[v8,0/5] Add Svade and Svadu Extensions Support

Message ID	20240726084931.28924-1-yongxuan.wang@sifive.com (mailing list archive)
Headers	show Return-Path: <linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org> From: Yong-Xuan Wang <yongxuan.wang@sifive.com> To: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org Cc: greentime.hu@sifive.com, vincent.chen@sifive.com, Yong-Xuan Wang <yongxuan.wang@sifive.com>, Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu> Subject: [PATCH v8 0/5] Add Svade and Svadu Extensions Support Date: Fri, 26 Jul 2024 16:49:25 +0800 Message-Id: <20240726084931.28924-1-yongxuan.wang@sifive.com> MIME-Version: 1.0 Precedence: list Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" <linux-riscv-bounces@lists.infradead.org> Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org
Series	Add Svade and Svadu Extensions Support \| expand [v8,0/5] Add Svade and Svadu Extensions Support [v8,1/5] RISC-V: Add Svade and Svadu Extensions Support [v8,2/5] dt-bindings: riscv: Add Svade and Svadu Entries [v8,3/5] RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM [v8,4/5] KVM: riscv: selftests: Fix compile error [v8,5/5] KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list test

Yong-Xuan Wang July 26, 2024, 8:49 a.m. UTC

Svade and Svadu extensions represent two schemes for managing the PTE A/D
bit. When the PTE A/D bits need to be set, Svade extension intdicates that
a related page fault will be raised. In contrast, the Svadu extension
supports hardware updating of PTE A/D bits. This series enables Svade and
Svadu extensions for both host and guest OS.

Regrading the mailing thread[1], we have 4 possible combinations of
these extensions in the device tree, the default hardware behavior for
these possibilities are:
1) Neither Svade nor Svadu present in DT => It is technically
   unknown whether the platform uses Svade or Svadu. Supervisor
   software should be prepared to handle either hardware updating
   of the PTE A/D bits or page faults when they need updated.
2) Only Svade present in DT => Supervisor must assume Svade to be
   always enabled.
3) Only Svadu present in DT => Supervisor must assume Svadu to be
   always enabled.
4) Both Svade and Svadu present in DT => Supervisor must assume
   Svadu turned-off at boot time. To use Svadu, supervisor must
   explicitly enable it using the SBI FWFT extension.

The Svade extension is mandatory and the Svadu extension is optional in
RVA23 profile. Platforms want to take the advantage of Svadu can choose
3. Those are aware of the profile can choose 4, and Linux won't get the
benefit of svadu until the SBI FWFT extension is available.

[1] https://lore.kernel.org/linux-kernel/20240527-e9845c06619bca5cd285098c@orel/T/#m29644eb88e241ec282df4ccd5199514e913b06ee

---
v8:
- fix typo in PATCH1 (Samuel)
- use the new extension validating API in PATCH1 (Clément)
- update the dtbinding in PATCH2 (Samuel, Conor)
- add PATCH4 to fix compile error in get-reg-list test.

v7:
- fix alignment in PATCH1
- update the dtbinding in PATCH2 (Conor, Jessica)

v6:
- reflect the platform's behavior by riscv_isa_extension_available() and
  update the the arch_has_hw_pte_young() in PATCH1 (Conor, Andrew)
- update the dtbinding in PATCH2 (Alexandre, Andrew, Anup, Conor)
- update the henvcfg condition in PATCH3 (Andrew)
- check if Svade is allowed to disabled based on arch_has_hw_pte_young()
  in PATCH3

v5:
- remove all Acked-by and Reviewed-by (Conor, Andrew)
- add Svade support
- update the arch_has_hw_pte_young() in PATCH1
- update the dtbinding in PATCH2 (Alexandre, Andrew)
- check the availibility of Svadu for Guest/VM based on
  arch_has_hw_pte_young() in PATCH3

v4:
- fix 32bit kernel build error in PATCH1 (Conor)
- update the status of Svadu extension to ratified in PATCH2
- add the PATCH4 to suporrt SBI_FWFT_PTE_AD_HW_UPDATING for guest OS
- update the PATCH1 and PATCH3 to integrate with FWFT extension
- rebase PATCH5 on the lastest get-reg-list test (Andrew)

v3:
- fix the control bit name to ADUE in PATCH1 and PATCH3
- update get-reg-list in PATCH4

v2:
- add Co-developed-by: in PATCH1
- use riscv_has_extension_unlikely() to runtime patch the branch in PATCH1
- update dt-binding

