Re: [PATCH 1/2] KVM: x86: fix APIC page invalidation

[Richard Purdie]

On Thu, 2017-11-30 at 19:05 +0100, Radim KrÄmÃÅ 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 KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> ---
> Âarch/x86/include/asm/kvm_host.h |ÂÂ3 +++
> Âarch/x86/kvm/x86.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂ| 14 ++++++++++++++
> Âvirt/kvm/kvm_main.cÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂ8 ++++++++
> Â3 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