Linaro-mm-sig June 2026

linaro-mm-sig@lists.linaro.org

123 participants
381 discussions

Pips Game Guide Complete Strategy Tips and Winning Methods Explained

by advanced.finch.jkak＠hidingmail.net

What Pips Game Is About Pips is a modern digital puzzle game that focuses on logic, pattern recognition, and quick decision making. The core idea is to complete tasks or solve challenges by placing or matching elements in a structured environment. Each level increases in difficulty and requires more attention to detail. https://pipsly.io/ Core Appeal of Pips The appeal of Pips comes from its simple start and gradually complex gameplay. Early stages are easy to understand, while later stages demand deeper thinking. This balance makes Pips suitable for both new players and experienced puzzle fans. How to Play Pips Game Basic Gameplay Rules In Pips, the main objective is to interact with puzzle elements and complete specific conditions required by each level. Players must analyze the layout and decide the best moves to achieve the goal in the most efficient way. Step by Step Progression The game usually follows a level based system. Each stage presents a new challenge that builds on previous mechanics. Players progress by solving puzzles correctly and unlocking new stages. Precision and observation are key factors for success. Core Mechanics in Pips Game Pattern Recognition System A major mechanic in Pips is identifying patterns. Players must observe repeating structures and predict outcomes based on visual clues. This helps in solving complex puzzles faster and more accurately. Logic Based Decision Making Every action in Pips requires logical thinking. Random moves often lead to failure or inefficient solutions. Players are encouraged to evaluate all possible outcomes before making a move. Progressive Difficulty Design The difficulty in Pips increases gradually. Early levels focus on teaching basic mechanics, while later levels introduce more complex combinations and constraints. This progression helps maintain engagement over time. Strategies for Winning in Pips Game Careful Planning Before Moves One of the most effective strategies in Pips is planning before acting. Observing the full puzzle layout before making any decision helps avoid mistakes and reduces unnecessary steps. Focus on Efficiency Efficiency is important in Pips. Completing levels with fewer moves or faster decisions often leads to better results. Players should aim to find the most direct solution instead of trial and error approaches. Learning From Repeated Attempts Failure is part of the learning process in Pips. Each attempt provides new information about puzzle structure. By analyzing previous mistakes, players can improve their future performance. Common Mistakes in Pips Game Random Movements Without Strategy A frequent mistake is making random moves without understanding the puzzle. This often leads to confusion and longer completion time. Structured thinking is more effective. Ignoring Visual Clues Pips provides visual hints that guide players toward solutions. Ignoring these clues can make puzzles much harder than intended. Careful observation is essential. Rushing Through Levels Speed without accuracy can reduce success in Pips. Rushing often causes errors that require restarting the level. A balanced approach is recommended for better results. Advanced Tips for Pips Game Mastering Pattern Prediction Advanced players improve by predicting patterns before they fully appear. This skill helps in solving higher difficulty levels with greater consistency. Adapting to New Mechanics Quickly As new mechanics are introduced, flexibility becomes important. Players who adapt quickly to changes in rules or structure perform better in later stages. Combining Multiple Strategies High level gameplay in Pips often requires combining several strategies. Logical analysis, pattern recognition, and efficiency planning must work together for optimal performance. Why Pips Game Attracts Players Simple Yet Deep Gameplay Pips attracts attention because it is easy to start but difficult to master. This combination creates long term interest and encourages repeated play. Rewarding Puzzle Experience Each solved level provides a sense of achievement. The satisfaction of completing complex puzzles motivates continued engagement. Suitable for All Skill Levels Pips is designed for a wide range of players. Beginners can enjoy early levels, while advanced players can challenge themselves with more complex stages. Final Thoughts on Pips Game Long Term Engagement Value Pips offers long term entertainment through its evolving puzzle structure. Continuous updates or level variations can keep the experience fresh and engaging. Skill Development Benefits Playing Pips can help improve logical thinking, pattern recognition, and decision making skills. These benefits extend beyond the game environment. Overall Experience Summary Pips stands out as a thoughtful puzzle game that balances simplicity and depth. Its structured design and increasing challenge levels make it appealing for puzzle enthusiasts who enjoy strategic thinking and problem solving.

2 months, 1 week

Rolling into the Fun: A Guide to the Addictive World of Slope Game

by specific.salmon.rrgs＠hidingmail.net

Ever found yourself in need of a quick, engaging, and surprisingly challenging game that you can jump into anytime, anywhere? Look no further than the captivating world of Slope Game. This seemingly simple title offers a deceptively deep experience, testing your reflexes and spatial awareness in a way that’s both frustrating and incredibly rewarding. If you've never rolled into its vibrant, geometric landscapes, you're in for a treat! https://slopegamefree.com/ Gameplay: Master the Art of the Tilt Playing Slope Game is refreshingly straightforward. Your primary objective is to keep your ball from falling off the edges of the platforms or colliding with red obstacles. The ball is always moving forward, and your only controls are to steer it left or right. Steering: On a desktop, you'll typically use the A and D keys or the left and right arrow keys to shift the ball's direction. On mobile devices, it’s often a touch-and-drag or tilt-to-steer mechanism. The key is subtlety. Small, precise adjustments are far more effective than wild, sweeping movements, which will often send your ball careening off the edge. Speed: The ball constantly gains speed, which is where the real challenge lies. As you progress, the platforms become narrower, the gaps wider, and the red obstacles more frequent. What was a gentle curve at the start becomes a frantic maneuver later on. Obstacles: Keep a keen eye out for the static and sometimes moving red blocks. Touching these spells instant doom. Learning their patterns and anticipating their appearance is crucial for long-term survival. Tips for Rolling Success While it may seem like pure luck at first, there are definite strategies you can employ to improve your high score: Focus on the Path Ahead: Don't just look at where your ball is; always be scanning the screen for what's coming up next. This allows you to plan your turns and avoid sudden surprises. Small Adjustments are Key: Resist the urge to oversteer. Gentle taps or small nudges are almost always more effective than holding down a direction key, especially as your speed increases. Embrace the Center: Whenever possible, try to keep your ball centered on the path. This gives you the most leeway for unexpected obstacles or sudden turns. Learn from Your Fails: Every time you fall, take a moment to understand why. Did you oversteer? Miss an obstacle? Knowing your weaknesses will help you avoid repeating the same mistakes. Practice Makes Perfect: Like any skill-based game, consistent practice is the best way to improve. Your reflexes will sharpen, and your muscle memory for precise steering will develop over time. Conclusion: A Simple Game, Endless Fun Slope Game embodies the beauty of simplicity in game design. It doesn't rely on flashy graphics or complex storylines, but rather on addictive gameplay that challenges your reflexes and keeps you coming back for "just one more run." Whether you have a few minutes to spare or an hour to dedicate, this game offers a rewarding and endlessly replayable experience. So, if you're looking for a fun and engaging way to test your agility, give Slope Game a try – you might just find your new favorite time-waster.

2 months, 1 week

Unlocking the Joy of Spatial Puzzles: A Deep Dive into Block Blast

by yappy.mink.rxln＠hidingmail.net

Feeling the itch for a satisfying puzzle challenge? Look no further than games like Block Blast. These engaging tile-matching experiences offer a delightful blend of strategy and spatial reasoning, perfect for a quick mental workout or a longer, relaxing session. Let's explore how to get the most out of these captivating games. https://blockblasts.io/ Introduction: What is Block Blasting? At its core, a block-blasting game is about clearing a grid by strategically placing various-shaped blocks. Imagine a blend of Tetris and a jigsaw puzzle, where your goal isn't just to complete lines, but to eliminate entire clusters of blocks. The beauty lies in its simplicity: no complex narratives or intricate controls, just pure, unadulterated puzzle-solving fun. Many versions of this game exist, but for this article, we’ll be focusing on a general approach that applies to most variations, including Block Blast itself. Gameplay: The Fundamentals of Cube Clearing The basic premise is straightforward. You're presented with a grid, typically 8x8 or 10x10, and a queue of three randomly generated blocks at the bottom of your screen. Your task is to drag and drop these blocks onto the grid. The magic happens when you form a complete horizontal or vertical line (or sometimes both) with your placed blocks. Once a line is complete, it disappears, freeing up space and earning you points. The challenge intensifies as the grid fills up. If you run out of space to place any of the three available blocks, the game ends. This creates a constant tension and encourages careful planning. Some games also feature special blocks – perhaps a bomb that clears a small area, or a rotating block that offers more placement options. These additions add another layer of strategic depth, keeping the gameplay fresh and exciting. Tips for Becoming a Block Blast Champion While Block Blast is easy to pick up, mastering it requires a bit of strategy. Here are a few tips to help you maximize your scores and playtime: Look Ahead: Always consider the next few blocks in your queue. Don't just place a block to clear one line if it compromises your ability to place subsequent, larger blocks. Keep the Center Clear: It's tempting to fill up the edges first, but an open center gives you far more flexibility for larger, irregularly shaped blocks. Prioritize Large Blocks: While clearing single lines is good, try to set up opportunities to clear multiple lines simultaneously, or to use your larger blocks effectively. Don't Be Afraid to Sacrifice: Sometimes, you might need to place a block in a less-than-ideal spot to avoid an immediate game over. It's about damage control. Identify Patterns: As you play more, you'll start to recognize common block combinations and how they fit together best. Practice truly makes perfect here. Utilize Special Blocks Wisely: If your game has them, don't just use special blocks impulsively. Save bombs for truly sticky situations, or use rotators to maximize space. Conclusion: A Refreshing Puzzle Experience Games like Block Blast offer a genuinely enjoyable and mentally stimulating experience. They're easy to pick up, yet provide endless opportunities for strategic refinement. Whether you're looking to unwind after a long day or sharpen your problem-solving skills, these block-clearing puzzles are a fantastic choice. So, what are you waiting for? Dive in and start blasting those blocks!

2 months, 1 week

MUYERN TRUST HAC KER || Private Digital Security

by priyankaragade6＠gmail.com

If you have lost cryptocurrency to fraud, hacks, or scams, time is critical. The faster you act, the higher the chance of recovery. You do not have to face this alone. Join the thousands of clients who have reclaimed their financial freedom with MUYERN TRUST HACKER. Ready to Start Your Recovery? Contact our specialist team today for a confidential, no-obligation case assessment. What App: [ +1.2.0.2.7.0.3.2.2.3.9 ]

2 months, 1 week

MUYERN TRUST HAC KER || Private Digital Security

by priyankaragade6＠gmail.com

2 months, 1 week

[PATCH] dma-buf: move system_cc_shared heap under separate Kconfig

by Sumit Semwal

From: Arnd Bergmann <arnd(a)arndb.de> While system heap and system_cc_shared heap share a lot of code and hence the same source file, their users have different needs. system heap users need it to be a loadable module, while system_cc_shared heap users don't. Building as a loadable module breaks system_cc_shared heap on powerpc and s390 due to un-exported set_memory_encrypted / set_memory_decrypted functions. Fix these by reorganising code to put the system_cc_shared heap under a new Kconfig symbol, which allows either building both into the kernel, or leave encryption up to the consumers of the system heap. Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module") Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Signed-off-by: Sumit Semwal <sumit.semwal(a)linaro.org> --- drivers/dma-buf/heaps/Kconfig | 8 ++++++++ drivers/dma-buf/heaps/system_heap.c | 16 ++++++++++------ 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index e273fb18feca..a39decdcf067 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -5,6 +5,14 @@ config DMABUF_HEAPS_SYSTEM Choose this option to enable the system dmabuf heap. The system heap is backed by pages from the buddy allocator. If in doubt, say Y. +config DMABUF_HEAPS_CC_SYSTEM + bool "DMA-BUF System Heap for decrypted CoCo VMs" + depends on DMABUF_HEAPS && ARCH_HAS_MEM_ENCRYPT && DMABUF_HEAPS_SYSTEM=y + help + Choose this option to enable the system_cc_shared dmabuf heap. This + allows allocating shared (decrypted) memory for confidential computing + (CoCo) VMs. + config DMABUF_HEAPS_CMA tristate "DMA-BUF CMA Heap" depends on DMABUF_HEAPS && DMA_CMA diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index c92bdec356fc..71d9028cc3df 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -48,6 +48,9 @@ struct dma_heap_attachment { bool cc_shared; }; +#define cc_shared_buffer(b) (IS_ENABLED(CONFIG_DMABUF_HEAPS_CC_SYSTEM) && \ + (b)->cc_shared) + #define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO) #define HIGH_ORDER_GFP (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \ | __GFP_NORETRY) & ~__GFP_RECLAIM) \ @@ -161,7 +164,7 @@ static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attac unsigned long attrs; int ret; - attrs = a->cc_shared ? DMA_ATTR_CC_SHARED : 0; + attrs = cc_shared_buffer(a) ? DMA_ATTR_CC_SHARED : 0; ret = dma_map_sgtable(attachment->dev, table, direction, attrs); if (ret) return ERR_PTR(ret); @@ -233,7 +236,7 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) int i, ret; prot = vma->vm_page_prot; - if (buffer->cc_shared) + if (cc_shared_buffer(buffer)) prot = pgprot_decrypted(prot); for_each_sgtable_sg(table, sg, i) { @@ -282,7 +285,7 @@ static void *system_heap_do_vmap(struct system_heap_buffer *buffer) } prot = PAGE_KERNEL; - if (buffer->cc_shared) + if (cc_shared_buffer(buffer)) prot = pgprot_decrypted(prot); vaddr = vmap(pages, npages, VM_MAP, prot); vfree(pages); @@ -349,7 +352,7 @@ static void system_heap_dma_buf_release(struct dma_buf *dmabuf) * Intentionally leak pages that cannot be re-encrypted * to prevent shared memory from being reused. */ - if (buffer->cc_shared && + if (cc_shared_buffer(buffer) && system_heap_set_page_encrypted(page)) continue; @@ -456,7 +459,7 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap, list_del(&page->lru); } - if (cc_shared) { + if (cc_shared_buffer(buffer)) { for_each_sgtable_sg(table, sg, i) { ret = system_heap_set_page_decrypted(sg_page(sg)); if (ret) @@ -485,7 +488,7 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap, * Intentionally leak pages that cannot be re-encrypted * to prevent shared memory from being reused. */ - if (buffer->cc_shared && + if (cc_shared_buffer(buffer) && system_heap_set_page_encrypted(p)) continue; __free_pages(p, compound_order(p)); @@ -525,6 +528,7 @@ static int __init system_heap_create(void) return PTR_ERR(sys_heap); if (IS_ENABLED(CONFIG_HIGHMEM) || + !IS_ENABLED(CONFIG_DMABUF_HEAPS_CC_SYSTEM) || !cc_platform_has(CC_ATTR_MEM_ENCRYPT)) return 0; -- 2.43.0

2 months, 1 week

Discovering the Blocky Worlds of Eaglercraft

by limited.toad.zjzg＠hidingmail.net

Have you ever felt the urge to build towering castles, explore deep caves, or simply survive a night in a world made entirely of blocks? If you've heard of Minecraft, you know the feeling. But what if you could jump into a similar sandbox experience right from your web browser, with no installation required? Enter Eaglercraft, a fascinating project that brings a familiar block-based adventure to everyone with an internet connection. https://eaglercraftweb.com/ What is Eaglercraft and How Do You Play? At its core, Eaglercraft is an open-source project that emulates the classic Minecraft experience (specifically, older versions like 1.5.2) and runs entirely in a web browser. This means you can play on a school computer, a friend’s laptop, or any device that can open a website, making it incredibly accessible. Getting started is as simple as it sounds: Launch the Game: Navigate to an Eaglercraft website. Choose Your Name: Pick a username for your in-game character. Select a Game Mode: You’ll typically find two main options: Singleplayer: This is your own private world. You can choose between Survival Mode, where you must gather resources and fend off monsters to survive, or Creative Mode, where you have unlimited resources and can fly, allowing you to build anything you can imagine without limits. Multiplayer: This is where you can join servers and play with others. You can team up to build massive cities, compete in mini-games like sky-wars, or join survival servers to brave the world together. Once in the game, the controls are straightforward for anyone who has played a first-person PC game. You use W, A, S, D to move, the mouse to look around, the left mouse button to break blocks or attack, and the right mouse button to place blocks or interact with objects. Tips for a Great First Experience Jumping into a new world can be a bit overwhelming, so here are a few friendly tips to get you started on the right foot: Your First Day is Crucial: If you're in Survival mode, your first priority is to gather wood. Punch a tree to get logs, then use your inventory to craft them into planks. From there, make a crafting table. This table is your key to unlocking all other tools and items. Shelter Before Dark: Nighttime brings monsters. Before the sun sets, use your newly gathered wood or dirt to build a simple shelter. Even a small dirt hut will keep you safe until morning. A bed, crafted from wool and planks, will allow you to skip the night entirely. Explore Multiplayer Servers: The real magic of Eaglercraft often lies in its community. Don't be shy about joining a multiplayer server. You’ll find incredible player-made creations and different game modes you can’t experience in singleplayer. Just remember to be respectful and follow the server’s rules. Don't Be Afraid to Experiment: The beauty of a sandbox game is that there is no right or wrong way to play. Want to spend your time farming? Go for it. Feel like digging straight down to find diamonds? Be careful, but have fun! Let your curiosity guide you. A World of Your Own Making Eaglercraft serves as a wonderful gateway into the world of sandbox games. It captures the essence of creative freedom and survival adventure that has made the genre so beloved, while removing the barrier of installations or powerful hardware. Whether you’re looking to relive some nostalgic moments or trying a block-building game for the very first time, it offers a simple and delightful way to explore, build, and connect with a community of fellow players. So go ahead, load it up, and see what kind of world you can create.

