mbox series

[v4,00/13] RISC-V: Add steal-time support

Message ID 20231220160012.40184-15-ajones@ventanamicro.com (mailing list archive)
Headers show
Series RISC-V: Add steal-time support | expand

Message

Andrew Jones Dec. 20, 2023, 4 p.m. UTC 
One frequently touted benefit of virtualization is the ability to
consolidate machines, increasing resource utilization.  It may even be
desirable to overcommit, at the risk of one or more VCPUs having to wait.
Hypervisors which have interfaces for guests to retrieve the amount of
time each VCPU had to wait give observers within the guests ways to
account for less progress than would otherwise be expected. The SBI STA
extension[1] provides a standard interface for guest VCPUs to retrieve
the amount of time "stolen".

This series has three parts:
 1) Patches 01-03 - Add paravirt support to RISC-V and implement
                    steal-time accounting support using the SBI STA
                    extension.
 2) Patches 04-09 - Implement SBI STA in KVM so KVM guests, such as
                    Linux guests which enable the paravirt steal-time
                    support, can be enlightened about stolen time.
 3) Patches 10-13 - Add RISC-V support to the KVM selftests steal_time
                    test and the SBI extension regs in the get-reg-list
                    test.

These patches are based on kvm-riscv/riscv_kvm_queue

[1] https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-steal-time.adoc

This patches are also available here
https://github.com/jones-drew/linux/commits/kvm/steal-time-v4

Changes since v3:
 - Use work "Computing" instead of "using" in pr_info [Atish]
 - Rename KVM_REG_RISCV_SBI to KVM_REG_RISCV_SBI_STATE [Atish, Anup]
 - Picked up r-b's from Atish and Anup

Changes since v2:
 - Always check sequence in case the SBI impl isn't writing steal
   atomically [Anup]
 - Create a reset function for sta and also reset last_steal [Anup]
 - Picked up Anup's r-b's

Changes since v1:
 - sbi_sta_steal_time_set_shmem() now maps SBI errors to linux errors [Conor]
 - Squashed v1 patch 4 into v1 patch 3 [Conor]
 - Moved kvm_riscv_vcpu_set/get_reg_sbi() to arch/riscv/kvm/vcpu_sbi.c
   which seems like a more appropriate file for them
 - Rebased on kvm-riscv/riscv_kvm_queue which has all the dependencies

Changes since RFC:
 - Rebased on v6.7-rc3 (plus the patches mentioned above)
 - Added defines for the -1's [Conor]
 - Added a comment to the steal read sequence [Conor]
 - Only do the steal read sequence for 32-bit and added READ_ONCE's
 - Check for SBI v2.0 implementation
 - Rename set_steal_time_shmem to steal_time_set_shmem
 - Add get-reg-list support and test with get-reg-list kselftest
 - A few other minor improvements
 - Picked up one r-b from Conor

Thanks,
drew


Andrew Jones (13):
  RISC-V: paravirt: Add skeleton for pv-time support
  RISC-V: Add SBI STA extension definitions
  RISC-V: paravirt: Implement steal-time support
  RISC-V: KVM: Add SBI STA extension skeleton
  RISC-V: KVM: Add steal-update vcpu request
  RISC-V: KVM: Add SBI STA info to vcpu_arch
  RISC-V: KVM: Add support for SBI extension registers
  RISC-V: KVM: Add support for SBI STA registers
  RISC-V: KVM: Implement SBI STA extension
  RISC-V: KVM: selftests: Move sbi_ecall to processor.c
  RISC-V: KVM: selftests: Add guest_sbi_probe_extension
  RISC-V: KVM: selftests: Add steal_time test support
  RISC-V: KVM: selftests: Add get-reg-list test for STA registers

