In order for memory locking to work, the hard limit on memory locking (and usage) has to be set appropriately by the user. The documentation mentions the requirement already: with this patch, it's going to be enforced by runtime checks as well. Note that this will make existing guests that don't satisfy the requirement disappear; that said, such guests have never been able to start in the first place. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1316774 --- src/qemu/qemu_domain.c | 20 ++++++++++++++++++++ tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml | 3 +++ ....xml => qemuxml2argv-mlock-without-hardlimit.xml} | 0 tests/qemuxml2argvtest.c | 1 + 4 files changed, 24 insertions(+) copy tests/qemuxml2argvdata/{qemuxml2argv-mlock-on.xml => qemuxml2argv-mlock-without-hardlimit.xml} (100%) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index c6ce090..bb29cfe 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -2629,6 +2629,23 @@ qemuDomainDefVcpusPostParse(virDomainDefPtr def) static int +qemuDomainDefMemoryLockingPostParse(virDomainDefPtr def) +{ + /* Memory locking can only work properly if the memory locking limit + * for the QEMU process has been raised appropriately: the default one + * is extrememly low, so there's no way the guest will fit in there */ + if (def->mem.locked && !virMemoryLimitIsSet(def->mem.hard_limit)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("Setting <memoryBacking><locked> requires " + "<memtune><hard_limit> to be set as well")); + return -1; + } + + return 0; +} + + +static int qemuDomainDefPostParse(virDomainDefPtr def, virCapsPtr caps, unsigned int parseFlags, @@ -2692,6 +2709,9 @@ qemuDomainDefPostParse(virDomainDefPtr def, if (qemuDomainDefVcpusPostParse(def) < 0) goto cleanup; + if (qemuDomainDefMemoryLockingPostParse(def) < 0) + goto cleanup; + ret = 0; cleanup: virObjectUnref(qemuCaps); diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml b/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml index 20a5eaa..2046663 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml @@ -3,6 +3,9 @@ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid> <memory unit='KiB'>219136</memory> <currentMemory unit='KiB'>219136</currentMemory> + <memtune> + <hard_limit unit='KiB'>256000</hard_limit> + </memtune> <memoryBacking> <locked/> </memoryBacking> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml b/tests/qemuxml2argvdata/qemuxml2argv-mlock-without-hardlimit.xml similarity index 100% copy from tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml copy to tests/qemuxml2argvdata/qemuxml2argv-mlock-without-hardlimit.xml diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c index 3532cb5..9b2fec5 100644 --- a/tests/qemuxml2argvtest.c +++ b/tests/qemuxml2argvtest.c @@ -2129,6 +2129,7 @@ mymain(void) DO_TEST_FAILURE("mlock-on", NONE); DO_TEST("mlock-off", QEMU_CAPS_REALTIME_MLOCK); DO_TEST("mlock-unsupported", NONE); + DO_TEST_PARSE_ERROR("mlock-without-hardlimit", NONE); DO_TEST_PARSE_ERROR("pci-bridge-negative-index-invalid", QEMU_CAPS_DEVICE_PCI_BRIDGE); -- 2.7.4