Re: Xen 4.21 Development Update [May]

[Mykola Kvach <xakep.amatop@xxxxxxxxx>]

Hi Oleksii,

On Mon, Jun 2, 2025 at 7:37 PM 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 =
>
> As there hasn't been any feedback on the proposed timeline shared here:
> https://lore.kernel.org/xen-devel/666e3f49-2f92-4828-8897-8579832bcaa2@xxxxxxxxx/T/#u
>
> We can proceed with the suggested timeline as the release schedule for
> Xen 4.21.
> I've updated the Xen 4.21 Release Notes with this schedule, which can now be
> accessed via the RN link:
>    https://xenbits.xen.org/docs/unstable/support-matrix.html
>
> = Updates =
>
> The following items ( the links for them could be found int the list below )
> were moved to completed:
>    [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)
>        - 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 ==
>
> * xen/console: cleanup console input switch logic (v1 -> v5)
>    - Denis Mukhin
>    -
> https://lore.kernel.org/xen-devel/20250530231841.73386-1-dmukhin@xxxxxxxx/
>    - https://patchew.org/Xen/20250530231841.73386-1-dmukhin@xxxxxxxx/
>
> * xen: introduce CONFIG_SYSCTL (v3 -> v4)
>    -  Penny Zheng
>    -
> https://lore.kernel.org/xen-devel/20250528091708.390767-1-Penny.Zheng@xxxxxxx/
>    - https://patchew.org/Xen/20250528091708.390767-1-Penny.Zheng@xxxxxxx/
>
> * Physical address hypercall ABI ("HVMv2")
>    - Teddy Astie
>    -
> https://lore.kernel.org/xen-devel/cover.1744981654.git.teddy.astie@xxxxxxxxxx/
>
> * 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/
>
> * 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/
>
> * 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/
>
> *  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/
>
> *  automation: Refresh the remaining Debian containers (v2)
>    -  Javi Merino
>    -
> https://lore.kernel.org/xen-devel/cover.1730743077.git.javi.merino@xxxxxxxxx/T/#m5d9acb7cf5db3c2be3d6527de14b69b07812314e
>
> *  GRUB: Supporting Secure Boot of xen.gz (v1)
>    -  Ross Lagerwall
>    -
> https://patchew.org/Xen/20240313150748.791236-1-ross.lagerwall@xxxxxxxxxx/
>
> *  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.
>
> *  [RFC] Introduce xenbindgen to autogen hypercall structs (v1)
>    -  Alejandro Vallejo
>    -
> https://patchew.org/Xen/20241115115200.2824-1-alejandro.vallejo@xxxxxxxxx/
>
> *  Introduce NS8250 UART emulator (v2)
>    -  Denis Mukhin
>    -
> https://patchew.org/Xen/20241205-vuart-ns8250-v1-0-e9aa923127eb@xxxxxxxx/
>
> === x86 ===
>
> * Allow x86 to unflatten DTs
>    - Alejandro Vallejo
>    -
> https://lore.kernel.org/xen-devel/20250530120242.39398-1-agarciav@xxxxxxx/
>    - https://patchew.org/Xen/20250530120242.39398-1-agarciav@xxxxxxx/
>
> * hyperlaunch: move remaining pvh dom0 construction (v2)
>    - Daniel P. Smith
>    -
> https://lore.kernel.org/xen-devel/20250515131912.5019-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
>
> * x86/hyperlaunch: introduce concept of core domains (v2)
>    - Daniel P. Smith
>    -
> https://lore.kernel.org/xen-devel/20250515131951.5594-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
>
> * 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/
>
> * 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/
>
> * 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/
>
> * amd-cppc CPU Performance Scaling Driver (v4 -> v5)
>    - Penny Zheng
>    -
> https://lore.kernel.org/xen-devel/20250527084833.338427-1-Penny.Zheng@xxxxxxx/
>    - https://patchew.org/Xen/20250414074056.3696888-1-Penny.Zheng@xxxxxxx/
>
> * 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/
>
> * x86/EFI: prevent write-execute sections
>    - Roger Pau Monne <roger.pau@xxxxxxxxxx>
>    -
> https://lore.kernel.org/xen-devel/20250401130840.72119-1-roger.pau@xxxxxxxxxx/
>
> * 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/
>
> * Hyperlaunch domain builder
>    - Daniel P. Smith
>    -
> https://patchew.org/Xen/20250419220820.4234-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
>
> * kexec: add kexec support to Mini-OS
>    - Juergen Gross <jgross@xxxxxxxx>
>    -
