On 12/11/2024 10:49 am, Jan Beulich wrote: > On 12.11.2024 11:36, Andrew Cooper wrote: >> On 07/11/2024 9:58 pm, Andrew Cooper wrote: >>> On 07/11/2024 12:21 pm, Andrew Cooper wrote: >>>> With the tangle of logic starting to come under control, it is now plain to >>>> see that parse_blob()'s side effect of re-gathering the signature/revision >>>> is >>>> pointless. >>>> >>>> The cpu_request_microcode() hooks need the signature only. The BSP gathers >>>> this in early_microcode_init(), the APs and S3 in microcode_update_cpu(). >>>> For >>>> good measure, the apply_microcode() hooks also keep the revision correct as >>>> load attempts are made. >>>> >>>> This finally gets us down to a single call per CPU on boot / S3 resume, >>>> and no >>>> calls during late-load hypercalls. >>>> >>>> No functional change. >>>> >>>> Signed-off-by: Andrew Cooper <[email protected]> >>>> --- >>>> CC: Jan Beulich <[email protected]> >>>> CC: Roger Pau Monné <[email protected]> >>>> >>>> Slightly RFC. >>>> >>>> Just before posting, I've realised that cpu_request_microcode() does >>>> actually >>>> use the current CPU revision, and it's buggy, and it's the cause of >>>> `xen-ucode >>>> --force` not working as expected. >>>> >>>> I'm tempted to do another series cleaning that up in isolation, such that >>>> this >>>> patch becomes true in this form. >>> Actually no. Having tried a bit, I think it's easier to do with patch 2 >>> already in place. >>> >>> So instead I'm tempted to edit the middle paragraph to note that it >>> currently uses the revision but that's going to be fixed shortly. The >>> rest of the paragraph explains why it's still safe anyway. >> So, after the latter series, this patch happens to be accurate. >> >> cpu_request_microcode() does read the revision, but discards the result >> of the calculation which used it. > What's the intended overall sequence of patches then? With two series that > (aiui) now have grown some sort of dependency, and with this series have > gained a 4/3 patch, having a clear picture would certainly help. Might it > be best if you merge both series and re-submit as a single one?
The order turns out to be as emailed out and threaded. ~Andrew
