEST(wait_states) ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0); ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); + ASSERT_EQ(write(pfd[1], "C", 1), 1); + close(pfd[1]); ASSERT_EQ(info.si_signo, SIGCHLD); ASSERT_EQ(info.si_code, CLD_CONTINUED); ASSERT_EQ(info.si_pid, parent_tid); -- 2.33.0

2 years, 6 months

2
1
0 0

[PATCH v9 0/7] cgroup/cpuset: Add new cpuset partition type & empty effecitve cpus

by Waiman Long

v9: - Add a new patch 1 to remove the child cpuset restriction on parent's "cpuset.cpus". - Relax initial root partition entry limitation to allow cpuset.cpus to overlap that of parent's. - An "isolated invalid" displayed type is added to cpuset.cpus.partition. - Resetting partition root to "member" will leave child partition root as invalid. - Update documentation and test accordingly. v8: - Reorganize the patch series and rationalize the features and constraints of a partition. - Update patch descriptions and documentation accordingly. v7: - Simplify the documentation patch (patch 5) as suggested by Tejun. - Fix a typo in patch 2 and improper commit log in patch 3. This patchset includes one bug fix and four enhancements to the cpuset v2 code. Patch 1: Allow parent to set "cpuset.cpus" that may not be a superset of children's "cpuset.cpus" for default hierarchy. Patch 2: Enable partition with no task to have empty cpuset.cpus.effective. Patch 3: Refining the features and constraints of a cpuset partition clarifying what changes are allowed. Patch 4: Add a new partition state "isolated" to create a partition root without load balancing. This is for handling intermitten workloads that have a strict low latency requirement. Patch 5: Enable the "cpuset.cpus.partition" file to show the reason that causes invalid partition like "root invalid (No cpu available due to hotplug)". Patch 6 updates the cgroup-v2.rst file accordingly. Patch 7 adds a new cpuset test to test the new cpuset partition code. Waiman Long (7): cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective cgroup/cpuset: Refining features and constraints of a partition cgroup/cpuset: Add a new isolated cpus.partition type cgroup/cpuset: Show invalid partition reason string cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst kselftest/cgroup: Add cpuset v2 partition root state test Documentation/admin-guide/cgroup-v2.rst | 168 +++-- kernel/cgroup/cpuset.c | 440 +++++++----- tools/testing/selftests/cgroup/Makefile | 5 +- .../selftests/cgroup/test_cpuset_prs.sh | 667 ++++++++++++++++++ tools/testing/selftests/cgroup/wait_inotify.c | 87 +++ 5 files changed, 1142 insertions(+), 225 deletions(-) create mode 100755 tools/testing/selftests/cgroup/test_cpuset_prs.sh create mode 100644 tools/testing/selftests/cgroup/wait_inotify.c -- 2.27.0

2 years, 6 months

4
29
0 0

[RFC PATCH 00/10] KVM: selftests: Add support for test-selectable ucall implementations

