Hello all, I'm having a requirement to record values obtained by reading tsc clock. The command line I use to start QEMU in KVM mode is as below - sudo ./qemu-system-x86_64 -m 1024 --machine pc-i440fx-2.5 -cpu qemu64,-vme,-x2apic,-kvmclock,+lahf_lm,+3dnowprefetch,+vmx -enable-kvm -netdev tap,id=tap1,ifname=tap0,script=no,downscript=no -device virtio-net-pci,netdev=tap1,mac=00:00:00:00:00:00 -drive file=~/os_images_for_qemu/ubuntu-16.04.server.qcow2,format=qcow2,if=none,id=img-direct -device virtio-blk-pci,drive=img-direct I am using QEMU version 2.11.92 and the guest kernel is a 4.4.0-116-generic. I use the CPU model "qemu64" because I have a requirement to create a snapshot of this guest and load the snapshot in TCG mode. The generic CPU model helps, in this regard. Now when the guest is running, I want to intercept all rdtsc instructions and record the tsc clock values. I know that for this to happen, the CPU_BASED_RDTSC_EXITING flag needs to exist for the particular CPU model. How do I start adding support for causing VMEXIT upon rdtsc execution? I see that a fairly recent commit in QEMU helps adding nested VMX controls to named CPU models, but not "qemu64". Can I extend this commit to add these controls to "qemu64" as well? Will making this change immediately add support for intercepting VMEXITS for "qemu64" CPU? Thank you very much. Best Regards, Arnabjyoti Kalita
