search for: ptep_clear_flush

...switch back to the _start/_end methods unless you rewrite > > the locking. > > > > The difference with _start/_end, is that ->invalidate_range avoids the > > _start callback basically, but to avoid the _start callback safely, it > > has to be called in between the ptep_clear_flush and the set_pte_at > > whenever the pfn changes like during a COW. So it cannot be coalesced > > in a single TLB flush that invalidates all sptes in a range like we > > prefer for performance reasons for example in KVM. It also cannot > > sleep. > > > > In short...

...switch back to the _start/_end methods unless you rewrite > > the locking. > > > > The difference with _start/_end, is that ->invalidate_range avoids the > > _start callback basically, but to avoid the _start callback safely, it > > has to be called in between the ptep_clear_flush and the set_pte_at > > whenever the pfn changes like during a COW. So it cannot be coalesced > > in a single TLB flush that invalidates all sptes in a range like we > > prefer for performance reasons for example in KVM. It also cannot > > sleep. > > > > In short...

...most take a spinlock or trylock_page. So it must switch back to the _start/_end methods unless you rewrite the locking. The difference with _start/_end, is that ->invalidate_range avoids the _start callback basically, but to avoid the _start callback safely, it has to be called in between the ptep_clear_flush and the set_pte_at whenever the pfn changes like during a COW. So it cannot be coalesced in a single TLB flush that invalidates all sptes in a range like we prefer for performance reasons for example in KVM. It also cannot sleep. In short ->invalidate_range must be really fast (it shouldn't...

...most take a spinlock or trylock_page. So it must switch back to the _start/_end methods unless you rewrite the locking. The difference with _start/_end, is that ->invalidate_range avoids the _start callback basically, but to avoid the _start callback safely, it has to be called in between the ptep_clear_flush and the set_pte_at whenever the pfn changes like during a COW. So it cannot be coalesced in a single TLB flush that invalidates all sptes in a range like we prefer for performance reasons for example in KVM. It also cannot sleep. In short ->invalidate_range must be really fast (it shouldn't...

...o the _start/_end methods unless you rewrite >>> the locking. >>> >>> The difference with _start/_end, is that ->invalidate_range avoids the >>> _start callback basically, but to avoid the _start callback safely, it >>> has to be called in between the ptep_clear_flush and the set_pte_at >>> whenever the pfn changes like during a COW. So it cannot be coalesced >>> in a single TLB flush that invalidates all sptes in a range like we >>> prefer for performance reasons for example in KVM. It also cannot >>> sleep. >>> >...

...page. > > So it must switch back to the _start/_end methods unless you rewrite > the locking. > > The difference with _start/_end, is that ->invalidate_range avoids the > _start callback basically, but to avoid the _start callback safely, it > has to be called in between the ptep_clear_flush and the set_pte_at > whenever the pfn changes like during a COW. So it cannot be coalesced > in a single TLB flush that invalidates all sptes in a range like we > prefer for performance reasons for example in KVM. It also cannot > sleep. > > In short ->invalidate_range must be...

On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > + .invalidate_range = vhost_invalidate_range, > +}; > + > void vhost_dev_init(struct vhost_dev *dev, > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > { I also wonder here: when page is write protected then it does not look like

On Wed, Mar 06, 2019 at 02:18:12AM -0500, Jason Wang wrote: > +static const struct mmu_notifier_ops vhost_mmu_notifier_ops = { > + .invalidate_range = vhost_invalidate_range, > +}; > + > void vhost_dev_init(struct vhost_dev *dev, > struct vhost_virtqueue **vqs, int nvqs, int iov_limit) > { I also wonder here: when page is write protected then it does not look like

...d the pte lock */ + if (likely(map_page != NULL)) { + page_remove_rmap(map_page, false); + + /* the zero_page is not anonymous */ + if (!is_zero_pfn(pte_pfn(*ptep))) + dec_mm_counter(map_mm, MM_ANONPAGES); + + /* clear old PTE entry */ + flush_cache_page(map_vma, map_hva, pte_pfn(*ptep)); + ptep_clear_flush_notify(map_vma, map_hva, ptep); + + atomic_inc(&stat_mapped_pte); + } else { + /* fresh PTE or has been cleared before */ + if (likely(pte_none(*ptep))) { + atomic_inc(&stat_empty_pte); + goto out_unlock; + } + + /* a page was faulted in after follow_page() returned NULL */ + if (...

I''m sure everyone has seen the drop of VMI patches for Linux at this point, but just in case, the link is included below. I''ve read this version of the VMI spec and have made my way through most of the patches. While I wasn''t really that impressed with the first spec wrt Xen, the second version seems to be much more palatable. Specifically, the code inlining and

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VM-s (pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits in the shadow page tables (only for the hardware backed ones, eg. Intel's EPT) and receive notifications when events of interest have taken place

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VM-s (pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits in the shadow page tables (only for the hardware backed ones, eg. Intel's EPT) and receive notifications when events of interest have taken place