[PATCH 1/3] xen/mm: return more precise error from xen_remap_domain_range()

[David Vrabel <david.vrabel@citrix.com>]

From: David Vrabel <david.vrabel@citrix.com>

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.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
 arch/x86/xen/mmu.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index b65a761..fb187ea 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2355,8 +2355,8 @@ 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;
-- 
1.7.2.5