Re: [PATCH v4 00/15] arm64: Support for running as a guest in Arm CCA

Will Deacon
2024-07-09T12:04:19Z

Hi Steven,

On Mon, Jul 01, 2024 at 10:54:50AM +0100, Steven Price wrote:
> This series adds support for running Linux in a protected VM under the
> Arm Confidential Compute Architecture (CCA). This has been updated
> following the feedback from the v3 posting[1]. Thanks for the feedback!
> Individual patches have a change log. But things to highlight:

Hold onto your hat, I'm going to dust off our pKVM protected guest
changes and see what we can share here! I've left a few comments on the
series, but the main differences seem to be:

- You try to probe really early
- You have that horrible split IPA space thing from the RSI spec

but some of the mechanisms are broadly similar (e.g. implementing the
set_memory_*crypted() API).

Hopefully I can give your GIC changes a spin, too.

Just one minor (but probably annoying) comment:

> arch/arm64/Kconfig | 3 +
> arch/arm64/include/asm/fixmap.h | 2 +-
> arch/arm64/include/asm/io.h | 8 +-
> arch/arm64/include/asm/mem_encrypt.h | 17 ++
> arch/arm64/include/asm/pgtable-hwdef.h | 6 -
> arch/arm64/include/asm/pgtable-prot.h | 3 +
> arch/arm64/include/asm/pgtable.h | 13 +-
> arch/arm64/include/asm/rsi.h | 64 ++++++
> arch/arm64/include/asm/rsi_cmds.h | 134 +++++++++++
> arch/arm64/include/asm/rsi_smc.h | 142 ++++++++++++
> arch/arm64/include/asm/set_memory.h | 3 +
> arch/arm64/kernel/Makefile | 3 +-
> arch/arm64/kernel/efi.c | 2 +-
> arch/arm64/kernel/rsi.c | 104 +++++++++
> arch/arm64/kernel/setup.c | 8 +
> arch/arm64/mm/init.c | 10 +-
> arch/arm64/mm/pageattr.c | 76 ++++++-
> drivers/firmware/psci/psci.c | 25 +++
> drivers/irqchip/irq-gic-v3-its.c | 142 +++++++++---
> drivers/virt/coco/Kconfig | 2 +
> drivers/virt/coco/Makefile | 1 +
> drivers/virt/coco/arm-cca-guest/Kconfig | 11 +
> drivers/virt/coco/arm-cca-guest/Makefile | 2 +
> .../virt/coco/arm-cca-guest/arm-cca-guest.c | 211 ++++++++++++++++++
> include/linux/psci.h | 5 +
> 25 files changed, 953 insertions(+), 44 deletions(-)
> create mode 100644 arch/arm64/include/asm/mem_encrypt.h
> create mode 100644 arch/arm64/include/asm/rsi.h
> create mode 100644 arch/arm64/include/asm/rsi_cmds.h
> create mode 100644 arch/arm64/include/asm/rsi_smc.h
> create mode 100644 arch/arm64/kernel/rsi.c
> create mode 100644 drivers/virt/coco/arm-cca-guest/Kconfig
> create mode 100644 drivers/virt/coco/arm-cca-guest/Makefile
> create mode 100644 drivers/virt/coco/arm-cca-guest/arm-cca-guest.c

Any chance of some documentation, please?

Cheers,

Will