This series adds PMU event filter support to RISC-V KVM, allowing a userspace VMM to restrict which SBI PMU events a guest is permitted to program.
The KVM_SET_PMU_EVENT_FILTER ioctl and KVM_CAP_PMU_EVENT_FILTER already exist as generic KVM uAPI (include/uapi/linux/kvm.h); RISC-V KVM does not yet implement them. Wiring them up lets a VMM limit a guest's PMU event access, which is useful for sandboxing and for withholding host PMU events the host does not intend to expose. Patch 1 implements the kernel side: the uapi struct, the ioctl handler with an SRCU-protected filter, enforcement in kvm_riscv_vcpu_pmu_ctr_cfg_match() (a disallowed event fails with SBI_ERR_NOT_SUPPORTED), and advertisement of KVM_CAP_PMU_EVENT_FILTER. Patch 2 adds a selftest that covers the ALLOW/DENY semantics with the event in and out of the list, filter clearing, and ioctl argument rejection (EINVAL/E2BIG). Testing: built and run under QEMU TCG with nested KVM (an L1 KVM host running an L2 guest). The selftest (patch 2) passes - all ALLOW/DENY and argument-validation cases behave as expected - and dmesg stays clean throughout the run. Based on v7.2-rc2 (a635d6748234). Assisted-by: YuanSheng:deepseek-v4-pro Co-developed-by: Quan Zhou <[email protected]> Signed-off-by: Quan Zhou <[email protected]> Signed-off-by: Yuhang.chen <[email protected]> Yuhang.chen (2): RISC-V: KVM: Add PMU event filter support RISC-V: KVM: selftests: Add PMU event filter test arch/riscv/include/asm/kvm_host.h | 3 + arch/riscv/include/uapi/asm/kvm.h | 20 ++ arch/riscv/kvm/vcpu_pmu.c | 28 +++ arch/riscv/kvm/vm.c | 66 +++++- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../kvm/riscv/pmu_event_filter_test.c | 199 ++++++++++++++++++ 6 files changed, 316 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/kvm/riscv/pmu_event_filter_test.c -- 2.34.1
