On Mon, 15 Jul 2024 at 23:26, Philippe Mathieu-Daudé <phi...@linaro.org> wrote:
> Hi Phil, > > On 15/7/24 23:06, Phil Dennis-Jordan wrote: > > This change ensures that the MMIO write calls into the PVG > > framework are performed asynchronously on a background dispatch > > queue. Without this, we rapidly run into re-entrant MMIO issues. > > > > This problem only seems to exist on x86-64 hosts. Conversely, > > doing it async on arm64/vmapple causes other issues, > > Such as? > Sorry for being vague. I've just refreshed my memory by testing with async MMIO writes on aarch64, and the guest never manages to initialise the display at all. I've admittedly not attempted to debug through this in any significant way, though with PVG being something of a black box I'm not sure it's worth it. It works reliably on x86-64 with async writes, and on aarch64 with sync writes. I'll add comments to the #ifdefs for v2. Thanks, Phil
