xen/balloon: before adding hotplugged memory, set frames to invalid (3c56b3a1) · Commits · 戴 / test

Commit ("x86/xen: set regions above the end of RAM as 1:1") introduced a regression. To be able to add memory pages which were added via memory hotplug to a pv domain, the pages must be "invalid" instead of "identity" in the p2m list before they can be added. Suggested-by:

David Vrabel <david.vrabel@citrix.com> Signed-off-by:

Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by:

Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by:

David Vrabel <david.vrabel@citrix.com>

drivers/xen/balloon.c

+23 −0

Original line number	Diff line number	Diff line
		@@ -229,6 +229,29 @@ static enum bp_state reserve_additional_memory(long credit)
		balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION);
		nid = memory_add_physaddr_to_nid(hotplug_start_paddr);

		#ifdef CONFIG_XEN_HAVE_PVMMU
		/*
		* add_memory() will build page tables for the new memory so
		* the p2m must contain invalid entries so the correct
		* non-present PTEs will be written.
		*
		* If a failure occurs, the original (identity) p2m entries
		* are not restored since this region is now known not to
		* conflict with any devices.
		*/
		if (!xen_feature(XENFEAT_auto_translated_physmap)) {
		unsigned long pfn, i;

		pfn = PFN_DOWN(hotplug_start_paddr);
		for (i = 0; i < balloon_hotplug; i++) {
		if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
		pr_warn("set_phys_to_machine() failed, no memory added\n");
		return BP_ECANCELED;
		}
		}
		}
		#endif

		rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT);

		if (rc) {

Admin message