- Virtio-msg - lists.linaro.org

Legitimate Crypto Recovery Company You Can Trust To Recover Lost Bitcoin and Ethereum.

by raphaelleo894＠gmail.com

Dune Nectar Web Expert assists individuals and organisations in promptly and compassionately recovering misplaced or misappropriated funds. Our team comprises experienced specialists in financial recovery, fraud investigation, and client advocacy, with strong customer ratings on Google Reviews and Trustpilot. Each case is handled urgently, empathetically, and results-oriented. We address cryptocurrency scams, chargeback and payment-recovery disputes, forex and investment frauds, phishing and social-engineering schemes, and other misappropriations. For cryptocurrency matters, we combine blockchain tracing with investigative methods to map fund movements and identify parties. For chargebacks and payment disputes, we review merchant records, processor policies, and transaction timelines to build evidentiary support. For forex and investment fraud, we reconstruct transaction histories, verify counterparties’ regulatory status, and coordinate with compliance experts to seek restitution via legal and administrative channels. Our process is transparent and methodical: intake includes assessment of documents, transaction logs, and communications to determine feasibility and strategy; forensic examinations employ blockchain analytics, bank tracing, and digital forensics; targeted outreach is made to processors, exchanges, and institutions; and, when appropriate, we coordinate with law enforcement, regulators, and external counsel. Clients receive regular updates, defined timelines, and clear explanations of options and probable outcomes. We pursue proactive, pragmatic recovery strategies while openly communicating risks and impediments—jurisdictional limits, counterparty anonymity, and regulatory differences. To address these, we maintain a network of legal partners, compliance advisers, and international contacts to facilitate cross-border cooperation and remedies, including mutual legal assistance, exchange-freeze petitions, and civil recovery proceedings. Engaging Dune Nectar Web Expert provides a partner committed to integrity, transparency, and demonstrable results, with explicit engagement terms, documented action plans, periodic reports, and guidance on legal processes with projected timelines, costs, and expected outcomes. In summary, our objective is to recover clients’ assets through bespoke, transparent, and effective solutions combining forensic technology, regulatory expertise, and proven investigative workflows. To report a case, contact: Email: "Support (@) Dunenectaronlineexpert . Com" W/A: https://wa.link/3gfxoy

1 day, 2 hours

1
0
0 0

Re: [Linaro/virtio-msg-spec] Review v1/v0 (PR #31)

