On Tue, 2007-09-18 at 23:52 +0200, Andi Kleen wrote: > On Tuesday 18 September 2007 23:34, Rusty Russell wrote: > > How about a "select" based on Xen, lguest or VMI? There's no other > > reason to enable it, after all. > > I did an patch to do that recently because the current setup > is indeed unobvious. > > But I had to drop it again because > it ended up with Kconfig warnings. about undefined symbols > on x86-64. The problem is that lguest > is visible in Kconfig for all architectures and it warns > if you select something that doesn't exist on all architectures. I think that's fixed as a side-effect of this cleanup. At least, it works for me on x86-64. Patch below: if you agree, I'll re-xmit all three. > > > Also I would still consider it experimental. > > > > After 9 months in mainline and three kernel versions, > > Well it changed a lot each release. Well, the biggest change was the patching code getting enhanced in 2.6.22 (to cover all calls, not just 5). The 22 -> 23 changes were fairly trivial. So I think 2.6.24 is a reasonable time to remove EXPERIMENTAL. > > I'd hope not. > > It's been pretty damn stable (ok, you broke it once, but maybe that's > > because you consider it experimental). > > Is there a significant user base? It's enabled in Ubuntu Feisty (2.6.20). > At least the Xen port seems to have specific requirements > and essentially only work on xen-unstable (?) [or at least > some very new Xen version] which probably very few > people use. Sure, and that might well still be experimental (Jeremy?). But that's not CONFIG_PARAVIRT. Hope that helps, Rusty. == Andi points out that PARAVIRT is an option best selected when needed. We introduce PARAVIRT_GUEST for the menu itself, and select PARAVIRT if they ask for anything which needs it. This also makes PARAVIRT non-experimental. Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> diff -r 8efa5fdb22d8 arch/i386/Kconfig --- a/arch/i386/Kconfig Wed Sep 19 11:23:18 2007 +1000 +++ b/arch/i386/Kconfig Wed Sep 19 11:33:59 2007 +1000 @@ -214,24 +214,30 @@ config X86_ES7000 endchoice -menuconfig PARAVIRT +config PARAVIRT + bool + depends on !(X86_VISWS || X86_VOYAGER) + help + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. However, when run without a hypervisor + the kernel is theoretically slower and slightly larger. + +menuconfig PARAVIRT_GUEST - bool "Paravirtualized guest support (EXPERIMENTAL)" - depends on EXPERIMENTAL + bool "Paravirtualized guest support" - depends on !(X86_VISWS || X86_VOYAGER) - help - Paravirtualization is a way of running multiple instances of - Linux on the same machine, under a hypervisor. This option - changes the kernel so it can modify itself when it is run - under a hypervisor, improving performance significantly. - However, when run without a hypervisor the kernel is - theoretically slower. If in doubt, say N. - -if PARAVIRT + help + Say Y here to get to see options related to running Linux under + various hypervisors. This option alone does not add any kernel code. + + If you say N, all options in this submenu will be skipped and disabled. + +if PARAVIRT_GUEST source "arch/i386/xen/Kconfig" config VMI bool "VMI Guest support" + select PARAVIRT help VMI provides a paravirtualized interface to the VMware ESX server (it could be used by other hypervisors in theory too, but is not @@ -239,6 +246,7 @@ config VMI config LGUEST_GUEST bool "Lguest guest support" + select PARAVIRT depends on !X86_PAE help Lguest is a tiny in-kernel hypervisor. Selecting this will diff -r 8efa5fdb22d8 arch/i386/xen/Kconfig --- a/arch/i386/xen/Kconfig Wed Sep 19 11:23:18 2007 +1000 +++ b/arch/i386/xen/Kconfig Wed Sep 19 11:25:07 2007 +1000 @@ -4,6 +4,7 @@ config XEN bool "Xen guest support" + select PARAVIRT depends on X86_CMPXCHG && X86_TSC && !NEED_MULTIPLE_NODES help This is the Linux Xen port. Enabling this will allow the _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
