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    target-ppc: Add helpers for updating a CPU's SDR1 and external HPT · e5c0d3ce
    David Gibson 提交于
    When a Power cpu with 64-bit hash MMU has it's hash page table (HPT)
    pointer updated by a write to the SDR1 register we need to update some
    derived variables.  Likewise, when the cpu is configured for an external
    HPT (one not in the guest memory space) some derived variables need to be
    updated.
    
    Currently the logic for this is (partially) duplicated in ppc_store_sdr1()
    and in spapr_cpu_reset().  In future we're going to need it in some other
    places, so make some common helpers for this update.
    
    In addition the new ppc_hash64_set_external_hpt() helper also updates
    SDR1 in KVM - it's not updated by the normal runtime KVM <-> qemu CPU
    synchronization.  In a sense this belongs logically in the
    ppc_hash64_set_sdr1() helper, but that is called from
    kvm_arch_get_registers() so can't itself call cpu_synchronize_state()
    without infinite recursion.  In practice this doesn't matter because
    the only other caller is TCG specific.
    
    Currently there aren't situations where updating SDR1 at runtime in KVM
    matters, but there are going to be in future.
    Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
    Reviewed-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
    Reviewed-by: NThomas Huth <thuth@redhat.com>
    e5c0d3ce
spapr.c 76.7 KB