• Paul Mackerras's avatar
    KVM: PPC: Book3S HV: Save/restore XER in checkpointed register state · 0d808df0
    Paul Mackerras authored
    When switching from/to a guest that has a transaction in progress,
    we need to save/restore the checkpointed register state.  Although
    XER is part of the CPU state that gets checkpointed, the code that
    does this saving and restoring doesn't save/restore XER.
    
    This fixes it by saving and restoring the XER.  To allow userspace
    to read/write the checkpointed XER value, we also add a new ONE_REG
    specifier.
    
    The visible effect of this bug is that the guest may see its XER
    value being corrupted when it uses transactions.
    
    Fixes: e4e38121 ("KVM: PPC: Book3S HV: Add transactional memory support")
    Fixes: 0a8eccef ("KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit")
    Cc: stable@vger.kernel.org # v3.15+
    Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
    Reviewed-by: default avatarThomas Huth <thuth@redhat.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
    0d808df0
kvm.h 19.9 KB