On Thu, May 12, 2016 at 01:26:44PM +0200, Thomas Huth wrote: > The SIAR and SDAR registers are available twice, one time as SPRs > 780 / 781 (unprivileged, but read-only), and one time as the SPRs > 796 / 797 (privileged, but read and write). The Linux kernel code > currently uses the unprivileged SPRs - while this is OK for reading, > writing to that register of course does not work. > Since the KVM code tries to write to this register, too (see the mtspr > in book3s_hv_rmhandlers.S), the contents of this register sometimes get > lost for the guests, e.g. during migration of a VM. > To fix this issue, simply switch to the privileged SPR numbers instead. > > Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx> Acked-by: Paul Mackerras <paulus@xxxxxxxxxx> -- 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