by Michael Roth

These patches are based on kvm/next, and are also available at: https://github.com/mdroth/linux/commits/sev-selftests-ucall-rfc1 == BACKGROUND == These patches are a prerequisite for adding selftest support for SEV guests and possibly other confidential computing implementations in the future. They were motivated by a suggestion Paolo made in response to the initial SEV selftest RFC: https://lore.kernel.org/lkml/20211025035833.yqphcnf5u3lk4zgg@amd.com/T/#m95… Since the changes touch multiple archs and ended up creating a bit more churn than expected, I thought it would be a good idea to carve this out into a separate standalone series for reviewers who may be more interested in the ucall changes than anything SEV-related. To summarize, x86 relies on a ucall based on using PIO intructions to generate an exit to userspace and provide the GVA of a dynamically-allocated ucall struct that resides in guest memory and contains information about how to handle/interpret the exit. This doesn't work for SEV guests for 3 main reasons: 1) The guest memory is generally encrypted during run-time, so the guest needs to ensure the ucall struct is allocated in shared memory. 2) The guest page table is also encrypted, so the address would need to be a GPA instead of a GVA. 3) The guest vCPU register may also be encrypted in the case of SEV-ES/SEV-SNP, so the approach of examining vCPU register state has additional requirements such as requiring guest code to implement a #VC handler that can provide the appropriate registers via a vmgexit. To address these issues, the SEV selftest RFC1 patchset introduced a set of new SEV-specific interfaces that closely mirrored the functionality of ucall()/get_ucall(), but relied on a pre-allocated/static ucall buffer in shared guest memory so it that guest code could pass messages/state to the host by simply writing to this pre-arranged shared memory region and then generating an exit to userspace (via a halt instruction). Paolo suggested instead implementing support for test/guest-specific ucall implementations that could be used as an alternative to the default PIO-based ucall implementations as-needed based on test/guest requirements, while still allowing for tests to use a common set interfaces like ucall()/get_ucall(). == OVERVIEW == This series implements the above functionality by introducing a new ucall_ops struct that can be used to register a particular ucall implementation as need, then re-implements x86/arm64/s390x in terms of the ucall_ops. But for the purposes of introducing a new ucall_ops implementation appropriate for SEV, there are a couple issues that resulted in the need for some additional ucall interfaces as well: a) ucall() doesn't take a pointer to the ucall struct it modifies, so to make it work in the case of an implementation that relies a pre-allocated ucall struct in shared guest memory some sort of global lookup functionality would be needed to locate the appropriate ucall struct for a particular VM/vcpu combination, and this would need to be made accessible for use by the guest as well. guests would then need some way of determining what VM/vcpu identifiers they need to use to do the lookup, which to do reliably would likely require seeding the guest with those identifiers in advance, which is possible, but much more easily achievable by simply adding a ucall() alternative that accepts a pointer to the ucall struct for that particular VM/vcpu. b) get_ucall() *does* take a pointer to a ucall struct, but currently zeroes it out and uses it to copy the guest's ucall struct into. It *could* be re-purposed to handle the case where the pointer is an actual pointer to the ucall struct in shared guest memory, but that could cause problems since callers would need some idea of what the underlying ucall implementation expects. Ideally the interfaces would be agnostic to the ucall implementation. So to address those issues, this series also allows ucall implementations to optionally be extended to support a set of 'shared' ops that are used in the following manner: host: uc_gva = ucall_shared_alloc() setup_vm_args(vm, uc_gva) guest: ucall_shared(uc_gva, ...) host: uget_ucall_shared(uc_gva, ...) and then implements a new ucall implementation, ucall_ops_halt, based around these shared interfaces and halt instructions. While this doesn't really meet the initial goal of re-using the existing ucall interfaces as-is, the hope is that these *_shared interfaces are general enough to be re-usable things other than SEV, or at least improve on code readability over the initial SEV-specific interfaces. Any review/comments are greatly appreciated! ---------------------------------------------------------------- Michael Roth (10): kvm: selftests: move base kvm_util.h declarations to kvm_util_base.h kvm: selftests: move ucall declarations into ucall_common.h kvm: selftests: introduce ucall_ops for test/arch-specific ucall implementations kvm: arm64: selftests: use ucall_ops to define default ucall implementation (COMPILE-TESTED ONLY) kvm: s390: selftests: use ucall_ops to define default ucall implementation kvm: selftests: add ucall interfaces based around shared memory kvm: selftests: add ucall_shared ops for PIO kvm: selftests: introduce ucall implementation based on halt instructions kvm: selftests: add GUEST_SHARED_* macros for shared ucall implementations kvm: selftests: add ucall_test to test various ucall functionality tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 5 +- .../testing/selftests/kvm/include/aarch64/ucall.h | 18 + tools/testing/selftests/kvm/include/kvm_util.h | 408 +-------------------- .../testing/selftests/kvm/include/kvm_util_base.h | 368 +++++++++++++++++++ tools/testing/selftests/kvm/include/s390x/ucall.h | 18 + tools/testing/selftests/kvm/include/ucall_common.h | 147 ++++++++ tools/testing/selftests/kvm/include/x86_64/ucall.h | 19 + tools/testing/selftests/kvm/lib/aarch64/ucall.c | 43 +-- tools/testing/selftests/kvm/lib/s390x/ucall.c | 45 +-- tools/testing/selftests/kvm/lib/ucall_common.c | 133 +++++++ tools/testing/selftests/kvm/lib/x86_64/ucall.c | 82 +++-- tools/testing/selftests/kvm/ucall_test.c | 182 +++++++++ 13 files changed, 982 insertions(+), 487 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/aarch64/ucall.h create mode 100644 tools/testing/selftests/kvm/include/kvm_util_base.h create mode 100644 tools/testing/selftests/kvm/include/s390x/ucall.h create mode 100644 tools/testing/selftests/kvm/include/ucall_common.h create mode 100644 tools/testing/selftests/kvm/include/x86_64/ucall.h create mode 100644 tools/testing/selftests/kvm/lib/ucall_common.c create mode 100644 tools/testing/selftests/kvm/ucall_test.c

