kernel/tools/testing/selftests/kvm/access_tracking_perf_test.c, branch linux-6.2.y

Merge remote-tracking branch 'kvm/queue' into HEAD

2022-12-12T20:54:07Z

x86 Xen-for-KVM: * Allow the Xen runstate information to cross a page boundary * Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured * add support for 32-bit guests in SCHEDOP_poll x86 fixes: * One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). * Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. * Clean up the MSR filter docs. * Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. * Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. * Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. * Advertise (on AMD) that the SMM_CTL MSR is not supported * Remove unnecessary exports Selftests: * Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. * Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). * Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. * Introduce actual atomics for clear/set_bit() in selftests Documentation: * Remove deleted ioctls from documentation * Various fixes

Merge tag 'kvmarm-6.2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2022-12-09T08:12:12Z

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

KVM: selftests: Restore assert for non-nested VMs in access tracking test

2022-12-01T23:31:39Z

Restore the assert (on x86-64) that <10% of pages are still idle when NOT running as a nested VM in the access tracking test. The original assert was converted to a "warning" to avoid false failures when running the test in a VM, but the non-nested case does not suffer from the same "infinite TLB size" issue. Using the HYPERVISOR flag isn't infallible as VMMs aren't strictly required to enumerate the "feature" in CPUID, but practically speaking anyone that is running KVM selftests in VMs is going to be using a VMM and hypervisor that sets the HYPERVISOR flag. Cc: David Matlack Reviewed-by: Emanuele Giuseppe Esposito Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221129175300.4052283-3-seanjc@google.com

KVM: selftests: Fix inverted "warning" in access tracking perf test

2022-12-01T23:31:32Z

Warn if the number of idle pages is greater than or equal to 10% of the total number of pages, not if the percentage of idle pages is less than 10%. The original code asserted that less than 10% of pages were still idle, but the check got inverted when the assert was converted to a warning. Opportunistically clean up the warning; selftests are 64-bit only, there is no need to use "%PRIu64" instead of "%lu". Fixes: 6336a810db5c ("KVM: selftests: replace assertion with warning in access_tracking_perf_test") Reviewed-by: Emanuele Giuseppe Esposito Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221129175300.4052283-2-seanjc@google.com

KVM: selftests: Have perf_test_util signal when to stop vCPUs

2022-11-29T17:29:42Z

Signal that a test run is complete through perf_test_args instead of having tests open code a similar solution. Ensure that the field resets to false at the beginning of a test run as the structure is reused between test runs, eliminating a couple of bugs: access_tracking_perf_test hangs indefinitely on a subsequent test run, as 'done' remains true. The bug doesn't amount to much right now, as x86 supports a single guest mode. However, this is a precondition of enabling the test for other architectures with >1 guest mode, like arm64. memslot_modification_stress_test has the exact opposite problem, where subsequent test runs complete immediately as 'run_vcpus' remains false. Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson [oliver: added commit message, preserve spin_wait_for_next_iteration()] Signed-off-by: Oliver Upton Reviewed-by: Gavin Shan Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221118211503.4049023-2-oliver.upton@linux.dev

KVM: selftests: Rename perf_test_util symbols to memstress

2022-11-16T18:58:32Z

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 Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221012165729.3505266-4-dmatlack@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Rename perf_test_util.[ch] to memstress.[ch]

2022-11-16T18:57:34Z

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 Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221012165729.3505266-2-dmatlack@google.com Signed-off-by: Sean Christopherson

KVM: selftests: randomize which pages are written vs read

2022-11-16T18:57:19Z

Randomize which pages are written vs read using the random number generator. Change the variable wr_fract and associated function calls to write_percent that now operates as a percentage from 0 to 100 where X means each page has an X% chance of being written. Change the -f argument to -w to reflect the new variable semantics. Keep the same default of 100% writes. Population always uses 100% writes to ensure all memory is actually populated and not just mapped to the zero page. The prevents expensive copy-on-write faults from occurring during the dirty memory iterations below, which would pollute the performance results. Each vCPU calculates its own random seed by adding its index to the seed provided. Signed-off-by: Colton Lewis Reviewed-by: David Matlack Link: https://lore.kernel.org/r/20221107182208.479157-4-coltonlewis@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Add atoi_positive() and atoi_non_negative() for input validation

2022-11-16T18:03:24Z

Many KVM selftests take command line arguments which are supposed to be positive (>0) or non-negative (>=0). Some tests do these validation and some missed adding the check. Add atoi_positive() and atoi_non_negative() to validate inputs in selftests before proceeding to use those values. Signed-off-by: Vipin Sharma Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221103191719.1559407-7-vipinsh@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

2022-11-16T18:03:24Z

atoi() doesn't detect errors. There is no way to know that a 0 return is correct conversion or due to an error. Introduce atoi_paranoid() to detect errors and provide correct conversion. Replace all atoi() calls with atoi_paranoid(). Signed-off-by: Vipin Sharma Suggested-by: David Matlack Suggested-by: Sean Christopherson Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221103191719.1559407-4-vipinsh@google.com Signed-off-by: Sean Christopherson