On Thu, Feb 23, 2023 at 2:03 AM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > On Thu, 23 Feb 2023 03:58:47 +0000, > Yu Zhao <yuzhao@xxxxxxxxxx> wrote: > > > > On Fri, Feb 17, 2023 at 2:00 AM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > > > > > On Fri, 17 Feb 2023 04:21:28 +0000, > > > Yu Zhao <yuzhao@xxxxxxxxxx> wrote: > > > > > > > > On Thu, Feb 16, 2023 at 9:12 PM Yu Zhao <yuzhao@xxxxxxxxxx> wrote: > > > > > > > > > > This patch adds kvm_arch_test_clear_young() for the vast majority of > > > > > VMs that are not pKVM and run on hardware that sets the accessed bit > > > > > in KVM page tables. > > > > > > I'm really interested in how you can back this statement. 90% of the > > > HW I have access to is not FEAT_HWAFDB capable, either because it > > > predates the feature or because the feature is too buggy to be useful. > > > > This is my expericen too -- most devices are pre v8.2. > > And yet you have no issue writing the above. Puzzling. That's best to my knowledge. Mind enlightening me? > > > Do you have numbers? > > > > Let's do a quick market survey by segment. The following only applies > > to ARM CPUs: > > > > 1. Phones: none of the major Android phone vendors sell phones running > > VMs; no other major Linux phone vendors. > > Maybe you should have a reality check and look at what your own > employer is shipping. Which model? I'll look it up and see how/how I missed it. > > 2. Laptops: only a very limited number of Chromebooks run VMs, namely > > ACRVM. No other major Linux laptop vendors. > > Again, your employer disagree. What do you mean? Sorry, I'm a little surprised here... I do know *a lot* about Chromebooks. > > 3. Desktops: no major Linux desktop vendors. > > My desktop disagree (I send this from my arm64 desktop VM ). A model number please? > > 4. Embedded/IoT/Router: no major Linux vendors run VMs (Android Auto > > can be a VM guest on QNX host). > > This email is brought to you via a router VM on an arm64 box. More details? > > 5. Cloud: this is where the vast majority VMs come from. Among the > > vendors available to the general public, Ampere is the biggest player. > > Here [1] is a list of its customers. The A-bit works well even on its > > EVT products (Neoverse cores). > > Just the phone stuff dwarfs the number of cloud hosts. Please point me to something that I can work on so that I wouldn't sound so ignorant next time.