Date:   Mon, 6 Feb 2023 12:45:36 +0100
From:   Andrew Jones <ajones@ventanamicro.com>
To:     Atish Patra <atishp@rivosinc.com>
Cc:     linux-kernel@vger.kernel.org, Anup Patel <anup@brainfault.org>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Atish Patra <atishp@atishpatra.org>,
        Guo Ren <guoren@kernel.org>, Heiko Stuebner <heiko@sntech.de>,
        kvm-riscv@lists.infradead.org, kvm@vger.kernel.org,
        linux-riscv@lists.infradead.org,
        Mark Rutland <mark.rutland@arm.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Will Deacon <will@kernel.org>
Subject: Re: [PATCH v5 07/14] RISC-V: KVM: Add skeleton support for perf
Message-ID: <20230206114536.oif5huw4jqhsdtic@orel>
References: <20230205011515.1284674-1-atishp@rivosinc.com>
 <20230205011515.1284674-8-atishp@rivosinc.com>
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In-Reply-To: <20230205011515.1284674-8-atishp@rivosinc.com>
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On Sat, Feb 04, 2023 at 05:15:08PM -0800, Atish Patra wrote:
> 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>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
>  arch/riscv/include/asm/kvm_host.h     |   4 +
>  arch/riscv/include/asm/kvm_vcpu_pmu.h |  78 +++++++++++++++
>  arch/riscv/kvm/Makefile               |   1 +
>  arch/riscv/kvm/vcpu.c                 |   7 ++
>  arch/riscv/kvm/vcpu_pmu.c             | 135 ++++++++++++++++++++++++++
>  5 files changed, 225 insertions(+)
>  create mode 100644 arch/riscv/include/asm/kvm_vcpu_pmu.h
>  create mode 100644 arch/riscv/kvm/vcpu_pmu.c
> 
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 93f43a3..b90be9a 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -18,6 +18,7 @@
>  #include <asm/kvm_vcpu_insn.h>
>  #include <asm/kvm_vcpu_sbi.h>
>  #include <asm/kvm_vcpu_timer.h>
> +#include <asm/kvm_vcpu_pmu.h>
>  
>  #define KVM_MAX_VCPUS			1024
>  
> @@ -228,6 +229,9 @@ struct kvm_vcpu_arch {
>  
>  	/* Don't run the VCPU (blocked) */
>  	bool pause;
> +
> +	/* Performance monitoring context */
> +	struct kvm_pmu pmu_context;
>  };
>  
>  static inline void kvm_arch_hardware_unsetup(void) {}
> diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h b/arch/riscv/include/asm/kvm_vcpu_pmu.h
> new file mode 100644
> index 0000000..40905db
> --- /dev/null
> +++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h
> @@ -0,0 +1,78 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2023 Rivos Inc
> + *
> + * Authors:
> + *     Atish Patra <atishp@rivosinc.com>
> + */
> +
> +#ifndef __KVM_VCPU_RISCV_PMU_H
> +#define __KVM_VCPU_RISCV_PMU_H
> +
> +#include <linux/perf/riscv_pmu.h>
> +#include <asm/kvm_vcpu_sbi.h>
> +#include <asm/sbi.h>
> +
> +#ifdef CONFIG_RISCV_PMU_SBI
> +#define RISCV_KVM_MAX_FW_CTRS	32
> +
> +#if RISCV_KVM_MAX_FW_CTRS > 32
> +#error "Maximum firmware counter can not exceed 32 without increasing the RISCV_MAX_COUNTERS"
                                    ^cannot                              ^ no the

> +#endif
> +
> +#define RISCV_MAX_COUNTERS 64

I'm still not sure about the above. I wrote more in the v4 thread
about it.

Otherwise,

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew