On Thu, Feb 14, 2013 at 01:13:18PM +0100, Paolo Bonzini wrote: > Il 14/02/2013 12:18, Eduardo Habkost ha scritto: > >> > qemu boots from disk image 3 times faster than direct kernel load. > > That's surprising. Do you have any idea why that happens? > > Because kernel load uses MMIO (from fw_cfg), while booting from disk > uses at worst PCI DMA and at best virtio.
Is it something worth trying to optimize, or a reasonable solution would be so similar to having a disk+bootloader that's easier to simply recommend people to set up a real disk with a real bootloader if they care about speed? -- Eduardo
