On Fri, 18 Dec 2020 13:50:40 +1100 Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> The PAPR platform which describes an OS environment that's presented by > a combination of a hypervisor and firmware. The features it specifies > require collaboration between the firmware and the hypervisor. > > Since the beginning, the runtime component of the firmware (RTAS) has > been implemented as a 20 byte shim which simply forwards it to > a hypercall implemented in qemu. The boot time firmware component is > SLOF - but a build that's specific to qemu, and has always needed to be > updated in sync with it. Even though we've managed to limit the amount > of runtime communication we need between qemu and SLOF, there's some, > and it has become increasingly awkward to handle as we've implemented > new features. > > This implements a boot time OF client interface (CI) which is > enabled by a new "x-vof" pseries machine option (stands for "Virtual Open > Firmware). When enabled, QEMU implements the custom H_OF_CLIENT hcall > which implements Open Firmware Client Interface (OF CI). This allows > using a smaller stateless firmware which does not have to manage > the device tree. > > The new "vof.bin" firmware image is included with source code under > pc-bios/. It also includes RTAS blob. > > This implements a handful of CI methods just to get -kernel/-initrd > working. In particular, this implements the device tree fetching and > simple memory allocator - "claim" (an OF CI memory allocator) and updates > "/memory@0/available" to report the client about available memory. > > This implements changing some device tree properties which we know how > to deal with, the rest is ignored. To allow changes, this skips > fdt_pack() when x-vof=on as not packing the blob leaves some room for > appending. > > In absence of SLOF, this assigns phandles to device tree nodes to make > device tree traversing work. > > When x-vof=on, this adds "/chosen" every time QEMU (re)builds a tree. > > This adds basic instances support which are managed by a hash map > ihandle -> [phandle]. > > Before the guest started, the used memory is: > 0..4000 - the initial firmware > 10000..180000 - stack > > This OF CI does not implement "interpret". > > Unlike SLOF, this does not format uninitialized nvram. Instead, this > includes a disk image with pre-formatted nvram. > > With this basic support, this can only boot into kernel directly. > However this is just enough for the petitboot kernel and initradmdisk to > boot from any possible source. Note this requires reasonably recent guest > kernel with: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=df5be5be8735 > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > --- > > The example command line is: > > -c 0 /home/aik/pbuild/qemu-killslof-localhost-ppc64/qemu-system-ppc64 \ > -nodefaults \ > -chardev stdio,id=STDIO0,signal=off,mux=on \ > -device spapr-vty,id=svty0,reg=0x71000110,chardev=STDIO0 \ > -mon id=MON0,chardev=STDIO0,mode=readline \ > -nographic \ > -vga none \ > -enable-kvm \ > -m 2G \ > -machine > pseries,x-vof=on,cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken,cap-ccf-assist=off > \ > -kernel pbuild/kernel-le-guest/vmlinux \ > -initrd t/le.cpio \ > -drive > id=DRIVE0,if=none,file=./p/qemu-killslof/pc-bios/vof/nvram.bin,format=raw \ > -global spapr-nvram.drive=DRIVE0 \ > -snapshot \ > -smp 8,threads=8 \ > -L /home/aik/t/qemu-ppc64-bios/ \ > -trace events=qemu_trace_events \ > -d guest_errors \ > -chardev socket,id=SOCKET0,server,nowait,path=qemu.mon.tmux26 \ > -mon chardev=SOCKET0,mode=control > > --- > Changes: > v12: > * split VOF and SPAPR > Thanks for the split. The VOF paths are now clearly identified in the sPAPR code, and well guarded by a check on x-vof. Rest of the patch looks good to me. I gave it a try with a stock fedora 33 kernel and initramfs and it booted really fast ! With the checkpatch complaints addressed, Acked-by: Greg Kurz <gr...@kaod.org> and Tested-by: Greg Kurz <gr...@kaod.org>