We base it on the OS endian, as reflected by the endianness of the interrupt vectors (handled through the ILE bit in the LPCR register).
This patch implements virtio_get_byteswap() over LPCR. Using first_cpu to fetch the registers from KVM may look arbitrary and awkward, but it is okay because KVM sets/unsets the ILE bit on all CPUs. Changes in v3: - dropped the explicit calls to kvm_[get|put]_one_reg as LPCR is now properly handled by the generic SPR code. Changes in v2: - call cpu_synchronize_state() instead of kvm_arch_get_registers(). Suggested-by: Benjamin Herrenschmidt <b...@kernel.crashing.org> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au> Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com> Reviewed-by: Alexander Graf <ag...@suse.de> --- target-ppc/misc_helper.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/target-ppc/misc_helper.c b/target-ppc/misc_helper.c index 616aab6..e8fc8a3 100644 --- a/target-ppc/misc_helper.c +++ b/target-ppc/misc_helper.c @@ -20,6 +20,8 @@ #include "helper.h" #include "helper_regs.h" +#include "hw/virtio/virtio.h" +#include "sysemu/kvm.h" /*****************************************************************************/ /* SPR accesses */ @@ -116,3 +118,13 @@ void ppc_store_msr(CPUPPCState *env, target_ulong value) { hreg_store_msr(env, value, 0); } + +bool virtio_get_byteswap(void) +{ + PowerPCCPU *cp = POWERPC_CPU(first_cpu); + CPUPPCState *env = &cp->env; + + cpu_synchronize_state(first_cpu); + + return env->spr[SPR_LPCR] & LPCR_ILE; +}