Re: [PATCH v3] doc: kvm: Fix return description of KVM_SET_MSRS
From: Paolo Bonzini
Date: Tue Sep 10 2019 - 13:14:12 EST
On 05/09/19 02:57, Xiaoyao Li wrote:
> Userspace can use ioctl KVM_SET_MSRS to update a set of MSRs of guest.
> This ioctl set specified MSRs one by one. If it fails to set an MSR,
> e.g., due to setting reserved bits, the MSR is not supported/emulated by
> KVM, etc..., it stops processing the MSR list and returns the number of
> MSRs have been set successfully.
> Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
> refine the description based on Sean's comment.
> elaborate the changelog and description of ioctl KVM_SET_MSRS based on
> Sean's comments.
> Documentation/virt/kvm/api.txt | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
> diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
> index 2d067767b617..24541e52e96e 100644
> --- a/Documentation/virt/kvm/api.txt
> +++ b/Documentation/virt/kvm/api.txt
> @@ -586,7 +586,7 @@ Capability: basic
> Architectures: x86
> Type: vcpu ioctl
> Parameters: struct kvm_msrs (in)
> -Returns: 0 on success, -1 on error
> +Returns: number of msrs successfully set (see below), -1 on error
> Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the
> data structures.
> @@ -595,6 +595,11 @@ Application code should set the 'nmsrs' member (which indicates the
> size of the entries array), and the 'index' and 'data' members of each
> array entry.
> +It tries to set the MSRs in array entries one by one. If setting an MSR
> +fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated
> +by KVM, etc..., it stops processing the MSR list and returns the number of
> +MSRs that have been set successfully.
> 4.20 KVM_SET_CPUID