On Fri, 14 Jun 2019 23:56:24 +0800
Tao Xu <address@hidden> wrote:
From: Liu Jingqi <address@hidden>
HMAT is defined in ACPI 6.2: 5.2.27 Heterogeneous Memory Attribute Table (HMAT).
The specification references below link:
http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf
It describes the memory attributes, such as memory side cache
attributes and bandwidth and latency details, related to the
System Physical Address (SPA) Memory Ranges. The software is
expected to use this information as hint for optimization.
This structure describes the System Physical Address(SPA) range
occupied by memory subsystem and its associativity with processor
proximity domain as well as hint for memory usage.
Signed-off-by: Liu Jingqi <address@hidden>
Signed-off-by: Tao Xu <address@hidden>
Hi Tao,
Apologies if I missed an earlier discussion on this...
It's probably not letting an secrets out to say that there are very few
real hardware systems out there using the 6.2 version of HMAT.
Does it make sense to implement it rather than the somewhat tidied
up version in ACPI 6.3?
I would go so far as to say that one of the pushes behind making those
changes was that it shouldn't have much impact as no one was shipping
a firmware using the 6.2 version. So any chance we can avoid
qemu effectively doing so, or at least defaulting to doing so?
I'm entirely in favor of the patch set in general btw as it's much
more useful than having to override with a hand crafted table, when
wanting to test unusual topologies.
Thanks,
Jonathan