by Bill Mills

Hi All, This email comes from the github PR but I am going to respond here. On 2/23/26 4:45 AM, bertrand-marquis wrote: > Hi Everyone, > > This pull request include a number of fixes or changes to handle the review > comment we got on virtio mailing list. > > Some points are not handled because they need a decision between us first > (following summary was generated by chatgpt): > > Ordering / Out‑of‑Order Feature Discussion > > * Parav Pandit proposes relaxing the strict request/response ordering > because it is too constraining for high‑performance data paths. He > suggests that the bus may need to deliver responses out of > order, and the spec should support that for performance. > * Demi Marie Obenour raises reset and out‑of‑order race risks if ordering > is relaxed. She suggests a generation/stream number or bus‑level reset > semantics to avoid stale or mis‑matched responses. > * Michael S. Tsirkin recommends keeping v1 simple and introducing > performance features via optional feature bits. This aligns with making > relaxed ordering a negotiated capability rather than a > baseline requirement. > I don't think transport level operations (excepting Virtqueue notifications ) have a big impact on performance. Demi seemed to understand our POV once she saw the option for events to go out of band. At least part of the time Parav was looking at virtio-msg NOT as a transport replacement (using existing virtqueue's in shared memory) and instead was looking at it as full virtio over a message channel (like virtio over tcp). Michael seemed to agree that was out of scope for our work and would need to be its own thing. However it is not clear if or when Parav has changed his thinking. > Configuration Generation Optional Feature Discussion > > * Peter Hilber suggests making the SET_CONFIG generation count optional > or dropping it, because Linux drivers assume config writes are not > rejected and do not retry. His rationale is avoiding > incompatibility with existing driver behavior. TL;DR include the generation counter in the message but eliminate the "rejection" of the SET_CONFIG and make it the devices job to coalesce the new value into the config space. virtio-msg has a race condition in config write that virtio-pci and virtio-mmio does not have due to its trap and emulate nature. In virtio-msg a write can race with a device side change to the same word(s). I agree with Peter that we should not expect the individual Linux drivers to respond to this. My initial thought was to do this in the driver side transport but Peter made we realize this is dumb. The transport will not have any extra info. It is better to push this race resolution back to the device. Giving the device the generation count allows the device to know if the driver was modifying the old value or the new value. I fully expect many device side implementations to ignore the generation count and just to take the new value but providing the generation count allows it to be more sophisticated if it wants to be. > > VQ Enabled Flag Discussion > > * Peter Hilber suggests adding an explicit “queue enabled” indication in > SET_VQUEUE (and also reporting it in GET_VQUEUE) so drivers can avoid > an extra GET_VQUEUE round‑trip just to confirm > enablement. This is aimed at reducing overhead in the initialization flow. > Ack > Device Number Size Discussion > > * Parav Pandit argues the 16‑bit device number is too small; he suggests > 32‑bit to cover >64k devices and PCI BDF domain usage. > * Demi Marie Obenour argues device identifiers should be 64‑bit or even > 128‑bit to ensure long‑term uniqueness. > * Peter Hilber highlights that reuse of device numbers after removal can > cause races, and suggests adding a reuse‑limiting policy. He ties this > to the broader question of expanding the device number > space. > 32 or 64 is fine. 128 seems overkill yes? One PCI bus has a limit of 2^64 devices. > EVENT_CONFIG Data Mandatory Discussion > > * Demi Marie Obenour proposes making EVENT_CONFIG always include > configuration data (MUST), to avoid a round trip. If data is mandatory, > she notes that offset/length‑only signaling becomes > unnecessary. NAK. This will prevent simple out of band notification for the EVENT_AVAIL. Demi seemed to want OOB notifications so this seems in contradiction. > * There is a noted contradiction with earlier guidance (Peter Hilber) and > the current spec change ( I already updated the spec to require offset/ > length even when data is omitted, Even this will prevent OOB. The existing mechanisum allow this to be negociated. Any bus that uses OOB can NAK these feature bits to prevent use. > keeping data optional as I think this > makes sense and i am not quite sure we can mandate the data without > breaking compatibility with other transports or existing devices). This > needs a clear decision. > > --------------------------------------------------------------------------- > > > You can view, comment on, or merge this pull request online at: > > https://github.com/Linaro/virtio-msg-spec/pull/31 <https://github.com/ > Linaro/virtio-msg-spec/pull/31> > > > Commit Summary > > * 52ffe64 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/52ffe641810d26860fbdbb45e7437c8df9360f6a> virtio-msg: clarify > device number vs device ID (Peter Hilber) > * 3a70c3a <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/3a70c3ad6a277cf08931a4efb86b3a41fd29eb7b> virtio-msg: fix minor > grammar in device topology (Peter Hilber) > * d677fc8 <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > d677fc8c1717320416460d911143fa243b8f4eb8> virtio-msg: use “transport > revision” consistently (Peter Hilber) > * c0020f1 <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > c0020f12b985b25c66e3afcf348c1b7aaa81fb78> virtio-msg: use active voice > for reserved header bits (Peter Hilber) > * 7eafee2 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/7eafee2d67d847862f6ff7a9a2899fb5b081b217> virtio-msg: drop > duplicate GET_DEVICE_INFO requirement (Peter Hilber) > * 623334c <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/623334cf0ae1c2289d23c3b47bdd7f2cfa801ed7> virtio-msg: clarify > removal handling (Peter Hilber) > * 4c75e07 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/4c75e07c29f4aa2dbdccfcde8c89d7d9953f28f6> virtio-msg: allow > zero devices per bus instance (Peter Hilber) > * 2bbad99 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/2bbad994805f216755ba6abfe3a1b844e41f30aa> virtio-msg: add note > on config vs virtqueue data (Demi Marie Obenour) > * 094111b <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/094111b9d9e019c9cc4e50d31bf1c27ea5c8d3dc> virtio-msg: rename > READY to ADDED in bus device events (Parav Pandit) > * 1e1e817 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/1e1e81778404d596f1216385a8c8945cf6dbdbdc> virtio-msg: clarify > transport feature negotiation (Peter Hilber) > * f50fe3c <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > f50fe3c985bd6061449f7ab50b45a045bbe15aa7> virtio-msg: clarify > generation count reset semantics (Peter Hilber) > * f462169 <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > f462169090b0907b59b14ed0b6ee952c67934df1> virtio-msg: clarify > notification wording (Peter Hilber) > * 2d8c995 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/2d8c9952035cf72331de5b22ea13aacd9b2c5a29> virtio-msg: require > EVENT_USED unless polling (Peter Hilber) > * 4b8c483 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/4b8c483c79709a509a5961309435a941a8e17110> virtio-msg: drop > RESET_VQUEUE-before-reprogramming (Peter Hilber) > * b783fc5 <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > b783fc534d8973167770515d12a5fd22703ba331> virtio-msg: align admin vq > field widths (Peter Hilber) > * 818142e <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/818142ed4c8612645a46ed211a0a172267684d35> virtio-msg: proposal: > clarify echoed fields (Peter Hilber) > * 6ba8c70 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/6ba8c708335f9068c0045f74714f9258b8faf488> virtio-msg: require > clearing FEATURES_OK (Peter Hilber) > * 21aeb49 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/21aeb4982be32a80ea2a4852cef9dae8f552786d> virtio-msg: widen > GET_SHM fields (Peter Hilber) > * 3e007fd <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/3e007fdbc75eadb931c2cb4eaf4954255f51e419> virtio-msg: clarify > EVENT_CONFIG ranges (Peter Hilber) > * f109559 <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > f1095590057baff76976d371a1ecd95357ca3f35> virtio-msg: streamline > DEVICE_NEEDS_RESET text (Peter Hilber) > * 835ef71 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/835ef718e432d7b8df08cf0e25f59f89a0a0bdc6> virtio-msg: scope > msg_id validation (Peter Hilber) > * 07b0d08 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/07b0d08d12c9038d59f07a627dbf408ec7424435> virtio-msg: drop > FEATURES_OK sentence (Peter Hilber) > * ba844e9 <https://github.com/Linaro/virtio-msg-spec/pull/31/commits/ > ba844e93dd1a685fae0d0c04eb216784962a91e1> virtio-msg: note bus-level > errors (Demi Marie Obenour) > * 3c685b6 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/3c685b6d5facca7ff01cce29869893c077153209> virtio-msg: reframe > ordering responses (Demi Marie Obenour) > * 8a529c0 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/8a529c0a6bd261ef0bdda92b1715bfb5e5e8e034> virtio-msg: clarify > virtqueue data path (Demi Marie Obenour) > * 0df8574 <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/0df8574759c0685e802a99c34ef09e0d7cef3af2> virtio-msg: allow > out-of-order events (Demi Marie Obenour) > * 773970f <https://github.com/Linaro/virtio-msg-spec/pull/31/ > commits/773970f939facdba7ba7f2ff70838d0133e6cd58> virtio-msg: use > physical address terminology (Demi Marie Obenour) > > > File Changes > > (1 file <https://github.com/Linaro/virtio-msg-spec/pull/31/files>) > > * *M* transport-msg.tex <https://github.com/Linaro/virtio-msg-spec/ > pull/31/files#diff- > ae43224efc56fefe20a4d5de6f7cfb5ccd94950be1246b6ece5274c6c994e167> (232) > > > Patch Links: > > * https://github.com/Linaro/virtio-msg-spec/pull/31.patch <https:// > github.com/Linaro/virtio-msg-spec/pull/31.patch> > * https://github.com/Linaro/virtio-msg-spec/pull/31.diff <https:// > github.com/Linaro/virtio-msg-spec/pull/31.diff> > > — > Reply to this email directly, view it on GitHub <https://github.com/Linaro/ > virtio-msg-spec/pull/31>, or unsubscribe <https://github.com/notifications/ > unsubscribe-auth/ > AIBXWC5SZFXJ2MVGMCE7AYL4NLD5PAVCNFSM6AAAAACV4PIWDWVHI2DSMVQWIX3LMV43ASLTON2WKOZTHE3TOMRUG42TEMI>. > You are receiving this because your review was requested.Message ID: > <Linaro/virtio-msg-spec/pull/31(a)github.com> >

