Re: Xen 4.21 Development Update [June-July]

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

Hi Oleksii,

> On 5 Aug 2025, at 19:19, Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx> wrote:
> 
> Hello everyone,
> 
> This email only tracks big items for xen.git tree. Please reply for items you
> would like to see in 4.21 so that people have an idea what is going on and
> prioritise accordingly.
> 
> You're welcome to provide description and use cases of the feature you're
> working on.
> 
> = Timeline =
> 
> The current release schedule could be found here:
>   https://wiki.xenproject.org/wiki/Xen_Project_X.YY_Release_Notes
> 
> And as a reminder I would like to remind at the of this week we will have
> Last posting date (Fri Aug 08, 2025).
> 
> = Updates =
> 
> The following items ( the links for them could be found int the list below )
> were moved to completed:
>   [since Jun2 - Aug5]:
>    Added some tags: [4.21], [next-rel(s)] to the list "Full list of items"
>    below.
>    * x86:
>     - kexec: add kexec support to Mini-OS.
>     - x86: memcpy() / memset() (non-)ERMS flavors plus fallout
>    * Arm:
>     - SMMU handling for PCIe Passthrough on ARM.
>     - Add support for R-Car Gen4 PCI host controller.
>     - First chunk for Arm R82 and MPU support.
>     - Enable R52 support for the first chunk of MPU support
>     - ARM split hardware and control domains.
>    * RISC-V:
>     - Introduce basic UART support and interrupts for hypervisor mode.
> 
>   [since May 6 - Jun2]:
>     * Hypervisor:
>       - tools: remove qemu-traditional
>     * Arm:
>       - PCI devices passthrough on Arm, part 3
>     * x86:
>       - xen: cache control improvements
>   [since 4.20 relese - May 6]:
>     * Hypervisor:
>       - Move parts of Arm's Dom0less to common code
>       - remove libxenctrl usage from xenstored
>     * Arm:
>       - Enable early bootup of Armv8-R AArch32 systems
>     * x86:
>       - x86/HVM: emulation (MMIO) improvements
>     * RISC-V:
>       - RISC-V some preinit calls.
>       - Fixes for UBSAN & GCOV support for RISC-V.
> 
> Some new items added:
>  [since May]
>     * x86:
>      - Allow x86 to unflatten DTs
>      - hyperlaunch: move remaining pvh dom0 construction
>      - x86/hyperlaunch: introduce concept of core domains
>      - Confidential computing and AMD SEV support
>     * Arm:
>      - SMMU handling for PCIe Passthrough on ARM
>      - xen/arm: scmi: introduce SCI SCMI SMC multi-agent support
>      - Add initial Xen Suspend-to-RAM support on ARM64
>     * RISC-V:
>      - introduce p2m functionality
>  [since 4.20 release]
>     * Hypervisor:
>       - tools: remove qemu-traditional
>       - Physical address hypercall ABI ("HVMv2")
>       - xen: Untangle mm.h
>       - xen: introduce CONFIG_SYSCTL
>       - Add support for exact-node memory claims
>       - Several CI cleanups and improvements, plus yet another new runner
>     * x86:
>       - x86/EFI: prevent write-execute sections
>       - x86: Trenchboot Secure Launch DRTM (Xen)
>       - Hyperlaunch device tree for dom0 (v6)
>       - amd-cppc CPU Performance Scaling Driver (v4)
>       - Hyperlaunch domain builder
>       - kexec: add kexec support to Mini-OS
>       - xen: cache control improvements (should be moved to "Hypervisor"?)
>       - x86: generate xen.efi image with no write-execute sections
>       - x86/asm: cleanups after toolchain baseline upgrade
>     * Arm:
>       - Add support for R-Car Gen4 PCI host controller (v4)
>       - FF-A VM to VM support (v5)

This serie is currently under review at v7 and should be merged before the 
release.
I have an other one pending for FF-A v1.2 support that i need to push once this 
one
is merged but it will have to wait after the release for now.