2 months, 1 week

Rediscovering the Simple Joy of Snake Game

by semantic.rooster.guyw＠hidingmail.net

In a world filled with hyper-realistic graphics and complex narratives, there's a timeless charm to be found in the classics. One such gem that continues to captivate players, young and old, is the ubiquitous Snake Game. Its elegant simplicity belies a surprising depth of strategy and a satisfyingly addictive quality. If you've ever found yourself with a few minutes to spare, or just craving a dose of nostalgic fun, understanding how to play or experience this iconic game is a delightful journey. https://snakegame.onl The Basics: A Dance of Pixels and Precision At its core, Snake Game is wonderfully straightforward. You control a "snake" – typically a series of colored blocks – navigating a confined playing field. Your objective is to guide the snake to consume "food" (often represented as a single pixel or fruit) that appears randomly on the screen. Each time your snake eats, it grows longer. The challenge arises from this very growth; the longer your snake becomes, the more difficult it is to maneuver without hitting the boundaries of the playing area or, crucially, hitting your own ever-expanding body. Movement is typically controlled with arrow keys or a simple swipe mechanic on touchscreens. Up, down, left, and right are your only commands, but the timing and foresight with which you use them are paramount. The game progresses in a continuous loop, with your snake constantly moving forward. The moment you collide with a wall or your own tail, it's game over. Your score is usually determined by the number of food items you've consumed. Beyond the Basics: Tips for Becoming a Serpent Savant While the rules are easy to grasp, mastering Snake Game requires a bit of practice and a few strategic insights. The Art of the Open Space: Always try to keep a significant portion of the playing field open, especially in front of your snake. Don't box yourself into corners or create unavoidable dead-ends too early. Think a few moves ahead about where your tail will be. Perimeter Prowling: A common strategy is to keep your snake moving along the outer edges of the playing area. This gives you more room to react and lessens the chance of an unexpected collision with your own body. Controlled Chaos: Sometimes, the food appears in a tricky spot. Don't be afraid to make a quick, daring move to grab it, but always have an escape plan. Rapid changes in direction can be your friend, but only if executed with precision. Embrace the Challenge: As your snake grows, the game inevitably becomes more intense. Embrace this escalating difficulty! It's where the true thrill of the game lies. Don't get discouraged by early "game over" screens; each attempt refines your reflexes and strategic thinking. A Timeless Classic for Everyone Whether you remember it from early mobile phones or are discovering it for the first time on a web browser, the allure of the Snake Game remains potent. Its simple mechanics make it accessible to anyone, while its increasing difficulty offers a continuous challenge. It's a fantastic way to unwind, test your reflexes, and experience the satisfaction of a well-executed plan. So, why not give it a try? You can easily find it online, for instance, at Snake Game, and embark on your own pixelated adventure. You might just find yourself happily lost in the pursuit of the longest snake.