1 day, 12 hours

2
1
0 0

Virtio Specification comment handling

by Bertrand Marquis

Hi Everyone, I pushed a first pull request to try to handle some of the comments we got on virtio mailing list: https://github.com/Linaro/virtio-msg-spec/pull/31 In my comment i list some of the points for which we will need to have a discussion on thursday to decide how and if we handle them. Please check and add any comments you might have. Cheers Bertrand IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

4 days, 13 hours

1
0
0 0

Hire SAFEGUARD RECOVERY, a Bitcoin recovery specialist, to retrieve stolen or lost coins.

by sophia fourest

Hire SAFEGUARD RECOVERY, a Bitcoin recovery specialist, to retrieve stolen or lost coins. I invested $320,000 in Tether (USDT) on a fraudulent website after falling for a romantic scam. I felt completely helpless and in need of assistance after realizing I had been duped. I started looking for a hacker online and found SAFEGUARD RECOVERY. I had optimism because of his professionalism and knowledge. I'm happy to report that SAFEGUARD RECOVERY successfully recovered my stolen money after working relentlessly to do so! I am immensely appreciative of their help and heartily urge anyone in a comparable circumstance to use their services. I'm grateful Email: safeguardbitcoin(a)consultant.com WhatsApp: +44 7426 168300 Website: https://safeguardbitcoin.wixsite.com/safeguard-bitcoin--1

