On 09/15/2014 07:48 AM, Michal Privoznik wrote:
> As of 136ad4974 it is possible to specify different huge pages per
> guest NUMA node. However, there's no check if nodeset specified in
> ./hugepages/page contains only those guest NUMA nodes that exist.
> In other words with current code it is possible to define meaningless
> combination:
>
> <memoryBacking>
> <hugepages>
> <page size='1048576' unit='KiB' nodeset='0,2-3'/>
> <page size='2048' unit='KiB' nodeset='1,4'/>
> </hugepages>
> </memoryBacking>
> <vcpu placement='static'>4</vcpu>
> <cpu>
> <numa>
> <cell id='0' cpus='0' memory='1048576'/>
> <cell id='1' cpus='1' memory='1048576'/>
> <cell id='2' cpus='2' memory='1048576'/>
> <cell id='3' cpus='3' memory='1048576'/>
> </numa>
> </cpu>
>
> Notice the node 4 in <hugepages/>?
>
Coverity detected an issue with this - it's innocuous, but I wasn't sure
which way it should be handled... That is whether to add a check or
remove a check...
> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> ---
> src/qemu/qemu_command.c | 24 ++++++++++++
> .../qemuxml2argv-hugepages-pages4.xml | 45 ++++++++++++++++++++++
> tests/qemuxml2argvtest.c | 2 +
> 3 files changed, 71 insertions(+)
> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages4.xml
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index e5270bd..1148aec 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -6542,6 +6542,30 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,
> goto cleanup;
> }
>
> + for (i = 0; i < def->mem.nhugepages; i++) {
> + ssize_t next_bit, pos = 0;
> +
> + if (!def->mem.hugepages[i].nodemask) {
> + /* This is the master hugepage to use. Skip it as it has no
> + * nodemask anyway. */
> + continue;
> + }
> +
> + if (def->cpu && def->cpu->ncells) {
Because you check for def->cpu here
(16) Event cond_false: Condition "def->cpu", taking false branch
(18) Event var_compare_op: Comparing "def->cpu" to null implies that
"def->cpu" might be null.
Also see events: [var_deref_op]
> + /* Fortunately, we allow only guest NUMA nodes to be continuous
> + * starting from zero. */
> + pos = def->cpu->ncells - 1;
> + }
> +
> + next_bit = virBitmapNextSetBit(def->mem.hugepages[i].nodemask, pos);
> + if (next_bit >= 0) {
> + virReportError(VIR_ERR_XML_DETAIL,
> + _("hugepages: node %zd not found"),
> + next_bit);
> + goto cleanup;
> + }
> + }
> +
> for (i = 0; i < def->cpu->ncells; i++) {
his makes Coverity unhappy here because it doesn't check for def->cpu first.
(23) Event var_deref_op: Dereferencing null pointer "def->cpu".
Also see events: [var_compare_op]
John
> int cellmem = VIR_DIV_UP(def->cpu->cells[i].mem, 1024);
> def->cpu->cells[i].mem = cellmem * 1024;
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages4.xml b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages4.xml
> new file mode 100644
> index 0000000..a3ed29b
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages4.xml
> @@ -0,0 +1,45 @@
> +<domain type='qemu'>
> + <name>QEMUGuest1</name>
> + <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> + <memory unit='KiB'>4194304</memory>
> + <currentMemory unit='KiB'>4194304</currentMemory>
> + <memoryBacking>
> + <hugepages>
> + <page size='2048' unit='KiB' nodeset='1,4'/>
> + <page size='1048576' unit='KiB' nodeset='0,2-3'/>
> + </hugepages>
> + </memoryBacking>
> + <vcpu placement='static'>4</vcpu>
> + <numatune>
> + <memory mode='strict' nodeset='0-3'/>
> + <memnode cellid='3' mode='strict' nodeset='3'/>
> + </numatune>
> + <os>
> + <type arch='i686' machine='pc'>hvm</type>
> + <boot dev='hd'/>
> + </os>
> + <cpu>
> + <numa>
> + <cell id='0' cpus='0' memory='1048576'/>
> + <cell id='1' cpus='1' memory='1048576'/>
> + <cell id='2' cpus='2' memory='1048576'/>
> + <cell id='3' cpus='3' memory='1048576'/>
> + </numa>
> + </cpu>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu</emulator>
> + <disk type='block' device='disk'>
> + <source dev='/dev/HostVG/QEMUGuest1'/>
> + <target dev='hda' bus='ide'/>
> + <address type='drive' controller='0' bus='0' target='0' unit='0'/>
> + </disk>
> + <controller type='usb' index='0'/>
> + <controller type='ide' index='0'/>
> + <controller type='pci' index='0' model='pci-root'/>
> + <memballoon model='virtio'/>
> + </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
> index 5c28253..c528499 100644
> --- a/tests/qemuxml2argvtest.c
> +++ b/tests/qemuxml2argvtest.c
> @@ -684,6 +684,8 @@ mymain(void)
> QEMU_CAPS_OBJECT_MEMORY_FILE);
> DO_TEST("hugepages-pages3", QEMU_CAPS_MEM_PATH, QEMU_CAPS_OBJECT_MEMORY_RAM,
> QEMU_CAPS_OBJECT_MEMORY_FILE);
> + DO_TEST_FAILURE("hugepages-pages4", QEMU_CAPS_MEM_PATH,
> + QEMU_CAPS_OBJECT_MEMORY_RAM, QEMU_CAPS_OBJECT_MEMORY_FILE);
> DO_TEST("nosharepages", QEMU_CAPS_MACHINE_OPT, QEMU_CAPS_MEM_MERGE);
> DO_TEST("disk-cdrom", NONE);
> DO_TEST("disk-cdrom-network-http", QEMU_CAPS_KVM, QEMU_CAPS_DEVICE,
>
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list