[PATCH 0/6] Support for running as a pKVM protected guest
Suzuki K Poulose
suzuki.poulose at arm.com
Wed Jul 31 06:55:13 PDT 2024
Hi Will,
On 30/07/2024 16:11, Will Deacon wrote:
> Hi folks,
>
> Since the patches for running as a CCA guest were posted already at [1],
> I figured it was worth posting the equivalent pKVM changes needed to run
> as a protected guest under an Android host kernel. In particular, I've
> tried to structure the code so that the CCA patches can use the same
> hooks. I'd welcome feedback from the CCA developers (i.e. Steven and
> Suzuki) as to whether this is sufficient.
Thanks for the patches ! The hooks for set_memory_*crypted() and the
ioremap_prot() looks fitting for the CCA support. We will cherry pick
those and base our next version on it. On a side note, this doesn't
solve the "fixmap" for earlycon. Hopefully, we can push something
based on this in the coming weeks.
Kind regards
Suzuki
>
> There are also some pKVM-specific details which are worth discussion:
>
> * I've kept the code compatible with Android, so these patches allow
> an upstream kernel to run as a protected guest on a production
> (unlocked) Android device. This seemed like a good property for v1,
> but I'm happy to break compatibility if folks prefer a cleaner
> interface (e.g. using consecutive hypercall numbers).
>
> * I've included only the hypercalls that are necessary for a
> functioning guest. Android has some others, but I'd prefer to land
> the host support upstream before we expose optional interfaces as
> ABI.
>
> * For now, the stage-2 page size cannot be larger than the guest
> stage-1 page size otherwise the guest will fail to boot.
>
> * I don't forcefully configure SWIOTLB, as we rely on Restricted DMA
> pools (CONFIG_DMA_RESTRICTED_POOL) for devices that need it.
>
> I also pushed a branch at [2] based on -rc1.
>
> Cheers,
>
> Will
>
> [1] https://lore.kernel.org/r/20240701095505.165383-1-steven.price@arm.com
> [2] git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git kvm/protected-guest
>
> Cc: Sudeep Holla <sudeep.holla at arm.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Lorenzo Pieralisi <lpieralisi at kernel.org>
> Cc: Suzuki Poulose <suzuki.poulose at arm.com>
> Cc: Steven Price <steven.price at arm.com>
> Cc: Oliver Upton <oliver.upton at linux.dev>
> Cc: Marc Zyngier <maz at kernel.org>
> Cc: linux-coco at lists.linux.dev
>
> --->8
>
> Marc Zyngier (1):
> firmware/smccc: Call arch-specific hook on discovering KVM services
>
> Will Deacon (5):
> drivers/virt: pkvm: Add initial support for running as a protected
> guest
> arm64: mm: Add top-level dispatcher for internal mem_encrypt API
> drivers/virt: pkvm: Hook up mem_encrypt API using pKVM hypercalls
> arm64: mm: Add confidential computing hook to ioremap_prot()
> drivers/virt: pkvm: Intercept ioremap using pKVM MMIO_GUARD hypercall
>
> Documentation/virt/kvm/arm/hypercalls.rst | 98 ++++++++++++++
> arch/arm/include/asm/hypervisor.h | 2 +
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/hypervisor.h | 11 ++
> arch/arm64/include/asm/io.h | 4 +
> arch/arm64/include/asm/mem_encrypt.h | 15 +++
> arch/arm64/include/asm/set_memory.h | 1 +
> arch/arm64/mm/Makefile | 2 +-
> arch/arm64/mm/ioremap.c | 23 +++-
> arch/arm64/mm/mem_encrypt.c | 50 +++++++
> drivers/firmware/smccc/kvm_guest.c | 2 +
> drivers/virt/coco/Kconfig | 2 +
> drivers/virt/coco/Makefile | 1 +
> drivers/virt/coco/pkvm-guest/Kconfig | 10 ++
> drivers/virt/coco/pkvm-guest/Makefile | 2 +
> drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c | 127 ++++++++++++++++++
> include/linux/arm-smccc.h | 28 ++++
> 17 files changed, 377 insertions(+), 2 deletions(-)
> create mode 100644 arch/arm64/include/asm/mem_encrypt.h
> create mode 100644 arch/arm64/mm/mem_encrypt.c
> create mode 100644 drivers/virt/coco/pkvm-guest/Kconfig
> create mode 100644 drivers/virt/coco/pkvm-guest/Makefile
> create mode 100644 drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c
>
More information about the linux-arm-kernel
mailing list