On Thu, 29 Feb 2024 at 16:54, Sven Schnelle <sv...@stackframe.org> wrote: > > Peter Maydell <peter.mayd...@linaro.org> writes: > > > On Wed, 28 Feb 2024 at 21:12, Sven Schnelle <sv...@stackframe.org> wrote: > >> > >> HP-UX 10.20 seems to make the lsi53c895a spinning on a memory location > >> under certain circumstances. As the SCSI controller and CPU are not > >> running at the same time this loop will never finish. After some > >> time, the check loop interrupts with a unexpected device disconnect. > >> This works, but is slow because the kernel resets the scsi controller. > >> Instead of signaling UDC, add an option 'hpux-spin-workaround' which > >> emulates a INTERRUPT 2 script instruction. This instruction tells the > >> kernel that the request was fulfilled. With this change, SCSI speeds > >> improves significantly. > >> [..] > > I see we already have a hacky workaround for other OSes > > that do something similar. The ideal fix for both of these > > I think would be for lsi_execute_script() to, instead of stopping, > > arrange to defer executing more script instructions until > > after the guest has had a chance to run a bit more. > > I think setting a timer that calls lsi_resume_script() after > > a while would have that effect. > > Thanks, good idea. So something like this?
Yeah, something like that I think. (You probably want to delete the timer on reset, and you need to handle migration -- you can either put the timer state in a new vmstate section, or else in post-load if the state is 'LSI_WAIT_SCRIPTS' arm the timer.) Does it work? :-) -- PMM