 .../admin-guide/kernel-parameters.txt         |   6 +-
 arch/riscv/Kconfig                            |  19 ++
 arch/riscv/include/asm/kvm_host.h             |  10 +
 arch/riscv/include/asm/kvm_vcpu_sbi.h         |  10 +
 arch/riscv/include/asm/paravirt.h             |  28 +++
 arch/riscv/include/asm/paravirt_api_clock.h   |   1 +
 arch/riscv/include/asm/sbi.h                  |  17 ++
 arch/riscv/include/uapi/asm/kvm.h             |  13 ++
 arch/riscv/kernel/Makefile                    |   1 +
 arch/riscv/kernel/paravirt.c                  | 134 +++++++++++
 arch/riscv/kernel/time.c                      |   3 +
 arch/riscv/kvm/Kconfig                        |   1 +
 arch/riscv/kvm/Makefile                       |   1 +
 arch/riscv/kvm/vcpu.c                         |   7 +
 arch/riscv/kvm/vcpu_onereg.c                  |  51 ++++-
 arch/riscv/kvm/vcpu_sbi.c                     |  67 ++++++
 arch/riscv/kvm/vcpu_sbi_sta.c                 | 208 ++++++++++++++++++
 tools/testing/selftests/kvm/Makefile          |   5 +-
 .../selftests/kvm/include/riscv/processor.h   |  22 ++
 .../selftests/kvm/lib/riscv/processor.c       |  45 ++++
 tools/testing/selftests/kvm/lib/riscv/ucall.c |  26 ---
 .../selftests/kvm/riscv/get-reg-list.c        |  43 ++++
 tools/testing/selftests/kvm/steal_time.c      |  99 +++++++++
 23 files changed, 782 insertions(+), 35 deletions(-)
 create mode 100644 arch/riscv/include/asm/paravirt.h
 create mode 100644 arch/riscv/include/asm/paravirt_api_clock.h
 create mode 100644 arch/riscv/kernel/paravirt.c
 create mode 100644 arch/riscv/kvm/vcpu_sbi_sta.c

Comments

Anup Patel Dec. 20, 2023, 4:11 p.m. UTC | #1 
Hi Palmer,

On Wed, Dec 20, 2023 at 9:30 PM Andrew Jones <ajones@ventanamicro.com> wrote:
>
> One frequently touted benefit of virtualization is the ability to
> consolidate machines, increasing resource utilization.  It may even be
> desirable to overcommit, at the risk of one or more VCPUs having to wait.
> Hypervisors which have interfaces for guests to retrieve the amount of
> time each VCPU had to wait give observers within the guests ways to
> account for less progress than would otherwise be expected. The SBI STA
> extension[1] provides a standard interface for guest VCPUs to retrieve
> the amount of time "stolen".
>
> This series has three parts:
>  1) Patches 01-03 - Add paravirt support to RISC-V and implement
>                     steal-time accounting support using the SBI STA
>                     extension.
>  2) Patches 04-09 - Implement SBI STA in KVM so KVM guests, such as
>                     Linux guests which enable the paravirt steal-time
>                     support, can be enlightened about stolen time.
>  3) Patches 10-13 - Add RISC-V support to the KVM selftests steal_time
>                     test and the SBI extension regs in the get-reg-list
>                     test.
>
> These patches are based on kvm-riscv/riscv_kvm_queue
>
> [1] https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-steal-time.adoc
>
> This patches are also available here
> https://github.com/jones-drew/linux/commits/kvm/steal-time-v4
>
> Changes since v3:
>  - Use work "Computing" instead of "using" in pr_info [Atish]
>  - Rename KVM_REG_RISCV_SBI to KVM_REG_RISCV_SBI_STATE [Atish, Anup]
>  - Picked up r-b's from Atish and Anup
>
> Changes since v2:
>  - Always check sequence in case the SBI impl isn't writing steal
>    atomically [Anup]
>  - Create a reset function for sta and also reset last_steal [Anup]
>  - Picked up Anup's r-b's
>
> Changes since v1:
>  - sbi_sta_steal_time_set_shmem() now maps SBI errors to linux errors [Conor]
>  - Squashed v1 patch 4 into v1 patch 3 [Conor]
>  - Moved kvm_riscv_vcpu_set/get_reg_sbi() to arch/riscv/kvm/vcpu_sbi.c
>    which seems like a more appropriate file for them
>  - Rebased on kvm-riscv/riscv_kvm_queue which has all the dependencies
>
> Changes since RFC:
>  - Rebased on v6.7-rc3 (plus the patches mentioned above)
>  - Added defines for the -1's [Conor]
>  - Added a comment to the steal read sequence [Conor]
>  - Only do the steal read sequence for 32-bit and added READ_ONCE's
>  - Check for SBI v2.0 implementation
>  - Rename set_steal_time_shmem to steal_time_set_shmem
>  - Add get-reg-list support and test with get-reg-list kselftest
>  - A few other minor improvements
>  - Picked up one r-b from Conor
>
> Thanks,
> drew
>
>
> Andrew Jones (13):
>   RISC-V: paravirt: Add skeleton for pv-time support
>   RISC-V: Add SBI STA extension definitions
>   RISC-V: paravirt: Implement steal-time support
>   RISC-V: KVM: Add SBI STA extension skeleton
>   RISC-V: KVM: Add steal-update vcpu request
>   RISC-V: KVM: Add SBI STA info to vcpu_arch
>   RISC-V: KVM: Add support for SBI extension registers
>   RISC-V: KVM: Add support for SBI STA registers
>   RISC-V: KVM: Implement SBI STA extension
>   RISC-V: KVM: selftests: Move sbi_ecall to processor.c
>   RISC-V: KVM: selftests: Add guest_sbi_probe_extension
>   RISC-V: KVM: selftests: Add steal_time test support
>   RISC-V: KVM: selftests: Add get-reg-list test for STA registers

