On Fri, 14 Jul 2023 16:03:37 +0100 Suzuki K Poulose <suzuki.poulose@xxxxxxx> wrote: > Hi Jonathan > > On 14/07/2023 14:46, Jonathan Cameron wrote: > > On Fri, 27 Jan 2023 11:22:48 +0000 > > Suzuki K Poulose <suzuki.poulose@xxxxxxx> wrote: > > > > > > Hi Suzuki, > > > > Looking at this has been on the backlog for a while from our side and we are finally > > getting to it. So before we dive in and given it's been 6 months, I wanted to check > > if you expect to post a new version shortly or if there is a rebased tree available? > > Thanks for your interest. We have been updating our trees to the latest > RMM specification (v1.0-eac2 now) and also rebasing Linux/KVM on top of > v6.5-rc1. We will post this as soon as we have all the components ready > (and the TF-RMM). At the earliest, this would be around early September. > > That said, the revised version will have the following changes : > - Changes to the Stage2 management > - Changes to RMM memory management for Realm > - PMU/SVE support > > Otherwise, most of the changes remain the same (e.g., UABI). Happy to > hear feedback on those areas. Hi Suzuki, Thanks for the update. If there is any chance of visibility of changes via a git tree etc that would be great in the meantime. If not, such is life and I'll try to wait patiently :) + we'll review the existing code. Jonathan > > > Kind regards > Suzuki > > > > > Jonathan > > > >> We are happy to announce the early RFC version of the Arm > >> Confidential Compute Architecture (CCA) support for the Linux > >> stack. The intention is to seek early feedback in the following areas: > >> * KVM integration of the Arm CCA > >> * KVM UABI for managing the Realms, seeking to generalise the operations > >> wherever possible with other Confidential Compute solutions. > >> Note: This version doesn't support Guest Private memory, which will be added > >> later (see below). > >> * Linux Guest support for Realms > >> > >> Arm CCA Introduction > >> ===================== > >> > >> The Arm CCA is a reference software architecture and implementation that builds > >> on the Realm Management Extension (RME), enabling the execution of Virtual > >> machines, while preventing access by more privileged software, such as hypervisor. > >> The Arm CCA allows the hypervisor to control the VM, but removes the right for > >> access to the code, register state or data that is used by VM. > >> More information on the architecture is available here[0]. > >> > >> Arm CCA Reference Software Architecture > >> > >> Realm World || Normal World || Secure World || > >> || | || || > >> EL0 x-------x || x----x | x------x || || > >> | Realm | || | | | | | || || > >> | | || | VM | | | | || || > >> ----| VM* |---------||-| |---| |-||----------------|| > >> | | || | | | | H | || || > >> EL1 x-------x || x----x | | | || || > >> ^ || | | o | || || > >> | || | | | || || > >> ------- R*------------------------| s -|--------------------- > >> S || | | || || > >> I || | t | || || > >> | || | | || || > >> v || x------x || || > >> EL2 RMM* || ^ || || > >> ^ || | || || > >> ========|=============================|======================== > >> | | SMC > >> x--------- *RMI* -------------x > >> > >> EL3 Root World > >> EL3 Firmware > >> =============================================================== > >> Where : > >> RMM - Realm Management Monitor > >> RMI - Realm Management Interface > >> RSI - Realm Service Interface > >> SMC - Secure Monitor Call > >> > >> RME introduces a new security state "Realm world", in addition to the > >> traditional Secure and Non-Secure states. The Arm CCA defines a new component, > >> Realm Management Monitor (RMM) that runs at R-EL2. This is a standard piece of > >> firmware, verified, installed and loaded by the EL3 firmware (e.g, TF-A), at > >> system boot. > >> > >> The RMM