2 years, 6 months

4
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[PATCH 2/2] selftests: tpm: add async space test with noneexisting handle

by Tadeusz Struk

Add a test for tpm2 spaces in async mode that checks if the code handles invalid handles correctly. Cc: Jarkko Sakkinen <jarkko(a)kernel.org> Cc: Shuah Khan <shuah(a)kernel.org> Cc: <linux-integrity(a)vger.kernel.org> Cc: <linux-kselftest(a)vger.kernel.org> Cc: <linux-kernel(a)vger.kernel.org> Signed-off-by: Tadeusz Struk <tstruk(a)gmail.com> --- tools/testing/selftests/tpm2/tpm2_tests.py | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/tools/testing/selftests/tpm2/tpm2_tests.py b/tools/testing/selftests/tpm2/tpm2_tests.py index 9d764306887b..b373b0936e40 100644 --- a/tools/testing/selftests/tpm2/tpm2_tests.py +++ b/tools/testing/selftests/tpm2/tpm2_tests.py @@ -302,3 +302,19 @@ class AsyncTest(unittest.TestCase): log.debug("Calling get_cap in a NON_BLOCKING mode") async_client.get_cap(tpm2.TPM2_CAP_HANDLES, tpm2.HR_LOADED_SESSION) async_client.close() + + def test_flush_invlid_context(self): + log = logging.getLogger(__name__) + log.debug(sys._getframe().f_code.co_name) + + async_client = tpm2.Client(tpm2.Client.FLAG_SPACE | tpm2.Client.FLAG_NONBLOCK) + log.debug("Calling flush_context passing in an invalid handle ") + handle = 0x80123456 + rc = 0 + try: + async_client.flush_context(handle) + except OSError as e: + rc = e.errno + + self.assertEqual(rc, 22) + async_client.close() -- 2.30.2

2 years, 6 months

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[PATCH 1/3] selftest/kexec: fix "ignored null byte in input" warning

by Nageswara R Sastry

From: Mimi Zohar <zohar(a)linux.ibm.com> Instead of assigning the string to a variable, which might contain a null character, redirect the output and grep for the string directly. Signed-off-by: Mimi Zohar <zohar(a)linux.ibm.com> --- tools/testing/selftests/kexec/test_kexec_file_load.sh | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kexec/test_kexec_file_load.sh b/tools/testing/selftests/kexec/test_kexec_file_load.sh index 2ff600388c30..99f6fc23ee31 100755 --- a/tools/testing/selftests/kexec/test_kexec_file_load.sh +++ b/tools/testing/selftests/kexec/test_kexec_file_load.sh @@ -97,10 +97,11 @@ check_for_imasig() check_for_modsig() { local module_sig_string="~Module signature appended~" - local sig="$(tail --bytes $((${#module_sig_string} + 1)) $KERNEL_IMAGE)" local ret=0 - if [ "$sig" == "$module_sig_string" ]; then + tail --bytes $((${#module_sig_string} + 1)) $KERNEL_IMAGE | \ + grep -q "$module_sig_string" + if [ $? -eq 0 ]; then ret=1 log_info "kexec kernel image modsig signed" else -- 2.23.0

