Re: [Qemu-devel] [PATCH v8 0/5] add ACPI node for fw_cfg on pc and arm

["Gabriel L. Somlo" <somlo@cmu.edu>]

On Thu, Feb 11, 2016 at 05:06:00PM -0500, Gabriel L. Somlo wrote:
> Generate an ACPI DSDT node for fw_cfg on pc and arm guests.
> 
> New since v7:
> 
> 	- edited commit blurb on 3/5 to match updated content, i.e. that
> 	  the ACPI node is now inserted into the DSDT (no longer the SSDT).
> 	  (Thanks to Igor Mammedov for catching that!)

BTW, regarding Igor's question about Windows starting to search for a
driver: Just for grins, I installed Windows 10 (with qemu git master
*before* this series was applied). Then, after applying the series,
DeviceManager was happy and had no unknown hardware listed.

Only after setting the fw_cfg _STA to 0x0F did I get an unknown device
like so: http://imagebin.ca/v/2XDUfONVF3bY

So, on XP, Windows 7, and Windows 10, the fw_cfg device showing up in
ACPI with a _STA set to 0x0B will *NOT* prompt the device manager to 
start making trouble :)

Thanks,
--Gabriel

> >New since v6:
> >	- rebased to fit on top of fb306ff and f264d36, which moved things
> >	  around in pc's acpi-build.c (only patch 3/5 affected);
> >	- kernel-side fw_cfg sysfs driver accepted into upstream linux
> >
> >>New since v5:
> >>
> >>	- rebased on top of latest QEMU git master
> >>
> >>>New since v4:
> >>>
> >>>	- rebased on top of Marc's DMA series
> >>>	- drop machine compat dependency for insertion into x86/ssdt
> >>>	  (patch 3/5), following agreement between Igor and Eduardo
> >>>	- [mm]io register range now covers DMA register as well, if
> >>>	  available.
> >>>	- s/bios/firmware in doc file updates
> >>>
> >>>>New since v3:
> >>>>
> >>>>	- rebased to work on top of 87e896ab (introducing pc-*-25 classes),
> >>>>	  inserting fw_cfg acpi node only for machines >= 2.5.
> >>>>
> >>>>	- reintroduce _STA with value 0x0B (bit 2 for u/i visibility turned
> >>>>	  off to avoid Windows complaining -- thanks Igor for catching that!)
> >>>>
> >>>>If there's any other feedback besides questions regarding the
> >>>>appropriateness of "QEMU0002" as the value of _HID, please don't hesitate!
> >>>>
> >>>>>New since v2:
> >>>>>
> >>>>>	- pc/i386 node in ssdt only on machine types *newer* than 2.4
> >>>>>	  (as suggested by Eduardo)
> >>>>>
> >>>>>I appreciate any further comments and reviews. Hopefully we can make
> >>>>>this palatable for upstream, modulo the lingering concerns about whether
> >>>>>"QEMU0002" is ok to use as the value of _HID, which I'll hopefully get
> >>>>>sorted out with the kernel crew...
> >>>>>
> >>>>>>New since v1:
> >>>>>>
> >>>>>>	- expose control register size (suggested by Marc Marí)
> >>>>>>
> >>>>>>	- leaving out _UID and _STA fields (thanks Shannon & Igor)
> >>>>>>
> >>>>>>	- using "QEMU0002" as the value of _HID (thanks Michael)
> >>>>>>
> >>>>>>	- added documentation blurb to docs/specs/fw_cfg.txt
> >>>>>>	  (mainly to record usage of the "QEMU0002" string with fw_cfg).
> >>>>>>
> >>>>>>> This series adds a fw_cfg device node to the SSDT (on pc), or to the
> >>>>>>> DSDT (on arm).
> >>>>>>>
> >>>>>>> 	- Patch 1/3 moves (and renames) the BIOS_CFG_IOPORT (0x510)
> >>>>>>> 	  define from pc.c to pc.h, so that it could be used from
> >>>>>>> 	  acpi-build.c in patch 2/3.
> >>>>>>> 
> >>>>>>> 	- Patch 2/3 adds a fw_cfg node to the pc SSDT.
> >>>>>>> 
> >>>>>>> 	- Patch 3/3 adds a fw_cfg node to the arm DSDT.
> >>>>>>>
> >>>>>>> I made up some names - "FWCF" for the node name, and "FWCF0001"
> >>>>>>> for _HID; no idea whether that's appropriate, or how else I should
> >>>>>>> figure out what to use instead...
> >>>>>>>
> >>>>>>> Also, using scope "\\_SB", based on where fw_cfg shows up in the
> >>>>>>> output of "info qtree". Again, if that's wrong, please point me in
> >>>>>>> the right direction.
> >>>>>>>
> >>>>>>> Re. 3/3 (also mentioned after the commit blurb in the patch itself),
> >>>>>>> I noticed none of the other DSDT entries contain a _STA field, wondering
> >>>>>>> why it would (not) make sense to include that, same as on the PC.
> 
> Gabriel L. Somlo (5):
>   fw_cfg: expose control register size in fw_cfg.h
>   pc: fw_cfg: move ioport base constant to pc.h
>   acpi: pc: add fw_cfg device node to dsdt
>   acpi: arm: add fw_cfg device node to dsdt
>   fw_cfg: document ACPI device node information
> 
>  docs/specs/fw_cfg.txt     |  9 +++++++++
>  hw/arm/virt-acpi-build.c  | 15 +++++++++++++++
>  hw/i386/acpi-build.c      | 29 +++++++++++++++++++++++++++++
>  hw/i386/pc.c              |  5 ++---
>  hw/nvram/fw_cfg.c         |  4 +++-
>  include/hw/i386/pc.h      |  2 ++
>  include/hw/nvram/fw_cfg.h |  3 +++
>  7 files changed, 63 insertions(+), 4 deletions(-)
> 
> -- 
> 2.4.3
>