On 8/7/25 5:30 PM, Jan Beulich wrote:
On 07.08.2025 14:00, Oleksii Kurochko wrote:
On 8/5/25 12:37 PM, Jan Beulich wrote:
On 31.07.2025 17:58, Oleksii Kurochko wrote:
+ /*
+ * Return back nr_root_pages to assure the root table memory is also
+ * accounted against the P2M pool of the domain.
+ */
+ if ( !paging_ret_pages_to_domheap(d, nr_root_pages) )
+ return -ENOMEM;
+
+ page = p2m_allocate_root(d);
+ if ( !page )
+ return -ENOMEM;
Hmm, and the pool is then left shrunk by 4 pages?
Yes until they are used for root table it shouldn't be in p2m pool (freelist),
when root table will be freed then it makes sense to return them back.
Am I missing something?
I'm commenting specifically on the error path here.
Ohh, got it.
In this case, should we really care about this 4 pages as a domain can't be ran
without allocated page root table and a panic() will be occured anyway according
to the create_domUs() common code (construct_domU() ->
domain_p2m_set_allocation()
-> p2m_set_allocation() -> p2m_alloc_root_table()):
...
rc = construct_domU(&ki, node);
if ( rc )
panic("Could not set up domain %s (rc = %d)\n",
dt_node_name(node), rc);
...
(Note: I missed to return a value returned by p2m_alloc_root_table() in
p2m_set_allocation()
so it isn't really propagated, at the moment, but I will fix that in the next
patch
version) ...
Probably, you meant that it is needed to update p2m->pages?
That (I think) I commented on elsewhere, yes.
...
if it is needed really to update p2m->pages when a page is allocated, I think
it will be better to in p2m_allocate_root() immediately after
alloc_domheap_pages()
is called in p2m_allocate_root().
~ Oleksii
