[PATCH v2 00/13] Secure Virtual Machine Enablement

[Thiago Jung Bauermann]

Hello,

The main change in this version was to rebase on top of <asm/mem_encrypt.h>
cleanup series I just posted:

https://lore.kernel.org/linuxppc-dev/20190713044554.28719-1-bauerman@xxxxxxxxxxxxx/

In addition to the patches above, this patch series applies on top of v4 of
Claudio Carvalho's "kvmppc: Paravirtualize KVM to support ultravisor"
series:

https://lore.kernel.org/linuxppc-dev/20190628200825.31049-1-cclaudio@xxxxxxxxxxxxx/

I only actually need the following two patches from his series:

[PATCH v4 1/8] KVM: PPC: Ultravisor: Introduce the MSR_S bit
[PATCH v4 3/8] KVM: PPC: Ultravisor: Add generic ultravisor call handler

Everything is available in branch ultravisor-secure-vm at this repo:

https://github.com/bauermann/linux.git

Original cover letter below, and changelog at the bottom:

This series enables Secure Virtual Machines (SVMs) on powerpc. SVMs use the
Protected Execution Facility (PEF) and request to be migrated to secure
memory during prom_init() so by default all of their memory is inaccessible
to the hypervisor. There is an Ultravisor call that the VM can use to
request certain pages to be made accessible to (or shared with) the
hypervisor.

The objective of these patches is to have the guest perform this request
for buffers that need to be accessed by the hypervisor such as the LPPACAs,
the SWIOTLB memory and the Debug Trace Log.

Patch 2 ("powerpc: Add support for adding an ESM blob to the zImage
wrapper") is posted as RFC because we are still finalizing the details on
how the ESM blob will be passed along with the kernel. All other patches are
(hopefully) in upstreamable shape and don't depend on this patch.

Unfortunately this series still doesn't enable the use of virtio devices in
the secure guest. This support depends on a discussion that is currently
ongoing with the virtio community:

https://lore.kernel.org/linuxppc-dev/87womn8inf.fsf@xxxxxxxxxxxxxxxxxxxxx/

I was able to test it using Claudio's patches in the host kernel, booting
normally using an initramfs for the root filesystem.

This is the command used to start up the guest with QEMU 4.0:

qemu-system-ppc64				\
	-nodefaults				\
	-cpu host				\
	-machine pseries,accel=kvm,kvm-type=HV,cap-htm=off,cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken \
	-display none				\
	-serial mon:stdio			\
	-smp 1					\
	-m 4G					\
	-kernel /root/bauermann/vmlinux		\
	-initrd /root/bauermann/fs_small.cpio	\
	-append 'debug'

Changelog

Since v1:

- Patch "powerpc/pseries: Introduce option to build secure virtual machines"
  - Dropped redundant "default n" from CONFIG_PPC_SVM. Suggested by Christoph
    Hellwig.

- Patch "powerpc: Add support for adding an ESM blob to the zImage wrapper"
  - Renamed prom_rtas_os_term_hcall() to prom_rtas_hcall(). Suggested by Alexey
    Kardashevskiy.
  - In prom_rtas_hcall(), changed prom_printf() calls to prom_debug(), and
    use H_RTAS constant instead of raw value.
  - Changed enter_secure_mode() to new ABI passing ucall number in r3.
    Also changed it to accept kbase argument instead of ESM blob address.
  - Changed setup_secure_guest() to only make the ESM ultracall if svm=1 was
    passed on the kernel command line.

- Patch "powerpc/pseries/svm: Unshare all pages before kexecing a new kernel"
  - New patch from Ram Pai.

- Patch "powerpc/pseries/svm: Force SWIOTLB for secure guests"
  - No need to define sme_me_mask, sme_active() and sev_active() anymore.
  - Add definitions for mem_encrypt_active() and force_dma_unencrypted().
  - Select ARCH_HAS_FORCE_DMA_UNENCRYPTED in CONFIG_PPC_SVM.

Since the RFC from August:

- Patch "powerpc/pseries: Introduce option to build secure virtual machines"
  - New patch.

- Patch "powerpc: Add support for adding an ESM blob to the zImage wrapper"
  - Patch from Benjamin Herrenschmidt, first posted here:
    https://lore.kernel.org/linuxppc-dev/20180531043417.25073-1-benh@xxxxxxxxxxxxxxxxxxx/
  - Made minor adjustments to some comments. Code is unchanged.

- Patch "powerpc/prom_init: Add the ESM call to prom_init"
  - New patch from Ram Pai and Michael Anderson.

- Patch "powerpc/pseries/svm: Add helpers for UV_SHARE_PAGE and UV_UNSHARE_PAGE"
  - New patch from Ram Pai.

- Patch "powerpc/pseries: Add and use LPPACA_SIZE constant"
  - Moved LPPACA_SIZE macro inside the CONFIG_PPC_PSERIES #ifdef.
  - Put sizeof() operand left of comparison operator in BUILD_BUG_ON()
    macro to appease a checkpatch warning.

- Patch "powerpc/pseries/svm: Use shared memory for LPPACA structures"
  - Moved definition of is_secure_guest() helper to this patch.
  - Changed shared_lppaca and shared_lppaca_size from globals to static
    variables inside alloc_shared_lppaca().
  - Changed shared_lppaca to hold virtual address instead of physical
    address.

