On Fri, Jun 18, 2021 at 09:54:14AM +0100, Alex Bennée wrote: > > Marek Marczykowski-Górecki <marma...@invisiblethingslab.com> writes: > > > Kernel on Xen is loaded via fw_cfg. Previously it used non-DMA version, > > which loaded the kernel (and initramfs) byte by byte. Change this > > to DMA, to load in bigger chunks. > > This change alone reduces load time of a (big) kernel+initramfs from > > ~10s down to below 1s. > > > > This change was suggested initially here: > > https://lore.kernel.org/xen-devel/20180216204031.00005...@gmail.com/ > > Apparently this alone is already enough to get massive speedup. > > > > Signed-off-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com> > > --- > > hw/i386/pc.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > index 8a84b25a03..14e43d4da4 100644 > > --- a/hw/i386/pc.c > > +++ b/hw/i386/pc.c > > @@ -839,7 +839,8 @@ void xen_load_linux(PCMachineState *pcms) > > > > assert(MACHINE(pcms)->kernel_filename != NULL); > > > > - fw_cfg = fw_cfg_init_io(FW_CFG_IO_BASE); > > + fw_cfg = fw_cfg_init_io_dma(FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4, > > + &address_space_memory); > > fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, x86ms->boot_cpus); > > rom_set_fw(fw_cfg); > > Gentle ping. The fix looks perfectly sane to me but I don't have any x86 > Xen HW to test this one. Are the x86 maintainers happy to take this on?
Ping... > > FWIW: > > Reviewed-by: Alex Bennée <alex.ben...@linaro.org> > > -- > Alex Bennée > -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab
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