On Fri, Aug 12, 2011 at 07:35:42AM +0200, Alexander Graf wrote: > > Am 12.08.2011 um 05:33 schrieb David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>: > > > On Tue, Aug 09, 2011 at 06:31:47PM +0200, Alexander Graf wrote: > >> PAPR defines hypercalls as SC1 instructions. Using these, the guest modifies > >> page tables and does other privileged operations that it wouldn't be allowed > >> to do in supervisor mode. > >> > >> This patch adds support for PR KVM to trap these instructions and route them > >> through the same PAPR hypercall interface that we already use for HV style > >> KVM. > > > > This will work on a powermac or bare metal host. Unfortunately, it's > > not enough on a pSeries LPAR host - the sc 1 instruction from the > > guest problem state will go direct to the hypervisor, which will > > return an error rather than trapping to the guest kernel. > > > > The only way around this I can see is for qemu to search for and patch > > up sc 1 instructions to something else. Obviously that would also > > need some kernel support, and probably a capability to let it know if > > it's necessary. > > Well I'd like to keep Qemu out of the patching business, so the > guest kernel would have to patch itself. Well sure, but guest patching itself means it can't run existing kernels. I thought qemu already patched a few things, ugly though that approach is. > But yes, PHyP guests can't > run this target yet :). I'll take a stab at that too, but one > continent at a time! ;) -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