3 weeks, 5 days

1
0
0 0

Share vs Lend - Vsock memory sharing over virtio-msg-ffa

by Viresh Kumar

Hello, I am trying to get feedback / ideas (specially from the people in --to) before I reach out to LKML. Problem statement: Share memory (dma-buf/dma-heap fd) over VSock (over virtio-msg-ffa). Current status: I have implemented the first version [1]/[2]. The system-heap memory is successfully shared with OPTEE, test setup available here [3]. Workflow: Userspace: open("/dev/dma_heap/system", O_RDWR) + ioctl(heap_fd, DMA_HEAP_IOCTL_ALLOC, &alloc) + sendmsg(sock, &msg, 0) // msg: SCM_VSOCK_SHMEM / VSOCK_SHMEM_TYPE_FFA / VSOCK_SHMEM_SUBOP_OFFER Kernel: vsock_sendmsg_shmem(vsk, msg) | vsk->transport->map_dma_buf(dmabuf) | virtio_transport_map_dma_buf(dmabuf) | dma_buf_attach(dmabuf, dev); // Vsock's underlying device - virtio-msg device + dma_buf_map_attachment_unlocked(dbuf->attach, DMA_BIDIRECTIONAL); | system_heap_map_dma_buf(attach, dir); | dma_map_sgtable(attachment->dev, table, dir, attrs=0); | virtio_msg_dma_map_sg_dev(dev, sgl, nents, dir, attrs); // FFA dma-ops | ffa_dev->ops->mem_ops->memory_share(&args); + vmfdev->send(vmfdev, request, response, &vmfdev->idata); The memory is shared with FFA SHARE type. This doesn't require a custom heap and works with any DMA heap/buf, system heap is just an example here. FFA supports LEND-ing the memory as well and Google needs it. And this is where I am _blocked_ right now and need help. We need to support both SHARE (both sides can access memory) and LEND (Linux doesn't access it any further - unmapped) mechanisms and I am not sure how to move forward. - We can pass the share-type from userspace and that can reach up to vsock / dma-buf (with minor API change to dma_buf_map_attachment_unlocked()) / system-heap. - But after that the standard dma_map_sgtable() call takes only one configurable parameter, `attributes` (which is set to 0 for now by system heap). There is nothing else which I can use to pass the flag to FFA specific DMA OPs. - I thought maybe I can create a new DMA attribute: `DMA_ATTR_MEM_LEND`, which can be passed in the `attr` field and that will work I guess. - But I am not sure if it would be acceptable upstream to add a new attribute for this. - And so I am looking for some ideas. -- viresh [1] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux.git/log/?h=vi… [2] Patches of interest - vsock: Add shared-memory support for virtio and loopback - virtio-msg: ffa: Add device DMA-OPS [3] https://linaro.atlassian.net/wiki/spaces/HVAC/pages/30372528129

