[RFC] Initial virtualization support #1910
Conversation
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Oops. I accidentally pushed my local patch, which produces binary file ready to flashing with JTAG. Please ignore it. |
Added virtualization.c and virtualization.h files. Instead of term "virtual machine" I use term "client", because it is used in ARM SMC Calling Convention. I hope this will not be confusing. If CFG_VIRTUALIZATION is disabled, virtualization.h provides default client context. In this way, all code can be written in uniform way. Currently client context stores precached RPC command buffers and cache setings only. Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
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Removed that extra patch. XEN-side implementation lives there, if anyone is interested: https://github.com/lorc/xen/blob/optee/xen/arch/arm/tee/optee.c |
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@lorc Thanks |
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Hi @MrVan, Yes. This is why I'm doing this. My team is working on automotive platform, where components are isolated with virtualization. Suppose that OP-TEE needed both by Android (it will be used as infotaiment) system and by some other vendor-specific component. Proposed patches are hypervizor-agnostic. In the sense, that they can be used with any hypervisor. There are no XEN-specific parts. |
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Closing as a stale. |
Hello.
I want to discus how virtualization support can look in OP-TEE. This patch adds very basic support for it.
With this code I was able to use OP-TEE from two different VMs. Sequentially, of course. Currently, no cross-VM blocking is supported. I'll publish corresponding XEN code, if anyone is interested.
As I said in commit message, I try to move all client-bound global variables to a client context. Default client context will be used if virtualization is disabled. This adds small overhead (one extra
LDR, for variables access, I think), but it makes code more clean.Currently, only cached RPC commands buffers are stored in client context.
I don't ask you to do thorough code review. I just want to discuss proposed approach. This patch alone can't be used for production. On another hand, if you are okay with it, it can be merged with big warning "DO NOT enable CFG_VIRTULIZATION in production"
The biggest problem I see currently is thread termination if client VM dies in the middle of RPC. I propose to discuss this in #1890