On Thu, 2017-11-30 at 19:05 +0100, Radim Krčmář wrote: > Implementation of the unpinned APIC page didn't update the VMCS > address > cache when invalidation was done through range mmu notifiers. > This became a problem when the page notifier was removed. > > Re-introduce the arch-specific helper and call it from > ...range_start. > > Fixes: 38b9917350cb ("kvm: vmx: Implement set_apic_access_page_addr") > Fixes: 369ea8242c0f ("mm/rmap: update to new mmu_notifier semantic > v2") > Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx> > --- > arch/x86/include/asm/kvm_host.h | 3 +++ > arch/x86/kvm/x86.c | 14 ++++++++++++++ > virt/kvm/kvm_main.c | 8 ++++++++ > 3 files changed, 25 insertions(+) Thanks for this. I've been chasing APIC related hangs booting images with qemu-system-x86_64 on 4.13 and 4.14 host kernels where the guest doesn't have x2apic enabled. I can confirm this fixes issues the Yocto Project automated testing infrastructure was seeing. I'd like to add support for backporting this in stable. Tested-by: Richard Purdie <richard.purdie@xxxxxxxxxxxxxxxxxxx> Cheers, Richard