On Tue, 29 Mar 2011 08:09:09 -0500 Jimi Xenidis <jimix@xxxxxxxxx> wrote: > > On Mar 29, 2011, at 4:18 AM, Alexander Graf wrote: > > > > > On 28.03.2011, at 21:15, Scott Wood wrote: > > > >> Return the actual host SVR. On e500, qemu currently pretends in the device > >> tree to be an mpc8544 regardless of what the host is, but that's something > >> that ought to be changed. > > > > Let's please keep the abstraction layers intact. I really don't want to see any real hardware information leak through inside emulate.c. SVR should be implemented the same way as PVR. > > > > Also, I don't think the register is actually meaningful on book3s. So it'd be good to move it to BookE specific code. > > It certainly not part of the powerpc 4xx core or the Book3E ISA, so please define it accordingly. Sorry, this should have gone in e500_emulate.c. As for letting real hardware info leak through, this is how PVR is handled on e500 as well in the existing code -- and for the use case of directly assigning peripherals to guests (which isn't supported upstream yet, but we've got it running locally (more patches to come...), and it's what our customers are interested in), you really don't want to confuse the guest about what hardware it's running on. OTOH, with Qemu-emulated devices we want the guest to know what chip's quirks are being emulated. It gets ugly if you want some directly-assigned devices and some emulated devices... Even when not assigning devices directly, some "leakage" is inevitable. E.g. SPE, normal FPU, neither? Errata? e500mc features (other than E.HV)? Later in the patchset I'm working through for upstream is sregs support, including SVR -- we can do Qemu-supplied PVR/SVR then, if needed. I think the default sregs should have the real PVR/SVR, so Qemu can read it and try to make its emulated devices behave consistently with it, if it's not a situation where telling the guest it's running on some completely different hardware is going to work well. If Qemu wants to override instead, it can. Note that the current situation without this patch is that the guest kernel fails to boot when the gianfar driver checks SVR for errata. -Scott -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