2 months, 1 week

[PATCH v2 0/9] vfio/pci: Add mmap() for DMABUFs

by Matt Evans

Hi all, This series is based on previous RFCs/discussions: Tech topic: https://lore.kernel.org/linux-iommu/20250918214425.2677057-1-amastro@fb.com/ RFCv1: https://lore.kernel.org/all/20260226202211.929005-1-mattev@meta.com/ RFCv2: https://lore.kernel.org/kvm/20260312184613.3710705-1-mattev@meta.com/ The background/rationale is covered in more detail in the RFC cover letters. The TL;DR is: The goal is to enable userspace driver designs that use VFIO to export DMABUFs representing subsets of PCI device BARs, and "vend" those buffers from a primary process to other subordinate processes by fd. These processes then mmap() the buffers and their access to the device is isolated to the exported ranges. This is an improvement on sharing the VFIO device fd to subordinate processes, which would allow unfettered access. This is achieved by enabling mmap() of vfio-pci DMABUFs, passed by fd to subordinate processes. Second, a new ioctl()-based revocation mechanism is added to allow the primary process to forcibly revoke access to previously-shared BAR spans, even if the subordinate processes haven't cleanly exited. (The related topic of safe delegation of iommufd control to the subordinate processes is not addressed here, and is follow-up work.) As well as isolation and revocation, another advantage to accessing a BAR through a VMA backed by a DMABUF is that it's straightforward to mmap() the buffer with access attributes, such as write-combining. Feedback from the RFCs requested that, instead of creating DMABUF-specific vm_ops and .fault paths, to go the whole way and migrate the existing VFIO PCI BAR mmap() to be backed by a DMABUF too, resulting in a common vm_ops and fault handler for mmap()s of both the VFIO device and explicitly-exported DMABUFs. This will help future iommufd emulation of VFIO Type1 peer-to-peer, making it easier to get a DMABUF for a VFIO BAR as a DMA target. mmap() conversion to use DMABUF underneath has been done for vfio-pci, but not sub-drivers: nvgrace-gpu's mmap() override path is unchanged; I kept this out of scope for now not least because I don't have a thorough test setup for this system. I would prefer to help the nvgrace-gpu maintainers enable BAR mmap() DMABUFs themselves. Notes on patches ================ PCI/P2PDMA: Add CONFIG_PCI_P2PDMA_CORE Later in the series, vfio-pci's mmap() is going to depend on pcim_p2pdma_provider() which depended on CONFIG_PCI_P2PDMA, which in turn depended on ZONE_DEVICE (which isn't available on 32-bit and some archs, because they lack MEMORY_HOTPLUG and friends). VFIO does _not_ require actual P2P to be present for basic mmap() functionality, only for the optional CONFIG_DMA_SHARED_BUFFER feature. This splits P2PDMA into a CONFIG_PCI_P2PDMA_CORE (which currently contains pcim_p2pdma_provider()) and an optional CONFIG_PCI_P2PDMA (which depends on ZONE_DEVICE etc., and provides P2P functionality). vfio/pci: Add a helper to look up PFNs for DMABUFs vfio/pci: Add a helper to create a DMABUF for a BAR-map VMA The first is for a DMABUF VMA fault handler to determine arbitrary-sized PFNs from ranges in DMABUF. Secondly, refactor DMABUF export for use by the existing export feature and add a new helper that creates a DMABUF corresponding to a VFIO BAR mmap() request. vfio/pci: Convert BAR mmap() to use a DMABUF The vfio-pci core mmap() creates a DMABUF with the helper, and the vm_ops fault handler uses the other helper to resolve the fault. Because this depends on DMABUF structs/code, CONFIG_VFIO_PCI_CORE needs to depend on CONFIG_DMA_SHARED_BUFFER. The CONFIG_VFIO_PCI_DMABUF still conditionally enables the export support code. NOTE: The user mmap()s a device fd, but the resulting VMA's vm_file becomes that of the DMABUF which takes ownership of the device and puts it on release. This maintains the existing behaviour of a VMA keeping the VFIO device open. BAR zapping then happens via the existing vfio_pci_dma_buf_move() path, which now needs to unmap PTEs in the DMABUF's address_space. vfio/pci: Provide a user-facing name for BAR mappings There was a request for decent debug naming in /proc/<pid>/maps etc. comparable to the existing VFIO names: since the VMAs are DMABUFs, they have a "dmabuf:" prefix and can't be 100% identical to before. This is a user-visible change, but this patch at least now gives us extra info on the BDF & BAR being mapped. vfio/pci: Clean up BAR zap and revocation In general (see NOTE!) the vfio_pci_zap_bars() is now obsolete, since it unmaps PTEs in the VFIO device address_space which is now unused. This consolidates all calls (e.g. around reset) with the neighbouring vfio_pci_dma_buf_move()s into new functions, to revoke-zap/unrevoke. !!! NOTE: the nvgrace-gpu driver continues to use its own private vm_ops, fault handler, etc. for its special memregions, and these DO still add PTEs to the VFIO device address_space. So, a temporary flag, vdev->bar_needs_zap, maintains the old behaviour for this use. At least this patch's consolidation makes it easy to remove the remaining zap when this need goes away; a FIXME reminds that this can be removed when nvgrace-gpu is converted. vfio/pci: Support mmap() of a VFIO DMABUF Adds mmap() for a DMABUF fd exported from vfio-pci. It was a goal to keep the VFIO device fd lifetime behaviour unchanged with respect to the DMABUFs. An application can close all device fds, and this will revoke/clean up all DMABUFs; no mappings or other access can be performed now. When enabling mmap() of the DMABUFs, this means access through the VMA is also revoked. This complicates the fault handler because whilst the DMABUF exists, it has no guarantee that the corresponding VFIO device is still alive. Adds synchronisation ensuring the vdev is available before vdev->memory_lock is touched; this holds the device registration so that even if the buffer has been cleaned up, vdev hasn't been freed and so the lock can be safely taken. (I decided against the alternative of preventing cleanup by holding the VFIO device open if any DMABUFs exist, because it's both a change of behaviour and less clean overall.) I've added a chonky comment in place, happy to clarify more if you have ideas. This commit makes VFIO_PCI_CORE depend on