Hi Gerd, thanks for you prompt reply,
On Fri, 2018-11-30 at 14:48 +0100, Gerd Hoffmann wrote:
On Thu, Nov 29, 2018 at 05:37:41PM +0000, Rob Bradford wrote:
The virt machine in the NEMU project has the ambition to be a platform that has no emulated legacy hardware. This patch series enables support for that machine type in Seabios.
What exactly does "no legacy hardware" mean? Does that include lpc devices such as pit and pic?
That is correct, the host Linux kernel does provide some emulation of devices as part of KVM though.
What will seabios use as time source with -M virt? Seems there is no pmtimer ...
That is correct. There does not appear to negative side effects with lack of a time source when running Seabios against virt
(In the OVMF port I implement MicroSleep/NanoSleep with a KVM pvclock and TSC based solution but i'm currently evaluating if this can be a no-op as sleeping in a firmware is usually part of programming physical hardware which is something that is not required with the virt machine type.)
The impact that this has for a Seabios port is that the CMOS is not available to query details of CPUs or memory configuration; instead this patch series modifies the code that queries those details to prefer those from QEMU FW CFG over CMOS.
Doing that makes sense anyway, I'd say these three patches can be merged. The other two should wait until the qemu patches are merged, to be sure the pci ids are the final ones.
This PCI ID (0x8086 / 0x0d57) is from our internal registry which is allocated exclusively for the use of the PCI host bridge on the virt platform.
cheers, Gerd
Cheers,
Rob