Yong-Xuan Wang (5):
  RISC-V: Add Svade and Svadu Extensions Support
  dt-bindings: riscv: Add Svade and Svadu Entries
  RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
  KVM: riscv: selftests: Fix compile error
  KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list
    test

 .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++
 arch/riscv/Kconfig                            |  1 +
 arch/riscv/include/asm/csr.h                  |  1 +
 arch/riscv/include/asm/hwcap.h                |  2 ++
 arch/riscv/include/asm/pgtable.h              | 13 ++++++++-
 arch/riscv/include/uapi/asm/kvm.h             |  2 ++
 arch/riscv/kernel/cpufeature.c                | 12 ++++++++
 arch/riscv/kvm/vcpu.c                         |  4 +++
 arch/riscv/kvm/vcpu_onereg.c                  | 15 ++++++++++
 .../selftests/kvm/riscv/get-reg-list.c        | 16 ++++++++---
 10 files changed, 89 insertions(+), 5 deletions(-)

patchwork-bot+linux-riscv@kernel.org Aug. 6, 2024, 8:28 p.m. UTC | #1

Hello:

This series was applied to riscv/linux.git (fixes)
by Anup Patel <anup@brainfault.org>:

On Fri, 26 Jul 2024 16:49:25 +0800 you wrote:
> Svade and Svadu extensions represent two schemes for managing the PTE A/D
> bit. When the PTE A/D bits need to be set, Svade extension intdicates that
> a related page fault will be raised. In contrast, the Svadu extension
> supports hardware updating of PTE A/D bits. This series enables Svade and
> Svadu extensions for both host and guest OS.
> 
> Regrading the mailing thread[1], we have 4 possible combinations of
> these extensions in the device tree, the default hardware behavior for
> these possibilities are:
> 1) Neither Svade nor Svadu present in DT => It is technically
>    unknown whether the platform uses Svade or Svadu. Supervisor
>    software should be prepared to handle either hardware updating
>    of the PTE A/D bits or page faults when they need updated.
> 2) Only Svade present in DT => Supervisor must assume Svade to be
>    always enabled.
> 3) Only Svadu present in DT => Supervisor must assume Svadu to be
>    always enabled.
> 4) Both Svade and Svadu present in DT => Supervisor must assume
>    Svadu turned-off at boot time. To use Svadu, supervisor must
>    explicitly enable it using the SBI FWFT extension.
> 
> [...]

Here is the summary with links:
  - [v8,1/5] RISC-V: Add Svade and Svadu Extensions Support
    (no matching commit)
  - [v8,2/5] dt-bindings: riscv: Add Svade and Svadu Entries
    (no matching commit)
  - [v8,3/5] RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
    (no matching commit)
  - [v8,4/5] KVM: riscv: selftests: Fix compile error
    https://git.kernel.org/riscv/c/dd4a799bcc13
  - [v8,5/5] KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list test
    (no matching commit)

You are awesome, thank you!