Cheers
Bertrand

>       - First chunk for Arm R82 and MPU support (v4)
>       - ARM split hardware and control domains (v5)
>       - MPU mm subsistem skeleton
>     * RISC-V:
>       - introduce basic UART support and interrupts for hypervisor mode
> 
> * Full list of items : *
> 
> = Projects =
> 
> == Hypervisor ==
> 
> * [4.21] xen/console: cleanup console input switch logic (v5)
>   - Denis Mukhin
>   - https://lore.kernel.org/xen-devel/20250530231841.73386-1-dmukhin@xxxxxxxx/
> 
> * [4.21] xen: introduce CONFIG_SYSCTL (v4 -> v8)
>   -  Penny Zheng
>   - 
> https://lore.kernel.org/xen-devel/20250711043158.2566880-1-Penny.Zheng@xxxxxxx/
> 
> * [4.21] Several CI cleanups and improvements, plus yet another new runner
>   - Marek Marczykowski-Górecki
>   - 
> https://lore.kernel.org/xen-devel/cover.7da1777882774486a13e6f39ff4a2096f6b7901e.1744028549.git-series.marmarek@xxxxxxxxxxxxxxxxxxxxxx/
>   - 
> https://patchew.org/Xen/cover.7da1777882774486a13e6f39ff4a2096f6b7901e.1744028549.git-series.marmarek@xxxxxxxxxxxxxxxxxxxxxx/
> 
> * [4.21] automation: Refresh the remaining Debian containers (v2)
>   -  Javi Merino
>   - 
> https://lore.kernel.org/xen-devel/cover.1730743077.git.javi.merino@xxxxxxxxx/T/#m5d9acb7cf5db3c2be3d6527de14b69b07812314e
> 
> * [4.21] MSI-X support with qemu in stubdomain, and other related changes (v8)
>   -  Marek Marczykowski-Górecki
>   - 
> https://lore.kernel.org/xen-devel/cover.33fb4385b7dd6c53bda4acf0a9e91748b3d7b1f7.1715313192.git-series.marmarek@xxxxxxxxxxxxxxxxxxxxxx/
>   -  Only automation patch left to be reviewed/merged.
> 
> * [next-rel(s)] Physical address hypercall ABI ("HVMv2")
>   - Teddy Astie
>   - 
> https://lore.kernel.org/xen-devel/cover.1744981654.git.teddy.astie@xxxxxxxxxx/
> 
> * [next-rel(s)] xen: Untangle mm.h
>   -  Andrew Cooper
>   - 
> https://lore.kernel.org/xen-devel/20250312174513.4075066-1-andrew.cooper3@xxxxxxxxxx/
>   - 
> https://patchew.org/Xen/20250312174513.4075066-1-andrew.cooper3@xxxxxxxxxx/
> 
> * [next-rel(s)] Add support for exact-node memory claims
>   -  Alejandro Vallejo
>   - 
> https://lore.kernel.org/xen-devel/20250314172502.53498-1-alejandro.vallejo@xxxxxxxxx/
>   - 
> https://patchew.org/Xen/20250314172502.53498-1-alejandro.vallejo@xxxxxxxxx/
> 
> * [next-rel(s)] Remove the directmap (v5)
>   -  Alejandro Vallejo
>   - 
> https://lore.kernel.org/xen-devel/20250108151822.16030-1-alejandro.vallejo@xxxxxxxxx/
>   - 
> https://patchew.org/Xen/20250108151822.16030-1-alejandro.vallejo@xxxxxxxxx/
> 
> * [next-rel(s)] GRUB: Supporting Secure Boot of xen.gz (v1)
>   -  Ross Lagerwall
>   - https://patchew.org/Xen/20240313150748.791236-1-ross.lagerwall@xxxxxxxxxx/
> 
