On Fri, Mar 06, 2020 at 01:56:55AM +0800, Luwei Kang wrote: > From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> > > The PEBS event created by host needs to be assigned specific counters > requested by the guest, which means the guest and host counter indexes > have to be the same or fail to create. This is needed because PEBS leaks > counter indexes into the guest. Otherwise, the guest driver will be > confused by the counter indexes in the status field of the PEBS record. > > A guest_dedicated_idx field is added to indicate the counter index > specifically requested by KVM. The dedicated event constraints would > constrain the counter in the host to the same numbered counter in guest. > > A intel_ctrl_guest_dedicated_mask field is added to indicate the enabled > counters for guest PEBS events. The IA32_PEBS_ENABLE MSR will be switched > during the VMX transitions if intel_ctrl_guest_owned is set. > > + /* the guest specified counter index of KVM owned event, e.g PEBS */ > + int guest_dedicated_idx; We've always objected to guest 'owned' counters, they destroy scheduling freedom. Why are you expecting that to be any different this time?