provides standard interfaces - Realm Management Interface (RMI) - to the > >> Normal world hypervisor to manage the VMs running in the Realm world (also called > >> Realms in short). These are exposed via SMC and are routed through the EL3 > >> firmwre. > >> The RMI interface includes: > >> - Move a physical page from the Normal world to the Realm world > >> - Creating a Realm with requested parameters, tracked via Realm Descriptor (RD) > >> - Creating VCPUs aka Realm Execution Context (REC), with initial register state. > >> - Create stage2 translation table at any level. > >> - Load initial images into Realm Memory from normal world memory > >> - Schedule RECs (vCPUs) and handle exits > >> - Inject virtual interrupts into the Realm > >> - Service stage2 runtime faults with pages (provided by host, scrubbed by RMM). > >> - Create "shared" mappings that can be accessed by VMM/Hyp. > >> - Reclaim the memory allocated for the RAM and RTTs (Realm Translation Tables) > >> > >> However v1.0 of RMM specifications doesn't support: > >> - Paging protected memory of a Realm VM. Thus the pages backing the protected > >> memory region must be pinned. > >> - Live migration of Realms. > >> - Trusted Device assignment. > >> - Physical interrupt backed Virtual interrupts for Realms > >> > >> RMM also provides certain services to the Realms via SMC, called Realm Service > >> Interface (RSI). These include: > >> - Realm Guest Configuration. > >> - Attestation & Measurement services > >> - Managing the state of an Intermediate Physical Address (IPA aka GPA) page. > >> - Host Call service (Communication with the Normal world Hypervisor) > >> > >> The specifications for the RMM software is currently at *v1.0-Beta2* and the > >> latest version is available here [1]. > >> > >> The Trusted Firmware foundation has an implementation of the RMM - TF-RMM - > >> available here [3]. > >> > >> Implementation > >> ================= > >> > >> This version of the stack is based on the RMM specification v1.0-Beta0[2], with > >> following exceptions : > >> - TF-RMM/KVM currently doesn't support the optional features of PMU, > >> SVE and Self-hosted debug (coming soon). > >> - The RSI_HOST_CALL structure alignment requirement is reduced to match > >> RMM v1.0 Beta1 > >> - RMI/RSI version numbers do not match the RMM spec. This will be > >> resolved once the spec/implementation is complete, across TF-RMM+Linux stack. > >> > >> We plan to update the stack to support the latest version of the RMMv1.0 spec > >> in the coming revisions. > >> > >> This release includes the following components : > >> > >> a) Linux Kernel > >> i) Host / KVM support - Support for driving the Realms via RMI. This is > >> dependent on running in the Kernel at EL2 (aka VHE mode). Also provides > >> UABI for VMMs to manage the Realm VMs. The support is restricted to 4K page > >> size, matching the Stage2 granule supported by RMM. The VMM is responsible > >> for making sure the guest memory is locked. > >> > >> TODO: Guest Private memory[10] integration - We have been following the > >> series and support will be added once it is merged upstream. > >> > >> ii) Guest support - Support for a Linux Kernel to run in the Realm VM at > >> Realm-EL1, using RSI services. This includes virtio support (virtio-v1.0 > >> only). All I/O are treated as non-secure/shared. > >> > >> c) kvmtool - VMM changes required to manage Realm VMs. No guest private memory > >> as mentioned above. > >> d) kvm-unit-tests - Support for running in Realms along with additional tests > >> for RSI ABI. > >> > >> Running the stack > >> ==================== > >> > >> To run/test the stack, you would need the following components : > >> > >> 1) FVP Base AEM RevC model with FEAT_RME support [4] > >> 2) TF-A firmware for EL3 [5] > >> 3) TF-A RMM for