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  1. 20 3月, 2015 8 次提交
    • E
      numa: Print warning if no node is assigned to a CPU · 549fc54b
      由 Eduardo Habkost 提交于 
      We need all possible CPUs (including hotplug ones) to be present in the
SRAT when QEMU starts. QEMU already does that correctly today, the only
problem is that when a CPU is omitted from the NUMA configuration, it is
silently assigned to node 0.

Check if all CPUs up to max_cpus are present in the NUMA configuration
and warn about missing CPUs.

Make it just a warning, to allow management software to be updated if
necessary. In the future we may make it a fatal error instead.

Command-line examples:

* Correct, no warning:

  $ qemu-system-x86_64 -smp 2,maxcpus=4
  $ qemu-system-x86_64 -smp 2,maxcpus=4 -numa node,cpus=0-3

* Incomplete, with warnings:

  $ qemu-system-x86_64 -smp 2,maxcpus=4 -numa node,cpus=0
  qemu-system-x86_64: warning: CPU(s) not present in any NUMA nodes: 1 2 3
  qemu-system-x86_64: warning: All CPU(s) up to maxcpus should be described in NUMA config

  $ qemu-system-x86_64 -smp 2,maxcpus=4 -numa node,cpus=0-2
  qemu-system-x86_64: warning: CPU(s) not present in any NUMA nodes: 3
  qemu-system-x86_64: warning: All CPU(s) up to maxcpus should be described in NUMA config
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
---
v1 -> v2: (no changes)

v2 -> v3:
 * Use enumerate_cpus() and error_report() for error message
 * Simplify logic using bitmap_full()

v3 -> v4:
 * Clarify error message, mention that all CPUs up to
   maxcpus need to be described in NUMA config

v4 -> v5:
 * Commit log update, to make problem description clearer
      549fc54b
    • I
      pc: fix default VCPU to NUMA node mapping · fb43b73b
      由 Igor Mammedov 提交于 
      Since commit
   dd0247e0 pc: acpi: mark all possible CPUs as enabled in SRAT
Linux kernel actually tries to use CPU to Node mapping from
QEMU provided SRAT table instead of discarding it, and that
in some cases breaks build_sched_domains() which expects
sane mapping where cores/threads belonging to the same socket
are on the same NUMA node.

With current default round-robin mapping of VCPUs to nodes
guest ends-up with cores/threads belonging to the same socket
being on different NUMA nodes.

For example with following CLI:

   qemu-system-x86_64 -m 4G \
         -cpu Opteron_G3,vendor=AuthenticAMD \
         -smp 5,sockets=1,cores=4,threads=1,maxcpus=8 \
         -numa node,nodeid=0 -numa node,nodeid=1

2.6.32 based kernels will hang on boot due to incorrectly built
sched_group-s list in update_sd_lb_stats()

Replacing default mapping with a manual, where VCPUs belonging to
the same socket are on the same NUMA node, fixes the issue for
guests which can't handle nonsense topology i.e. changing CLI to:
  -numa node,nodeid=0,cpus=0-3 -numa node,nodeid=1,cpus=4-7

So instead of simply scattering VCPUs around nodes, provide
callback to map the same socket VCPUs to the same NUMA node,
which is what guests would expect from a sane hardware/BIOS.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
      fb43b73b
    • I
      numa: introduce machine callback for VCPU to node mapping · 57924bcd
      由 Igor Mammedov 提交于 
      Current default round-robin way of distributing VCPUs among
NUMA nodes might be wrong in case on multi-core/threads
CPUs. Making guests confused wrt topology where cores from
the same socket are on different nodes.

Allow a machine to override default mapping by providing
 MachineClass::cpu_index_to_socket_id()
callback which would allow it group VCPUs from a socket
on the same NUMA node.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
      57924bcd
    • E
      numa: Reject configuration if CPU appears on multiple nodes · 3ef71975
      由 Eduardo Habkost 提交于 
      Each CPU can appear in only one NUMA node on the NUMA config. Reject
configuration if a CPU appears in multiple nodes.
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
      3ef71975
    • E
      numa: Reject CPU indexes > max_cpus · 8979c945
      由 Eduardo Habkost 提交于 
      CPU index is always less than max_cpus, as documented at sysemu.h:

> The following shall be true for all CPUs:
>   cpu->cpu_index < max_cpus <= MAX_CPUMASK_BITS

Reject configuration which uses invalid CPU indexes.
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
      8979c945
    • E
      numa: Fix off-by-one error at MAX_CPUMASK_BITS check · ed26b922
      由 Eduardo Habkost 提交于 
      Fix the CPU index check to ensure we don't go beyond the size of the
node_cpu bitmap.

CPU index is always less than MAX_CPUMASK_BITS, as documented at
sysemu.h:

> The following shall be true for all CPUs:
>   cpu->cpu_index < max_cpus <= MAX_CPUMASK_BITS
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
      ed26b922
    • P
      Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging · 3e5f6234
      由 Peter Maydell 提交于 
      Block patches for 2.3.0-rc1

# gpg: Signature made Thu Mar 19 15:03:26 2015 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream:
  block: Fix blockdev-backup not to use funky error class
  raw-posix: Deprecate aio=threads fallback without O_DIRECT
  raw-posix: Deprecate host floppy passthrough
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
      3e5f6234
    • P
      Merge remote-tracking branch 'remotes/amit/tags/vser-for-2.3-3' into staging · 33a8d5b7
      由 Peter Maydell 提交于 
      virtio-serial api: guest_writable callback for users

# gpg: Signature made Thu Mar 19 12:06:55 2015 GMT using RSA key ID 854083B6
# gpg: Good signature from "Amit Shah <amit@amitshah.net>"
# gpg:                 aka "Amit Shah <amit@kernel.org>"
# gpg:                 aka "Amit Shah <amitshah@gmx.net>"

* remotes/amit/tags/vser-for-2.3-3:
  virtio: serial: expose a 'guest_writable' callback for users
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
      33a8d5b7
  3. 19 3月, 2015 32 次提交