Following are the requirements and restrictions on CPUs when you perform a migration:
The target machine must have sufficient free virtual CPUs to accommodate the number of virtual CPUs in use by the domain to be migrated.
Setting the cpu-arch property on the guest domain enables you to migrate the domain between systems that have different processor types. Note that the guest domain must be in a bound or inactive state to change the cpu-arch value.
The supported cpu-arch property values are as follows:
native uses CPU-specific hardware features to enable a guest domain to migrate only between platforms that have the same CPU type. native is the default value.
migration-class1 is a cross-CPU migration family for SPARC platforms starting with the SPARC T4. These platforms support hardware cryptography during and after these migrations so that there is a lower bound to the supported CPUs.
This value is not compatible with UltraSPARC T2, UltraSPARC T2 Plus, or SPARC T3 platforms, or Fujitsu M10 platforms.
sparc64-class1 is a cross-CPU migration family for SPARC64 platforms. Because the sparc64-class1 value is based on SPARC64 instructions, it has a greater number of instructions than the generic value. Therefore, it does not have a performance impact compared to the generic value.
This value is compatible only with Fujitsu M10 servers.
generic uses the lowest common CPU hardware features that are used by all platforms to enable a guest domain to perform a CPU-type-independent migration.
The following isainfo -v commands show the instructions that are available on a system when cpu-arch=generic and when cpu-arch=migration-class1.
cpu-arch=generic
# isainfo -v
64-bit sparcv9 applications
asi_blk_init vis2 vis popc
32-bit sparc applications
asi_blk_init vis2 vis popc v8plus div32 mul32cpu-arch=migration-class1
# isainfo -v
64-bit sparcv9 applications
crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5
camellia des aes ima hpc vis3 fmaf asi_blk_init vis2
vis popc
32-bit sparc applications
crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5
camellia des aes ima hpc vis3 fmaf asi_blk_init vis2
vis popc v8plus div32 mul32Using the generic value might result in reduced performance of the guest domain compared to using the native value. The possible performance degradation occurs because the guest domain uses only generic CPU features that are available on all supported CPU types instead of using the native hardware features of a particular CPU. By not using these features, the generic value enables the flexibility of migrating the domain between systems that use CPUs that support different features.
If migrating a domain between at least SPARC T4 systems, you can set cpu-arch=migration-class1 to improve the guest domain performance. While the performance is improved from using the generic value, the native value still provides the best performance for the guest domain.
Use the psrinfo -pv command when the cpu-arch property is set to native to determine the processor type, as follows:
# psrinfo -pv The physical processor has 2 virtual processors (0 1) SPARC-T5 (chipid 0, clock 3600 MHz)
Note that when the cpu-arch property is set to a value other than native, the psrinfo -pv output does not show the platform type. Instead, the command shows that the sun4v-cpu CPU module is loaded.
# psrinfo -pv
The physical processor has 2 cores and 13 virtual processors (0-12)
The core has 8 virtual processors (0-7)
The core has 5 virtual processors (8-12)
sun4v-cpu (chipid 0, clock 3600 MHz)