Re: [PATCH V11 14/17] RISC-V: paravirt: pvqspinlock: Add kconfig entry

[Leonardo Bras <leobras@redhat.com>]

On Sun, Sep 10, 2023 at 04:29:08AM -0400, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> Add kconfig entry for paravirt_spinlock, an unfair qspinlock
> virtualization-friendly backend, by halting the virtual CPU rather
> than spinning.
> 
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> ---
>  arch/riscv/Kconfig         | 12 ++++++++++++
>  arch/riscv/kernel/Makefile |  1 +
>  2 files changed, 13 insertions(+)
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 4bcff2860f48..ec0da24ed6fb 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -813,6 +813,18 @@ config RELOCATABLE
>  
>            If unsure, say N.
>  
> +config PARAVIRT_SPINLOCKS
> +	bool "Paravirtualization layer for spinlocks"
> +	depends on QUEUED_SPINLOCKS
> +	default y
> +	help
> +	  Paravirtualized spinlocks allow a unfair qspinlock to replace the
> +	  test-set kvm-guest virt spinlock implementation with something
> +	  virtualization-friendly, for example, halt the virtual CPU rather
> +	  than spinning.
> +
> +	  If you are unsure how to answer this question, answer Y.
> +
>  endmenu # "Kernel features"
>  
>  menu "Boot options"
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 671ad85f28f2..114b29234c46 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -103,3 +103,4 @@ obj-$(CONFIG_ARCH_RV64ILP32)	+= compat_signal.o
>  
>  obj-$(CONFIG_64BIT)		+= pi/
>  obj-$(CONFIG_ACPI)		+= acpi.o
> +obj-$(CONFIG_PARAVIRT_SPINLOCKS) += qspinlock_paravirt.o
> -- 
> 2.36.1
> 

LGTM:
Reviewed-by: Leonardo Bras <leobras@redhat.com>

Thanks!
Leo