Re: [Qemu-devel] [PATCH v4] Add optionrom compatible with fw_cfg DMA version

[Richard W.M. Jones]

My notes on this patch:

* It applies and compiles fine with current qemu on Linux/x86_64 host.
  However after building I had to do:

  cp pc-bios/optionrom/linuxboot_dma.bin pc-bios/

  I wasn't sure if that was supposed to be done automatically.

* It reduces libguestfs appliance boot time by about ½ second
  (2.00 s -> 1.53 s), so that's excellent.

* Overhead of BIOS-to-kernel drops from nearly 50% to under 20% of the
  total libguestfs appliance boot time.  SeaBIOS is still using 0.27
  seconds, of which at least 0.12 seconds is PCI bus scanning.

Anyway, all in all, a good change!

Rich.

-- 
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