Can you please review and ack the first three patches ?

Regards,
Anup

>
>  .../admin-guide/kernel-parameters.txt         |   6 +-
>  arch/riscv/Kconfig                            |  19 ++
>  arch/riscv/include/asm/kvm_host.h             |  10 +
>  arch/riscv/include/asm/kvm_vcpu_sbi.h         |  10 +
>  arch/riscv/include/asm/paravirt.h             |  28 +++
>  arch/riscv/include/asm/paravirt_api_clock.h   |   1 +
>  arch/riscv/include/asm/sbi.h                  |  17 ++
>  arch/riscv/include/uapi/asm/kvm.h             |  13 ++
>  arch/riscv/kernel/Makefile                    |   1 +
>  arch/riscv/kernel/paravirt.c                  | 134 +++++++++++
>  arch/riscv/kernel/time.c                      |   3 +
>  arch/riscv/kvm/Kconfig                        |   1 +
>  arch/riscv/kvm/Makefile                       |   1 +
>  arch/riscv/kvm/vcpu.c                         |   7 +
>  arch/riscv/kvm/vcpu_onereg.c                  |  51 ++++-
>  arch/riscv/kvm/vcpu_sbi.c                     |  67 ++++++
>  arch/riscv/kvm/vcpu_sbi_sta.c                 | 208 ++++++++++++++++++
>  tools/testing/selftests/kvm/Makefile          |   5 +-
>  .../selftests/kvm/include/riscv/processor.h   |  22 ++
>  .../selftests/kvm/lib/riscv/processor.c       |  45 ++++
>  tools/testing/selftests/kvm/lib/riscv/ucall.c |  26 ---
>  .../selftests/kvm/riscv/get-reg-list.c        |  43 ++++
>  tools/testing/selftests/kvm/steal_time.c      |  99 +++++++++
>  23 files changed, 782 insertions(+), 35 deletions(-)
>  create mode 100644 arch/riscv/include/asm/paravirt.h
>  create mode 100644 arch/riscv/include/asm/paravirt_api_clock.h
>  create mode 100644 arch/riscv/kernel/paravirt.c
>  create mode 100644 arch/riscv/kvm/vcpu_sbi_sta.c
>
> --
> 2.43.0
>
>
> --
> kvm-riscv mailing list
> kvm-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kvm-riscv
Anup Patel Dec. 29, 2023, 6:52 a.m. UTC | #2 
On Wed, Dec 20, 2023 at 9:30 PM Andrew Jones <ajones@ventanamicro.com> wrote:
>
> One frequently touted benefit of virtualization is the ability to
> consolidate machines, increasing resource utilization.  It may even be
> desirable to overcommit, at the risk of one or more VCPUs having to wait.
> Hypervisors which have interfaces for guests to retrieve the amount of
> time each VCPU had to wait give observers within the guests ways to
> account for less progress than would otherwise be expected. The SBI STA
> extension[1] provides a standard interface for guest VCPUs to retrieve
> the amount of time "stolen".
>
> This series has three parts:
>  1) Patches 01-03 - Add paravirt support to RISC-V and implement
>                     steal-time accounting support using the SBI STA