2 years, 6 months

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[PATCH v4 00/21] AMX Support in KVM

by Yang Zhong

Highly appreciate for your review. This version mostly addressed the comments from Sean. Most comments are adopted except three which are not closed and need more discussions: - Move the entire xfd write emulation code to x86.c. Doing so requires introducing a new kvm_x86_ops callback to disable msr write bitmap. According to Paolo's earlier comment he prefers to handle it in vmx.c. - Directly check msr_bitmap in update_exception_bitmap() (for trapping #NM) and vcpu_enter_guest() (for syncing guest xfd after vm-exit) instead of introducing an extra flag in the last patch. However, doing so requires another new kvm_x86_ops callback for checking msr_bitmap since vcpu_enter_guest() is x86 common code. Having an extra flag sounds simpler here (at least for the initial AMX support). It does penalize nested guest with one xfd sync per exit, but it's not worse than a normal guest which initializes xfd but doesn't run AMX applications at all. Those could be improved afterwards. - Disable #NM trap for nested guest. This version still chooses to always trap #NM (regardless in L1 or L2) as long as xfd write interception is disabled. In reality #NM is rare if nested guest doesn't intend to run AMX applications and always-trap is safer than dynamic trap for the basic support in case of any oversight here. (Jing is temporarily leave for family reason, Yang helped work out this version) ---- v3->v4: - Verify kvm selftest for AMX (Paolo) - Move fpstate buffer expansion from kvm_vcpu_after_set_cpuid () to kvm_check_cpuid() and improve patch description (Sean) - Drop 'preemption' word in #NM interception patch (Sean) - Remove 'trap_nm' flag. Replace it by: (Sean) * Trapping #NM according to guest_fpu::xfd when write to xfd is intercepted. * Always trapping #NM when xfd write interception is disabled - Use better name for #NM related functions (Sean) - Drop '#ifdef CONFIG_X86_64' in __kvm_set_xcr (Sean) - Update description for KVM_CAP_XSAVE2 and prevent the guest from using the wrong ioctl (Sean) - Replace 'xfd_out_of_sync' with a better name (Sean) v2->v3: - Trap #NM until write IA32_XFD with a non-zero value (Thomas) - Revise return value in __xstate_request_perm() (Thomas) - Revise doc for KVM_GET_SUPPORTED_CPUID (Paolo) - Add Thomas's reviewed-by on one patch - Reorder disabling read interception of XFD_ERR patch (Paolo) - Move disabling r/w interception of XFD from x86.c to vmx.c (Paolo) - Provide the API doc together with the new KVM_GET_XSAVE2 ioctl (Paolo) - Make KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2) return minimum size of struct kvm_xsave (4K) (Paolo) - Request permission at the start of vm_create_with_vcpus() in selftest - Request permission conditionally when XFD is supported (Paolo) v1->v2: - Live migration supported and verified with a selftest - Rebase to Thomas's new series for guest fpstate reallocation [1] - Expand fpstate at KVM_SET_CPUID2 instead of when emulating XCR0 and IA32_XFD (Thomas/Paolo) - Accordingly remove all exit-to-userspace stuff - Intercept #NM to save guest XFD_ERR and restore host/guest value at preemption on/off boundary (Thomas) - Accordingly remove all xfd_err logic in preemption callback and fpu_swap_kvm_fpstate() - Reuse KVM_SET_XSAVE to handle both legacy and expanded buffer (Paolo) - Don't return dynamic bits w/o prctl() in KVM_GET_SUPPORTED_CPUID (Paolo) - Check guest permissions for dynamic features in CPUID[0xD] instead of only for AMX at