Messages in this thread | | | Date | Thu, 28 Mar 2024 14:57:54 +0000 | From | Conor Dooley <> | Subject | Re: [PATCH 2/2] riscv: T-Head: Test availability bit before enabling MAEE errata |
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On Thu, Mar 28, 2024 at 03:18:22PM +0100, Christoph Müllner wrote:
> Switching from th.mxstatus to th.sxstatus should address all mentioned concerns: > * no dependency on OpenSBI changes > * no break of functionality > * no need for graceful handling of CSR read failures > * no need to differentiate between HW and emulation (assuming QEMU > accepts the emulation of th.sxstatus)
Yah, th.sxstatus seems ideal here, provided it is accepted by QEMU - but if they allow th.mxstatus I would hope emulating th.sxstatus would be okay too.
> Also note that DT handling would be difficult, because we need to probe before > setting up the page table.
IIRC the kaslr seed is also read from DT prior to calling the early alternatives stuff, so while it would be a bit more annoying than usual I do think it is possible. My (naive) hope here though is that we don't actually have to deal with this scenario though, as things like the c908 support Svpbmt as well as the maee version. For the k230 the plan is to use both Zicbom and Svpbmt rather than the non-standard T-Head alternatives: https://lore.kernel.org/all/tencent_DF5D7CD182AFDA188E0FB80E314A21038D08@qq.com/
Cheers, Conor. [unhandled content-type:application/pgp-signature] | |