Hi Oleksandr, Stefano,

Oleksandr olekstysh@gmail.com writes:

On 07.10.21 01:42, Stefano Stabellini wrote:

Hi Stefano, Julien.

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On Wed, 6 Oct 2021, Julien Grall wrote:

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Hi Stefano,

On 28/09/2021 06:52, Stefano Stabellini wrote:

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On Mon, 27 Sep 2021, Oleksandr Tyshchenko wrote:

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From: Oleksandr Tyshchenko oleksandr_tyshchenko@epam.com

Fix a possible copy-paste error in arm_smccc_smc's first argument (a0) for OPTEE_SMC_DISABLE_SHM_CACHE case.

This error causes Linux > v5.14-rc5 (b5c10dd04b7418793517e3286cde5c04759a86de optee: Clear stale cache entries during initialization) to stuck repeatedly issuing OPTEE_SMC_DISABLE_SHM_CACHE call and waiting for the result to be OPTEE_SMC_RETURN_ENOTAVAIL which will never happen.

Signed-off-by: Oleksandr Tyshchenko oleksandr_tyshchenko@epam.com

Acked-by: Stefano Stabellini sstabellini@kernel.org

I added Fixes: and Backport: tags to the commit

Per SUPPORT.MD, OP-TEE is still a technical preview. So I would argue that we should not do any backport because the feature itself is not officially considered supported.

Good point!

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That said, what's missing to make the feature officially supported?

If Oleksandr is also happy to make OP-TEE support in Xen "Supported" in SUPPORT.md I'd be happy with that too. Specifically I suggest to change it to:

Status: Supported, not security supported

Security Support is a bit of a heavy process and I am thinking that "Supported, not security supported" would be an excellent next step.

I would be happy, and can send a formal patch. But I am not an expert in this code.

I'm will be happy with this too. We are using this mediator in our projects and I know that OP-TEE community adopted tests for virtualization in theirs CI stack. So this is kind of official now.

Also, I helped other people to bring up virtualization on theirs platforms, so there are other users for this feature besides EPAM and Linaro.

(looks like there are some TODO left in the code and I have no idea what are the implications)

Well, there were a lot of TODOs when I submitted initial implementation. At that time it indeed wasn't ready for production. But I eventually fixed almost all of them. Only one left now. It is about very unlikely situation when one of guest pages in mapped at PA=0. I'm not sure that is even possible at all.