[PATCH RESEND v2 4/4] Update documentation to reflect memory_backing_dir change in qemu.conf

Michael Galaxy via Devel posted 4 patches 3 months, 2 weeks ago
There is a newer version of this series
[PATCH RESEND v2 4/4] Update documentation to reflect memory_backing_dir change in qemu.conf
Posted by Michael Galaxy via Devel 3 months, 2 weeks ago
From: Michael Galaxy <mgalaxy@akamai.com>

Update the documentation and changelog accordingly to reflect
that the syntax of the memory_backing_dir setting has changed.

Signed-off-by: Michael Galaxy <mgalaxy@akamai.com>
---
 NEWS.rst                | 7 +++++++
 docs/kbase/virtiofs.rst | 2 ++
 src/qemu/qemu.conf.in   | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/NEWS.rst b/NEWS.rst
index f3ca29443a..64be9a9509 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -54,6 +54,13 @@ v10.4.0 (2024-06-03)
     ebtables/iptables).
 
 * **Improvements**
+  * qemu: memory backing directories now support NUMA
+
+    The primary use case of this is when persistent memory is used on
+    NUMA-aware systems. The setting ``memory_backing_dir`` in qemu.conf
+    now supports either an array or the original string. This allows
+    you to provide a array of locations to use that are NUMA-compatible
+    if needed.
 
   * qemu: add zstd to supported compression formats
 
diff --git a/docs/kbase/virtiofs.rst b/docs/kbase/virtiofs.rst
index 457c15da7f..931ba96104 100644
--- a/docs/kbase/virtiofs.rst
+++ b/docs/kbase/virtiofs.rst
@@ -144,6 +144,8 @@ memobject interface).
 
        # This directory is used for memoryBacking source if configured as file.
        # NOTE: big files will be stored here
+       # NOTE: In the case of a NUMA-aware system (such has shm/tmpfs or PMEM),
+       #       one can also do: memory_backing_dir = [ "/path/to/node/0", "/path/to/node/1" ]
        memory_backing_dir = "/dev/shm/"
 
    * Use hugepage-backed memory
diff --git a/src/qemu/qemu.conf.in b/src/qemu/qemu.conf.in
index 6bc2140dcb..e6d1f8a675 100644
--- a/src/qemu/qemu.conf.in
+++ b/src/qemu/qemu.conf.in
@@ -897,6 +897,8 @@
 
 # This directory is used for memoryBacking source if configured as file.
 # NOTE: big files will be stored here
+# NOTE: In the case of a NUMA-aware system (such has shm/tmpfs or PMEM),
+#       one can also do: memory_backing_dir = [ "/path/to/node/0", "/path/to/node/1" ]
 #memory_backing_dir = "/var/lib/libvirt/qemu/ram"
 
 # Path to the SCSI persistent reservations helper. This helper is
-- 
2.34.1