> * [next-rel(s)] Introduce xenbindgen to autogen hypercall structs (v1)
>   -  Alejandro Vallejo
>   - https://patchew.org/Xen/20241115115200.2824-1-alejandro.vallejo@xxxxxxxxx/
> 
> * [next-rel(s)] Introduce NS8250 UART emulator (v2)
>   -  Denis Mukhin
>   - https://patchew.org/Xen/20241205-vuart-ns8250-v1-0-e9aa923127eb@xxxxxxxx/
> 
> * [next-rel(s)] xen: framework for UART emulators
>   - Denis Mukhin
>   - 
> https://lore.kernel.org/xen-devel/20250624035443.344099-1-dmukhin@xxxxxxxx/
> 
> === x86 ===
> * [4.21] x86/asm: cleanups after toolchain baseline upgrade (v1 -> v2)
>   - Denis Mukhin
>   - 
> https://lore.kernel.org/xen-devel/20250403182250.3329498-1-dmukhin@xxxxxxxx/
>   - https://patchew.org/Xen/20250403182250.3329498-1-dmukhin@xxxxxxxx/
> 
> * [4.21?] x86/efi: Fix booting when NX is disabled (v1 -> v2)
>   - Andrew Cooper
>   - 
> https://patchew.org/Xen/20240722101838.3946983-1-andrew.cooper3@xxxxxxxxxx/
>   - 
> https://lore.kernel.org/xen-devel/20240722101838.3946983-1-andrew.cooper3@xxxxxxxxxx/
> 
> * [4.21?] Hyperlaunch device tree for dom0 (v6)
>   - Alejandro Vallejo
>   - https://patchew.org/Xen/20250429123629.20839-1-agarciav@xxxxxxx/
>   - https://lore.kernel.org/xen-devel/20250429123629.20839-1-agarciav@xxxxxxx/
> 
> *  [4.21?] Boot modules for Hyperlaunch (v9)
>   -  Daniel P. Smith
>   - 
> https://lore.kernel.org/xen-devel/20241115131204.32135-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
>   - 
> https://patchew.org/Xen/20241115131204.32135-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
> 
> *  [4.21?] Address Space Isolation FPU preparations (v2->v3)
>   -  Alejandro Vallejo
>   - 
> https://patchew.org/Xen/20250110132823.24348-1-alejandro.vallejo@xxxxxxxxx/
> 
> * [next-rel(s)] Hyperlaunch domain builder
>   - Daniel P. Smith
>   - 
> https://lore.kernel.org/xen-devel/20250515131744.3843-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
> 
> * [next-rel(s)] Confidential computing and AMD SEV support
>   - Teddy Astie
>   - https://patchew.org/Xen/cover.1747312394.git.teddy.astie@xxxxxxxxxx/
>   - 
> https://lore.kernel.org/xen-devel/cover.1747312394.git.teddy.astie@xxxxxxxxxx/
> 
> * [next-rel(s)] amd-cppc CPU Performance Scaling Driver (v5 -> v6)
>   - Penny Zheng
>   - 
> https://lore.kernel.org/xen-devel/20250711035106.2540522-1-Penny.Zheng@xxxxxxx/
> 
> * [next-rel(s)] x86: Trenchboot Secure Launch DRTM (Xen) (v1 -> v3)
>   - Sergii Dmytruk
>   - https://patchew.org/Xen/cover.1745172094.git.sergii.dmytruk@xxxxxxxxx/
>   - 
> https://lore.kernel.org/xen-devel/cover.1748611041.git.sergii.dmytruk@xxxxxxxxx/
> 
> * [next-rel(s)] x86/EFI: prevent write-execute sections
>   - Roger Pau Monne <roger.pau@xxxxxxxxxx>
>   - 
