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David Gibson authored
The hypervisor needs to know a guest is capable of using the HPT resizing PAPR extension in order to make full advantage of it for memory hotplug. If the hypervisor knows the guest is HPT resize aware, it can size the initial HPT based on the initial guest RAM size, relying on the guest to resize the HPT when more memory is hot-added. Without this, the hypervisor must size the HPT for the maximum possible guest RAM, which can lead to a huge waste of space if the guest never actually expends to that maximum size. This patch advertises the guest's support for HPT resizing via the ibm,client-architecture-support OF interface. We use bit 5 of byte 6 of option vector 5 for this purpose, as defined in the PAPR ACR "HPT resizing option". Signed-off-by:
David Gibson <david@gibson.dropbear.id.au> Reviewed-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Reviewed-by:
Paul Mackerras <paulus@samba.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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