Realms (CoCo VMs on ARM) require host calls to be routed through the RMM
(Realm Management Monitor) via the RSI (Realm Service Interface). This
series implements most of the necessary changes to support Realms on
Hyper-V.
One required change is not included in this series. The two buffers
allocated via vzalloc() in netvsc_init_buf() cannot be decrypted in
vmbus_establish_gpadl(). Currently only linearly mapped memory can be
decrypted.
This patch series was tested by booting a Realm on Cobalt 200 running
Windows. I tested 4KB and 64KB page size. I replaced vzalloc() in
netvsc_init_buf() with alloc_pages_node() -> set_memory_decrypted() ->
vmap() in my testing as a workaround for the issue mentioned above [1].
Changes since v1 [2]:
Patch 1: Add explicit padding to the RSI host call structure
Patch 3: Change from a per-cpu pointer lazily allocated to an array
of host call structs indexed by cpu id
Patch 4: Align input_page + output_page allocation to PAGE_SIZE since
that is the smallest unit of memory that can be decrypted
~Remove KASAN tags before passing address to
set_memory_decrypted() since __is_lm_address() does pointer
arithmetic.~
Patch 5: Add a helper function to reduce repetition
Check for NULL before indexing into host call array
Changes since v2 [3]:
Patch 3: Remove hv_hostcall_free() and inline the logic for simplicity
Reorder edits to keep #include line at the end of the file
Patch 4: Remove kasan_reset_tag()
[1]
https://lore.kernel.org/all/[email protected]/
[2]
https://lore.kernel.org/all/[email protected]/
[3]
https://lore.kernel.org/all/[email protected]/
Kameron Carr (6):
arm64: rsi: Add RSI host call structure and helper function
firmware: smccc: Detect hypervisor via RSI host call in CCA Realms
arm64: hyperv: Add per-CPU RSI host call infrastructure for CCA Realms
Drivers: hv: Mark shared memory as decrypted for CCA Realms
arm64: hyperv: Route hypercalls through RSI host call in CCA Realms
arm64: hyperv: Implement hv_is_isolation_supported() for CCA Realms
arch/arm64/hyperv/hv_core.c | 155 +++++++++++++++++++++++-------
arch/arm64/hyperv/mshyperv.c | 38 +++++++-
arch/arm64/include/asm/mshyperv.h | 4 +
arch/arm64/include/asm/rsi_cmds.h | 22 +++++
arch/arm64/include/asm/rsi_smc.h | 7 ++
drivers/firmware/smccc/smccc.c | 41 +++++++-
drivers/hv/hv_common.c | 17 +++-
include/asm-generic/mshyperv.h | 1 +
8 files changed, 244 insertions(+), 41 deletions(-)
base-commit: a4ffc59238be84dd1c26bf1c001543e832674fc6
--
2.45.4
