On 17/10/2019 14:23, Peter Maydell wrote: > This patchset converts the devices used by sparc machines to the new > ptimer API. > > Currently the ptimer design uses a QEMU bottom-half as its mechanism > for calling back into the device model using the ptimer when the > timer has expired. Unfortunately this design is fatally flawed, > because it means that there is a lag between the ptimer updating its > own state and the device callback function updating device state, and > guest accesses to device registers between the two can return > inconsistent device state. This was reported as a bug in a specific > timer device but it's a problem with the generic ptimer code: > https://bugs.launchpad.net/qemu/+bug/1777777 > > The updates to the individual ptimer devices are straightforward: > we need to add begin/commit calls around the various places that > modify the ptimer state, and use the new ptimer_init() function > to create the timer. > > Testing has been 'make check', and a quick smoke test of a sparc > linux boot image I had lying around, which obviously doesn't > exercise the devices very much, so more specific testing would > be appreciated. I'm happy for these patches to go in via the > sparc tree if you want, or I can collect them up with the other > ptimer-related changes I'm sending for other archs. > > thanks > --PMM
I've given these patches a spin on my OpenBIOS test images and I don't see any obvious regressions, so for the sun4m (slavio) part: Tested-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> Frederic, are you able to make sure that the leon3 parts don't cause any problems? Currently I don't have any outstanding SPARC patches, so if you want to include them in a ptimer-related PR then that's fine with me. ATB, Mark.
