I inserted some printk() lines into init_vmcb() around the call of svm_set_guest_pat() to print out the g_pat value as well as svm->vcpu.vcpu_id and noticed that something was off: Initially, the PATs of all VCPUs are set to 0x0606060606060606. However, after attaching some devices (vfio-pci enabling device and vfio_ecap_init lines are being printed) init_vmcb() is only called again for vcpu_id > 0. Unless g_pat is changed somewhere else, VCPU #0 remains set to 0x0606060606060606 (according to comments in svm_set_guest_pat() this is bad for assigned devices) while all other VCPUs use 0x0007040600070406. I'd guess that could explain the slowdown. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