Anup Patel Aug. 21, 2024, 2:43 p.m. UTC | #2

Hi Palmer,

On Fri, Jul 26, 2024 at 2:19 PM Yong-Xuan Wang <yongxuan.wang@sifive.com> wrote:
>
> Svade and Svadu extensions represent two schemes for managing the PTE A/D
> bit. When the PTE A/D bits need to be set, Svade extension intdicates that
> a related page fault will be raised. In contrast, the Svadu extension
> supports hardware updating of PTE A/D bits. This series enables Svade and
> Svadu extensions for both host and guest OS.
>
> Regrading the mailing thread[1], we have 4 possible combinations of
> these extensions in the device tree, the default hardware behavior for
> these possibilities are:
> 1) Neither Svade nor Svadu present in DT => It is technically
>    unknown whether the platform uses Svade or Svadu. Supervisor
>    software should be prepared to handle either hardware updating
>    of the PTE A/D bits or page faults when they need updated.
> 2) Only Svade present in DT => Supervisor must assume Svade to be
>    always enabled.
> 3) Only Svadu present in DT => Supervisor must assume Svadu to be
>    always enabled.
> 4) Both Svade and Svadu present in DT => Supervisor must assume
>    Svadu turned-off at boot time. To use Svadu, supervisor must
>    explicitly enable it using the SBI FWFT extension.
>
> The Svade extension is mandatory and the Svadu extension is optional in
> RVA23 profile. Platforms want to take the advantage of Svadu can choose
> 3. Those are aware of the profile can choose 4, and Linux won't get the
> benefit of svadu until the SBI FWFT extension is available.
>
> [1] https://lore.kernel.org/linux-kernel/20240527-e9845c06619bca5cd285098c@orel/T/#m29644eb88e241ec282df4ccd5199514e913b06ee
>
> ---
> v8:
> - fix typo in PATCH1 (Samuel)
> - use the new extension validating API in PATCH1 (Clément)
> - update the dtbinding in PATCH2 (Samuel, Conor)
> - add PATCH4 to fix compile error in get-reg-list test.
>
> v7:
> - fix alignment in PATCH1
> - update the dtbinding in PATCH2 (Conor, Jessica)
>
> v6:
> - reflect the platform's behavior by riscv_isa_extension_available() and
>   update the the arch_has_hw_pte_young() in PATCH1 (Conor, Andrew)
> - update the dtbinding in PATCH2 (Alexandre, Andrew, Anup, Conor)
> - update the henvcfg condition in PATCH3 (Andrew)
> - check if Svade is allowed to disabled based on arch_has_hw_pte_young()
>   in PATCH3
>
> v5:
> - remove all Acked-by and Reviewed-by (Conor, Andrew)
> - add Svade support
> - update the arch_has_hw_pte_young() in PATCH1
> - update the dtbinding in PATCH2 (Alexandre, Andrew)
> - check the availibility of Svadu for Guest/VM based on
>   arch_has_hw_pte_young() in PATCH3
>
> v4:
> - fix 32bit kernel build error in PATCH1 (Conor)
> - update the status of Svadu extension to ratified in PATCH2
> - add the PATCH4 to suporrt SBI_FWFT_PTE_AD_HW_UPDATING for guest OS
> - update the PATCH1 and PATCH3 to integrate with FWFT extension
> - rebase PATCH5 on the lastest get-reg-list test (Andrew)
>
> v3:
> - fix the control bit name to ADUE in PATCH1 and PATCH3
> - update get-reg-list in PATCH4
>
> v2:
> - add Co-developed-by: in PATCH1
> - use riscv_has_extension_unlikely() to runtime patch the branch in PATCH1
> - update dt-binding
>
> Yong-Xuan Wang (5):
>   RISC-V: Add Svade and Svadu Extensions Support
>   dt-bindings: riscv: Add Svade and Svadu Entries
>   RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
>   KVM: riscv: selftests: Fix compile error
>   KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list
>     test
>
>  .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++
>  arch/riscv/Kconfig                            |  1 +
>  arch/riscv/include/asm/csr.h                  |  1 +
>  arch/riscv/include/asm/hwcap.h                |  2 ++
>  arch/riscv/include/asm/pgtable.h              | 13 ++++++++-
>  arch/riscv/include/uapi/asm/kvm.h             |  2 ++
>  arch/riscv/kernel/cpufeature.c                | 12 ++++++++
>  arch/riscv/kvm/vcpu.c                         |  4 +++
>  arch/riscv/kvm/vcpu_onereg.c                  | 15 ++++++++++
>  .../selftests/kvm/riscv/get-reg-list.c        | 16 ++++++++---
>  10 files changed, 89 insertions(+), 5 deletions(-)
>
> --
> 2.17.1
>
>

Let me know if this series can be taken through the KVM RISC-V tree.
I can provide you with a shared tag as well.