4 weeks, 1 day

5
14
0 0

[PATCH v1 0/4] virtio-msg transport layer

by Bill Mills

This series adds the virtio-msg transport layer. The individuals and organizations involved in this effort have had difficulty in using the existing virtio-transports in various situations and desire to add one more transport that performs its transport layer operations by sending and receiving messages. Implementations of virtio-msg will normally be done in multiple layers: * common / device level * bus level The common / device level defines the messages exchanged between the driver and a device. This common part should lead to a common driver holding most of the virtio specifics and can be shared by all virtio-msg bus implementations. The kernel implementation in [3] shows this separation. As with other transport layers, virtio-msg should not require modifications to existing virtio device implementations (virtio-net, virtio-blk etc). The common / device level is the main focus of this version of the patch series. The virtio-msg bus level implements the normal things a bus defines (enumeration, dma operations, etc) but also implements the message send and receive operations. A number of bus implementations are envisioned, some of which will be reusable and general purpose. Other bus implementations might be unique to a given situation, for example only used by a PCIe card and its driver. How much of the bus level should be described in the virtio spec is one item we wish to discuss. This draft takes a middle approach by describing the bus level and defining some standard bus level messages that MAY be used by the bus. It also describes a range of bus messages that are implementation dependent. The standard bus messages are an effort to avoid different bus implementations doing the same thing in different ways for no good reason. However the different environments will require different things. Instead of trying to anticipate all needs and provide something very abstract, we think implementation specific messages will be needed at the bus level. Over time, if we see similar messages across multiple bus implementations, we will move to standardize a bus level message for that. We are working on a few reusable bus implementations: * virtio-msg-ffa based on Arm FF-A interface for use between: * normal world and secure world * host and VM or VM to VM * Can be used w/ or with out a hypervisor * Any Hypervisor that implements FF-A can be used * We have this working with pKVM and Xen * We have this working with Trusty and OP-TEE * virtio-msg-amp for use between heterogenous systems * The main processors and its co-processors on an AMP SOC * Two or more systems connected via PCIe * Minimal requirements: bi-directional interrupts and at least one shared memory area * hvac-demo has 2 demos of this * This is working on two hardware platforms * virtio-msg-loopback for userspace implemented devices * Allows user space to provide devices to its own kernel * This is similar to fuse, cuse or loopback block devices but for virtio * hvac-demo has a demo We also anticipate a few more: * virtio-msg-xen specific to Xen * Usable on any Xen system (including x86 where FF-A does not exist) * Using Xen events and page grants * virtio-msg over admin virtqueues * This allows any virtio-pci device that supports admin virtqueues to also support a virtio-msg bus that supports sub devices * [We are looking for collaborators for this work] Changes since RFC2: Spec Functional: * Made the common message header 8 bytes and added a token for optional use when parallel outstanding requests are possible * Made the 8 byte fields align to 8 byte offsets. This effects the {SET,GET}_VQUEUE messages * Many conformance cases have been tightened. Spec Editorial: * Major restructure to better align with virtio spec * Conformance model now matches other transports * Use C structures to define messages instead of tables * Added a section to describe how responses are matched to requests This includes the use of the new token field * Redefined / better described error handling between transport and bus layers to eliminate the need for the bus to generate fake response messages * Included editorial feedback from RFC2 Eco-system: * Added virtio-msg-loopback demo * Arm has published the first draft of the virtio-msg over FFA spec [6] * virtio-msg over FFA has been demonstrated with both Trusty and OP-TEE secure world * LKML RFC has been sent [7] * QEMU RFC has been sent [8] This is the first non-RFC patch series. The known short comings have been addressed. We ask for review in earnest on this series and thank you for any feedback you can provide. Background info and work in progress implementations: * HVAC project page with intro slides [1] * HVAC demo repo w/ instructions in README.md [2] * Kernel w/ virtio-msg common level and ffa support [3] * QEMU w/ support for one form of virtio-msg-amp [4] * Portable RTOS library w/ one form of virtio-msg-amp [5] In addition to the QEMU system based demos in the hvac-demo repo, we also have two hardware systems running: * AMD x86 + AMD Arm Versal connected via PCIe * ST STM32MP157 A7 Linux using virtio-i2c provided by M4 Zephyr Please note that although the demos work, a few have not been aligned with this version of the spec. [1] https://linaro.atlassian.net/wiki/spaces/HVAC/overview [2] https://github.com/wmamills/hvac-demo [3] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux.git/log/?h=vi… [4] https://github.com/edgarigl/qemu/commits/edgar/virtio-msg-rfc/ [5] https://github.com/arnopo/open-amp/commits/virtio-msg/ [6] https://documentation-service.arm.com/static/68f647791134f773ab3f0a7c [7] https://lore.kernel.org/all/cover.1753865268.git.viresh.kumar@linaro.org/ [8] https://mail.gnu.org/archive/html/qemu-devel/2025-10/msg07438.html Bertrand Marquis (2): virtio-msg: add new command for bus normative virtio-msg: add conformance entries in conformance chapter Bill Mills (2): virtio-msg: Add virtio-msg, a message based virtio transport layer virtio-msg: link virtio-msg content commands.tex | 3 +- conformance.tex | 105 ++- content.tex | 1 + transport-msg.tex | 1640 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 1746 insertions(+), 3 deletions(-) create mode 100644 transport-msg.tex -- 2.34.1

