On 30/10/13 17:06, Anup Patel wrote: > On Wed, Oct 30, 2013 at 1:58 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> On 2013-10-30 01:10, Anup Patel wrote: >>> >>> On Wed, Oct 30, 2013 at 12:19 AM, Marc Zyngier <marc.zyngier@xxxxxxx> >>> wrote: >>>> >>>> Do the necessary byteswap when host and guest have different >>>> views of the universe. Actually, the only case we need to take >>>> care of is when the guest is BE. All the other cases are naturally >>>> handled. >>> >>> >>> You might want to handle the case where we have LE guest on BE host >>> because for ARM64 kernel we might have lot of people interested in >>> running host kernel in BE mode with KVM enabled. >> >> >> What makes you think it is not handled already? > > What I understood here is that you are trying to ensure that MMIO data > passed to/from user space (i.e. QEMU or KVMTOOL) is host endian > using vcpu_data_guest_to_host() and vcpu_data_host_to_guest(). This > makes lot of sense for having all combinations of host and guest endianness. > > If the above is correct then I see an issue in vcpu_data_guest_to_host() and > vcpu_data_host_to_guest() for LE guest on BE host because this patch does > endianness conversion for BE VCPUs only in vcpu_data_guest_to_host() and > vcpu_data_host_to_guest(). If we have LE guest on BE host then these > functions won't do any endianness conversion. And no conversion is exactly what we want. MMIO is always LE. M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
