Hi,
On 22.08.18 20:28, Julien Grall wrote:
Hi,
Please only CC relevant people to the patches. This could be done easily using the new script add_maintainers.pl.
Oh, I'm sorry. I used get_maintainers.pl.
On 22/08/18 15:11, Volodymyr Babchuk wrote:
Add OP-TEE mediator, so guests can access OP-TEE services.
OP-TEE mediator support address translation for DomUs. It tracks execution of STD calls, correctly handles memory-related RPC requests, tracks buffer allocated for RPCs.
With this patch OP-TEE sucessfully passes own tests, while client is running in DomU.
Signed-off-by: Volodymyr Babchuk volodymyr_babchuk@epam.com
Changes from "RFC": - Removed special case for Dom0/HwDOM - No more support for plain OP-TEE (only OP-TEE with virtualization config enabled is supported) - Multiple domains is now supported - Pages that are shared between OP-TEE and domain are now pinned - Renamed CONFIG_ARM_OPTEE to CONFIG_OPTEE - Command buffers from domain are now shadowed by XEN - Mediator now filters out unknown capabilities and requests - call contexts, shared memory object now stored per-domain
xen/arch/arm/tee/Kconfig | 4 + xen/arch/arm/tee/Makefile | 1 + xen/arch/arm/tee/optee.c | 972 ++++++++++++++++++++++++++++++++++++
This patch is far to big to get a proper review with understanding of the code. Can you split it in smaller ones with appropriate commit message?
Yes, it is a quite big. But this is a complete feature. I can't remove anything from it, because it will not work. I can split it into series of patches, that will add various pieces of code... But this will lead to patches with not-working code until the final one. Is this okay?
From a quick look at it, I would like to understand how the memory allocated in Xen is bounded for a given guest? Same question for the time.
I store references to allocated pages in per-domain context. But they are not accounted as a domain memory. This pages are needed by XEN to conceal real PAs from guest. I'm not sure it they should be accounted as a memory allocated by domain.
And what about a time? Did you mean time accounting?
I am interested in a normal case but also in the case where someone malicious is using that API. How much damage can it do to the hypervisor?
Every standard (long-lasting) call requires small amount of memory to store context. Every shared buffer requires enough memory to store references to shared pages. OP-TEE has limited resources, so it will not allow you to create, say, 100 calls and couple of GBs of shared memory. I expect that it will limit caller in memory overuse.
Apart from that I can't imagine how malicious user can damage the hypervisor.