Re: [PATCH RESEND v2 04/17] KVM: Cache as_id in kvm_memory_slot

Paolo Bonzini
2020-01-08T17:47:25Z

On 21/12/19 02:49, Peter Xu wrote:
> Let's cache the address space ID just like the slot ID.

Please add a not that it will be useful in order to fill in the dirty
page ring buffer.

Paolo

> Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> include/linux/kvm_host.h | 1 +
> virt/kvm/kvm_main.c | 2 ++
> 2 files changed, 3 insertions(+)
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 4e34cf97ca90..24854c9e3717 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -348,6 +348,7 @@ struct kvm_memory_slot {
> unsigned long userspace_addr;
> u32 flags;
> short id;
> + u8 as_id;
> };
>
> static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index b1047173d78e..cea4b8dd4ac9 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1027,6 +1027,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
>
> new = old = *slot;
>
> + BUILD_BUG_ON(U8_MAX < KVM_ADDRESS_SPACE_NUM);
> + new.as_id = as_id;
> new.id = id;
> new.base_gfn = base_gfn;
> new.npages = npages;
>