| Message ID | 20241220013906.3518334-1-seanjc@google.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: selftests: Binary stats fixes and infra updates | expand |
On Thu, 19 Dec 2024 17:38:58 -0800, Sean Christopherson wrote: > Fix a handful of bugs in the binary stats infrastructure, expand support > to vCPU-scoped stats, enumerate all KVM stats in selftests, and use the > enumerated stats to assert at compile-time that {vm,vcpu}_get_stat() is > getting a stat that actually exists. > > Most of the bugs are benign, and AFAICT, none actually cause problems in > the current code base. The worst of the bugs is lack of validation that > the requested stat actually exists, which is quite annoying if someone > fat fingers a stat name, tries to get a vCPU stat on a VM FD, etc. > > [...] Applied 1-7 to kvm-x86 selftests (x86 wants to build tests on the vCPU-scoped stats infrastructure). I'll hold off on the compile-time assertions stuff until there's consensus that we want to go that route for all architectures (not at all urgent). [1/8] KVM: selftests: Fix mostly theoretical leak of VM's binary stats FD https://github.com/kvm-x86/linux/commit/b68ec5b6869f [2/8] KVM: selftests: Close VM's binary stats FD when releasing VM https://github.com/kvm-x86/linux/commit/a59768d6cb64 [3/8] KVM: selftests: Assert that __vm_get_stat() actually finds a stat https://github.com/kvm-x86/linux/commit/52ef723593fe [4/8] KVM: selftests: Macrofy vm_get_stat() to auto-generate stat name string https://github.com/kvm-x86/linux/commit/7884da344973 [5/8] KVM: selftests: Add struct and helpers to wrap binary stats cache https://github.com/kvm-x86/linux/commit/384544c026f6 [6/8] KVM: selftests: Get VM's binary stats FD when opening VM https://github.com/kvm-x86/linux/commit/6d22ccb1c309 [7/8] KVM: selftests: Add infrastructure for getting vCPU binary stats https://github.com/kvm-x86/linux/commit/60d432517838 [8/8] KVM: selftests: Add compile-time assertions to guard against stats typos not applied -- https://github.com/kvm-x86/linux/tree/next
On Thu, Jan 09, 2025, Sean Christopherson wrote: > On Thu, 19 Dec 2024 17:38:58 -0800, Sean Christopherson wrote: > > Fix a handful of bugs in the binary stats infrastructure, expand support > > to vCPU-scoped stats, enumerate all KVM stats in selftests, and use the > > enumerated stats to assert at compile-time that {vm,vcpu}_get_stat() is > > getting a stat that actually exists. > > > > Most of the bugs are benign, and AFAICT, none actually cause problems in > > the current code base. The worst of the bugs is lack of validation that > > the requested stat actually exists, which is quite annoying if someone > > fat fingers a stat name, tries to get a vCPU stat on a VM FD, etc. > > > > [...] > > Applied 1-7 to kvm-x86 selftests (x86 wants to build tests on the vCPU-scoped > stats infrastructure). > > I'll hold off on the compile-time assertions stuff until there's consensus that > we want to go that route for all architectures (not at all urgent). > > [1/8] KVM: selftests: Fix mostly theoretical leak of VM's binary stats FD > https://github.com/kvm-x86/linux/commit/b68ec5b6869f > [2/8] KVM: selftests: Close VM's binary stats FD when releasing VM > https://github.com/kvm-x86/linux/commit/a59768d6cb64 > [3/8] KVM: selftests: Assert that __vm_get_stat() actually finds a stat > https://github.com/kvm-x86/linux/commit/52ef723593fe > [4/8] KVM: selftests: Macrofy vm_get_stat() to auto-generate stat name string > https://github.com/kvm-x86/linux/commit/7884da344973 > [5/8] KVM: selftests: Add struct and helpers to wrap binary stats cache > https://github.com/kvm-x86/linux/commit/384544c026f6 > [6/8] KVM: selftests: Get VM's binary stats FD when opening VM > https://github.com/kvm-x86/linux/commit/6d22ccb1c309 > [7/8] KVM: selftests: Add infrastructure for getting vCPU binary stats > https://github.com/kvm-x86/linux/commit/60d432517838 Argh, apparently I only tested this series on platforms with high RLIMIT_NOFILE values. Creating the stats fd for all vCPUs causes kvm_create_max_vcpus to fail on some of my systems due to doubling the number of fds needed. One option would be to figure out a clean way to avoid creating the stats fds for barebones VMs, but x86's recalc_apic_map_test also fails. That test creates 512 (max "supported" by selftests) using vm_create_with_vcpus(). Doubling the rlimit from 1024+100 to 2048+100 for the max test doesn't seem insane, so my plan is to move the rlimit twiddling into common code, and then account for the vCPU stats fds. I'll drop the above commits and post a v2.
Fix a handful of bugs in the binary stats infrastructure, expand support to vCPU-scoped stats, enumerate all KVM stats in selftests, and use the enumerated stats to assert at compile-time that {vm,vcpu}_get_stat() is getting a stat that actually exists. Most of the bugs are benign, and AFAICT, none actually cause problems in the current code base. The worst of the bugs is lack of validation that the requested stat actually exists, which is quite annoying if someone fat fingers a stat name, tries to get a vCPU stat on a VM FD, etc. FWIW, I'm not entirely convinced enumerating all stats is worth doing in selftests. It seems nice to have? But I don't know that it'll be worth the maintenance cost. It was easy enough to implement, so here it is... Sean Christopherson (8): KVM: selftests: Fix mostly theoretical leak of VM's binary stats FD KVM: selftests: Close VM's binary stats FD when releasing VM KVM: selftests: Assert that __vm_get_stat() actually finds a stat KVM: selftests: Macrofy vm_get_stat() to auto-generate stat name string KVM: selftests: Add struct and helpers to wrap binary stats cache KVM: selftests: Get VM's binary stats FD when opening VM KVM: selftests: Add infrastructure for getting vCPU binary stats KVM: selftests: Add compile-time assertions to guard against stats typos Sean Christopherson (8): KVM: selftests: Fix mostly theoretical leak of VM's binary stats FD KVM: selftests: Close VM's binary stats FD when releasing VM KVM: selftests: Assert that __vm_get_stat() actually finds a stat KVM: selftests: Macrofy vm_get_stat() to auto-generate stat name string KVM: selftests: Add struct and helpers to wrap binary stats cache KVM: selftests: Get VM's binary stats FD when opening VM KVM: selftests: Add infrastructure for getting vCPU binary stats KVM: selftests: Add compile-time assertions to guard against stats typos .../kvm/include/arm64/kvm_util_arch.h | 12 ++ .../testing/selftests/kvm/include/kvm_util.h | 49 ++++++-- .../selftests/kvm/include/kvm_util_types.h | 6 + .../kvm/include/riscv/kvm_util_arch.h | 14 +++ .../kvm/include/s390/kvm_util_arch.h | 113 ++++++++++++++++++ .../selftests/kvm/include/x86/kvm_util_arch.h | 52 ++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 79 ++++++------ .../kvm/x86/dirty_log_page_splitting_test.c | 6 +- .../selftests/kvm/x86/nx_huge_pages_test.c | 4 +- .../selftests/kvm/x86/xapic_ipi_test.c | 2 + 10 files changed, 286 insertions(+), 51 deletions(-) base-commit: dcab55cef6f247a71a75a239d4063018dc83a671