> https://lore.kernel.org/xen-devel/20250321092451.17309-1-jgross@xxxxxxxx/
>
> * 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/
>
> *  Expose consistent topology to guests (v7)
>    -  Alejandro Vallejo
>    -
> https://patchew.org/Xen/20241021154600.11745-1-alejandro.vallejo@xxxxxxxxx/
>
> *  Boot modules for Hyperlaunch (v9)
>    -  Daniel P. Smith
>    -
> https://patchew.org/Xen/20241115131204.32135-1-dpsmith@xxxxxxxxxxxxxxxxxxxx/
>
> *  Address Space Isolation FPU preparations (v2->v3)
>    -  Alejandro Vallejo
>    -
> https://patchew.org/Xen/20250110132823.24348-1-alejandro.vallejo@xxxxxxxxx/
>
> *  x86/alternatives: Adjust all insn-relative fields (v2)
>    -  Andrew Cooper
>    -
> https://lore.kernel.org/xen-devel/20241002152725.1841575-1-andrew.cooper3@xxxxxxxxxx/T/#mac2deaea7e02a343210d61887486433d946ad129
>
> *  x86emul: misc additions (v7)
>    -  Jan Beulich
>    - https://patchew.org/Xen/3a25cd59-e1cb-4bfc-b868-fb11599d22f5@xxxxxxxx/
>
> *  x86: support AVX10 (v3)
>    -  Jan Beulich
>    - https://patchew.org/Xen/516b7f9a-048e-409d-8a4e-89aeb8ffacc4@xxxxxxxx/
>
> *  VT-d: SATC handling; ATS: tidying (v2)
>    -  Jan Beulich
>    - https://patchew.org/Xen/64b028be-2197-4951-ae5b-32f9eabfa84a@xxxxxxxx/
>
> *  x86: parallelize AP bring-up during boot (v1)
>    -  Krystian Hebel
>    -
> https://lore.kernel.org/xen-devel/cover.1699982111.git.krystian.hebel@xxxxxxxxx/
>
> *  x86/spec-ctrl: IBPB improvements (v4)
>    -  Jan Beulich
>    - https://patchew.org/Xen/06591b64-2f05-a4cc-a2f3-a74c3c4a76d6@xxxxxxxx/
>
> *  Move some boot code from assembly to C (v2)
>    -  Frediano Ziglio
>    -
> https://patchew.org/Xen/20241122093358.478774-1-frediano.ziglio@xxxxxxxxx/
>
> *  x86: memcpy() / memset() (non-)ERMS flavors plus fallout (v4)
>    -  Jan Beulich
>    - https://patchew.org/Xen/14b65231-b83b-43fb-bbcf-dec5c07d285b@xxxxxxxx/
>
> *  amd-pstate CPU Performance Scaling Driver (v1)
>    -  Penny Zheng
>    - https://patchew.org/Xen/20241203081111.463400-1-Penny.Zheng@xxxxxxx/
>
> === ARM ===
>
> * SMMU handling for PCIe Passthrough on ARM (v11)
>    - Mykyta Poturai
>    -
> https://lore.kernel.org/xen-devel/cover.1741958647.git.mykyta_poturai@xxxxxxxx/
>    -
> https://patchew.org/Xen/cover.1748422217.git.mykyta._5Fpoturai@xxxxxxxx/
>
> * xen/arm: scmi: introduce SCI SCMI SMC multi-agent support
>    - Grygorii Strashko
>    -
> https://lore.kernel.org/xen-devel/20250311111618.1850927-1-grygorii_strashko@xxxxxxxx/
>
> * Add initial Xen Suspend-to-RAM support on ARM64 (v4)
>    - Mykola Kvach
>    -
> https://lore.kernel.org/xen-devel/cover.1741164138.git.xakep.amatop@xxxxxxxxx/
>    - https://patchew.org/Xen/cover.1748848482.git.mykola._5Fkvach@xxxxxxxx/

I'd like to propose including initial support for Suspend-to-RAM in Xen 4.21.

This feature enables Xen and its guests to enter suspend state via
PSCI SYSTEM_SUSPEND. Xen suspend is triggered from the hardware domain.

Support is currently Experimental.

>
> * 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/
>
> * FF-A VM to VM support (v5 -> 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/
>
> * 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/
>
> * 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/
>
> * 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/
>
> *  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/
>
> *  DOMCTL-based guest magic region allocation for 11 domUs (v4)
>    -  Henry Wang
>    - https://patchew.org/Xen/20240409045357.236802-1-xin.wang2@xxxxxxx/
>
> === RISCV ===
>
> * 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/
>
> * xen/riscv: introduce p2m functionality (v1)
>    - Oleksii Kurochko
>    -
> https://lore.kernel.org/xen-devel/cover.1746805907.git.oleksii.kurochko@xxxxxxxxx/
>    -
> https://patchew.org/Xen/cover.1746805907.git.oleksii.kurochko@xxxxxxxxx/
>
> === 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 ===
>
> * 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 ===
> *  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 ===
>
> * 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
>

Best regards,
Mykola