[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v3 1/8] serial: fake IRQ-regs context in poll handlers
On Tue, Feb 13, 2024 at 08:45:54AM +0100, Jan Beulich wrote: > On 13.02.2024 04:43, Marek Marczykowski wrote: > > On Mon, Feb 12, 2024 at 10:04:38AM +0100, Jan Beulich wrote: > >> On 08.02.2024 23:00, Julien Grall wrote: > >>> On 05/02/2024 13:27, Jan Beulich wrote: > >>>> In preparation of dropping the register parameters from > >>>> serial_[rt]x_interrupt() and in turn from IRQ handler functions, > >>>> register state needs making available another way for the few key > >>>> handlers which need it. Fake IRQ-like state. > >>>> > >>>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> > >>>> --- > >>>> The use of guest_cpu_user_regs() in dbc_uart_poll() is inconsistent with > >>>> other console poll functions we have, and it's unclear whether that's > >>>> actually generally correct. > >>> > >>> Is it? Looking at ns16550_poll() we would pass guest_user_regs() if > >>> run_in_exception() doesn't exist. But looking at the caller, no-on seems > >>> to care about the 'regs'. So is this just a latent bug? > >> > >> What do you mean by "doesn't exist"? ns16550_poll() assumes it exists. > >> And I can spot any use of guest_user_regs() on the respective generic > >> or Arm-specific bug.c paths. > >> > >>> BTW, do you have an idea why the poll function is not run in an > >>> exception handler? > >> > >> "The poll function" being which one? If you mean the one in xhci-dbc.c > >> then that's why I had Cc-ed Marek. Moving him to To: - maybe that > >> manages to finally catch his attention. > > > > TBH, I don't know. That's part of the original xue patch at > > https://github.com/connojd/xue/blob/master/patches/xen-xue-dbgp.patch > > and it works for me as it is. > > "Works" meaning what? Doesn't crash on you? Or does also provide > sensible output in _all_ cases (i.e. including when e.g. the poll > happens to run on an idle vCPU)? Generally provides sensible output, for example during boot (it is using idle vCPU then, right?). -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab Attachment:
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