1 month

2
7
0 0

[PATCH v1 0/8] virtio-msg transport layer

by Bill Mills

This series adds the virtio-msg transport layer. The individuals and organizations involved in this effort have had difficulty in using the existing virtio-transports in various situations and desire to add one more transport that performs its transport layer operations by sending and receiving messages. Implementations of virtio-msg will normally be done in multiple layers: * common / device level * bus level The common / device level defines the messages exchanged between the driver and a device. This common part should lead to a common driver holding most of the virtio specifics and can be shared by all virtio-msg bus implementations. The kernel implementation in [3] shows this separation. As with other transport layers, virtio-msg should not require modifications to existing virtio device implementations (virtio-net, virtio-blk etc). The common / device level is the main focus of this version of the patch series. The virtio-msg bus level implements the normal things a bus defines (enumeration, dma operations, etc) but also implements the message send and receive operations. A number of bus implementations are envisioned, some of which will be reusable and general purpose. Other bus implementations might be unique to a given situation, for example only used by a PCIe card and its driver. How much of the bus level should be described in the virtio spec is one item we wish to discuss. This draft takes a middle approach by describing the bus level and defining some standard bus level messages that MAY be used by the bus. It also describes a range of bus messages that are implementation dependent. The standard bus messages are an effort to avoid different bus implementations doing the same thing in different ways for no good reason. However the different environments will require different things. Instead of trying to anticipate all needs and provide something very abstract, we think implementation specific messages will be needed at the bus level. Over time, if we see similar messages across multiple bus implementations, we will move to standardize a bus level message for that. We are working on a few reusable bus implementations: * virtio-msg-ffa based on Arm FF-A interface for use between: * normal world and secure world * host and VM or VM to VM * Can be used w/ or with out a hypervisor * Any Hypervisor that implements FF-A can be used * We have this working with pKVM and Xen * We have this working with Trusty and OP-TEE * virtio-msg-amp for use between heterogenous systems * The main processors and its co-processors on an AMP SOC * Two or more systems connected via PCIe * Minimal requirements: bi-directional interrupts and at least one shared memory area * hvac-demo has 2 demos of this * This is working on two hardware platforms * virtio-msg-loopback for userspace implemented devices * Allows user space to provide devices to its own kernel * This is similar to fuse, cuse or loopback block devices but for virtio * hvac-demo has a demo We also anticipate a few more: * virtio-msg-xen specific to Xen * Usable on any Xen system (including x86 where FF-A does not exist) * Using Xen events and page grants * virtio-msg over admin virtqueues * This allows any virtio-pci device that supports admin virtqueues to also support a virtio-msg bus that supports sub devices * [We are looking for collaborators for this work] Changes since RFC2: Spec Functional: * Made the common message header 8 bytes and added a token for optional use when parallel outstanding requests are possible * Made the 8 byte fields align to 8 byte offsets. This effects the {SET,GET}_VQUEUE messages * Many conformance cases have been tightened. Spec Editorial: * Major restructure to better align with virtio spec * Conformance model now matches other transports * Use C structures to define messages instead of tables * Added a section to describe how responses are matched to requests This includes the use of the new token field * Redefined / better described error handling between transport and bus layers to eliminate the need for the bus to generate fake response messages * Included editorial feedback from RFC2 Eco-system: * Added virtio-msg-loopback demo * Arm has published the first draft of the virtio-msg over FFA spec [6] * virtio-msg over FFA has been demonstrated with both Trusty and OP-TEE secure world * LKML RFC has been sent [7] * QEMU RFC has been sent [8] This is the first non-RFC patch series. The known short comings have been addressed. We ask for review in earnest on this series and thank you for any feedback you can provide. Background info and work in progress implementations: * HVAC project page with intro slides [1] * HVAC demo repo w/ instructions in README.md [2] * Kernel w/ virtio-msg common level and ffa support [3] * QEMU w/ support for one form of virtio-msg-amp [4] * Portable RTOS library w/ one form of virtio-msg-amp [5] In addition to the QEMU system based demos in the hvac-demo repo, we also have two hardware systems running: * AMD x86 + AMD Arm Versal connected via PCIe * ST STM32MP157 A7 Linux using virtio-i2c provided by M4 Zephyr Please note that although the demos work, a few have not been aligned with this version of the spec. [1] https://linaro.atlassian.net/wiki/spaces/HVAC/overview [2] https://github.com/wmamills/hvac-demo [3] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux.git/log/?h=vi… [4] https://github.com/edgarigl/qemu/commits/edgar/virtio-msg-rfc/ [5] https://github.com/arnopo/open-amp/commits/virtio-msg/ [6] https://documentation-service.arm.com/static/68f647791134f773ab3f0a7c [7] https://lore.kernel.org/all/cover.1753865268.git.viresh.kumar@linaro.org/ [8] https://mail.gnu.org/archive/html/qemu-devel/2025-10/msg07438.html Alex Bennée (1): local: add local build help and github automation (!UPSTREAM) Bertrand Marquis (2): virtio-msg: add new command for bus normative virtio-msg: add conformance entries in conformance chapter Bill Mills (5): email: Add script and cover letter for RFC1 email: adjust cover letter for RFC2 email: adjust cover letter for RFC3 virtio-msg: Add virtio-msg, a message based virtio transport layer virtio-msg: link virtio-msg content .github/PULL_REQUEST_TEMPLATE.md | 14 +- .github/workflows/deploy.yaml | 38 + .github/workflows/test.yml | 15 + .prjinfo/sendmail/cover.txt | 125 +++ .prjinfo/sendmail/send.sh | 57 ++ Makefile | 33 + REVISION | 2 +- commands.tex | 3 +- conformance.tex | 105 +- content.tex | 1 + make-setup-generated.sh | 31 +- makeall.sh | 4 +- makehtml.sh | 2 +- makepdf.sh | 2 +- transport-msg.tex | 1640 ++++++++++++++++++++++++++++++ 15 files changed, 2052 insertions(+), 20 deletions(-) create mode 100644 .github/workflows/deploy.yaml create mode 100644 .github/workflows/test.yml create mode 100644 .prjinfo/sendmail/cover.txt create mode 100755 .prjinfo/sendmail/send.sh create mode 100644 Makefile create mode 100644 transport-msg.tex -- 2.34.1