KVM_SET_CPUID (Paolo) - Remove dynamic bit check for 32-bit guest in __kvm_set_xcr() (Paolo) - Fix CPUID emulation for 0x1d and 0x1e (Paolo) - Move "disable interception" to the end of the series (Paolo) This series brings AMX (Advanced Matrix eXtensions) virtualization support to KVM. The preparatory series from Thomas [1] is also included. A large portion of the changes in this series is to deal with eXtended Feature Disable (XFD) which allows resizing of the fpstate buffer to support dynamically-enabled XSTATE features with large state component (e.g. 8K for AMX). There are a lot of simplications when comparing v2/v3 to the original proposal [2] and the first version [3]. Thanks to Thomas and Paolo for many good suggestions. The support is based on following key changes: - Guest permissions for dynamically-enabled XSAVE features Native tasks have to request permission via prctl() before touching a dynamic-resized XSTATE compoenent. Introduce guest permissions for the similar purpose. Userspace VMM is expected to request guest permission only once when the first vCPU is created. KVM checks guest permission in KVM_SET_CPUID2. Setting XFD in guest cpuid w/o proper permissions fails this operation. In the meantime, unpermitted features are also excluded in KVM_GET_SUPPORTED_CPUID. - Extend fpstate reallocation mechanism to cover guest fpu Unlike native tasks which have reallocation triggered from #NM handler, guest fpstate reallocation is requested by KVM when it identifies the intention on using dynamically-enabled XSAVE features inside guest. Extend fpu core to allow KVM request fpstate buffer expansion for a guest fpu containter. - Trigger fpstate reallocation in KVM This could be done either statically (before guest runs) or dynamically (in the emulation path). According to discussion [1] we decide to statically enable all xfeatures allowed by guest perm in KVM_SET_CPUID2, with fpstate buffer sized accordingly. This spares a lot of code and also avoid imposing an ordered restore sequence (XCR0, XFD and XSTATE) to userspace VMM. - RDMSR/WRMSR emulation for IA32_XFD Because fpstate expansion is completed in KVM_SET_CPUID2, emulating r/w access to IA32_XFD simply involves the xfd field in the guest fpu container. If write and guest fpu is currently active, the software state (guest_fpstate::xfd and per-cpu xfd cache) is also updated. - RDMSR/WRMSR emulation for XFD_ERR When XFD causes an instruction to generate #NM, XFD_ERR contains information about which disabled state components are being accessed. It'd be problematic if the XFD_ERR value generated in guest is consumed/clobbered by the host before the guest itself doing so. Intercept #NM exception to save the guest XFD_ERR value when write IA32_XFD with a non-zero value for 1st time. There is at most one interception per guest task given a dynamic feature. RDMSR/WRMSR emulation uses the saved value. The host value (always ZERO outside of the host #NM handler) is restored before enabling preemption. The saved guest value is restored right before entering the guest (with preemption disabled). - Get/set dynamic xfeature state for migration Introduce new capability (KVM_CAP_XSAVE2) to deal with >4KB fpstate buffer. Reading this capability returns the size of the current guest fpstate (e.g. after expansion). Userspace VMM uses a new ioctl (KVM_GET_XSAVE2) to read guest fpstate from the kernel and reuses the existing ioctl (KVM_SET_XSAVE) to update guest fpsate to the kernel. KVM_SET_XSAVE is extended to do properly_sized memdup_user() based on the guest fpstate. - Expose