>                     extension.
>  2) Patches 04-09 - Implement SBI STA in KVM so KVM guests, such as
>                     Linux guests which enable the paravirt steal-time
>                     support, can be enlightened about stolen time.
>  3) Patches 10-13 - Add RISC-V support to the KVM selftests steal_time
>                     test and the SBI extension regs in the get-reg-list
>                     test.
>
> These patches are based on kvm-riscv/riscv_kvm_queue
>
> [1] https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-steal-time.adoc
>
> This patches are also available here
> https://github.com/jones-drew/linux/commits/kvm/steal-time-v4
>
> Changes since v3:
>  - Use work "Computing" instead of "using" in pr_info [Atish]
>  - Rename KVM_REG_RISCV_SBI to KVM_REG_RISCV_SBI_STATE [Atish, Anup]
>  - Picked up r-b's from Atish and Anup
>
> Changes since v2:
>  - Always check sequence in case the SBI impl isn't writing steal
>    atomically [Anup]
>  - Create a reset function for sta and also reset last_steal [Anup]
>  - Picked up Anup's r-b's
>
> Changes since v1:
>  - sbi_sta_steal_time_set_shmem() now maps SBI errors to linux errors [Conor]
>  - Squashed v1 patch 4 into v1 patch 3 [Conor]
>  - Moved kvm_riscv_vcpu_set/get_reg_sbi() to arch/riscv/kvm/vcpu_sbi.c
>    which seems like a more appropriate file for them
>  - Rebased on kvm-riscv/riscv_kvm_queue which has all the dependencies
>
> Changes since RFC:
>  - Rebased on v6.7-rc3 (plus the patches mentioned above)
>  - Added defines for the -1's [Conor]
>  - Added a comment to the steal read sequence [Conor]
>  - Only do the steal read sequence for 32-bit and added READ_ONCE's
>  - Check for SBI v2.0 implementation
>  - Rename set_steal_time_shmem to steal_time_set_shmem
>  - Add get-reg-list support and test with get-reg-list kselftest
>  - A few other minor improvements
>  - Picked up one r-b from Conor
>
> Thanks,
> drew
>
>
> Andrew Jones (13):
>   RISC-V: paravirt: Add skeleton for pv-time support
>   RISC-V: Add SBI STA extension definitions
>   RISC-V: paravirt: Implement steal-time support
>   RISC-V: KVM: Add SBI STA extension skeleton
>   RISC-V: KVM: Add steal-update vcpu request
>   RISC-V: KVM: Add SBI STA info to vcpu_arch
>   RISC-V: KVM: Add support for SBI extension registers
>   RISC-V: KVM: Add support for SBI STA registers
>   RISC-V: KVM: Implement SBI STA extension
>   RISC-V: KVM: selftests: Move sbi_ecall to processor.c
>   RISC-V: KVM: selftests: Add guest_sbi_probe_extension
>   RISC-V: KVM: selftests: Add steal_time test support
>   RISC-V: KVM: selftests: Add get-reg-list test for STA registers