- Patch "powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL)"
  - Add get_dtl_cache_ctor() macro. Suggested by Ram Pai.

- Patch "powerpc/pseries/svm: Export guest SVM status to user space via sysfs"
  - New patch from Ryan Grimm.

- Patch "powerpc/pseries/svm: Disable doorbells in SVM guests"
  - New patch from Sukadev Bhattiprolu.

- Patch "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests"
  - New patch.

- Patch "powerpc/pseries/svm: Force SWIOTLB for secure guests"
  - New patch with code that was previously in other patches.

- Patch "powerpc/configs: Enable secure guest support in pseries and ppc64 defconfigs"
  - New patch from Ryan Grimm.

- Patch "powerpc/pseries/svm: Detect Secure Virtual Machine (SVM) platform"
  - Dropped this patch by moving its code to other patches.

- Patch "powerpc/svm: Select CONFIG_DMA_DIRECT_OPS and CONFIG_SWIOTLB"
  - No need to select CONFIG_DMA_DIRECT_OPS anymore. The CONFIG_SWIOTLB
    change was moved to another patch and this patch was dropped.

- Patch "powerpc/pseries/svm: Add memory conversion (shared/secure) helper functions"
  - Dropped patch since the helper functions were unnecessary wrappers
    around uv_share_page() and uv_unshare_page().

- Patch "powerpc/svm: Convert SWIOTLB buffers to shared memory"
  - Squashed into patch "powerpc/pseries/svm: Force SWIOTLB for secure
    guests"

- Patch "powerpc/svm: Don't release SWIOTLB buffers on secure guests"
  - Squashed into patch "powerpc/pseries/svm: Force SWIOTLB for secure
    guests"

- Patch "powerpc/svm: Use SWIOTLB DMA API for all virtio devices"
  - Dropped patch. Enablement of virtio will use a difference approach.

- Patch "powerpc/svm: Force the use of bounce buffers"
  - Squashed into patch "powerpc/pseries/svm: Force SWIOTLB for secure
    guests"
  - Added comment explaining why it's necessary.to force use of SWIOTLB.
    Suggested by Christoph Hellwig.

- Patch "powerpc/svm: Increase SWIOTLB buffer size"
  - Dropped patch.

Anshuman Khandual (3):
  powerpc/pseries/svm: Use shared memory for LPPACA structures
  powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL)
  powerpc/pseries/svm: Force SWIOTLB for secure guests

Benjamin Herrenschmidt (1):
  powerpc: Add support for adding an ESM blob to the zImage wrapper

Ram Pai (3):
  powerpc/prom_init: Add the ESM call to prom_init
  powerpc/pseries/svm: Add helpers for UV_SHARE_PAGE and UV_UNSHARE_PAGE
  powerpc/pseries/svm: Unshare all pages before kexecing a new kernel

Ryan Grimm (2):
  powerpc/pseries/svm: Export guest SVM status to user space via sysfs
  powerpc/configs: Enable secure guest support in pseries and ppc64
    defconfigs

Sukadev Bhattiprolu (1):
  powerpc/pseries/svm: Disable doorbells in SVM guests

Thiago Jung Bauermann (3):
  powerpc/pseries: Introduce option to build secure virtual machines
  powerpc/pseries: Add and use LPPACA_SIZE constant
  powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests

 .../admin-guide/kernel-parameters.txt         |  5 +
 arch/powerpc/boot/main.c                      | 41 ++++++++
 arch/powerpc/boot/ops.h                       |  2 +
 arch/powerpc/boot/wrapper                     | 24 ++++-
 arch/powerpc/boot/zImage.lds.S                |  8 ++
 arch/powerpc/configs/ppc64_defconfig          |  1 +
 arch/powerpc/configs/pseries_defconfig        |  1 +
 arch/powerpc/include/asm/mem_encrypt.h        | 26 +++++
 arch/powerpc/include/asm/svm.h                | 31 ++++++
 arch/powerpc/include/asm/ultravisor-api.h     |  4 +
 arch/powerpc/include/asm/ultravisor.h         | 23 ++++-
 arch/powerpc/kernel/Makefile                  |  4 +-
 arch/powerpc/kernel/machine_kexec_64.c        |  8 ++
 arch/powerpc/kernel/paca.c                    | 52 +++++++++-
 arch/powerpc/kernel/prom_init.c               | 99 +++++++++++++++++++
 arch/powerpc/kernel/sysfs.c                   | 29 ++++++
 arch/powerpc/platforms/pseries/Kconfig        | 14 +++
 arch/powerpc/platforms/pseries/Makefile       |  1 +
 arch/powerpc/platforms/pseries/iommu.c        |  6 +-
 arch/powerpc/platforms/pseries/setup.c        |  5 +-
 arch/powerpc/platforms/pseries/smp.c          |  3 +-
 arch/powerpc/platforms/pseries/svm.c          | 85 ++++++++++++++++
 22 files changed, 459 insertions(+), 13 deletions(-)
 create mode 100644 arch/powerpc/include/asm/mem_encrypt.h
 create mode 100644 arch/powerpc/include/asm/svm.h
 create mode 100644 arch/powerpc/platforms/pseries/svm.c