Re: [libvirt] [PATCH 00/12] qemu: Enforce guest CPU specification

When starting a domain with custom guest CPU specification QEMU may add or remove some CPU features. There are several reasons for this, e.g., QEMU/KVM does not support some requested features or the definition of the requested CPU model in libvirt's cpu_map.xml differs from the one QEMU is using. We can't really avoid this because CPU models are allowed to change with machine types and libvirt doesn't know (and probably doesn't even want to know) about such changes. Thus when we want to make sure guest ABI doesn't change when a domain gets migrated to another host, we need to update our live CPU definition according to the CPU QEMU created. Once updated, we will change CPU checking to VIR_CPU_CHECK_FULL to make sure the virtual CPU created after migration exactly matches the one on the source. https://bugzilla.redhat.com/show_bug.cgi?id=822148 https://bugzilla.redhat.com/show_bug.cgi?id=824989 Jiri Denemark (12): tests: Switch to sparse initialization of virCPUDef docs: Clarify /domain/cpu/@match description Introduce /domain/cpu/@check XML attribute qemu: Set default values for CPU check attribute qemu: Refactor Hyper-V features check qemu: Refactor KVM features check qemu: Refactor CPU features check qemu: Refactor qemuProcessVerifyGuestCPU qemu: Use ARCH_IS_X86 in qemuMonitorJSONGetGuestCPU qemu: Ask QEMU for filtered CPU features qemu: Update CPU definition according to QEMU qemu: Enforce guest CPU specification