> https://lore.kernel.org/xen-devel/20250401130840.72119-1-roger.pau@xxxxxxxxxx/
> 
> * [next-rel(s)] x86: generate xen.efi image with no write-execute sections
>   - Roger Pau Monne
>   - 
> https://lore.kernel.org/xen-devel/20250318173547.59475-1-roger.pau@xxxxxxxxxx/
> 
> *  [next-rel(s)] Expose consistent topology to guests (v7)
>   -  Alejandro Vallejo
>   - 
> https://patchew.org/Xen/20241021154600.11745-1-alejandro.vallejo@xxxxxxxxx/
> 
> *  [next-rel(s)] x86/alternatives: Adjust all insn-relative fields (v2)
>   -  Andrew Cooper
>   - 
> https://lore.kernel.org/xen-devel/20241002152725.1841575-1-andrew.cooper3@xxxxxxxxxx/T/#mac2deaea7e02a343210d61887486433d946ad129
> 
> *  [next-rel(s)] x86emul: misc additions (v7)
>   -  Jan Beulich
>   - https://patchew.org/Xen/3a25cd59-e1cb-4bfc-b868-fb11599d22f5@xxxxxxxx/
> 
> *  [next-rel(s)] x86: support AVX10 (v3)
>   -  Jan Beulich
>   - 
> https://lore.kernel.org/xen-devel/516b7f9a-048e-409d-8a4e-89aeb8ffacc4@xxxxxxxx/
>   - https://patchew.org/Xen/516b7f9a-048e-409d-8a4e-89aeb8ffacc4@xxxxxxxx/
> 
> *  [next-rel(s)] VT-d: SATC handling; ATS: tidying (v2)
>   -  Jan Beulich
>   - https://patchew.org/Xen/64b028be-2197-4951-ae5b-32f9eabfa84a@xxxxxxxx/
> 
> *  [next-rel(s)] x86: parallelize AP bring-up during boot (v1)
>   -  Krystian Hebel
>   - 
> https://lore.kernel.org/xen-devel/cover.1699982111.git.krystian.hebel@xxxxxxxxx/
> 
> *  [next-rel(s)] x86/spec-ctrl: IBPB improvements (v4)
>   -  Jan Beulich
>   - https://patchew.org/Xen/06591b64-2f05-a4cc-a2f3-a74c3c4a76d6@xxxxxxxx/
> 
> *  [next-rel(s)] Move some boot code from assembly to C (v2)
>   -  Frediano Ziglio
>   - 
> https://lore.kernel.org/xen-devel/20241122093358.478774-1-frediano.ziglio@xxxxxxxxx/
>   - https://patchew.org/Xen/20241122093358.478774-1-frediano.ziglio@xxxxxxxxx/
> 
> *  [next-rel(s)]amd-pstate CPU Performance Scaling Driver (v1)
>   -  Penny Zheng
>   - https://patchew.org/Xen/20241203081111.463400-1-Penny.Zheng@xxxxxxx/
>   - 
> https://lore.kernel.org/xen-devel/593baee2-9bf1-4db4-86e8-015cae48dc1a@xxxxxxxx/
> 
> * [next-rel(s)] x86: adventures in Address Space Isolation
>   - Roger Pau Monne <roger.pau@xxxxxxxxxx>
>   - 
> https://lore.kernel.org/xen-devel/20250108142659.99490-1-roger.pau@xxxxxxxxxx/
> 
> === ARM ===
> 
> * [4.21?] MPU mm subsistem skeleton
>   - Luca Fancellu
>   - 
> https://lore.kernel.org/xen-devel/20250312135258.1815706-1-luca.fancellu@xxxxxxx/
>   - https://patchew.org/Xen/20250312135258.1815706-1-luca.fancellu@xxxxxxx/
> 
> * [4.21?] Add initial Xen Suspend-to-RAM support on ARM64 (v4)
>   - Mykola Kvach
>   - 
> https://lore.kernel.org/xen-devel/cover.1748848482.git.mykola_kvach@xxxxxxxx/
> 
> * [4.21?] xen/arm: scmi: introduce SCI SCMI SMC multi-agent support (->v4)
