On Thu, Nov 30, 2017 at 07:05:45PM +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>
Tested-by: Fabian Grünbichler <f.gruenbichler@xxxxxxxxxxx>
no further issues observed with this patch applied on top of 4.13 and
4.14 - thanks!
> ---
> 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(+)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 977de5fb968b..c16c3f924863 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1435,4 +1435,7 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
> #define put_smstate(type, buf, offset, val) \
> *(type *)((buf) + (offset) - 0x7e00) = val
>
> +void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
> + unsigned long start, unsigned long end);
> +
> #endif /* _ASM_X86_KVM_HOST_H */
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index eee8e7faf1af..a219974cdb89 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6778,6 +6778,20 @@ static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
> kvm_x86_ops->tlb_flush(vcpu);
> }
>
> +void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
> + unsigned long start, unsigned long end)
> +{
> + unsigned long apic_address;
> +
> + /*
> + * The physical address of apic access page is stored in the VMCS.
> + * Update it when it becomes invalid.
> + */
> + apic_address = gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
> + if (start <= apic_address && apic_address < end)
> + kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
> +}
> +
> void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
> {
> struct page *page = NULL;
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index c01cff064ec5..b7f4689e373f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -135,6 +135,11 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
> static unsigned long long kvm_createvm_count;
> static unsigned long long kvm_active_vms;
>
> +__weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
> + unsigned long start, unsigned long end)
> +{
> +}
> +
> bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
> {
> if (pfn_valid(pfn))
> @@ -360,6 +365,9 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
> kvm_flush_remote_tlbs(kvm);
>
> spin_unlock(&kvm->mmu_lock);
> +
> + kvm_arch_mmu_notifier_invalidate_range(kvm, start, end);
> +
> srcu_read_unlock(&kvm->srcu, idx);
> }
>
> --
> 2.14.2
>
>
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