On Mon, Jun 22, 2015 at 09:44:48AM +0100, Peter Maydell wrote: > On 17 June 2015 at 10:00, Suzuki K. Poulose <suzuki.poulose@xxxxxxx> wrote: > > From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx> > > > > This patch adds a generic ARM v8 KVM target cpu type for use > > by the new CPUs which eventualy ends up using the common sys_reg > > table. For backward compatibility the existing targets have been > > preserved. Any new target CPU that can be covered by generic v8 > > sys_reg tables should make use of the new generic target. > > How do you intend this to work for cross-host migration? > Is the idea that the kernel guarantees that "generic" looks > 100% the same to the guest regardless of host hardware? I'm > not sure that can be made to work, given impdef differences > in ID register values, bp/wp registers, and so on. > > Given that, it seems to me that we still need to provide > KVM_ARM_TARGET_$THISCPU defines so userspace can request > a specific guest CPU flavour; so what does this patch > provide that isn't already provided by just having userspace > query for the "preferred" CPU type as it does already? > I'm guessing the intention is to avoid having to add code in the kernel to support KVM on a new CPU where nothing else needs to be done to support KVM on that system. Wrt. migration, I was also wondering about this. Would the differences in the CPU architecture be detected when feeding back the invariant sysregs from userspace on VM restore? -Christoffer -- 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