1 month, 1 week

1
9
0 0

[PATCH v1 0/4] virtio-msg transport layer

by Bill Mills

This series adds the virtio-msg transport layer. The individuals and organizations involved in this effort have had difficulty in using the existing virtio-transports in various situations and desire to add one more transport that performs its transport layer operations by sending and receiving messages. Implementations of virtio-msg will normally be done in multiple layers: * common / device level * bus level The common / device level defines the messages exchanged between the driver and a device. This common part should lead to a common driver holding most of the virtio specifics and can be shared by all virtio-msg bus implementations. The kernel implementation in [3] shows this separation. As with other transport layers, virtio-msg should not require modifications to existing virtio device implementations (virtio-net, virtio-blk etc). The common / device level is the main focus of this version of the patch series. The virtio-msg bus level implements the normal things a bus defines (enumeration, dma operations, etc) but also implements the message send and receive operations. A number of bus implementations are envisioned, some of which will be reusable and general purpose. Other bus implementations might be unique to a given situation, for example only used by a PCIe card and its driver. How much of the bus level should be described in the virtio spec is one item we wish to discuss. This draft takes a middle approach by describing the bus level and defining some standard bus level messages that MAY be used by the bus. It also describes a range of bus messages that are implementation dependent. The standard bus messages are an effort to avoid different bus implementations doing the same thing in different ways for no good reason. However the different environments will require different things. Instead of trying to anticipate all needs and provide something very abstract, we think implementation specific messages will be needed at the bus level. Over time, if we see similar messages across multiple bus implementations, we will move to standardize a bus level message for that. We are working on a few reusable bus implementations: * virtio-msg-ffa based on Arm FF-A interface for use between: * normal world and secure world * host and VM or VM to VM * Can be used w/ or with out a hypervisor * Any Hypervisor that implements FF-A can be used * We have this working with pKVM and Xen * We have this working with Trusty and OP-TEE * virtio-msg-amp for use between heterogenous systems * The main processors and its co-processors on an AMP SOC * Two or more systems connected via PCIe * Minimal requirements: bi-directional interrupts and at least one shared memory area * hvac-demo has 2 demos of this * This is working on two hardware platforms * virtio-msg-loopback for userspace implemented devices * Allows user space to provide devices to its own kernel * This is similar to fuse, cuse or loopback block devices but for virtio * hvac-demo has a demo We also anticipate a few more: * virtio-msg-xen specific to Xen * Usable on any Xen system (including x86 where FF-A does not exist) * Using Xen events and page grants * virtio-msg over admin virtqueues * This allows any virtio-pci device that supports admin virtqueues to also support a virtio-msg bus that supports sub devices * [We are looking for collaborators for this work] Changes since RFC2: Spec Functional: * Made the common message header 8 bytes and added a token for optional use when parallel outstanding requests are possible * Made the 8 byte fields align to 8 byte offsets. This effects the {SET,GET}_VQUEUE messages Spec Editorial: * Major restructure to better align with virtio spec * Conformance model now matches * Use C structures to define messages instead of tables * Added a section to describe how responses are matched to requests This includes the use of the new token field * Redefined / better described error handling between transport and bus layers to eliminate the need for the bus to generate fake response messages * Included editorial feedback from RFC2 Eco-system: * Add virtio-msg-loopback demo * Arm has published the first draft of the virtio-msg over FFA spec * virtio-msg over FFA has been demonstrated with both Trusty and OP-TEE secure world * QEMU RFCv1 has been sent * LKML RFCs have been sent Background info and work in progress implementations: * HVAC project page with intro slides [1] * HVAC demo repo w/ instructions in README.md [2] * Kernel w/ virtio-msg common level and ffa support [3] * QEMU w/ support for one form of virtio-msg-amp [4] * Portable RTOS library w/ one form of virtio-msg-amp [5] In addition to the QEMU system based demos in the hvac-demo repo, we also have two hardware systems running: * AMD x86 + AMD Arm Versal connected via PCIe * ST STM32MP157 A7 Linux using virtio-i2c provided by M4 Zephyr Please note that although the demos work, not all of them have been aligned with this version of the spec. [1] https://linaro.atlassian.net/wiki/spaces/HVAC/overview [2] https://github.com/wmamills/hvac-demo [3] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux.git/log/?h=vi… [4] https://github.com/edgarigl/qemu/commits/edgar/virtio-msg-new [5] https://github.com/arnopo/open-amp/commits/virtio-msg/ Bertrand Marquis (2): virtio-msg: add new command for bus normative virtio-msg: add conformance entries in conformance chapter Bill Mills (2): virtio-msg: Add virtio-msg, a message based virtio transport layer virtio-msg: link virtio-msg content commands.tex | 3 +- conformance.tex | 105 ++- content.tex | 1 + transport-msg.tex | 1640 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 1746 insertions(+), 3 deletions(-) create mode 100644 transport-msg.tex -- 2.34.1

