search for: find_special_pag

On 02/10/19 19:04, Jerome Glisse wrote: > On Wed, Oct 02, 2019 at 06:18:06PM +0200, Paolo Bonzini wrote: >>>> If the mapping of the source VMA changes, mirroring can update the >>>> target VMA via insert_pfn. But what ensures that KVM's MMU notifier >>>> dismantles its own existing page tables (so that they can be recreated >>>> with the new

On 02/10/19 19:04, Jerome Glisse wrote: > On Wed, Oct 02, 2019 at 06:18:06PM +0200, Paolo Bonzini wrote: >>>> If the mapping of the source VMA changes, mirroring can update the >>>> target VMA via insert_pfn. But what ensures that KVM's MMU notifier >>>> dismantles its own existing page tables (so that they can be recreated >>>> with the new

...ill see > > > those pte (inside the process that is mirroring the other process) as > > > special which is the case either because insert_pfn() mark the pte as > > > special or the kvm device driver which control the vm_operation struct > > > set a > > > find_special_page() callback that always return NULL, or the vma has > > > either VM_PFNMAP or VM_MIXEDMAP set (which is the case with > > insert_pfn). > > > > > > So you can keep the existing kvm code unmodified. > > > > Great, thanks. And KVM is already able to handl...

...on_lock); } All that is needed is to make sure that vm_normal_page() will see those pte (inside the process that is mirroring the other process) as special which is the case either because insert_pfn() mark the pte as special or the kvm device driver which control the vm_operation struct set a find_special_page() callback that always return NULL, or the vma has either VM_PFNMAP or VM_MIXEDMAP set (which is the case with insert_pfn). So you can keep the existing kvm code unmodified. Cheers, J?r?me

...an control the > > mmap callback). > > > > So now kernel side you have a vma with a vm_operations_struct under your > > control this means that everything you want to block mm wise from within > > the inspector process can be block through those call- backs > > (find_special_page() specificaly for which you have to return NULL all the > > time). > > > > To mirror target process memory you can use hmm_mirror, when you > > populate the inspector process page table you use insert_pfn() (mmap of > > the kvm device file must mark this vma as PFNMA...

From: Mircea C?rjaliu <mcirjaliu at bitdefender.com> The following two new mm exports are introduced: * mm_remote_map(struct mm_struct *req_mm, unsigned long req_hva, unsigned long map_hva) * mm_remote_unmap(unsigned long map_hva) * mm_remote_reset(void) * rmap_walk_remote(struct page *page, struct rmap_walk_control *rwc) This patch