[libvirt] [PATCH v2 3/7] qemu: Add qemuDomainAdjustMaxMemLock()

This function detects whether a domain needs RLIMIT_MEMLOCK to be set, and if so, uses an appropriate value. --- src/qemu/qemu_domain.c | 30 ++++++++++++++++++++++++++++++ src/qemu/qemu_domain.h | 1 + 2 files changed, 31 insertions(+) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 6f19d49..4b796ab 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -41,6 +41,7 @@ #include "virstring.h" #include "virthreadjob.h" #include "viratomic.h" +#include "virprocess.h" #include "logging/log_manager.h" #include "storage/storage_driver.h" @@ -4117,6 +4118,35 @@ qemuDomainRequiresMlock(virDomainDefPtr def) return false; } +/** + * qemuDomainAdjustMaxMemLock: + * @vm: domain + * + * Adjust the memory locking limit for the QEMU process associated to @vm, in + * order to comply with VFIO or architecture requirements. + * + * The limit will not be changed unless doing so is needed. + * + * Returns: 0 on success, <0 on failure + */ +int +qemuDomainAdjustMaxMemLock(virDomainObjPtr vm) +{ + unsigned long long bytes = 0; + int ret = -1; + + if (qemuDomainRequiresMlock(vm->def)) + bytes = qemuDomainGetMlockLimitBytes(vm->def); + + /* Trying to set the memory locking limit to zero is a no-op */ + if (virProcessSetMaxMemLock(vm->pid, bytes) < 0) + goto out; + + ret = 0; + + out: + return ret; +} /** * qemuDomainHasVcpuPids: diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 916d5d3..704351b 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -500,6 +500,7 @@ int qemuDomainUpdateCurrentMemorySize(virQEMUDriverPtr driver, unsigned long long qemuDomainGetMlockLimitBytes(virDomainDefPtr def); bool qemuDomainRequiresMlock(virDomainDefPtr def); +int qemuDomainAdjustMaxMemLock(virDomainObjPtr vm); int qemuDomainDefValidateMemoryHotplug(const virDomainDef *def, virQEMUCapsPtr qemuCaps, -- 2.5.0