This patchset provides minimal functionality to start a Realm VM from an Arm RME capable host using the following command line:
qemu-system-aarch64 \ -M confidential-guest-support=rme0 -object rme-guest,id=rme0 \ -cpu host -M virt -enable-kvm -M gic-version=3,its=on -nodefaults .. It is a refactoring of Jean-Philippe Brucker's initial work dating from a while back. It is compatible with Steven Price's v14 revision [1] of his work adding CCA support to KVM. * We are currently working on rebasing the work to v15. It was tested on the QEMU SBSA machine. For convenience, a repository is hosted here [2], along with the TF-A [3], RMM [4] and Linux kernel [5] for the SBSA machine (compatible with Steven's v14 patchset). Instructions to compile and run the entire stack can be found here [6]. Device Assignment is not included. Thanks, Mathieu [1]. https://lore.kernel.org/kvm/[email protected]/T/#m06dd14216aaf76acab65b0a76fb84653141ea64f [2]. https://gitlab.com/Linaro/cca-public/qemu/-/tree/upstream-v2?ref_type=heads [3]. https://gitlab.com/Linaro/cca-public/tf-a/trusted-firmware-a/-/tree/cca/v13?ref_type=heads [4]. https://gitlab.com/Linaro/cca-public/rmm/-/tree/cca/v14?ref_type=heads [5]. https://gitlab.com/Linaro/cca-public/linux/-/tree/upstream-v2?ref_type=heads [6]. https://gitlab.com/Linaro/cca-public/build-instructions RFC v1: https://lists.gnu.org/archive/html/qemu-devel/2026-07/msg02307.html Changes for V2: - Fixed linux headers to include correct bit shift for Realm VM (Gavin). - Removed obsolete rme-guest options (Markus). - Set ConfidentialGuestSupportClass::kvm_init() to kvm_arm_rme_init() (Gavin). - Got rid of kvm_arm_rme_vm_type() (Gavin). - Used kvm_vm_check_extension() instead of kvm_check_extension() to avoid error message when starting a Realm (Gavin). - Removed obsolete kvm_arm_rme_init_guest_ram() (Gavin). - Collected A-B and R-B. Jean-Philippe Brucker (23): linux-headers: Add RME related definitions target/arm/kvm: Return immediately on error in kvm_arch_init() target/arm: Add confidential guest support target/arm/kvm: Split kvm_arch_get/put_registers target/arm/kvm-rme: Initialize vCPU target/arm/kvm: Create scratch Realm VM when requested target/arm/kvm: Use kvm_vm_check_extension() where necessary hw/core/loader: Add a ROM loader notifier target/arm/kvm-rme: Keep track of images loaded in Realm memory target/arm/kvm-rme: Populate Realm with runtime images target/arm/cpu: Set number of breakpoints and watchpoints in KVM target/arm/cpu: Set number of PMU counters in KVM target/arm/cpu: Don't read Realm registers hw/arm/virt: Set proper conduit method for Realms hw/arm/virt: Embed Realm VM type with IPA address space hw/arm/virt: Reserve one bit of guest physical address for RME hw/arm/virt: Disable DTB randomness for confidential VMs hw/arm/virt: Move virt_flash_create() to machvirt_init() hw/arm/virt: Use RAM instead of flash for confidential guest firmware target/arm/kvm-rme: Add DMA remapping for the shared memory region docs/interop/firmware.json: Add arm-rme firmware feature hw/arm/boot: Load DTB as is for confidential VMs hw/arm/boot: Skip bootloader for confidential guests Mathieu Poirier (1): target/arm/kvm-rme: Add mechanic to initialize realms docs/interop/firmware.json | 5 +- docs/system/arm/virt.rst | 9 +- docs/system/confidential-guest-support.rst | 1 + hw/arm/boot.c | 70 ++++- hw/arm/virt.c | 142 ++++++++-- hw/core/loader.c | 15 + include/hw/arm/boot.h | 9 + include/hw/arm/virt.h | 2 +- include/hw/core/loader.h | 17 ++ linux-headers/asm-arm64/kvm.h | 9 + linux-headers/linux/kvm.h | 10 +- qapi/qom.json | 1 + target/arm/arm-qmp-cmds.c | 1 + target/arm/cpu.c | 5 + target/arm/cpu.h | 10 + target/arm/cpu64.c | 122 ++++++++ target/arm/kvm-rme.c | 313 +++++++++++++++++++++ target/arm/kvm-stub.c | 9 + target/arm/kvm.c | 202 ++++++++++++- target/arm/kvm_arm.h | 20 ++ target/arm/meson.build | 5 +- 21 files changed, 927 insertions(+), 50 deletions(-) create mode 100644 target/arm/kvm-rme.c -- 2.43.0
