similar to: [PATCH hmm 0/5] Adjust hmm_range_fault() API

From: Jason Gunthorpe <jgg at mellanox.com> The API is a bit complicated for the uses we actually have, and disucssions for simplifying have come up a number of times. This small series removes the customizable pfn format and simplifies the return code of hmm_range_fault() All the drivers are adjusted to process in the simplified format. I would appreciated tested-by's for the two

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

When acting on device private mappings a driver needs to know if the device (or other entity in case of kvmppc) actually owns this private mapping. This series adds an owner field and converts the migrate_vma code over to check it. I looked into doing the same for hmm_range_fault, but as far as I can tell that code has never been wired up to actually work for device private memory, so instead of

When acting on device private mappings a driver needs to know if the device (or other entity in case of kvmppc) actually owns this private mapping. This series adds an owner field and converts the migrate_vma code over to check it. I looked into doing the same for hmm_range_fault, but as far as I can tell that code has never been wired up to actually work for device private memory, so instead of

From: Jason Gunthorpe <jgg at mellanox.com> Presumably the intent here was that hmm_range_fault() could put the data into some HW specific format and thus avoid some work. However, nothing actually does that, and it isn't clear how anything actually could do that as hmm_range_fault() provides CPU addresses which must be DMA mapped. Perhaps there is some special HW that does not need

From: Jason Gunthorpe <jgg at mellanox.com> Presumably the intent here was that hmm_range_fault() could put the data into some HW specific format and thus avoid some work. However, nothing actually does that, and it isn't clear how anything actually could do that as hmm_range_fault() provides CPU addresses which must be DMA mapped. Perhaps there is some special HW that does not need

[+Philip Yang] Am 2020-04-21 um 8:21 p.m. schrieb Jason Gunthorpe: > From: Jason Gunthorpe <jgg at mellanox.com> > > Presumably the intent here was that hmm_range_fault() could put the data > into some HW specific format and thus avoid some work. However, nothing > actually does that, and it isn't clear how anything actually could do that > as hmm_range_fault()

Hi Jérôme, Ben, Felxi and Jason, below is a series against the hmm tree which cleans up various minor bits and allows HMM_MIRROR to be built on all architectures. Diffstat: 7 files changed, 81 insertions(+), 171 deletions(-) A git tree is also available at: git://git.infradead.org/users/hch/misc.git hmm-cleanups Gitweb:

Hi Jérôme, Ben, Felix and Jason, below is a series against the hmm tree which cleans up various minor bits and allows HMM_MIRROR to be built on all architectures. Diffstat: 11 files changed, 94 insertions(+), 210 deletions(-) A git tree is also available at: git://git.infradead.org/users/hch/misc.git hmm-cleanups.2 Gitweb:

hmm_range_fault() returns an array of page frame numbers and flags for how the pages are mapped in the requested process' page tables. The PFN can be used to get the struct page with hmm_pfn_to_page() and the page size order can be determined with compound_order(page) but if the page is larger than order 0 (PAGE_SIZE), there is no indication that the page is mapped using a larger page size. To

From: Yonatan Maman <Ymaman at Nvidia.com> This patch series aims to enable Peer-to-Peer (P2P) DMA access in GPU-centric applications that utilize RDMA and private device pages. This enhancement is crucial for minimizing data transfer overhead by allowing the GPU to directly expose device private page data to devices such as NICs, eliminating the need to traverse system RAM, which is the

On 2020-05-01 11:20, Jason Gunthorpe wrote: > From: Jason Gunthorpe <jgg at mellanox.com> > > Presumably the intent here was that hmm_range_fault() could put the data > into some HW specific format and thus avoid some work. However, nothing > actually does that, and it isn't clear how anything actually could do that > as hmm_range_fault() provides CPU addresses which

On 3/16/20 10:52 AM, Christoph Hellwig wrote: > No driver has actually used properly wire up and support this feature. > There is various code related to it in nouveau, but as far as I can tell > it never actually got turned on, and the only changes since the initial > commit are global cleanups. This is not actually true. OpenCL 2.x does support SVM with nouveau and device private

Here are seven more patches for things I found to clean up. This was based on top of Christoph's seven patches: "hmm_range_fault related fixes and legacy API removal v3". I assume this will go into Jason's tree since there will likely be more HMM changes in this cycle. Changes from v1 to v2: Added AMD GPU to hmm_update removal. Added 2 patches from Christoph. Added 2 patches as

On 3/17/20 5:59 AM, Christoph Hellwig wrote: > On Tue, Mar 17, 2020 at 09:47:55AM -0300, Jason Gunthorpe wrote: >> I've been using v7 of Ralph's tester and it is working well - it has >> DEVICE_PRIVATE support so I think it can test this flow too. Ralph are >> you able? >> >> This hunk seems trivial enough to me, can we include it now? > > I can send

On Tue, Apr 21, 2020 at 09:21:46PM -0300, Jason Gunthorpe wrote: > +void nouveau_hmm_convert_pfn(struct nouveau_drm *drm, struct hmm_range *range, > + u64 *ioctl_addr) > { > unsigned long i, npages; > > + /* > + * The ioctl_addr prepared here is passed through nvif_object_ioctl() > + * to an eventual DMA map on some call chain like: > + *

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

hmm_range_fault() returns an array of page frame numbers and flags for how the pages are mapped in the requested process' page tables. The PFN can be used to get the struct page with hmm_pfn_to_page() and the page size order can be determined with compound_order(page) but if the page is larger than order 0 (PAGE_SIZE), there is no indication that a compound page is mapped by the CPU using a

These changes are based on Jason's latest hmm branch. Patch 1 was previously posted here [1] but was dropped from the orginal series. Hopefully, the tests will reduce concerns about edge conditions. I'm sure more tests could be usefully added but I thought this was a good starting point. [1] https://lore.kernel.org/linux-mm/20190726005650.2566-6-rcampbell at nvidia.com/ Ralph Campbell