search for: mmap_read_lock

...where the zero page came from? > > The zero page comes from an anonymous private VMA that is read-only > and the user level CPU process tries to read the page data (or any > other read page fault). > > > Jason > > > > The overall migration process is: > > mmap_read_lock() > > migrate_vma_setup() > // invalidates range, locks/isolates pages, puts migration entry in page table > > <driver allocates destination pages and copies source to dest> > > migrate_vma_pages() > // moves source struct page info to destination struct...

On Thu, Jul 23, 2020 at 03:30:04PM -0700, Ralph Campbell wrote: > When migrating the special zero page, migrate_vma_pages() calls > mmu_notifier_invalidate_range_start() before replacing the zero page > PFN in the CPU page tables. This is unnecessary since the range was > invalidated in migrate_vma_setup() and the page table entry is checked > to be sure it hasn't changed

...b_update(struct vhost_vdpa *v, > gup_flags |= FOLL_WRITE; > > npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT; > - if (!npages) > - return -EINVAL; > + if (!npages) { > + ret = -EINVAL; > + goto free_page; > + } > > mmap_read_lock(dev->mm); > > @@ -666,6 +668,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v, > atomic64_sub(npages, &dev->mm->pinned_vm); > } > mmap_read_unlock(dev->mm); > + > +free_page: > free_page((unsigned long)page_list); > r...

...t that case? > > I'm also not sure I follow where the zero page came from? The zero page comes from an anonymous private VMA that is read-only and the user level CPU process tries to read the page data (or any other read page fault). > Jason > The overall migration process is: mmap_read_lock() migrate_vma_setup() // invalidates range, locks/isolates pages, puts migration entry in page table <driver allocates destination pages and copies source to dest> migrate_vma_pages() // moves source struct page info to destination struct page info. // clears migration...

...return -EINVAL; > > - page_list = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); > - vmas = kvmalloc_array(npages, sizeof(struct vm_area_struct *), > - GFP_KERNEL); > - if (!page_list || !vmas) { > - ret = -ENOMEM; > - goto free; > - } > - > mmap_read_lock(dev->mm); > > + locked = atomic64_add_return(npages, &dev->mm->pinned_vm); > lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; > - if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { > - ret = -ENOMEM; > - goto unlock; > - }...

...otlb_update(struct vhost_vdpa *v, if (!npages) return -EINVAL; + page_list = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + vmas = kvmalloc_array(npages, sizeof(struct vm_area_struct *), + GFP_KERNEL); + if (!page_list || !vmas) { + ret = -ENOMEM; + goto free; + } + mmap_read_lock(dev->mm); - locked = atomic64_add_return(npages, &dev->mm->pinned_vm); lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - - if (locked > lock_limit) { + if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { ret = -ENOMEM; - goto out; + goto un...

...otlb_update(struct vhost_vdpa *v, if (!npages) return -EINVAL; + page_list = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + vmas = kvmalloc_array(npages, sizeof(struct vm_area_struct *), + GFP_KERNEL); + if (!page_list || !vmas) { + ret = -ENOMEM; + goto free; + } + mmap_read_lock(dev->mm); - locked = atomic64_add_return(npages, &dev->mm->pinned_vm); lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - - if (locked > lock_limit) { + if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { ret = -ENOMEM; - goto out; + goto un...

...); - continue; - } - - /* Intersect fault window with the CPU VMA, cancelling - * the fault if the address is invalid. + /* + * Prepare the GPU-side update of all pages within the + * fault window, determining required pages and access + * permissions based on pending faults. */ - mmap_read_lock(mm); - vma = find_vma_intersection(mm, start, limit); - if (!vma) { - SVMM_ERR(svmm, "wndw %016llx-%016llx", start, limit); - mmap_read_unlock(mm); - mmput(mm); - nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]); - continue; + args.i.p.addr = start; + args.i.p.page...

...); - continue; - } - - /* Intersect fault window with the CPU VMA, cancelling - * the fault if the address is invalid. + /* + * Prepare the GPU-side update of all pages within the + * fault window, determining required pages and access + * permissions based on pending faults. */ - mmap_read_lock(mm); - vma = find_vma_intersection(mm, start, limit); - if (!vma) { - SVMM_ERR(svmm, "wndw %016llx-%016llx", start, limit); - mmap_read_unlock(mm); - mmput(mm); - nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]); - continue; + args.i.p.addr = start; + args.i.p.page...

...ro(mm)) return -EINVAL; + src_pfns = kmalloc_array(PTRS_PER_PTE, sizeof(*src_pfns), GFP_KERNEL); + if (!src_pfns) { + ret = -ENOMEM; + goto out_put; + } + dst_pfns = kmalloc_array(PTRS_PER_PTE, sizeof(*dst_pfns), GFP_KERNEL); + if (!dst_pfns) { + ret = -ENOMEM; + goto out_free_src; + } + mmap_read_lock(mm); for (addr = start; addr < end; addr = next) { vma = find_vma(mm, addr); @@ -706,7 +832,7 @@ static int dmirror_migrate(struct dmirror *dmirror, ret = -EINVAL; goto out; } - next = min(end, addr + (ARRAY_SIZE(src_pfns) << PAGE_SHIFT)); + next = min(end, addr + (PTRS_P...

The goal for this series is to introduce the hmm_range_fault() output array flags HMM_PFN_PMD and HMM_PFN_PUD. This allows a device driver to know that a given 4K PFN is actually mapped by the CPU using either a PMD sized or PUD sized CPU page table entry and therefore the device driver can safely map system memory using larger device MMU PTEs. The series is based on 5.8.0-rc3 and is intended for

The goal for this series is to introduce the hmm_pfn_to_map_order() function. This allows a device driver to know that a given 4K PFN is actually mapped by the CPU using a larger sized CPU page table entry and therefore the device driver can safely map system memory using larger device MMU PTEs. The series is based on 5.8.0-rc3 and is intended for Jason Gunthorpe's hmm tree. These were

These patches apply to linux-5.8.0-rc1. Patches 1-3 should probably go into 5.8, the others can be queued for 5.9. Patches 4-6 improve the HMM self tests. Patch 7-8 prepare nouveau for the meat of this series which adds support and testing for compound page mapping of system memory (patches 9-11) and compound page migration to device private memory (patches 12-16). Since these changes are split

This series adds support for transparent huge page migration to migrate_vma_*() and adds nouveau SVM and HMM selftests as consumers. Earlier versions were posted previously [1] and [2]. The patches apply cleanly to the linux-mm 5.10.0-rc2 tree. There are a lot of other THP patches being posted. I don't think there are any semantic conflicts but there may be some merge conflicts depending on

This series adds support for transparent huge page migration to migrate_vma_*() and adds nouveau SVM and HMM selftests as consumers. An earlier version was posted previously [1]. This version now supports splitting a THP midway in the migration process which led to a number of changes. The patches apply cleanly to the current linux-mm tree. Since there are a couple of patches in linux-mm from Dan

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VMs (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