The Intel PT feature includes some sub-features(CPUID.(EAX=14H,ECX=0H)) and these sub-features are different on different HW platforms. To make the live migration safety(get the same CPUID info with same cpu model on different HW platform), the current Intel PT CPUID information is set to a constant value(from ICELAKE Server).
It will block the new feature in the later HW platform. what's more, the support of "IP payloads" will disable the Intel PT in KVM guest(patch 1) but it will come soon. This patchset remove this limitation and expose all the capabilities to KVM guest. As it will break the live migration safe, Intel PT will be masked as unmigratable. Luwei Kang (3): i386: Remove the limitation of IP payloads for Intel PT i386: Remove the CPUID limitation of Intel PT i386: Mark the 'INTEL_PT' CPUID bit as unmigratable target/i386/cpu.c | 69 ++++--------------------------------------------------- 1 file changed, 5 insertions(+), 64 deletions(-) -- 1.8.3.1
