https://bugzilla.kernel.org/show_bug.cgi?id=103321 Bug ID: 103321 Summary: NPT page attribute support causes extreme slowdown Product: Virtualization Version: unspecified Kernel Version: 4.2-rc3+ Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: dracon@xxxxxxxxxx Regression: No Created attachment 185501 --> https://bugzilla.kernel.org/attachment.cgi?id=185501&action=edit dmesg For some reason the new NPT attribute support that has been introduced with 4.3-RC3 causes my VM to run awfully slow, I managed to track this issue to commit 3c2e7f7de3 ("KVM: SVM: use NPT page attributes"). The VM runs Win7 64bit via Qemu and uses PCI passthrough with several devices (primary GPU, USB, audio) on a AMD 970/SB950 based Asrock 970 EXTREME3 2.0 motherboard and an AMD Phenom II X6 CPU. There are no error/warning messages whatsoever, booting the VM takes several minutes just to get past the first boot screen. -- You are receiving this mail because: You are watching the assignee of the bug. -- 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
