Hi all,
This is v6 of the SPM (Specific Purpose Memory) patch. Thank you for
the feedback on v5, especially Gregory's review.
Changes in v6:
- Added validation: memmap-type now requires memdev to be specified,
to avoid misconfiguration on memory-less NUMA nodes
- Simplified pc_update_numa_memory_types() by replacing switch/goto
with a direct conditional expression
- Reserved memory nodes are now excluded from SRAT memory affinity
entries, since E820 already marks them as reserved and SRAT should
not report them as enabled memory affinity
Use case:
This feature allows marking NUMA node memory as Specific Purpose Memory
(SPM) or reserved in the E820 table. SPM serves as a hint to the guest
that this memory might be managed by device drivers based on guest policy
Example usage:
-object memory-backend-ram,size=8G,id=m0
-object memory-backend-memfd,size=8G,id=m1
-numa node,nodeid=0,memdev=m0
-numa node,nodeid=1,memdev=m1,memmap-type=spm
Supported memmap-type values:
- normal: Regular system RAM (E820 type 1, default)
- spm: Specific Purpose Memory (E820 type 0xEFFFFFFF), a hint
that this memory might be managed by device drivers
- reserved: Reserved memory (E820 type 2), not usable as RAM
OS-facing test results:
1. memmap-type=spm
~~~~~~~~~~~~~~~~~~
-numa node,cpus=4-7,nodeid=1,memdev=m1,memmap-type=spm
Guest dmesg output:
[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000027fffffff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000280000000-0x000000047fffffff] soft
reserved
[ 0.000000] BIOS-e820: [mem 0x000000fd00000000-0x000000ffffffffff] reserved
[ 0.042582] ACPI: SRAT: Node 1 PXM 1 [mem 0x280000000-0x47fffffff]
2. memmap-type=reserved
~~~~~~~~~~~~~~~~~~~~~~~
-numa node,cpus=4-7,nodeid=1,memdev=m1,memmap-type=reserved
Guest dmesg output:
[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000027fffffff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000280000000-0x000000047fffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x000000fd00000000-0x000000ffffffffff] reserved
[ 0.042728] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
[ 0.042729] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0x7fffffff]
[ 0.042731] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x27fffffff]
Note: Node 1 is excluded from SRAT memory affinity entries since v6,
because E820 already marks it as reserved and it should not be reported
as enabled memory.
3. normal (default, no memmap-type specified)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-numa node,cpus=4-7,nodeid=1,memdev=m1
Guest dmesg output:
[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000047fffffff] usable
[ 0.000000] BIOS-e820: [mem 0x000000fd00000000-0x000000ffffffffff] reserved
[ 0.042413] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
[ 0.042414] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0x7fffffff]
[ 0.042416] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x27fffffff]
[ 0.042417] ACPI: SRAT: Node 1 PXM 1 [mem 0x280000000-0x47fffffff]
The results show:
- Node association is correct (Node 1 at 0x280000000-0x47fffffff)
- E820 types are correctly applied (usable/soft reserved/reserved)
- SRAT entries are generated for normal and spm configurations
- Reserved nodes are excluded from SRAT memory affinity (new in v6)
Please review. Thanks!
Best regards,
Jerry Huang
fanhuang (1):
numa: add 'memmap-type' option for memory type configuration
hw/core/numa.c | 24 ++++++++++++
hw/i386/acpi-build.c | 8 ++++
hw/i386/e820_memory_layout.c | 72 ++++++++++++++++++++++++++++++++++++
hw/i386/e820_memory_layout.h | 12 +++---
hw/i386/pc.c | 48 ++++++++++++++++++++++++
include/system/numa.h | 7 ++++
qapi/machine.json | 24 ++++++++++++
qemu-options.hx | 14 ++++++-
8 files changed, 202 insertions(+), 7 deletions(-)
--
2.34.1
