From: Andrew Jones <ajones@ventanamicro.com>
To: Atish Patra <atishp@rivosinc.com>
Cc: linux-kernel@vger.kernel.org, Anup Patel <anup@brainfault.org>,
Atish Patra <atishp@atishpatra.org>, Guo Ren <guoren@kernel.org>,
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>,
Sergey Matyukevich <sergey.matyukevich@syntacore.com>,
Eric Lin <eric.lin@sifive.com>, Will Deacon <will@kernel.org>
Subject: Re: [PATCH v2 08/11] RISC-V: KVM: Disable all hpmcounter access for VS/VU mode
Date: Thu, 12 Jan 2023 16:47:04 +0100 [thread overview]
Message-ID: <20230112154704.x6ml27hnsxh25my2@orel> (raw)
In-Reply-To: <20221215170046.2010255-9-atishp@rivosinc.com>
On Thu, Dec 15, 2022 at 09:00:43AM -0800, Atish Patra wrote:
> Any guest must not get access to any hpmcounter including cycle/instret
> without any checks. We achieve that by disabling all the bits except TM
> bit in hcountern.
hcounteren
>
> However, instret and cycle access for guest userspace can be enabled
> upon explicit request (via ONE REG) or on first trap from VU mode
> to maintain ABI requirement in the future. This patch doesn't support
> that as ONE REG inteface is not settled yet.
>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
> arch/riscv/kvm/main.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
> index 58c5489..9c2efd3 100644
> --- a/arch/riscv/kvm/main.c
> +++ b/arch/riscv/kvm/main.c
> @@ -49,7 +49,8 @@ int kvm_arch_hardware_enable(void)
> hideleg |= (1UL << IRQ_VS_EXT);
> csr_write(CSR_HIDELEG, hideleg);
>
> - csr_write(CSR_HCOUNTEREN, -1UL);
> + /* VS should access only TM bit. Everything else should trap */
s/TM bit/the time counter/
> + csr_write(CSR_HCOUNTEREN, 0x02);
>
> csr_write(CSR_HVIP, 0);
>
> --
> 2.25.1
>
Otherwise,
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Thanks,
drew
next prev parent reply other threads:[~2023-01-12 15:57 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-15 17:00 [PATCH v2 00/11] KVM perf support Atish Patra
2022-12-15 17:00 ` [PATCH v2 01/11] RISC-V: Define helper functions expose hpm counter width and count Atish Patra
2023-01-12 10:06 ` Andrew Jones
2023-01-12 18:18 ` Atish Kumar Patra
2023-01-13 7:22 ` Andrew Jones
2023-01-24 20:41 ` Atish Patra
2022-12-15 17:00 ` [PATCH v2 02/11] RISC-V: KVM: Define a probe function for SBI extension data structures Atish Patra
2023-01-12 10:21 ` Andrew Jones
2023-01-12 18:19 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 03/11] RISC-V: KVM: Return correct code for hsm stop function Atish Patra
2023-01-12 10:28 ` Andrew Jones
2023-01-12 18:25 ` Atish Kumar Patra
2023-01-13 7:25 ` Andrew Jones
2022-12-15 17:00 ` [PATCH v2 04/11] RISC-V: KVM: Modify SBI extension handler to return SBI error code Atish Patra
2023-01-12 11:04 ` Andrew Jones
2023-01-12 18:47 ` Atish Kumar Patra
2023-01-13 7:42 ` Andrew Jones
2022-12-15 17:00 ` [PATCH v2 05/11] RISC-V: KVM: Improve privilege mode filtering for perf Atish Patra
2022-12-15 20:17 ` Conor Dooley
2022-12-15 21:10 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 06/11] RISC-V: KVM: Add skeleton support " Atish Patra
2023-01-12 15:10 ` Andrew Jones
2023-01-12 18:09 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 07/11] RISC-V: KVM: Add SBI PMU extension support Atish Patra
2023-01-12 15:29 ` Andrew Jones
2023-01-12 18:04 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 08/11] RISC-V: KVM: Disable all hpmcounter access for VS/VU mode Atish Patra
2023-01-12 15:47 ` Andrew Jones [this message]
2022-12-15 17:00 ` [PATCH v2 09/11] RISC-V: KVM: Implement trap & emulate for hpmcounters Atish Patra
2023-01-13 11:47 ` Andrew Jones
2022-12-15 17:00 ` [PATCH v2 10/11] RISC-V: KVM: Implement perf support without sampling Atish Patra
2023-01-13 11:45 ` Andrew Jones
2023-01-23 7:23 ` Andrew Jones
2023-01-26 0:50 ` Atish Patra
2022-12-15 17:00 ` [PATCH v2 11/11] RISC-V: KVM: Implement firmware events Atish Patra
2023-01-13 12:08 ` Andrew Jones
2023-01-26 3:08 ` Atish Patra
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