On Wed, Sep 04, 2019 at 02:01:18PM +0800, Xiaoyao Li wrote: > Userspace can use ioctl KVM_SET_MSRS to update a set of MSRs of guest. > This ioctl sets specified MSRs one by one. Once it fails to set an MSR > due to setting reserved bits, the MSR is not supported/emulated by kvm, > or violating other restrictions, it stops further processing and returns > the number of MSRs have been set successfully. > > Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> > --- > v2: > 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..4638e893dec0 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. Once failing to Probably better to say 'If' as opposed to 'Once', don't want to imply that userspace is incompetent :) > +set an MSR (due to setting reserved bits, the MSR is not supported/emulated > +by kvm, or violating other restrctions), Make it clear the list is not exhaustive, e.g.: 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. > it stops setting following MSRs > +and returns the number of MSRs have been set successfully. > + > > 4.20 KVM_SET_CPUID > > -- > 2.19.1 >
