https://bugzilla.kernel.org/show_bug.cgi?id=203477 Bug ID: 203477 Summary: [AMD][KVM] Windows L1 guest becomes extremely slow and unusable after enabling Hyper-V Product: Virtualization Version: unspecified Kernel Version: Debian 4.19.28-2~bpo9+1 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: hjc@xxxxxx Regression: No Created attachment 282583 --> https://bugzilla.kernel.org/attachment.cgi?id=282583&action=edit libvirt XML I'm not sure if it is a supported scenario to run Hyper-V inside KVM, however this worked for me on Intel platform, and I only have this issue on AMD Ryzen. After enabling Hyper-V feature in Windows guest, I could successfully boot into Windows L1 guest desktop, however after that the L1 guest system consumes all available CPU cores, freezes and becomes unusable. Hardware platform: CPU: AMD Ryzen Threadripper 2950X Board: ASUS Prime X399-A (SVM, IOMMU related settings enabled in BIOS) Linux boot command line: BOOT_IMAGE=/boot/vmlinuz-4.19.0-0.bpo.4-amd64 root=UUID=<guid> ro quiet apparmor=0 amd_iommu=pt nopti noibrs noibpb nospectre_v2 nospec_store_bypass_disable pcie_aspm=off apparmor=0 KVM module parameters: options kvm ignore_msrs=1 options kvm report_ignored_msrs=0 options kvm allow_unsafe_assigned_interrupts=1 options vfio_iommu_type1 allow_unsafe_interrupts=1 QEMU: QEMU emulator version 4.0.0 built with ./configure --target-list=x86_64-softmmu --audio-drv-list=pa,alsa,sdl,oss --enable-attr --enable-bluez --enable-brlapi --enable-virtfs --enable-cap-ng --enable-curl --enable-fdt --enable-gnutls --disable-gtk --disable-vte --enable-libiscsi --enable-libnfs --enable-curses --enable-numa --enable-rbd --enable-glusterfs --enable-vnc-sasl --enable-sdl --enable-seccomp --enable-spice --enable-libusb --enable-usb-redir --enable-libssh2 --enable-vde --enable-xfsctl --enable-vnc --enable-vnc-jpeg --enable-vnc-png --enable-kvm --enable-vhost-net --enable-opengl --enable-virglrenderer --enable-avx2 --enable-tpm --enable-vhost-kernel --enable-virtfs libvirt XML is attached L1 Guest OS: Windows Server 2016, 2019 and Windows 10 L2 Guest OS: (Not ever had a chance to start one) `perf kvm stat live` shows unusual numbers of vmrun and msr, comparing to normal VMs: VM-EXIT Samples Samples% Time% Min Time Max Time Avg time vmrun 71298 47.13% 2.61% 1.07us 46197.83us 19.09us ( +- 9.11% ) msr 71217 47.08% 1.24% 0.61us 31213.68us 9.04us ( +- 10.45% ) hlt 3465 2.29% 95.58% 0.70us 78318.83us 14370.28us ( +- 0.93% ) npf 2053 1.36% 0.38% 0.64us 15532.20us 96.25us ( +- 26.48% ) invlpga 1514 1.00% 0.00% 0.28us 60.25us 1.06us ( +- 10.58% ) interrupt 740 0.49% 0.04% 0.22us 15289.36us 25.67us ( +- 80.62% ) vintr 328 0.22% 0.12% 0.37us 31341.32us 194.65us ( +- 59.60% ) stgi 134 0.09% 0.00% 0.32us 49.18us 1.34us ( +- 31.81% ) iret 133 0.09% 0.00% 0.28us 1.52us 0.58us ( +- 3.36% ) io 119 0.08% 0.00% 2.37us 51.02us 14.38us ( +- 4.98% ) hypercall 104 0.07% 0.03% 0.77us 15522.73us 152.12us ( +- 98.10% ) nmi 96 0.06% 0.00% 0.67us 40.84us 2.89us ( +- 20.49% ) write_cr8 66 0.04% 0.00% 0.72us 3.09us 1.77us ( +- 3.19% ) There are also a few number of errors in kmsg after L1 guest boots: [755580.533587] svm_set_msr: 2 callbacks suppressed [755580.533588] SVM: kvm [14227]: vcpu0, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755581.191889] SVM: kvm [14227]: vcpu1, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755581.323561] SVM: kvm [14227]: vcpu2, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755581.482291] SVM: kvm [14227]: vcpu3, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755581.642842] SVM: kvm [14227]: vcpu4, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755581.803020] SVM: kvm [14227]: vcpu5, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755581.963498] SVM: kvm [14227]: vcpu6, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755582.123565] SVM: kvm [14227]: vcpu7, guest rIP: 0xfffff986014dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755616.107080] SVM: kvm [14227]: vcpu0, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755616.778183] SVM: kvm [14227]: vcpu1, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755616.910078] SVM: kvm [14227]: vcpu2, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755617.047056] SVM: kvm [14227]: vcpu3, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755617.180127] SVM: kvm [14227]: vcpu4, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755617.327040] SVM: kvm [14227]: vcpu5, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755617.487152] SVM: kvm [14227]: vcpu6, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 [755617.626337] SVM: kvm [14227]: vcpu7, guest rIP: 0xfffffb735a8dca0c unimplemented wrmsr: 0xc0010115 data 0x0 -- You are receiving this mail because: You are watching the assignee of the bug.
