Re: [PATCH v3 13/13] KVM: x86/xen: Convert evtchn_ports from IDR to XArray

[Paul Durrant <xadimgnik@gmail.com>]

On 31/08/2026 22:26, David Woodhouse wrote:
> From: Furkan Caliskan <frn1furkan10@gmail.com>
> 
> IDR is deprecated in favor of XArray: see
> Documentation/core-api/idr.rst. Convert evtchn_ports accordingly.
> 
> kvm_xen_eventfd_assign()'s single-slot idr_alloc() becomes
> xa_insert(), since it was really an insert-at-index, not an
> allocation: -EBUSY replaces -ENOSPC, still mapped to -EEXIST.
> 
> kvm_xen_hcall_evtchn_send() drops its explicit rcu_read_lock(),
> since xa_load() takes its own RCU read-side section internally.
> evtchnfd's lifetime is still guaranteed by kvm->srcu.
> 
> xen_lock is left in place: it protects state beyond the map itself.
> 
> Signed-off-by: Furkan Caliskan <frn1furkan10@gmail.com>
> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
>   arch/x86/include/asm/kvm_host.h |  3 ++-
>   arch/x86/kvm/xen.c              | 34 ++++++++++++++++-----------------
>   2 files changed, 18 insertions(+), 19 deletions(-)
> 
Reviewed-by: Paul Durrant <paul@xen.org>