PCI_P2PDMA_CORE (commit 1) to bring in (only) the P2PDMA provider code. vfio/pci: Permanently revoke a DMABUF on request By weight, this is mostly a rename of revoked to an enum, status. There are now 3 states for a buffer, usable and revoked temporary/permanent. A new VFIO device ioctl is added, VFIO_DEVICE_PCI_DMABUF_REVOKE, which passes a DMABUF (exported from that device) and permanently revokes it. Thus a userspace driver can guarantee any downstream consumers of a shared fd are prevented from accessing a BAR range, and that range can be reused. The code doing revocation in vfio_pci_dma_buf_move() is moved, unchanged, to a common function for use by _move() and the new ioctl path. Q: I can't think of a good reason to temporarily revoke/unrevoke buffers from userspace, so didn't add a 'flags' field to the ioctl struct. Easy to add if people think it's worthwhile for future use. vfio/pci: Add mmap() attributes to DMABUF feature Adds a new VFIO feature, VFIO_DEVICE_FEATURE_DMA_BUF_MEMATTR. After a DMABUF is exported, this feature ioctl() isused to set a memory attribute that will be used by future mmap()s of the DMABUF fd (i.e. it does nothing for any existing maps). The default is UC, and via the feature one can specify CPU access as WC. The attribute is an enum/scalar rather than bitmap/cumulative. The attributes follow a "try-fail" model where a client can request an attribute and either succeed or fail with ENOTSUPP if it's unknown; if future attributes are platform-specific then their support can be probed. (Since it's just UC/WC for now, there is no reservation or numeric structure to the namespace yet, but we could support system/arch-specific values in future by carving out base + arch-specific + IMPDEF ranges.) Testing ======= (The [RFC ONLY] userspace test program, for QEMU edu-plus, has been dropped from the series, but can be found in the GitHub branch below. It at least illustrates the export, map, revoke, attribute, and close semantics interoperate.) This code has been tested in mapping DMABUFs of single/multiple ranges, aliasing mmap()s, aliasing ranges across DMABUFs, vm_pgoff > 0, revocation, shutdown/cleanup scenarios, and hugepage mappings seem to work correctly. I've lightly tested WC mappings also (by observing resulting PTEs as having the correct attributes...). No regressions observed on the VFIO selftests, or on our internal vfio-pci applications. End === This is based on VFIO next (e.g. at b9285405c5f6). These commits are on GitHub for easier browsing, along with "[RFC ONLY] selftests: vfio: Add standalone vfio_dmabuf_mmap_test": https://github.com/metamev/linux/compare/b9285405c5f6...metamev:linux:dev/m… Thanks for reading, Matt ================================================================================ Change log: v2: - Rebase on VFIO next, picking up Alex's vfio_pci_dma_buf_move()/vfio_pci_dma_buf_cleanup() fixes, and dropping "vfio/pci: Fix vfio_pci_dma_buf_cleanup() double-put" - Added "PCI/P2PDMA: Add CONFIG_PCI_P2PDMA_CORE" so that the newly-added vfio-pci hard dependency on the P2PDMA provider instead pulls in the _CORE variant and not the full-fat CONFIG_PCI_P2PDMA. This means that the core of vfio-pci does not need ZONE_DEVICE, but if it's available then enabling P2PDMA in turn enables DMABUF export. Fixes basic VFIO operation on 32b or other platforms without ZONE_DEVICE. - Fixed comment inaccuracy in vfio_pci_dma_buf_revoke() and cleaned up vdev validity test. - vfio_pci_dma_buf_find_pfn(): use PAGE_ALIGN(), better span variable naming, OVF check - Made vm_pgoffs use consistent (keeping the resource index at the top and masking where offset is used). For BAR mmap, use new vma_pgoff_adjust to create the DMABUF with the exact mmap()ed span instead of from the start of the BAR with an invisible portion before the mapping. - Added VFIO_DEVICE_FEATURE_DMA_BUF_MEMATTR to set memory attributes, instead of using the export `flags` field. - vfio_pci_ioctl_reset: Moved vfio_pci_zap_revoke_bars() (effectively, vfio_pci_dma_buf_move()) back after D0 transition. Note, if a BAR zap is needed, it's done in this function so now happens after this D0 transition with the _move; it was done before it at the time of the memory_lock taking. - Minimised vfio_pci_dma_buf_mmap() (removed redundant span check), added READ_ONCE for memattr - Misc fixes: comment in DMABUF name generation, removed superfluous READ_ONCE from faulthandler v1: https://lore.kernel.org/kvm/20260416131815.2729131-1-mattev@meta.com/ - Cleanup of the common DMABUF-aware VMA vm_ops fault handler and export code. - Fixed a lot of races, particularly faults racing with DMABUF cleanup (if the VFIO device fds close, for example). - Added nicer human-readable names for VFIO mmap() VMAs RFCv2: Respin based on the feedback/suggestions: https://lore.kernel.org/kvm/20260312184613.3710705-1-mattev@meta.com/ - Transform the existing VFIO BAR mmap path to also use DMABUFs behind the scenes, and then simply share that code for explicitly-mapped DMABUFs. Jason wanted to go that direction to enable iommufd VFIO type 1 emulation to pick up a DMABUF for an IO mapping. - Revoke buffers using a VFIO device fd ioctl RFCv1: https://lore.kernel.org/all/20260226202211.929005-1-mattev@meta.com/ Matt Evans (9): PCI/P2PDMA: Add CONFIG_PCI_P2PDMA_CORE vfio/pci: Add a helper to look up PFNs for DMABUFs vfio/pci: Add a helper to create a DMABUF for a BAR-map VMA vfio/pci: Convert BAR mmap() to use a DMABUF vfio/pci: Provide a user-facing name for BAR mappings vfio/pci: Clean up BAR zap and revocation vfio/pci: Support mmap() of a VFIO DMABUF vfio/pci: Permanently revoke a DMABUF on request vfio/pci: Add mmap() attributes to DMABUF feature drivers/pci/Kconfig | 10 +- drivers/pci/Makefile | 2 +- drivers/pci/p2pdma.c | 16 + drivers/vfio/pci/Kconfig | 4 +- drivers/vfio/pci/Makefile | 3 +- drivers/vfio/pci/nvgrace-gpu/main.c | 5 + drivers/vfio/pci/vfio_pci_config.c | 30 +- drivers/vfio/pci/vfio_pci_core.c | 225 +++++++++--- drivers/vfio/pci/vfio_pci_dmabuf.c | 548 ++++++++++++++++++++++++---- drivers/vfio/pci/vfio_pci_priv.h | 57 ++- include/linux/pci-p2pdma.h | 24 +- include/linux/pci.h | 2 +- include/linux/vfio_pci_core.h | 1 + include/uapi/linux/vfio.h | 57 +++ 14 files changed, 815 insertions(+), 169 deletions(-) -- 2.47.3

