From: Deepak Gupta <debug@rivosinc.com>
To: "Clément Léger" <cleger@rivosinc.com>
Cc: Conor Dooley <conor@kernel.org>, Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Anup Patel <anup@brainfault.org>,
Atish Patra <atishp@atishpatra.org>,
linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
kvm-riscv@lists.infradead.org, Ved Shanbhogue <ved@rivosinc.com>
Subject: Re: [RFC PATCH 6/7] riscv: kvm: add SBI FWFT support for SBI_FWFT_DOUBLE_TRAP_ENABLE
Date: Tue, 14 May 2024 09:05:35 -0700 [thread overview]
Message-ID: <ZkOLz0ANkESSv5qr@debug.ba.rivosinc.com> (raw)
In-Reply-To: <c8e4c44d-8125-417e-8c61-a1f6d438815e@rivosinc.com>
On Tue, May 14, 2024 at 11:43:15AM +0200, Clément Léger wrote:
>
>
>On 27/04/2024 03:17, Deepak Gupta wrote:
>> On Thu, Apr 18, 2024 at 04:26:45PM +0200, Clément Léger wrote:
>>> Add support in KVM SBI FWFT extension to allow VS-mode to request double
>>> trap enabling. Double traps can then be generated by VS-mode, allowing
>>> M-mode to redirect them to S-mode.
>>>
>>
>>> +
>>> + if (value)
>>> + csr_set(CSR_HENVCFG_DBLTRP, DBLTRP_DTE);
>>> + else
>>> + csr_clear(CSR_HENVCFG_DBLTRP, DBLTRP_DTE);
>>
>> I think vcpu->arch.cfg has `henvcfg` field. Can we reflect it there as
>> well so that current
>> `henvcfg` copy in vcpu arch specifci config is consistent? Otherwise
>> it'll be lost when vCPU
>> is scheduled out and later scheduled back in (on vcpu load)
>
>henvcfg is restored when loading the vpcu (kvm_arch_vcpu_load()) and
>saved when the CPU is put (kvm_arch_vcpu_put()). But I just saw that
>this change is included in the next patch. Should have been this one ,
>I'll fix that.
>
>
>>
>> Furthermore, lets not do feature specific alias names for CSR.
>>
>> Instead let's keep consistent 64bit image of henvcfg in vcpu->arch.cfg.
>>
>> And whenever it's time to pick up the setting, pick up logic either
>> perform the writes in
>> henvcfg. And if required it'll perform henvcfgh too (as
>> `kvm_arch_vcpu_load` already does)
>
>I don't have a strong opinion on that point so if you think it really is
>better, I'll switch to that.
Thanks.
>
>Thanks,
>
>Clément
>
>>
>>> +
>>> + return SBI_SUCCESS;
>>> +}
>>> +
>>> +static int kvm_sbi_fwft_get_double_trap(struct kvm_vcpu *vcpu,
>>> + struct kvm_sbi_fwft_config *conf,
>>> + unsigned long *value)
>>> +{
>>> + if (!riscv_double_trap_enabled())
>>> + return SBI_ERR_NOT_SUPPORTED;
>>> +
>>> + *value = (csr_read(CSR_HENVCFG_DBLTRP) & DBLTRP_DTE) != 0;
>>> +
>>> + return SBI_SUCCESS;
>>> +}
>>> +
>>> static struct kvm_sbi_fwft_config *
>>> kvm_sbi_fwft_get_config(struct kvm_vcpu *vcpu, enum sbi_fwft_feature_t
>>> feature)
>>> {
>>> @@ -111,6 +147,11 @@ static const struct kvm_sbi_fwft_feature
>>> features[] = {
>>> .id = SBI_FWFT_MISALIGNED_DELEG,
>>> .set = kvm_sbi_fwft_set_misaligned_delegation,
>>> .get = kvm_sbi_fwft_get_misaligned_delegation,
>>> + },
>>> + {
>>> + .id = SBI_FWFT_DOUBLE_TRAP_ENABLE,
>>> + .set = kvm_sbi_fwft_set_double_trap,
>>> + .get = kvm_sbi_fwft_get_double_trap,
>>> }
>>> };
>>>
>>> --
>>> 2.43.0
>>>
>>>
next prev parent reply other threads:[~2024-05-14 16:05 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 14:26 [RFC PATCH 0/7] riscv: Add support for Ssdbltrp extension Clément Léger
2024-04-18 14:26 ` [RFC PATCH 1/7] riscv: kvm: add support for FWFT SBI extension Clément Léger
2024-04-26 23:44 ` Deepak Gupta
2024-04-30 7:26 ` Clément Léger
2024-04-18 14:26 ` [RFC PATCH 2/7] dt-bindings: riscv: add Ssdbltrp ISA extension description Clément Léger
2024-04-23 16:30 ` Conor Dooley
2024-04-24 7:20 ` Clément Léger
2024-04-24 7:40 ` Conor Dooley
2024-04-24 21:38 ` Ved Shanbhogue
2024-04-18 14:26 ` [RFC PATCH 3/7] riscv: add Ssdbltrp ISA extension parsing Clément Léger
2024-04-18 14:26 ` [RFC PATCH 4/7] riscv: handle Ssdbltrp mstatus SDT bit Clément Léger
2024-04-18 14:26 ` [RFC PATCH 5/7] riscv: add double trap driver Clément Léger
2024-04-23 16:39 ` Conor Dooley
2024-04-24 8:56 ` Clément Léger
2024-04-26 23:59 ` Deepak Gupta
2024-05-14 8:06 ` Clément Léger
2024-05-14 14:38 ` Deepak Gupta
2024-04-18 14:26 ` [RFC PATCH 6/7] riscv: kvm: add SBI FWFT support for SBI_FWFT_DOUBLE_TRAP_ENABLE Clément Léger
2024-04-27 1:17 ` Deepak Gupta
2024-04-27 15:36 ` Deepak Gupta
2024-05-14 9:43 ` Clément Léger
2024-05-14 16:05 ` Deepak Gupta [this message]
2024-04-18 14:26 ` [RFC PATCH 7/7] RISC-V: KVM: add support for double trap exception Clément Léger
2024-04-27 1:33 ` Deepak Gupta
2024-04-30 15:35 ` Clément Léger
2024-04-23 16:24 ` [RFC PATCH 0/7] riscv: Add support for Ssdbltrp extension Conor Dooley
2024-04-24 7:23 ` Clément Léger
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