Regards,
Anup

Palmer Dabbelt Sept. 20, 2024, 8:23 a.m. UTC | #3

On Wed, 21 Aug 2024 07:43:20 PDT (-0700), anup@brainfault.org wrote:
> Hi Palmer,
>
> On Fri, Jul 26, 2024 at 2:19 PM Yong-Xuan Wang <yongxuan.wang@sifive.com> wrote:
>>
>> Svade and Svadu extensions represent two schemes for managing the PTE A/D
>> bit. When the PTE A/D bits need to be set, Svade extension intdicates that
>> a related page fault will be raised. In contrast, the Svadu extension
>> supports hardware updating of PTE A/D bits. This series enables Svade and
>> Svadu extensions for both host and guest OS.
>>
>> Regrading the mailing thread[1], we have 4 possible combinations of
>> these extensions in the device tree, the default hardware behavior for
>> these possibilities are:
>> 1) Neither Svade nor Svadu present in DT => It is technically
>>    unknown whether the platform uses Svade or Svadu. Supervisor
>>    software should be prepared to handle either hardware updating
>>    of the PTE A/D bits or page faults when they need updated.
>> 2) Only Svade present in DT => Supervisor must assume Svade to be
>>    always enabled.
>> 3) Only Svadu present in DT => Supervisor must assume Svadu to be
>>    always enabled.
>> 4) Both Svade and Svadu present in DT => Supervisor must assume
>>    Svadu turned-off at boot time. To use Svadu, supervisor must
>>    explicitly enable it using the SBI FWFT extension.
>>
>> The Svade extension is mandatory and the Svadu extension is optional in
>> RVA23 profile. Platforms want to take the advantage of Svadu can choose
>> 3. Those are aware of the profile can choose 4, and Linux won't get the
>> benefit of svadu until the SBI FWFT extension is available.
>>
>> [1] https://lore.kernel.org/linux-kernel/20240527-e9845c06619bca5cd285098c@orel/T/#m29644eb88e241ec282df4ccd5199514e913b06ee
>>
>> ---
>> v8:
>> - fix typo in PATCH1 (Samuel)
>> - use the new extension validating API in PATCH1 (Clément)
>> - update the dtbinding in PATCH2 (Samuel, Conor)
>> - add PATCH4 to fix compile error in get-reg-list test.
>>
>> v7:
>> - fix alignment in PATCH1
>> - update the dtbinding in PATCH2 (Conor, Jessica)
>>
>> v6:
>> - reflect the platform's behavior by riscv_isa_extension_available() and
>>   update the the arch_has_hw_pte_young() in PATCH1 (Conor, Andrew)
>> - update the dtbinding in PATCH2 (Alexandre, Andrew, Anup, Conor)
>> - update the henvcfg condition in PATCH3 (Andrew)
>> - check if Svade is allowed to disabled based on arch_has_hw_pte_young()
>>   in PATCH3
>>
>> v5:
>> - remove all Acked-by and Reviewed-by (Conor, Andrew)
>> - add Svade support
>> - update the arch_has_hw_pte_young() in PATCH1
>> - update the dtbinding in PATCH2 (Alexandre, Andrew)
>> - check the availibility of Svadu for Guest/VM based on
>>   arch_has_hw_pte_young() in PATCH3
>>
>> v4:
>> - fix 32bit kernel build error in PATCH1 (Conor)
>> - update the status of Svadu extension to ratified in PATCH2
>> - add the PATCH4 to suporrt SBI_FWFT_PTE_AD_HW_UPDATING for guest OS
>> - update the PATCH1 and PATCH3 to integrate with FWFT extension
>> - rebase PATCH5 on the lastest get-reg-list test (Andrew)
>>
>> v3:
>> - fix the control bit name to ADUE in PATCH1 and PATCH3
>> - update get-reg-list in PATCH4
>>
>> v2:
>> - add Co-developed-by: in PATCH1
>> - use riscv_has_extension_unlikely() to runtime patch the branch in PATCH1
>> - update dt-binding
>>
>> Yong-Xuan Wang (5):
>>   RISC-V: Add Svade and Svadu Extensions Support
>>   dt-bindings: riscv: Add Svade and Svadu Entries
>>   RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
>>   KVM: riscv: selftests: Fix compile error
>>   KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list
>>     test
>>
>>  .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++
>>  arch/riscv/Kconfig                            |  1 +
>>  arch/riscv/include/asm/csr.h                  |  1 +
>>  arch/riscv/include/asm/hwcap.h                |  2 ++
>>  arch/riscv/include/asm/pgtable.h              | 13 ++++++++-
>>  arch/riscv/include/uapi/asm/kvm.h             |  2 ++
>>  arch/riscv/kernel/cpufeature.c                | 12 ++++++++
>>  arch/riscv/kvm/vcpu.c                         |  4 +++
>>  arch/riscv/kvm/vcpu_onereg.c                  | 15 ++++++++++
>>  .../selftests/kvm/riscv/get-reg-list.c        | 16 ++++++++---
>>  10 files changed, 89 insertions(+), 5 deletions(-)
>>
>> --
>> 2.17.1
>>
>>
>
> Let me know if this series can be taken through the KVM RISC-V tree.
> I can provide you with a shared tag as well.

