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>,
Eric Lin <eric.lin@sifive.com>, 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 v4 04/14] RISC-V: KVM: Define a probe function for SBI extension data structures
Date: Thu, 2 Feb 2023 16:16:41 +0100 [thread overview]
Message-ID: <20230202151641.6edhtlf7fz7xsmdy@orel> (raw)
In-Reply-To: <20230202151433.kspo2g7cqsccoqsq@orel>
On Thu, Feb 02, 2023 at 04:14:35PM +0100, Andrew Jones wrote:
> On Wed, Feb 01, 2023 at 03:12:40PM -0800, Atish Patra wrote:
> > Currently the probe function just checks if an SBI extension is
> > registered or not. However, the extension may not want to advertise
> > itself depending on some other condition.
> > An additional extension specific probe function will allow
> > extensions to decide if they want to be advertised to the caller or
> > not. Any extension that does not require additional dependency checks
> > can avoid implementing this function.
> >
> > Reviewed-by: Anup Patel <anup@brainfault.org>
> > Signed-off-by: Atish Patra <atishp@rivosinc.com>
> > ---
> > arch/riscv/include/asm/kvm_vcpu_sbi.h | 3 +++
> > arch/riscv/kvm/vcpu_sbi_base.c | 13 +++++++++++--
> > 2 files changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> > index f79478a..45ba341 100644
> > --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
> > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> > @@ -29,6 +29,9 @@ struct kvm_vcpu_sbi_extension {
> > int (*handler)(struct kvm_vcpu *vcpu, struct kvm_run *run,
> > unsigned long *out_val, struct kvm_cpu_trap *utrap,
> > bool *exit);
> > +
> > + /* Extension specific probe function */
> > + unsigned long (*probe)(struct kvm_vcpu *vcpu);
> > };
> >
> > void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run);
> > diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c
> > index 5d65c63..846d518 100644
> > --- a/arch/riscv/kvm/vcpu_sbi_base.c
> > +++ b/arch/riscv/kvm/vcpu_sbi_base.c
> > @@ -19,6 +19,7 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
> > {
> > int ret = 0;
> > struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
> > + const struct kvm_vcpu_sbi_extension *sbi_ext;
> >
> > switch (cp->a6) {
> > case SBI_EXT_BASE_GET_SPEC_VERSION:
> > @@ -43,8 +44,16 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
> > */
> > kvm_riscv_vcpu_sbi_forward(vcpu, run);
> > *exit = true;
> > - } else
> > - *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0;
> > + } else {
> > + sbi_ext = kvm_vcpu_sbi_find_ext(cp->a0);
> > + if (sbi_ext) {
> > + if (sbi_ext->probe)
> > + *out_val = sbi_ext->probe(vcpu);
> > + else
> > + *out_val = 1;
> > + } else
> > + *out_val = 0;
>
> Conor points out elsewhere that we need {} on both arms if one arm needs
> it. We actually don't need {} on either arm, though, or even the if, if
> we rewrite as
>
> *out_val = sbi_ext && sbi_ext->probe ? sbi_ext->probe(vcpu) : !!sbi_ext;
I sent too soon, I meant to add
In any case,
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Thanks,
drew
>
> Thanks,
> drew
>
> > + }
> > break;
> > case SBI_EXT_BASE_GET_MVENDORID:
> > *out_val = vcpu->arch.mvendorid;
> > --
> > 2.25.1
> >
next prev parent reply other threads:[~2023-02-02 15:16 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-01 23:12 [PATCH v4 00/14] KVM perf support Atish Patra
2023-02-01 23:12 ` [PATCH v4 01/14] perf: RISC-V: Define helper functions expose hpm counter width and count Atish Patra
2023-02-02 14:59 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 02/14] perf: RISC-V: Improve privilege mode filtering for perf Atish Patra
2023-02-01 23:12 ` [PATCH v4 03/14] RISC-V: Improve SBI PMU extension related definitions Atish Patra
2023-02-02 4:00 ` Anup Patel
2023-02-02 15:01 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 04/14] RISC-V: KVM: Define a probe function for SBI extension data structures Atish Patra
2023-02-02 15:14 ` Andrew Jones
2023-02-02 15:16 ` Andrew Jones [this message]
2023-02-01 23:12 ` [PATCH v4 05/14] RISC-V: KVM: Return correct code for hsm stop function Atish Patra
2023-02-02 15:26 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 06/14] RISC-V: KVM: Modify SBI extension handler to return SBI error code Atish Patra
2023-02-02 4:01 ` Anup Patel
2023-02-02 8:52 ` Anup Patel
2023-02-02 15:56 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 07/14] RISC-V: KVM: Add skeleton support for perf Atish Patra
2023-02-02 4:02 ` Anup Patel
2023-02-02 11:33 ` Conor Dooley
2023-02-03 8:04 ` Atish Patra
2023-02-03 8:08 ` Conor Dooley
2023-02-02 17:03 ` Andrew Jones
2023-02-03 8:47 ` Atish Patra
2023-02-05 7:37 ` Atish Patra
2023-02-06 9:22 ` Andrew Jones
2023-02-06 11:39 ` Andrew Jones
2023-02-07 9:20 ` Atish Patra
2023-02-01 23:12 ` [PATCH v4 08/14] RISC-V: KVM: Add SBI PMU extension support Atish Patra
2023-02-02 7:52 ` Conor Dooley
2023-02-02 17:29 ` Andrew Jones
2023-02-03 9:07 ` Atish Patra
2023-02-01 23:12 ` [PATCH v4 09/14] RISC-V: KVM: Make PMU functionality depend on Sscofpmf Atish Patra
2023-02-02 17:30 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 10/14] RISC-V: KVM: Disable all hpmcounter access for VS/VU mode Atish Patra
2023-02-01 23:12 ` [PATCH v4 11/14] RISC-V: KVM: Implement trap & emulate for hpmcounters Atish Patra
2023-02-01 23:12 ` [PATCH v4 12/14] RISC-V: KVM: Implement perf support without sampling Atish Patra
2023-02-02 18:44 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 13/14] RISC-V: KVM: Support firmware events Atish Patra
2023-02-02 11:40 ` Conor Dooley
2023-02-03 10:14 ` Andrew Jones
2023-02-01 23:12 ` [PATCH v4 14/14] RISC-V: KVM: Increment firmware pmu events Atish Patra
2023-02-02 18:48 ` Andrew Jones
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