[PATCH] qemu: Don't ignore failure when building default memory backend

When building the default memory backend (which has id='pc.ram') and no guest NUMA is configured then qemuBuildMemCommandLineMemoryDefaultBackend() is called. However, its return value is ignored which means that on invalid configuration (e.g. when non-existent hugepage size was requested) an error is reported into the logs but QEMU is started anyway. And while QEMU does error out its error message doesn't give much clue what's going on: qemu-system-x86_64: Memory backend 'pc.ram' not found While at it, introduce a test case. While I could chose a nice looking value (e.g. 4MiB) that's exactly what I wanted to avoid, because while such value might not be possible on x84_64 it may be possible on other arches (e.g. ppc is notoriously known for supporting wide range of HP sizes). Let's stick with obviously wrong value of 5MiB. Reported-by: Charles Polisher <chas(a)chasmo.org&gt; Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_command.c | 5 ++-- .../hugepages-default-5M.x86_64-latest.err | 1 + .../qemuxml2argvdata/hugepages-default-5M.xml | 27 +++++++++++++++++++ tests/qemuxml2argvtest.c | 1 + 4 files changed, 32 insertions(+), 2 deletions(-) create mode 100644 tests/qemuxml2argvdata/hugepages-default-5M.x86_64-latest.err create mode 100644 tests/qemuxml2argvdata/hugepages-default-5M.xml diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 2c963a7297..c836799888 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -7369,8 +7369,9 @@ qemuBuildMemCommandLine(virCommand *cmd, * regular memory because -mem-path and -mem-prealloc are obsolete. * However, if domain has one or more NUMA nodes then there is no * default RAM and we mustn't generate the memory object. */ - if (!virDomainNumaGetNodeCount(def->numa)) - qemuBuildMemCommandLineMemoryDefaultBackend(cmd, def, priv, defaultRAMid); + if (!virDomainNumaGetNodeCount(def->numa) && + qemuBuildMemCommandLineMemoryDefaultBackend(cmd, def, priv, defaultRAMid) < 0) + return -1; } else { /* * Add '-mem-path' (and '-mem-prealloc') parameter here if diff --git a/tests/qemuxml2argvdata/hugepages-default-5M.x86_64-latest.err b/tests/qemuxml2argvdata/hugepages-default-5M.x86_64-latest.err new file mode 100644 index 0000000000..bf5e54c9e4 --- /dev/null +++ b/tests/qemuxml2argvdata/hugepages-default-5M.x86_64-latest.err @@ -0,0 +1 @@ +internal error: Unable to find any usable hugetlbfs mount for 5120 KiB diff --git a/tests/qemuxml2argvdata/hugepages-default-5M.xml b/tests/qemuxml2argvdata/hugepages-default-5M.xml new file mode 100644 index 0000000000..280ea4bb71 --- /dev/null +++ b/tests/qemuxml2argvdata/hugepages-default-5M.xml @@ -0,0 +1,27 @@ +<domain type="kvm"> + <name>NonExistentPageSize</name> + <uuid>21433e10-aea8-434a-8f81-55781c2e9035</uuid> + <memory unit="KiB">4194304</memory> + <currentMemory unit="KiB">4194304</currentMemory> + <memoryBacking> + <hugepages> + <page size="5" unit="MiB"/> + </hugepages> + </memoryBacking> + <vcpu placement="static">2</vcpu> + <os> + <type arch="x86_64" machine="pc">hvm</type> + </os> + <features> + <acpi/> + <apic/> + <pae/> + </features> + <clock offset="utc"/> + <on_poweroff>destroy</on_poweroff> + <on_reboot>restart</on_reboot> + <on_crash>restart</on_crash> + <devices> + <emulator>/usr/bin/qemu-system-x86_64</emulator> + </devices> +</domain> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c index 9c5c394e03..a32c5a8250 100644 --- a/tests/qemuxml2argvtest.c +++ b/tests/qemuxml2argvtest.c @@ -1270,6 +1270,7 @@ mymain(void) DO_TEST("hugepages-default", QEMU_CAPS_OBJECT_MEMORY_FILE); DO_TEST("hugepages-default-2M", QEMU_CAPS_OBJECT_MEMORY_FILE); DO_TEST("hugepages-default-system-size", QEMU_CAPS_OBJECT_MEMORY_FILE); + DO_TEST_CAPS_LATEST_FAILURE("hugepages-default-5M"); DO_TEST_PARSE_ERROR_NOCAPS("hugepages-default-1G-nodeset-2M"); DO_TEST("hugepages-nodeset", QEMU_CAPS_OBJECT_MEMORY_FILE); DO_TEST_PARSE_ERROR("hugepages-nodeset-nonexist", -- 2.34.1