[PATCH v4 4/4] KVM: Add documentation for KVM_ARM_PREFERRED_TARGET ioctl

Christoffer Dall christoffer.dall at linaro.org
Wed Sep 25 16:10:59 EDT 2013


On Wed, Sep 25, 2013 at 02:56:03PM +0530, Anup Patel wrote:
> To implement CPU=Host we have added KVM_ARM_PREFERRED_TARGET
> vm ioctl which provides information to user space required for
> creating VCPU matching underlying Host.
> 
> This patch adds info related to this new KVM_ARM_PREFERRED_TARGET
> vm ioctl in the KVM API documentation.
> 
> Signed-off-by: Anup Patel <anup.patel at linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
> ---
>  Documentation/virtual/kvm/api.txt |   27 +++++++++++++++++++++++----
>  1 file changed, 23 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index 858aecf..f31e6e8 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -2303,8 +2303,28 @@ Possible features:
>  	- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
>  	  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
>  
> +4.83 KVM_ARM_PREFERRED_TARGET
>  
> -4.83 KVM_GET_REG_LIST

I think the convention here is to keep two new lines after a Section.

> +Capability: basic
> +Architectures: arm, arm64
> +Type: vm ioctl
> +Parameters: struct struct kvm_vcpu_init (out)
> +Returns: 0 on success; -1 on error
> +Errors:
> +  ENODEV:    no preferred target available for the host
> +
> +This queries KVM for preferred CPU target type which can be emulated
> +by KVM on underlying host.
> +
> +The ioctl returns struct kvm_vcpu_init instance containing information
> +about preferred CPU target type and target specific features available
> +for it.
> +
> +The information returned by this ioctl can be used to prepare instance

an instance

> +of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result

the KVM_ARM_VCPU_INIT ioctl.
(the last part is not necessarily true is it?  It's only a best bet,
think for example about Big.Little...)

> +in VCPU matching underlying host.

You also need to add something about the features here:

The kvm_vcpu_init->features bitmap will have feature bits set if the
preferred target recommends setting these features, but this is not
required.

> +
> +4.84 KVM_GET_REG_LIST
>  
>  Capability: basic
>  Architectures: arm, arm64
> @@ -2323,8 +2343,7 @@ struct kvm_reg_list {
>  This ioctl returns the guest registers that are supported for the
>  KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
>  
> -
> -4.84 KVM_ARM_SET_DEVICE_ADDR
> +4.85 KVM_ARM_SET_DEVICE_ADDR
>  
>  Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
>  Architectures: arm, arm64
> @@ -2362,7 +2381,7 @@ must be called after calling KVM_CREATE_IRQCHIP, but before calling
>  KVM_RUN on any of the VCPUs.  Calling this ioctl twice for any of the
>  base addresses will return -EEXIST.
>  
> -4.85 KVM_PPC_RTAS_DEFINE_TOKEN
> +4.86 KVM_PPC_RTAS_DEFINE_TOKEN
>  
>  Capability: KVM_CAP_PPC_RTAS
>  Architectures: ppc
> -- 
> 1.7.9.5
> 



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