<html> <head> <style></style></head> <body class='hmmessage'><div dir='ltr'> <style type="text/css">p { margin-bottom: 0.1in; line-height: 120%; }a:link { }</style> Hello everyone, I try to strengthen my virtual machine against malware by trying, as much as I can, to hide the fact that malware is running inside a virtual machine. One possible way to do it is to suppress the string “KVMKVMKVM” and the value 1 of the Qemu variable 'CPUID_EXT_HYPERVISOR', which are both specified in the file in './qemu-2.3.0-rc4/target-i386/kvm.c'. Step 1) I'm doing the following modifications: - Original unmodified version of kvm.c includes the following values: ret |= CPUID_EXT_HYPERVISOR; //line 219 in 'kvm.c' memcpy(signature, "KVMKVMKVM\0\0\0", 12); //Line 538 in 'kvm.c' - My objective is to replace those values with the following : ret |= 0; //line 219 in 'kvm.c' memcpy(signature, "blablabla\0\0\0", 12); //Line 538 in 'kvm.c' Step 2) I do “sudo make” and “sudo make install” in the qemu-2.3.0-rc4 directory, and then I replace the original file './usr/bin/qemu-system-x86_64' with the new one. While everything works fine with qemu-kvm and sdl (following the command line that I'm using) : sudo qemu-system-x86_64 -enable-kvm -m 4096 img.qcow2 -smp cores=2 With virt-manager I'm not able to start correctly the virtual machine. I have the following problems : If I'm using a Windows 7 .qcow2, Windows will start but right after windows starts loading, It halts and I get the famous windows blue error screen saying : *** STOP: 0x000000A5 (0x0001000A, 0x00000000, 0x00000000, 0x00000000). While it could be an ACPI problem, I tried to uncheck the ACPI option in virt-manager VM configuration but I still get the same error. If I'm using a WindowsXP .qcow2, I always have the message “We apologize for the inconvenience, but Windows did not start successfully […] Start Windows Normally […] “ and no way to dodge/escape it. I will be gratefull if someone may help me or have an idea about how to implement these CPU modifications ! Running version: Ubuntu 14.04 QEMU emulator version 2.2.94 Libvirt 1.2.2 Regards. </div></body> </html>