I think the patchwork bot got confused by patch 4 going to fixes?  It 
says this was merged.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

if you still want to take it, otherwise just LMK and I'll pick it up.

> Regards,
> Anup

Anup Patel Sept. 20, 2024, 8:34 a.m. UTC | #4

On Fri, Sep 20, 2024 at 1:53 PM Palmer Dabbelt <palmer@rivosinc.com> wrote:
>
> On Wed, 21 Aug 2024 07:43:20 PDT (-0700), anup@brainfault.org wrote:
> > Hi Palmer,
> >
> > On Fri, Jul 26, 2024 at 2:19 PM Yong-Xuan Wang <yongxuan.wang@sifive.com> wrote:
> >>
> >> Svade and Svadu extensions represent two schemes for managing the PTE A/D
> >> bit. When the PTE A/D bits need to be set, Svade extension intdicates that
> >> a related page fault will be raised. In contrast, the Svadu extension
> >> supports hardware updating of PTE A/D bits. This series enables Svade and
> >> Svadu extensions for both host and guest OS.
> >>
> >> Regrading the mailing thread[1], we have 4 possible combinations of
> >> these extensions in the device tree, the default hardware behavior for
> >> these possibilities are:
> >> 1) Neither Svade nor Svadu present in DT => It is technically
> >>    unknown whether the platform uses Svade or Svadu. Supervisor
> >>    software should be prepared to handle either hardware updating
> >>    of the PTE A/D bits or page faults when they need updated.
> >> 2) Only Svade present in DT => Supervisor must assume Svade to be
> >>    always enabled.
> >> 3) Only Svadu present in DT => Supervisor must assume Svadu to be
> >>    always enabled.
> >> 4) Both Svade and Svadu present in DT => Supervisor must assume
> >>    Svadu turned-off at boot time. To use Svadu, supervisor must
> >>    explicitly enable it using the SBI FWFT extension.
> >>
> >> The Svade extension is mandatory and the Svadu extension is optional in
> >> RVA23 profile. Platforms want to take the advantage of Svadu can choose
> >> 3. Those are aware of the profile can choose 4, and Linux won't get the
> >> benefit of svadu until the SBI FWFT extension is available.
> >>
> >> [1] https://lore.kernel.org/linux-kernel/20240527-e9845c06619bca5cd285098c@orel/T/#m29644eb88e241ec282df4ccd5199514e913b06ee
> >>
> >> ---
> >> v8:
> >> - fix typo in PATCH1 (Samuel)
> >> - use the new extension validating API in PATCH1 (Clément)
> >> - update the dtbinding in PATCH2 (Samuel, Conor)
> >> - add PATCH4 to fix compile error in get-reg-list test.
> >>
> >> v7:
> >> - fix alignment in PATCH1
> >> - update the dtbinding in PATCH2 (Conor, Jessica)
> >>
> >> v6:
> >> - reflect the platform's behavior by riscv_isa_extension_available() and
> >>   update the the arch_has_hw_pte_young() in PATCH1 (Conor, Andrew)
> >> - update the dtbinding in PATCH2 (Alexandre, Andrew, Anup, Conor)
> >> - update the henvcfg condition in PATCH3 (Andrew)
> >> - check if Svade is allowed to disabled based on arch_has_hw_pte_young()
> >>   in PATCH3
> >>
> >> v5:
> >> - remove all Acked-by and Reviewed-by (Conor, Andrew)
> >> - add Svade support
> >> - update the arch_has_hw_pte_young() in PATCH1
> >> - update the dtbinding in PATCH2 (Alexandre, Andrew)
> >> - check the availibility of Svadu for Guest/VM based on
> >>   arch_has_hw_pte_young() in PATCH3
> >>
> >> v4:
> >> - fix 32bit kernel build error in PATCH1 (Conor)
> >> - update the status of Svadu extension to ratified in PATCH2
> >> - add the PATCH4 to suporrt SBI_FWFT_PTE_AD_HW_UPDATING for guest OS
> >> - update the PATCH1 and PATCH3 to integrate with FWFT extension
> >> - rebase PATCH5 on the lastest get-reg-list test (Andrew)
> >>
> >> v3:
> >> - fix the control bit name to ADUE in PATCH1 and PATCH3
> >> - update get-reg-list in PATCH4
> >>
> >> v2:
> >> - add Co-developed-by: in PATCH1
> >> - use riscv_has_extension_unlikely() to runtime patch the branch in PATCH1
> >> - update dt-binding
> >>
> >> Yong-Xuan Wang (5):
> >>   RISC-V: Add Svade and Svadu Extensions Support
> >>   dt-bindings: riscv: Add Svade and Svadu Entries
> >>   RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
> >>   KVM: riscv: selftests: Fix compile error
> >>   KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list
> >>     test
> >>
> >>  .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++
> >>  arch/riscv/Kconfig                            |  1 +
> >>  arch/riscv/include/asm/csr.h                  |  1 +
> >>  arch/riscv/include/asm/hwcap.h                |  2 ++
> >>  arch/riscv/include/asm/pgtable.h              | 13 ++++++++-
> >>  arch/riscv/include/uapi/asm/kvm.h             |  2 ++
> >>  arch/riscv/kernel/cpufeature.c                | 12 ++++++++
> >>  arch/riscv/kvm/vcpu.c                         |  4 +++
> >>  arch/riscv/kvm/vcpu_onereg.c                  | 15 ++++++++++
> >>  .../selftests/kvm/riscv/get-reg-list.c        | 16 ++++++++---
> >>  10 files changed, 89 insertions(+), 5 deletions(-)
> >>
> >> --
> >> 2.17.1
> >>
> >>
> >
> > Let me know if this series can be taken through the KVM RISC-V tree.
> > I can provide you with a shared tag as well.
>
> I think the patchwork bot got confused by patch 4 going to fixes?  It
> says this was merged.
>
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
>
> if you still want to take it, otherwise just LMK and I'll pick it up.
>