R-EL2 [3] > >> 4) Linux Kernel [6] > >> 5) kvmtool [7] > >> 6) kvm-unit-tests [8] > >> > >> Instructions for building the firmware components and running the model are > >> available here [9]. Once, the host kernel is booted, a Realm can be launched by > >> invoking the `lkvm` commad as follows: > >> > >> $ lkvm run --realm \ > >> --measurement-algo=["sha256", "sha512"] \ > >> --disable-sve \ > >> <normal-vm-options> > >> > >> Where: > >> * --measurement-algo (Optional) specifies the algorithm selected for creating the > >> initial measurements by the RMM for this Realm (defaults to sha256). > >> * GICv3 is mandatory for the Realms. > >> * SVE is not yet supported in the TF-RMM, and thus must be disabled using > >> --disable-sve > >> > >> You may also run the kvm-unit-tests inside the Realm world, using the similar > >> options as above. > >> > >> > >> Links > >> ============ > >> > >> [0] Arm CCA Landing page (See Key Resources section for various documentations) > >> https://www.arm.com/architecture/security-features/arm-confidential-compute-architecture > >> > >> [1] RMM Specification Latest > >> https://developer.arm.com/documentation/den0137/latest > >> > >> [2] RMM v1.0-Beta0 specification > >> https://developer.arm.com/documentation/den0137/1-0bet0/ > >> > >> [3] Trusted Firmware RMM - TF-RMM > >> https://www.trustedfirmware.org/projects/tf-rmm/ > >> GIT: https://git.trustedfirmware.org/TF-RMM/tf-rmm.git > >> > >> [4] FVP Base RevC AEM Model (available on x86_64 / Arm64 Linux) > >> https://developer.arm.com/Tools%20and%20Software/Fixed%20Virtual%20Platforms > >> > >> [5] Trusted Firmware for A class > >> https://www.trustedfirmware.org/projects/tf-a/ > >> > >> [6] Linux kernel support for Arm-CCA > >> https://gitlab.arm.com/linux-arm/linux-cca > >> Host Support branch: cca-host/rfc-v1 > >> Guest Support branch: cca-guest/rfc-v1 > >> > >> [7] kvmtool support for Arm CCA > >> https://gitlab.arm.com/linux-arm/kvmtool-cca cca/rfc-v1 > >> > >> [8] kvm-unit-tests support for Arm CCA > >> https://gitlab.arm.com/linux-arm/kvm-unit-tests-cca cca/rfc-v1 > >> > >> [9] Instructions for Building Firmware components and running the model, see > >> section 4.19.2 "Building and running TF-A with RME" > >> https://trustedfirmware-a.readthedocs.io/en/latest/components/realm-management-extension.html#building-and-running-tf-a-with-rme > >> > >> [10] fd based Guest Private memory for KVM > >> https://lkml.kernel.org/r/20221202061347.1070246-1-chao.p.peng@xxxxxxxxxxxxxxx > >> > >> Cc: Alexandru Elisei <alexandru.elisei@xxxxxxx> > >> Cc: Andrew Jones <andrew.jones@xxxxxxxxx> > >> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > >> Cc: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx> > >> Cc: Christoffer Dall <christoffer.dall@xxxxxxx> > >> Cc: Fuad Tabba <tabba@xxxxxxxxxx> > >> Cc: James Morse <james.morse@xxxxxxx> > >> Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> > >> Cc: Joey Gouly <Joey.Gouly@xxxxxxx> > >> Cc: Marc Zyngier <maz@xxxxxxxxxx> > >> Cc: Mark Rutland <mark.rutland@xxxxxxx> > >> Cc: Oliver Upton <oliver.upton@xxxxxxxxx> > >> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > >> Cc: Quentin Perret <qperret@xxxxxxxxxx> > >> Cc: Sean Christopherson <seanjc@xxxxxxxxxx> > >> Cc: Steven Price <steven.price@xxxxxxx> > >> Cc: Thomas Huth <thuth@xxxxxxxxxx> > >> Cc: Will Deacon <will@xxxxxxxxxx> > >> Cc: Zenghui Yu <yuzenghui@xxxxxxxxxx> > >> To: linux-coco@xxxxxxxxxxxxxxx > >> To: kvmarm@xxxxxxxxxxxxxxx > >> Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx > >> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > >> To: linux-kernel@xxxxxxxxxxxxxxx > >> To: kvm@xxxxxxxxxxxxxxx > >> > >> _______________________________________________ > >> linux-arm-kernel mailing list > >> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > > >
