Re: [PATCH v3 21/52] xen: introduce CONFIG_HAS_PAGING_MEMPOOL

[Penny Zheng]

Hi Jan

On 2023/6/26 15:01, Jan Beulich wrote:

On 26.06.2023 05:34, Penny Zheng wrote:

--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -54,6 +54,9 @@ config HAS_IOPORTS
  config HAS_KEXEC
        bool

+config HAS_PAGING_MEMPOOL

+       bool
+
  config HAS_PDX
        bool

--- a/xen/common/domctl.c

+++ b/xen/common/domctl.c
@@ -844,6 +844,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
          ret = iommu_do_domctl(op, d, u_domctl);
          break;

+#ifdef CONFIG_HAS_PAGING_MEMPOOL

      case XEN_DOMCTL_get_paging_mempool_size:
          ret = arch_get_paging_mempool_size(d, &op->u.paging_mempool.size);
          if ( !ret )
@@ -857,6 +858,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
              ret = hypercall_create_continuation(
                  __HYPERVISOR_domctl, "h", u_domctl);
          break;
+#endif

While I'm not outright opposed to doing it this way, I wonder
whether it wouldn't be better to leave common code untouched by
making arch_get_paging_mempool_size() do what you want done.
That's part of what arch hooks are for, after all.

Sure, I'll try.

Jan