>   - Oleksii Moisieiev
>   - 
> https://lore.kernel.org/xen-devel/cover.1753184487.git.oleksii_moisieiev@xxxxxxxx/
> 
> * [next-rel(s)] FF-A VM to VM support (v6)
>   - Bertrand Marquis <bertrand.marquis@xxxxxxx>
>   - 
> https://lore.kernel.org/xen-devel/cover.1747925287.git.bertrand.marquis@xxxxxxx/
>   - https://patchew.org/Xen/cover.1747925287.git.bertrand.marquis@xxxxxxx/
> 
> *  [next-rel(s)] Add Virtio-PCI for dom0less on ARM (v1)
>   -  Edgar E. Iglesias
>   - 
> https://lore.kernel.org/xen-devel/20240924162359.1390487-1-edgar.iglesias@xxxxxxxxx/T/#mfa148991b9408f223a079d4cef610244d5b04c2b
>   - https://patchew.org/Xen/20240924162359.1390487-1-edgar.iglesias@xxxxxxxxx/
> 
> *  [next-rel(s)] DOMCTL-based guest magic region allocation for 11 domUs (v4)
>   -  Henry Wang
>   - https://patchew.org/Xen/20240409045357.236802-1-xin.wang2@xxxxxxx/
> 
> === RISCV ===
> 
> * [4.21] xen/riscv: introduce p2m functionality (v1->v3)
>   - Oleksii Kurochko
>   - 
> https://lore.kernel.org/xen-devel/cover.1753973161.git.oleksii.kurochko@xxxxxxxxx/T/#t
> 
> === PPC ===
> 
> *  Early Boot Allocation on Power (v5)
>   -  Shawn Anastasio
>   - 
> https://lore.kernel.org/xen-devel/cover.1727388925.git.sanastasio@xxxxxxxxxxxxxxxxxxxxx/T/#m8cac91a93b56a359fa2d5f08596c4be61dca290d
>   - 
> https://patchew.org/Xen/cover.1727388925.git.sanastasio@xxxxxxxxxxxxxxxxxxxxx/
> 
> == Completed ==
> 
> === Hypervisor ===
> 
> * tools: remove qemu-traditional
>   - Juergen Gross <jgross@xxxxxxxx>
>   - https://lore.kernel.org/xen-devel/20250527132035.985-1-jgross@xxxxxxxx/
> 
> *  remove libxenctrl usage from xenstored (v8)
>   -  Juergen Gross
>   - https://lore.kernel.org/xen-devel/20250204113407.16839-1-jgross@xxxxxxxx/
> 
> * xen/config.h: Move BITS_PER_* definitions from asm/config.h to xen/config.h
>   - Oleksii Kurochko
>   - 
> https://lore.kernel.org/xen-devel/6b21fb046cf1c8ca760f5ad72fa3cc13b59c4069.1743092485.git.oleksii.kurochko@xxxxxxxxx/
> 
> * Move parts of Arm's Dom0less to common code
>   - Oleksii Kurochko
>   - https://patchew.org/Xen/cover.1746468003.git.oleksii.kurochko@xxxxxxxxx/
>   - 
> https://lore.kernel.org/xen-devel/cover.1746468003.git.oleksii.kurochko@xxxxxxxxx/T/#t
> 
> === x86 ===
> 
> *  x86: memcpy() / memset() (non-)ERMS flavors plus fallout (v4 -> v5)
>   -  Jan Beulich
>   - https://patchew.org/Xen/14b65231-b83b-43fb-bbcf-dec5c07d285b@xxxxxxxx/
> 
> * kexec: add kexec support to Mini-OS (v1 -> v2)
>   - Juergen Gross <jgross@xxxxxxxx>
>   - https://lore.kernel.org/xen-devel/20250616084619.11112-1-jgross@xxxxxxxx/
> 
> * [4.21] Allow x86 to unflatten DTs (v8)
>   - Alejandro Vallejo
>   - 
> https://lore.kernel.org/xen-devel/20250722000525.7247-1-alejandro.garciavallejo@xxxxxxx/#t