related cpuid bits to guest The last step is to allow exposing XFD, AMX_TILE, AMX_INT8 and AMX_BF16 in guest cpuid. Adding those bits into kvm_cpu_caps finally activates all previous logics in this series - Optimization: disable interception for IA32_XFD IA32_XFD can be frequently updated by the guest, as it is part of the task state and swapped in context switch when prev and next have different XFD setting. Always intercepting WRMSR can easily cause non-negligible overhead. Disable r/w emulation for IA32_XFD after intercepting the first WRMSR(IA32_XFD) with a non-zero value. However MSR passthrough implies the software state (guest_fpstate::xfd and per-cpu xfd cache) might be out of sync with MSR. This suggests KVM needs to re-sync them at VM-exit before preemption is enabled. Thanks Jun Nakajima and Kevin Tian for the design suggestions when this version is being internally worked on. [1] https://lore.kernel.org/all/20211214022825.563892248@linutronix.de/ [2] https://www.spinics.net/lists/kvm/msg259015.html [3] https://lore.kernel.org/lkml/20211208000359.2853257-1-yang.zhong@intel.com/ Thanks, Yang --- Guang Zeng (1): kvm: x86: Add support for getting/setting expanded xstate buffer Jing Liu (11): kvm: x86: Fix xstate_required_size() to follow XSTATE alignment rule kvm: x86: Exclude unpermitted xfeatures at KVM_GET_SUPPORTED_CPUID x86/fpu: Make XFD initialization in __fpstate_reset() a function argument kvm: x86: Check and enable permitted dynamic xfeatures at KVM_SET_CPUID2 kvm: x86: Add emulation for IA32_XFD x86/fpu: Prepare xfd_err in struct fpu_guest kvm: x86: Intercept #NM for saving IA32_XFD_ERR kvm: x86: Emulate IA32_XFD_ERR for guest kvm: x86: Disable RDMSR interception of IA32_XFD_ERR kvm: x86: Add XCR0 support for Intel AMX kvm: x86: Add CPUID support for Intel AMX Kevin Tian (3): x86/fpu: Provide fpu_update_guest_perm_features() for guest x86/fpu: Provide fpu_update_guest_xfd() for IA32_XFD emulation kvm: x86: Disable interception for IA32_XFD on demand Thomas Gleixner (5): x86/fpu: Extend fpu_xstate_prctl() with guest permissions x86/fpu: Prepare guest FPU for dynamically enabled FPU features x86/fpu: Add guest support to xfd_enable_feature() x86/fpu: Add uabi_size to guest_fpu x86/fpu: Provide fpu_sync_guest_vmexit_xfd_state() Wei Wang (1): kvm: selftests: Add support for KVM_CAP_XSAVE2 Documentation/virt/kvm/api.rst | 46 +++++- arch/x86/include/asm/cpufeatures.h | 2 + arch/x86/include/asm/fpu/api.h | 11 ++ arch/x86/include/asm/fpu/types.h | 32 ++++ arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/uapi/asm/kvm.h | 16 +- arch/x86/include/uapi/asm/prctl.h | 26 ++-- arch/x86/kernel/fpu/core.c | 104 ++++++++++++- arch/x86/kernel/fpu/xstate.c | 147 +++++++++++------- arch/x86/kernel/fpu/xstate.h | 15 +- arch/x86/kernel/process.c | 2 + arch/x86/kvm/cpuid.c | 99 +++++++++--- arch/x86/kvm/vmx/vmcs.h | 5 + arch/x86/kvm/vmx/vmx.c | 45 +++++- arch/x86/kvm/vmx/vmx.h | 2 +- arch/x86/kvm/x86.c | 105 ++++++++++++- include/uapi/linux/kvm.h | 4 + tools/arch/x86/include/uapi/asm/kvm.h | 16 +- tools/include/uapi/linux/kvm.h | 3 + .../testing/selftests/kvm/include/kvm_util.h | 2 + .../selftests/kvm/include/x86_64/processor.h | 10 ++ tools/testing/selftests/kvm/lib/kvm_util.c | 32 ++++ .../selftests/kvm/lib/x86_64/processor.c | 67 +++++++- .../testing/selftests/kvm/x86_64/evmcs_test.c | 2 +- tools/testing/selftests/kvm/x86_64/smm_test.c | 2 +- .../testing/selftests/kvm/x86_64/state_test.c | 2 +- .../kvm/x86_64/vmx_preemption_timer_test.c | 2 +- 27 files changed, 691 insertions(+), 109 deletions(-)