I already sent KVM RISC-V PR for 6.12 which has been merged
as well. Please take this series (except PATCH4) through the
RISC-V tree.

Thanks,
Anup

Anup Patel Oct. 5, 2024, 11:01 a.m. UTC | #5

Hi Palmer,

On Fri, Sep 20, 2024 at 1:53 PM Palmer Dabbelt <palmer@rivosinc.com> wrote:
>
> On Wed, 21 Aug 2024 07:43:20 PDT (-0700), anup@brainfault.org wrote:
> > Hi Palmer,
> >
> > On Fri, Jul 26, 2024 at 2:19 PM Yong-Xuan Wang <yongxuan.wang@sifive.com> wrote:
> >>
> >> Svade and Svadu extensions represent two schemes for managing the PTE A/D
> >> bit. When the PTE A/D bits need to be set, Svade extension intdicates that
> >> a related page fault will be raised. In contrast, the Svadu extension
> >> supports hardware updating of PTE A/D bits. This series enables Svade and
> >> Svadu extensions for both host and guest OS.
> >>
> >> Regrading the mailing thread[1], we have 4 possible combinations of
> >> these extensions in the device tree, the default hardware behavior for
> >> these possibilities are:
> >> 1) Neither Svade nor Svadu present in DT => It is technically
> >>    unknown whether the platform uses Svade or Svadu. Supervisor
> >>    software should be prepared to handle either hardware updating
> >>    of the PTE A/D bits or page faults when they need updated.
> >> 2) Only Svade present in DT => Supervisor must assume Svade to be
> >>    always enabled.
> >> 3) Only Svadu present in DT => Supervisor must assume Svadu to be
> >>    always enabled.
> >> 4) Both Svade and Svadu present in DT => Supervisor must assume
> >>    Svadu turned-off at boot time. To use Svadu, supervisor must
> >>    explicitly enable it using the SBI FWFT extension.
> >>
> >> The Svade extension is mandatory and the Svadu extension is optional in
> >> RVA23 profile. Platforms want to take the advantage of Svadu can choose
> >> 3. Those are aware of the profile can choose 4, and Linux won't get the
> >> benefit of svadu until the SBI FWFT extension is available.
> >>
> >> [1] https://lore.kernel.org/linux-kernel/20240527-e9845c06619bca5cd285098c@orel/T/#m29644eb88e241ec282df4ccd5199514e913b06ee
> >>
> >> ---
> >> v8:
> >> - fix typo in PATCH1 (Samuel)
> >> - use the new extension validating API in PATCH1 (Clément)
> >> - update the dtbinding in PATCH2 (Samuel, Conor)
> >> - add PATCH4 to fix compile error in get-reg-list test.
> >>
> >> v7:
> >> - fix alignment in PATCH1
> >> - update the dtbinding in PATCH2 (Conor, Jessica)
> >>
> >> v6:
> >> - reflect the platform's behavior by riscv_isa_extension_available() and
> >>   update the the arch_has_hw_pte_young() in PATCH1 (Conor, Andrew)
> >> - update the dtbinding in PATCH2 (Alexandre, Andrew, Anup, Conor)
