xen/mm: return more precise error from xen_remap_domain_range()

Callers of xen_remap_domain_range() need to know if the remap failed
because frame is currently paged out.  So they can retry the remap
later on.  Return -ENOENT in this case.

This assumes that the error codes returned by Xen are a subset of
those used by the kernel.  It is unclear if this is defined as part of
the hypercall ABI.

Acked-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 885a223..2d9e7c9 100644 (file)
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2331,8 +2331,8 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
                if (err)
                        goto out;
 
-               err = -EFAULT;
-               if (HYPERVISOR_mmu_update(mmu_update, batch, NULL, domid) < 0)
+               err = HYPERVISOR_mmu_update(mmu_update, batch, NULL, domid);
+               if (err < 0)
                        goto out;
 
                nr -= batch;