In version 7 of the subject patch, I wanted to try to implement this qmp method with the help of existing kvm ioctl KVM_GET_CPUID2. The reasoning behind my decision is the fact that QEMU uses KVM_SET_CPUID2 to set full cpuid response table to the virtual cpu, and KVM_GET_CPUID2 is a convenient and complementary method for extracting the same cpuid entry table back from the kernel. So I've pushed a patch into Linux KVM subtree to fine tune ioctl KVM_GET_CPUID2 for this type of application. This has triggered a small discussion. One of the responses here https://lkml.org/lkml/2021/5/4/109 is from Paolo Bonzini. There he suggests to cache the the whole cpuid entries table that we pass to the kernel via KVM_SET_CPUID2 and later just output this cached data instead of calling the same table via KVM_GET_CPUID2. Current patch is the reflection of that idea. Valeriy Vdovin (1): qapi: introduce 'query-cpu-model-cpuid' action qapi/machine-target.json | 51 ++++++++++++++++++++++++++++++++++++++ target/i386/kvm/kvm.c | 45 ++++++++++++++++++++++++++++++--- tests/qtest/qmp-cmd-test.c | 1 + 3 files changed, 93 insertions(+), 4 deletions(-) -- 2.17.1
