Hi Jan,
On 22/09/2020 08:35, Jan Beulich wrote:
On 21.09.2020 20:02, Julien Grall wrote:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -504,6 +504,7 @@ static bool propagate_node(unsigned int xmf, unsigned int
*memflags)
static long memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg)
{
+#ifdef CONFIG_PV
struct xen_memory_exchange exch;
PAGE_LIST_HEAD(in_chunk_list);
PAGE_LIST_HEAD(out_chunk_list);
@@ -516,6 +517,9 @@ static long
memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg)
struct domain *d;
struct page_info *page;
+ if ( !is_pv_domain(d) )
+ return -EOPNOTSUPP;
I think "paging_mode_translate(d)" would be more correct, at which
point the use later in the function ought to be dropped (as that's
precisely one of the things making this function not really
sensible to use on translated guests).
I have used paging_mode_translate(d) and remove the later use.
I also wonder whether the #ifdef wouldn't better be left out. Yes,
that'll mean retaining a stub mfn_to_gmfn(), but it could expand
to simply BUG() then, for example.
Keeping mfn_to_gmfn() will not discourage developper to add more use of
it. The risk is we don't notice it when reviewing and this would lead
to hit a BUG_ON().
Given this will be the only place where mfn_to_gmfn() is used, I think
it is best to stub the code. Bear in mind that long term, this function
should leave outside of common/mm.c (see Andrew's e-mail).
Cheers,
--
Julien Grall