> >> - update the henvcfg condition in PATCH3 (Andrew)
> >> - check if Svade is allowed to disabled based on arch_has_hw_pte_young()
> >>   in PATCH3
> >>
> >> v5:
> >> - remove all Acked-by and Reviewed-by (Conor, Andrew)
> >> - add Svade support
> >> - update the arch_has_hw_pte_young() in PATCH1
> >> - update the dtbinding in PATCH2 (Alexandre, Andrew)
> >> - check the availibility of Svadu for Guest/VM based on
> >>   arch_has_hw_pte_young() in PATCH3
> >>
> >> v4:
> >> - fix 32bit kernel build error in PATCH1 (Conor)
> >> - update the status of Svadu extension to ratified in PATCH2
> >> - add the PATCH4 to suporrt SBI_FWFT_PTE_AD_HW_UPDATING for guest OS
> >> - update the PATCH1 and PATCH3 to integrate with FWFT extension
> >> - rebase PATCH5 on the lastest get-reg-list test (Andrew)
> >>
> >> v3:
> >> - fix the control bit name to ADUE in PATCH1 and PATCH3
> >> - update get-reg-list in PATCH4
> >>
> >> v2:
> >> - add Co-developed-by: in PATCH1
> >> - use riscv_has_extension_unlikely() to runtime patch the branch in PATCH1
> >> - update dt-binding
> >>
> >> Yong-Xuan Wang (5):
> >>   RISC-V: Add Svade and Svadu Extensions Support
> >>   dt-bindings: riscv: Add Svade and Svadu Entries
> >>   RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
> >>   KVM: riscv: selftests: Fix compile error
> >>   KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list
> >>     test
> >>
> >>  .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++
> >>  arch/riscv/Kconfig                            |  1 +
> >>  arch/riscv/include/asm/csr.h                  |  1 +
> >>  arch/riscv/include/asm/hwcap.h                |  2 ++
> >>  arch/riscv/include/asm/pgtable.h              | 13 ++++++++-
> >>  arch/riscv/include/uapi/asm/kvm.h             |  2 ++
> >>  arch/riscv/kernel/cpufeature.c                | 12 ++++++++
> >>  arch/riscv/kvm/vcpu.c                         |  4 +++
> >>  arch/riscv/kvm/vcpu_onereg.c                  | 15 ++++++++++
> >>  .../selftests/kvm/riscv/get-reg-list.c        | 16 ++++++++---
> >>  10 files changed, 89 insertions(+), 5 deletions(-)
> >>
> >> --
> >> 2.17.1
> >>
> >>
> >
> > Let me know if this series can be taken through the KVM RISC-V tree.
> > I can provide you with a shared tag as well.
>
> I think the patchwork bot got confused by patch 4 going to fixes?  It
> says this was merged.
>
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
>
> if you still want to take it, otherwise just LMK and I'll pick it up.
>

I have queued this series for Linux-6.13

Thanks,
Anup

[v8,0/5] Add Svade and Svadu Extensions Support

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