2 years, 6 months

4
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[PATCH v2 00/13] KVM: selftests: Add tests for SEV and SEV-ES guests

by Michael Roth

These patches and are also available at: https://github.com/mdroth/linux/commits/sev-selftests-v2 They are based on top of the recent RFC: "KVM: selftests: Add support for test-selectable ucall implementations" https://lore.kernel.org/all/20211210164620.11636-1-michael.roth@amd.com/T/ https://github.com/mdroth/linux/commits/sev-selftests-ucall-rfc1 which provides a new ucall implementation that this series relies on. Those patches were in turn based on kvm/next as of 2021-12-10. == OVERVIEW == This series introduces a set of memory encryption-related parameter/hooks in the core kselftest library, then uses the hooks to implement a small library for creating/managing SEV, SEV-ES, and (eventually) SEV-SNP guests. This library is then used to implement a basic boot/memory test that's run for variants of SEV/SEV-ES guests. - Patches 1-8 implement SEV boot tests and should run against existing kernels - Patch 9 is a KVM changes that's required to allow SEV-ES/SEV-SNP guests to boot with an externally generated page table, and is a host kernel prequisite for the remaining patches in the series. - Patches 10-13 extend the boot tests to cover SEV-ES Any review/comments are greatly appreciated! v2: - rebased on ucall_ops patchset (which is based on kvm/next 2021-12-10) - remove SEV-SNP support for now - provide encryption bitmap as const* to original rather than as a copy (Mingwei, Paolo) - drop SEV-specific synchronization helpers in favor of ucall_ops_halt (Paolo) - don't pass around addresses with c-bit included, add them as-needed via addr_gpa2raw() (e.g. when adding PTEs, or initializing initial cr3/vm->pgd) (Paolo) - rename lib/sev.c functions for better consistency (Krish) - move more test setup code out of main test function and into setup_test_common() (Krish) - suppress compiler warnings due to -Waddress-of-packed-member like kernel does - don't require SNP support in minimum firmware version detection (Marc) - allow SEV device path to be configured via make SEV_PATH= (Marc) ---------------------------------------------------------------- Michael Roth (13): KVM: selftests: move vm_phy_pages_alloc() earlier in file KVM: selftests: sparsebit: add const where appropriate KVM: selftests: add hooks for managing encrypted guest memory KVM: selftests: handle encryption bits in page tables KVM: selftests: add support for encrypted vm_vaddr_* allocations KVM: selftests: ensure ucall_shared_alloc() allocates shared memory KVM: selftests: add library for creating/interacting with SEV guests KVM: selftests: add SEV boot tests KVM: SVM: include CR3 in initial VMSA state for SEV-ES guests KVM: selftests: account for error code in #VC exception frame KVM: selftests: add support for creating SEV-ES guests KVM: selftests: add library for handling SEV-ES-related exits KVM: selftests: add SEV-ES boot tests arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm/svm.c | 19 ++ arch/x86/kvm/vmx/vmx.c | 6 + arch/x86/kvm/x86.c | 1 + tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 10 +- .../testing/selftests/kvm/include/kvm_util_base.h | 10 + tools/testing/selftests/kvm/include/sparsebit.h | 36 +-- tools/testing/selftests/kvm/include/x86_64/sev.h | 44 +++ .../selftests/kvm/include/x86_64/sev_exitlib.h | 14 + tools/testing/selftests/kvm/include/x86_64/svm.h | 35 +++ .../selftests/kvm/include/x86_64/svm_util.h | 1 + tools/testing/selftests/kvm/lib/kvm_util.c | 270 ++++++++++++------ .../testing/selftests/kvm/lib/kvm_util_internal.h | 10 + tools/testing/selftests/kvm/lib/sparsebit.c | 48 ++-- tools/testing/selftests/kvm/lib/ucall_common.c | 4 +- tools/testing/selftests/kvm/lib/x86_64/handlers.S | 4 +- tools/testing/selftests/kvm/lib/x86_64/processor.c | 16 +- tools/testing/selftests/kvm/lib/x86_64/sev.c | 252 ++++++++++++++++ .../testing/selftests/kvm/lib/x86_64/sev_exitlib.c | 249 ++++++++++++++++ .../selftests/kvm/x86_64/sev_all_boot_test.c | 316 +++++++++++++++++++++ 22 files changed, 1215 insertions(+), 133 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/x86_64/sev.h create mode 100644 tools/testing/selftests/kvm/include/x86_64/sev_exitlib.h create mode 100644 tools/testing/selftests/kvm/lib/x86_64/sev.c create mode 100644 tools/testing/selftests/kvm/lib/x86_64/sev_exitlib.c create mode 100644 tools/testing/selftests/kvm/x86_64/sev_all_boot_test.c

2 years, 6 months

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Linux-kselftest-mirror December 2021