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path: root/arch/riscv/kvm/vcpu_pmu.c
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2023-02-07RISC-V: KVM: Support firmware eventsAtish Patra1-33/+108
SBI PMU extension defines a set of firmware events which can provide useful information to guests about the number of SBI calls. As hypervisor implements the SBI PMU extension, these firmware events correspond to ecall invocations between VS->HS mode. All other firmware events will always report zero if monitored as KVM doesn't implement them. This patch adds all the infrastructure required to support firmware events. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07RISC-V: KVM: Implement perf support without samplingAtish Patra1-4/+356
RISC-V SBI PMU & Sscofpmf ISA extension allows supporting perf in the virtualization enviornment as well. KVM implementation relies on SBI PMU extension for the most part while trapping & emulating the CSRs read for counter access. This patch doesn't have the event sampling support yet. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07RISC-V: KVM: Implement trap & emulate for hpmcountersAtish Patra1-1/+58
As the KVM guests only see the virtual PMU counters, all hpmcounter access should trap and KVM emulates the read access on behalf of guests. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07RISC-V: KVM: Make PMU functionality depend on SscofpmfAtish Patra1-0/+8
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 <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07RISC-V: KVM: Add skeleton support for perfAtish Patra1-0/+141
This patch only adds barebone structure of perf implementation. Most of the function returns zero at this point and will be implemented fully in the future. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>