This region is exported at /machine/smram. It is "empty" if
SMRAME=0 and points to SMRAM if SMRAME=1. The CPU will
enable/disable it as it enters or exits SMRAM.
While touching nearby code, the existing memory region setup was
slightly inconsistent. The smram_region is *disabled* in order to open
SMRAM (because the smram_region shows the low VRAM instead of the RAM
at 0xa0000). Because SMRAM is closed at startup, the smram_region must
be enabled when creating the i440fx or q35 devices.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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