2 months, 1 week

[PATCH net-next 0/4] net: devmem: allow rx-buf-size > PAGE_SIZE per binding

by Bobby Eshleman

Every devmem dmabuf binding hands the page_pool PAGE_SIZE niovs today. On NICs that consume one descriptor per netmem, this caps a single RX descriptor at PAGE_SIZE and burns CPU on buffer churn. In this series, we add a bind-time netlink attribute, NETDEV_A_DMABUF_RX_BUF_SIZE, that lets userspace request a larger niov size (power of two >= PAGE_SIZE). Drivers must opt in via queue_mgmt_ops.QCFG_RX_PAGE_SIZE. Selftests use udmabuf, but udmabuf sgtables were previously hardcoded to PAGE_SIZE. This series modifies udmabuf to respect folio sizes in its exported sgtable. The result is that when backing udmabuf with MFD_HUGETLB 2MB pages, the sgtable is populated with 2MB entries, allowing devmem's gen_pool to carve out large (eg. 64K) niovs. Measurements ------------ Setup: kperf devmem RX/TX cuda, 4 flows, 64 MB messages, 60s, dctcp, num-rx-queues=4, dmabuf-rx/tx-size-mb=2048, 10 runs per niov size, mlx5. niov RX dev Gbps RX flow avg Gbps app sys % ----- ---------------- ----------------- ---------------- 4K 300.63 +/- 53.21 75.16 +/- 13.30 54.15 +/- 10.23 16K 321.35 +/- 28.20 80.34 +/- 7.05 41.05 +/- 8.87 32K 347.63 +/- 2.20 86.91 +/- 0.55 44.54 +/- 3.51 64K 332.11 +/- 14.26 83.03 +/- 3.56 35.47 +/- 3.11 RX app sys % drops ~19% from 4K to 64K. kperf support (not yet merged): https://github.com/facebookexperimental/kperf/commit/8837577f920876bce6986e… Signed-off-by: Bobby Eshleman <bobbyeshleman(a)meta.com> --- Bobby Eshleman (4): net: devmem: allow rx-buf-size > PAGE_SIZE per dmabuf binding udmabuf: emit one sg entry per pinned folio selftests/net: ncdevmem: add -b option to set rx-buf-size on bind selftests/net: devmem.py: add check_rx_large_niov Documentation/netlink/specs/netdev.yaml | 8 ++++ drivers/dma-buf/udmabuf.c | 47 ++++++++++++++++--- include/uapi/linux/netdev.h | 1 + net/core/devmem.c | 52 +++++++++++++--------- net/core/devmem.h | 13 ++++-- net/core/netdev-genl-gen.c | 5 ++- net/core/netdev-genl.c | 18 +++++++- tools/include/uapi/linux/netdev.h | 1 + tools/testing/selftests/drivers/net/hw/config | 1 + tools/testing/selftests/drivers/net/hw/devmem.py | 12 ++++- .../testing/selftests/drivers/net/hw/devmem_lib.py | 46 ++++++++++++++++++- tools/testing/selftests/drivers/net/hw/ncdevmem.c | 49 ++++++++++++++++++-- .../testing/selftests/drivers/net/hw/nk_devmem.py | 11 ++++- 13 files changed, 220 insertions(+), 44 deletions(-) --- base-commit: dfcc2ff12925d99e858eaf539eaa4aaaf81fe2a6 change-id: 20260602-tcpdm-large-niovs-56523a3a1077 Best regards, -- Bobby Eshleman <bobbyeshleman(a)meta.com>

2 months, 1 week

← Newer
1
...
32
33
34
35
36
37
38
39
Older →

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

Linaro-mm-sig June 2026