> 
> * xen: cache control improvements
>   - Roger Pau Monne
>   - 
> https://lore.kernel.org/xen-devel/20250506083148.34963-1-roger.pau@xxxxxxxxxx/
> 
> *  x86/HVM: emulation (MMIO) improvements (v3)
>   -  Jan Beulich
>   - https://patchew.org/Xen/729f7896-55b7-4b5b-a7e9-6eb0420e0b14@xxxxxxxx/
> 
> === ARM ===
> 
> * Enable R52 support for the first chunk of MPU support
>  -  Ayan Kumar Halder
>  - 
> https://lore.kernel.org/xen-devel/20250619113152.2723066-1-ayan.kumar.halder@xxxxxxx/
> 
> * ARM split hardware and control domains (v5)
>   - Jason Andryuk
>   - 
> https://lore.kernel.org/xen-devel/20250416212911.410946-1-jason.andryuk@xxxxxxx/
>   - https://patchew.org/Xen/20250416212911.410946-1-jason.andryuk@xxxxxxx/
> 
> * First chunk for Arm R82 and MPU support (v4 -> v6)
>   - Luca Fancellu
>   - 
> https://lore.kernel.org/xen-devel/20250523065406.3795420-1-luca.fancellu@xxxxxxx/
>   - https://patchew.org/Xen/20250523065406.3795420-1-luca.fancellu@xxxxxxx/
> 
> * Add support for R-Car Gen4 PCI host controller (v4 -> v5)
>   - Mykyta Poturai
>   - 
> https://lore.kernel.org/xen-devel/cover.1747820844.git.mykyta_poturai@xxxxxxxx/
>   - https://patchew.org/Xen/cover.1747820844.git.mykyta._5Fpoturai@xxxxxxxx/
> 
> * SMMU handling for PCIe Passthrough on ARM (v11 -> v12)
>   - Mykyta Poturai
>   - 
> https://lore.kernel.org/xen-devel/cover.1751439885.git.mykyta_poturai@xxxxxxxx/
> 
> *  PCI devices passthrough on Arm, part 3 (v16->v20->v21)
>   -  Stewart Hildebrand
>   - 
> https://patchew.org/Xen/20250508104608.531079-1-stewart.hildebrand@xxxxxxx/
>   - 
> https://lore.kernel.org/xen-devel/20250508104608.531079-1-stewart.hildebrand@xxxxxxx/
> 
> * Enable early bootup of Armv8-R AArch32 systems
>   - Ayan Kumar Halder
>   - 
> https://lore.kernel.org/xen-devel/20250414164514.588373-1-ayan.kumar.halder@xxxxxxx/
>   - https://patchew.org/Xen/20250414164514.588373-1-ayan.kumar.halder@xxxxxxx/
> 
> === RISC-V ===
> 
> * riscv: introduce basic UART support and interrupts for hypervisor mode (v2 
> -> v3)
>   -  Oleksii Kurochko
>   - 
> https://lore.kernel.org/xen-devel/cover.1747843009.git.oleksii.kurochko@xxxxxxxxx/
>   - https://patchew.org/Xen/cover.1747843009.git.oleksii.kurochko@xxxxxxxxx/
> 
> * RISC-V some preinit calls:
>   -  Oleksii Kurochko
>   - 
> https://lore.kernel.org/xen-devel/4ddde60347edf6740fbc69b5739d099616f5b5ff.1743165791.git.oleksii.kurochko@xxxxxxxxx/
> 
> * Fixes for UBSAN & GCOV support for RISC-V:
>   -  Oleksii Kurochko
>   - 
> https://lore.kernel.org/xen-devel/9fbb5e1389b84bed2e95f99e4c383d0215c7a524.1744889185.git.oleksii.kurochko@xxxxxxxxx/
> 
> Have a good week!
> 
> Best regards,
>  Oleksii