Virtualization - Apr 2007 - Xen i386 paravirtualization support

Hi,Chris?
    I wonder which version of Xen did the para-Linux works with.
I applied the patches, compiled them and tried them on both xen-3.0.2 
and the latest xen-unstable. 
	Both result in panics when booting Xen and complain as follows:
(XEN) Domain 0 kernel supports features = { 00000005 }.
(XEN) Domain 0 kernel requires features = { 00000005 }.
(XEN)
(XEN) ****************************************
(XEN) Panic on CPU 0:
(XEN) Domain 0 requires an unsupported hypervisor feature.
(XEN) ****************************************

It seems that the xen loader for dom0 isn't compatible with the para-Linux.
I tried to fix it by replacing the XEN_FEATURE string in head.S
from 
     .ascii	",FEATURES= !writable_page_tables"
	 .ascii		 "|!auto_translated_physmap"
to 
     .ascii	",FEATURES= writable_page_tables"
	 .ascii		 "| auto_translated_physmap"
Then booting Xen succeeds for Xen-unstable and hangs when booting Linux and 
reports the following message:
(XEN) domain_crash called from mm.c:1783
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-3.0-unstable    Not tainted ]----
(XEN) CPU:    0
(XEN) EIP:    e019:[<c02ce06a>]
(XEN) EFLAGS: 00010287   CONTEXT: guest
(XEN) eax: 002f7000   ebx: 00000000   ecx: c02f7fb8   edx: c02f7fbc
(XEN) esi: 00000000   edi: c02f9eec   ebp: c02c3ff8   esp: c02c3fc0
(XEN) cr0: 8005003b   cr3: 001a0000
(XEN) ds: e021   es: e021   fs: 0000   gs: 0000   ss: e021   cs: e019
(XEN) Guest stack trace from esp=c02c3fc0:
(XEN)   Fault while accessing guest memory.
(XEN) Domain 0 crashed: rebooting machine in 5 seconds.     

Thanks.

======= 2006-07-18 17:20:03 You wrote?======>Unlike full virtualization in
which the virtual machine provides 
>the same platform interface as running natively on the hardware,
>paravirtualization requires modification to the guest operating system
>to work with the platform interface provided by the hypervisor.
>
>Xen was designed with performance in mind.  Calls to the hypervisor
>are minimized, batched if necessary, and non-critical codepaths are left
>unmodified in the case where the privileged instruction can be trapped and
>emulated by the hypervisor.  The Xen API is designed to be OS agnostic and
>has had Linux, NetBSD, FreeBSD, Solaris, Plan9 and Netware ported to it.
>Xen also provides support for running directly on native hardware.
>

haibo chen wrote:
> Hi,Chris?
>     I wonder which version of Xen did the para-Linux works with.
> I applied the patches, compiled them and tried them on both xen-3.0.2 
> and the latest xen-unstable. 
>   
The patches only implement domU, so you can't use the kernel as dom0. In
general that patch series is primarily for review; if you're interested
in actually using Xen, the xen-unstable tree is a better bet for now.

J

* haibo chen (hbchen@fudan.edu.cn) wrote:
> Hi,Chris?
>     I wonder which version of Xen did the para-Linux works with.
> I applied the patches, compiled them and tried them on both xen-3.0.2 
> and the latest xen-unstable. 
> 	Both result in panics when booting Xen and complain as follows:
> (XEN) Domain 0 kernel supports features = { 00000005 }.
> (XEN) Domain 0 kernel requires features = { 00000005 }.
> (XEN)
> (XEN) ****************************************
> (XEN) Panic on CPU 0:
> (XEN) Domain 0 requires an unsupported hypervisor feature.
> (XEN) ****************************************
> 
> It seems that the xen loader for dom0 isn't compatible with the
para-Linux.
This patchset is for domU only.  You still need a dom0 from upstream
xen.  Thanks for testing these patches.

thanks,
-chris