Queued this series for Linux-6.8

Thanks,
Anup

>
>  .../admin-guide/kernel-parameters.txt         |   6 +-
>  arch/riscv/Kconfig                            |  19 ++
>  arch/riscv/include/asm/kvm_host.h             |  10 +
>  arch/riscv/include/asm/kvm_vcpu_sbi.h         |  10 +
>  arch/riscv/include/asm/paravirt.h             |  28 +++
>  arch/riscv/include/asm/paravirt_api_clock.h   |   1 +
>  arch/riscv/include/asm/sbi.h                  |  17 ++
>  arch/riscv/include/uapi/asm/kvm.h             |  13 ++
>  arch/riscv/kernel/Makefile                    |   1 +
>  arch/riscv/kernel/paravirt.c                  | 134 +++++++++++
>  arch/riscv/kernel/time.c                      |   3 +
>  arch/riscv/kvm/Kconfig                        |   1 +
>  arch/riscv/kvm/Makefile                       |   1 +
>  arch/riscv/kvm/vcpu.c                         |   7 +
>  arch/riscv/kvm/vcpu_onereg.c                  |  51 ++++-
>  arch/riscv/kvm/vcpu_sbi.c                     |  67 ++++++
>  arch/riscv/kvm/vcpu_sbi_sta.c                 | 208 ++++++++++++++++++
>  tools/testing/selftests/kvm/Makefile          |   5 +-
>  .../selftests/kvm/include/riscv/processor.h   |  22 ++
>  .../selftests/kvm/lib/riscv/processor.c       |  45 ++++
>  tools/testing/selftests/kvm/lib/riscv/ucall.c |  26 ---
>  .../selftests/kvm/riscv/get-reg-list.c        |  43 ++++
>  tools/testing/selftests/kvm/steal_time.c      |  99 +++++++++
>  23 files changed, 782 insertions(+), 35 deletions(-)
>  create mode 100644 arch/riscv/include/asm/paravirt.h
>  create mode 100644 arch/riscv/include/asm/paravirt_api_clock.h
>  create mode 100644 arch/riscv/kernel/paravirt.c
>  create mode 100644 arch/riscv/kvm/vcpu_sbi_sta.c
>
> --
> 2.43.0
>
patchwork-bot+linux-riscv@kernel.org Jan. 20, 2024, 9:09 p.m. UTC | #3 
Hello:

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

On Wed, 20 Dec 2023 17:00:13 +0100 you wrote:
> One frequently touted benefit of virtualization is the ability to
> consolidate machines, increasing resource utilization.  It may even be
> desirable to overcommit, at the risk of one or more VCPUs having to wait.
> Hypervisors which have interfaces for guests to retrieve the amount of
> time each VCPU had to wait give observers within the guests ways to
> account for less progress than would otherwise be expected. The SBI STA
> extension[1] provides a standard interface for guest VCPUs to retrieve
> the amount of time "stolen".
> 
> [...]

Here is the summary with links:
  - [v4,01/13] RISC-V: paravirt: Add skeleton for pv-time support
    (no matching commit)
  - [v4,02/13] RISC-V: Add SBI STA extension definitions
    https://git.kernel.org/riscv/c/6cfc624576a6
  - [v4,03/13] RISC-V: paravirt: Implement steal-time support
    (no matching commit)
  - [v4,04/13] RISC-V: KVM: Add SBI STA extension skeleton
    (no matching commit)
  - [v4,05/13] RISC-V: KVM: Add steal-update vcpu request
    (no matching commit)
  - [v4,06/13] RISC-V: KVM: Add SBI STA info to vcpu_arch
    (no matching commit)
  - [v4,07/13] RISC-V: KVM: Add support for SBI extension registers
    (no matching commit)
  - [v4,08/13] RISC-V: KVM: Add support for SBI STA registers
    (no matching commit)
  - [v4,09/13] RISC-V: KVM: Implement SBI STA extension
    (no matching commit)
  - [v4,10/13] RISC-V: KVM: selftests: Move sbi_ecall to processor.c
    (no matching commit)
  - [v4,11/13] RISC-V: KVM: selftests: Add guest_sbi_probe_extension
    (no matching commit)
  - [v4,12/13] RISC-V: KVM: selftests: Add steal_time test support
    (no matching commit)
  - [v4,13/13] RISC-V: KVM: selftests: Add get-reg-list test for STA registers
    (no matching commit)

You are awesome, thank you!