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path: root/tools/testing/selftests/kvm/lib/memstress.c
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2023-06-01KVM: selftests: Move dirty logging functions to memstress.(c|h)Ben Gardon
Move some helper functions from dirty_log_perf_test.c to the memstress library so that they can be used in a future commit which tests page splitting during dirty logging. Reviewed-by: Vipin Sharma <vipinsh@google.com> Signed-off-by: Ben Gardon <bgardon@google.com> Link: https://lore.kernel.org/r/20230131181820.179033-2-bgardon@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-01KVM: selftests: touch all pages of args on each memstress iterationPaolo Bonzini
Access the same memory addresses on each iteration of the memstress guest code. This ensures that the state of KVM's page tables is the same after every iteration, including the pages that host the guest page tables for args and vcpu_args. This difference is visible when running the proposed dirty_log_page_splitting_test[*] on AMD, or on Intel with pml=0 and eptad=0. The tests fail due to different semantics of dirty bits for page-table pages on AMD (and eptad=0) and Intel. Both AMD and Intel with eptad=0 treat page-table accesses as writes, therefore more pages are dropped before the repopulation phase when dirty logging is disabled. The "missing" page had been included in the population phase because it hosts the page tables for vcpu_args, but repopulation does not need it." Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Vipin Sharma <vipinsh@google.com> Link: https://lore.kernel.org/r/20230412200913.1570873-1-pbonzini@redhat.com [sean: add additional details in changelog] Signed-off-by: Sean Christopherson <seanjc@google.com>
2022-12-09Merge tag 'kvmarm-6.2' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.2 - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on. - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Add/Enable/Fix a bunch of selftests covering memslots, breakpoints, stage-2 faults and access tracking. You name it, we got it, we probably broke it. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. As a side effect, this tag also drags: - The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring series - A shared branch with the arm64 tree that repaints all the system registers to match the ARM ARM's naming, and resulting in interesting conflicts
2022-11-16KVM: selftests: Drop now-unnecessary ucall_uninit()Sean Christopherson
Drop ucall_uninit() and ucall_arch_uninit() now that ARM doesn't modify the host's copy of ucall_exit_mmio_addr, i.e. now that there's no need to reset the pointer before potentially creating a new VM. The few calls to ucall_uninit() are all immediately followed by kvm_vm_free(), and that is likely always going to hold true, i.e. it's extremely unlikely a test will want to effectively disable ucall in the middle of a test. Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-7-seanjc@google.com
2022-11-16KVM: selftests: Automatically do init_ucall() for non-barebones VMsSean Christopherson
Do init_ucall() automatically during VM creation to kill two (three?) birds with one stone. First, initializing ucall immediately after VM creations allows forcing aarch64's MMIO ucall address to immediately follow memslot0. This is still somewhat fragile as tests could clobber the MMIO address with a new memslot, but it's safe-ish since tests have to be conversative when accounting for memslot0. And this can be hardened in the future by creating a read-only memslot for the MMIO page (KVM ARM exits with MMIO if the guest writes to a read-only memslot). Add a TODO to document that selftests can and should use a memslot for the ucall MMIO (doing so requires yet more rework because tests assumes thay can use all memslots except memslot0). Second, initializing ucall for all VMs prepares for making ucall initialization meaningful on all architectures. aarch64 is currently the only arch that needs to do any setup, but that will change in the future by switching to a pool-based implementation (instead of the current stack-based approach). Lastly, defining the ucall MMIO address from common code will simplify switching all architectures (except s390) to a common MMIO-based ucall implementation (if there's ever sufficient motivation to do so). Cc: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-4-seanjc@google.com
2022-11-16KVM: selftests: Rename perf_test_util symbols to memstressDavid Matlack
Replace the perf_test_ prefix on symbol names with memstress_ to match the new file name. "memstress" better describes the functionality proveded by this library, which is to provide functionality for creating and running a VM that stresses VM memory by reading and writing to guest memory on all vCPUs in parallel. "memstress" also contains the same number of chracters as "perf_test", making it a drop-in replacement in symbols, e.g. function names, without impacting line lengths. Also the lack of underscore between "mem" and "stress" makes it clear "memstress" is a noun. Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221012165729.3505266-4-dmatlack@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2022-11-16KVM: selftests: Rename pta (short for perf_test_args) to argsDavid Matlack
Rename the local variables "pta" (which is short for perf_test_args) for args. "pta" is not an obvious acronym and using "args" mirrors "vcpu_args". Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221012165729.3505266-3-dmatlack@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2022-11-16KVM: selftests: Rename perf_test_util.[ch] to memstress.[ch]David Matlack
Rename the perf_test_util.[ch] files to memstress.[ch]. Symbols are renamed in the following commit to reduce the amount of churn here in hopes of playiing nice with git's file rename detection. The name "memstress" was chosen to better describe the functionality proveded by this library, which is to create and run a VM that reads/writes to guest memory on all vCPUs in parallel. "memstress" also contains the same number of chracters as "perf_test", making it a drop-in replacement in symbols, e.g. function names, without impacting line lengths. Also the lack of underscore between "mem" and "stress" makes it clear "memstress" is a noun. Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221012165729.3505266-2-dmatlack@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>