Re: [PATCH] x86: Add a Kconfig shortcut for a kvm-bootable kernel

Borislav Petkov
2013-04-17T07:50:44Z

On Tue, Apr 16, 2013 at 08:38:56PM -0400, Sasha Levin wrote:
> > select NET
> > select NETDEVICES
> > select PCI
> > select BLOCK
> > select BLK_DEV
> > select NETWORK_FILESYSTEMS
> > select INET
> > select EXPERIMENTAL
> > select TTY
> > select SERIAL_8250
> > select SERIAL_8250_CONSOLE
> > select IP_PNP
> > select IP_PNP_DHCP
> > select BINFMT_ELF
> > select PCI_MSI
> > select HAVE_ARCH_KGDB
> > select DEBUG_KERNEL
> > select KGDB
> > select KGDB_SERIAL_CONSOLE
> > select VIRTUALIZATION
> > select VIRTIO
> > select VIRTIO_RING
> > select VIRTIO_PCI
> > select VIRTIO_BLK
> > select VIRTIO_CONSOLE
> > select VIRTIO_NET
> > select 9P_FS
> > select NET_9P
> > select NET_9P_VIRTIO
> >
> > to the option below which we already have. It is in the same sense a KVM
> > guest support deal.
> >
> > Hmm.
> >
> > KVM people, any objections?
> >
> > config KVM_GUEST
> > bool "KVM Guest support (including kvmclock)"
> > depends on PARAVIRT
> > select PARAVIRT_CLOCK
> > default y
> > ---help---
> > This option enables various optimizations for running under the KVM
> > hypervisor. It includes a paravirtualized clock, so that instead
> > of relying on a PIT (or probably other) emulation by the
> > underlying device model, the host provides the guest with
> > timing infrastructure such as time of day, and system time
>
> KVM guests don't need a serial device, KGDB, DEBUG_KERNEL or 9p in particular.

Let's see:

* we need serial device for catching serial output on the host from the guest
kernel

* KGDB - I guess this was meant to jump into the debugger when the guest crashes
or so, we could drop it.

* DEBUG_KERNEL is also good for testing kernels
* 9p is needed for -virtfs folder sharing, AFAICT: http://wiki.qemu.org/Documentation/9psetup

So, I guess we can have another KVM_GUEST_KERNEL_TESTING option which
enables those additional, good for debugging options (except 9p - it
should be in the main thing) and which depends on KVM_GUEST. It would also
contain other DEBUG_* stuff.

Thanks.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
--