Re: [PATCH RFC 04/15] KVM: Implement ring-based dirty memory tracking

Paolo Bonzini
2019-12-17T16:29:03Z

On 17/12/19 17:24, Peter Xu wrote:
>> No, please pass it all the way down to the [&] functions but not to
>> kvm_write_guest_page. Those should keep using vcpu->kvm.
> Actually I even wanted to refactor these helpers. I mean, we have two
> sets of helpers now, kvm_[vcpu]_{read|write}*(), so one set is per-vm,
> the other set is per-vcpu. IIUC the only difference of these two are
> whether we should consider ((vcpu)->arch.hflags & HF_SMM_MASK) or we
> just write to address space zero always.

Right.

> Could we unify them into a
> single set of helper (I'll just drop the *_vcpu_* helpers because it's
> longer when write) but we always pass in vcpu* as the first parameter?
> Then we add another parameter "vcpu_smm" to show whether we want to
> consider the HF_SMM_MASK flag.

You'd have to check through all KVM implementations whether you always
have the vCPU. Also non-x86 doesn't have address spaces, and by the
time you add ", true" or ", false" it's longer than the "_vcpu_" you
have removed. So, not a good idea in my opinion. :D

Paolo