From: Atish Patra Date: Tue, 7 Feb 2023 09:55:24 +0000 (-0800) Subject: RISC-V: KVM: Make PMU functionality depend on Sscofpmf X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=470926a2900cfdc39b300d87a0ccdf037fa67b9a;p=linux.git RISC-V: KVM: Make PMU functionality depend on Sscofpmf The privilege mode filtering feature must be available in the host so that the host can inhibit the counters while the execution is in HS mode. Otherwise, the guests may have access to critical guest information. Reviewed-by: Anup Patel Reviewed-by: Andrew Jones Signed-off-by: Atish Patra Signed-off-by: Anup Patel --- diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c index dc3c118efb578..921340413846c 100644 --- a/arch/riscv/kvm/vcpu_pmu.c +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -80,6 +80,14 @@ void kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu) struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); struct kvm_pmc *pmc; + /* + * PMU functionality should be only available to guests if privilege mode + * filtering is available in the host. Otherwise, guest will always count + * events while the execution is in hypervisor mode. + */ + if (!riscv_isa_extension_available(NULL, SSCOFPMF)) + return; + ret = riscv_pmu_get_hpm_info(&hpm_width, &num_hw_ctrs); if (ret < 0 || !hpm_width || !num_hw_ctrs) return;