1 month, 1 week

1
4
0 0

[RFC] Vsock: Which device should we use for mapping memory ?

by Viresh Kumar

Happy new year everyone, I have a few questions regarding the design of the whole memory sharing over Vsock work and looking to get some feedback before I spend time making the changes. The initial design (from Nov): - Initially I implemented a FFA based DMA heap (no DMA ops used), which would allocate memory and make direct FFA calls to send the memory to the other endpoint. - The userspace would open this heap, allocated dma-buf and pass its FD over Vsock. - The Vsock layer would then call ->shmem() (a new callback I added to dma-buf/heap, which will send memory over FFA and return ffa bus address), to get the metadata to be shared over Vsock. The current design: - In one of the calls Bertrand suggested to not create parallel paths for sending memory over FFA. Instead we should use the exiting dma-ops for FFA (used for virtqueue and reserved-mem) somehow. - I created a platform device (as a child of the FFA device) and assigned a new set of DMA ops to it (the only difference from reserved-mem ops is that we don't do swiotlb here and allocate fresh instead of the reserved mem). - This pdev is used by the DMA heap to allocate memory using dma_alloc_coherent() and that made sure everything got mapped correctly. - I still need a dma-buf helper to get the metadata to send over Vsock. The existing helper was renamed as s/shmem/shmem_data. The future design (that I have questions about): - The FFA specific DMA heap I now have doesn't do anything special compared to the system heap, mostly exactly same. - Which made me realize that probably I shouldn't add a new heap (Google can add one later if they really want) and the solution should work with any heap / dma-buf. - So, userspace should allocate heap from system-heap, get a dma-buf from it and send its FD. - The vsock layer then should attach this dma-buf to a `struct device` somehow and then call map_dma_buf() for the dma-buf. This requires the dma-ops of the device to be set to the FFA based dma-ops and then it should just work. - The tricky point is finding that device struct (as Vsock can't get it from dma-buf or usersapce). - One way, I think (still needs exploring but should be possible) is to use the struct device of the virtio-msg device over which Vsock is implemented. We can set the dma-ops of the virtio-msg device accordingly. - The system heap doesn't guarantee contiguous allocation though (which my FFA heap did) and so we will be required to send a scatter-gather list over vsock, instead of just one address and size (what I am doing right now). - Does this make sense ? Or if there is a use-case that this won't solve, etc ? -- viresh

1 month, 3 weeks

2
4
0 0

Address space definition with virtio-msg and Xen grants ?

by Teddy Astie

Hello, I have some questions / feedback on the Xen side of virtio-msg. AFAIU virtio-msg defines a protocol in order to deal with discovery (optional) and configuration of the PV devices. But things are undefined regarding what is a "memory address". In Xen memory model with grants, each guest has its own memory space. The frontend shares memory pages with the backend through grants pages identified by grant references. So in a design based on grants, virtio addresses can't (or at least shouldn't) be guest physical address; but needs to be something derived on grants. A earlier design [1] was forging a address with the grant reference, but I feel it's not great, as it forces "map+unmap" cycles for temporary buffers thus has the same performance problem as Xen PV drivers (without persistent grants) where map+unmap cycles is a performance problem. And would make the address space very fragmented and in often limited to 4KB buffers. One idea that is already used by Xen displif (PV Display) is to have a "gref directory" and describe the address space on that. The gref directory is roughly a array of grant references (shared pages infos) that could describe a address space starting at 0, where each page is defined by a grant reference of the directory. That way, the backend can freely keep all or a part or the address space persistently mapped (or eventually map it all at once); and the address space is also contiguous which would help with >4KB buffers. Any thoughts ? [1] https://static.sched.com/hosted_files/xen2021/bf/Thursday_2021-Xen-Summit-v… -- Teddy Astie | Vates XCP-ng Developer XCP-ng & Xen Orchestra - Vates solutions web: https://vates.tech

1 month, 3 weeks

2
4
0 0

2026

2025

2024

Virtio-msg

2026

2025

2024

Virtio-msg ----- 2026 ----- February 2026 January 2026 ----- 2025 ----- December 2025 November 2025 October 2025 September 2025 August 2025 July 2025 June 2025 May 2025 April 2025 March 2025 February 2025 January 2025 ----- 2024 ----- December 2024 November 2024 October 2024 September 2024

Virtio-msg