From c5ad81eb029570c5ca5859539b0679f07a776d25 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 27 Sep 2019 17:46:28 +0200 Subject: xen/balloon: Set pages PageOffline() in balloon_add_region() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We are missing a __SetPageOffline(), which is why we can get !PageOffline() pages onto the balloon list, where alloc_xenballooned_pages() will complain: page:ffffea0003e7ffc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xffffe00001000(reserved) raw: 000ffffe00001000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(!PageOffline(page)) ------------[ cut here ]------------ kernel BUG at include/linux/page-flags.h:744! invalid opcode: 0000 [#1] SMP NOPTI Reported-by: Marek Marczykowski-Górecki Tested-by: Marek Marczykowski-Górecki Fixes: 77c4adf6a6df ("xen/balloon: mark inflated pages PG_offline") Cc: stable@vger.kernel.org # v5.1+ Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Signed-off-by: David Hildenbrand Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- drivers/xen/balloon.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 4e11de6cde81..91cba70b69df 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -688,6 +688,7 @@ static void __init balloon_add_region(unsigned long start_pfn, /* totalram_pages and totalhigh_pages do not include the boot-time balloon extension, so don't subtract from it. */ + __SetPageOffline(page); __balloon_append(page); } -- cgit v1.2.1 From dde3285ffa1a75dbd67c6a61e5f3eba2267c6593 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 1 Oct 2019 11:01:50 +0200 Subject: xen/balloon: Drop __balloon_append() Let's simply use balloon_append() directly. Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Signed-off-by: David Hildenbrand Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- drivers/xen/balloon.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 91cba70b69df..37443c5fda99 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -156,7 +156,7 @@ static DECLARE_DELAYED_WORK(balloon_worker, balloon_process); (GFP_HIGHUSER | __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC) /* balloon_append: add the given page to the balloon. */ -static void __balloon_append(struct page *page) +static void balloon_append(struct page *page) { /* Lowmem is re-populated first, so highmem pages go at list tail. */ if (PageHighMem(page)) { @@ -169,11 +169,6 @@ static void __balloon_append(struct page *page) wake_up(&balloon_wq); } -static void balloon_append(struct page *page) -{ - __balloon_append(page); -} - /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */ static struct page *balloon_retrieve(bool require_lowmem) { @@ -378,7 +373,7 @@ static void xen_online_page(struct page *page, unsigned int order) p = pfn_to_page(start_pfn + i); __online_page_set_limits(p); __SetPageOffline(p); - __balloon_append(p); + balloon_append(p); } mutex_unlock(&balloon_mutex); } @@ -689,7 +684,7 @@ static void __init balloon_add_region(unsigned long start_pfn, include the boot-time balloon extension, so don't subtract from it. */ __SetPageOffline(page); - __balloon_append(page); + balloon_append(page); } balloon_stats.total_pages += extra_pfn_end - start_pfn; -- cgit v1.2.1 From 59b52f105f23edebf497bf8f0e57660e649e3f17 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 1 Oct 2019 11:01:51 +0200 Subject: xen/balloon: Mark pages PG_offline in balloon_append() Let's move the __SetPageOffline() call which all callers perform into balloon_append(). In bp_state decrease_reservation(), pages are now marked PG_offline a little later than before, however, this should not matter for XEN. Suggested-by: Boris Ostrovsky Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Signed-off-by: David Hildenbrand Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- drivers/xen/balloon.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 37443c5fda99..8c245e99bb06 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -158,6 +158,8 @@ static DECLARE_DELAYED_WORK(balloon_worker, balloon_process); /* balloon_append: add the given page to the balloon. */ static void balloon_append(struct page *page) { + __SetPageOffline(page); + /* Lowmem is re-populated first, so highmem pages go at list tail. */ if (PageHighMem(page)) { list_add_tail(&page->lru, &ballooned_pages); @@ -372,7 +374,6 @@ static void xen_online_page(struct page *page, unsigned int order) for (i = 0; i < size; i++) { p = pfn_to_page(start_pfn + i); __online_page_set_limits(p); - __SetPageOffline(p); balloon_append(p); } mutex_unlock(&balloon_mutex); @@ -466,7 +467,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) state = BP_EAGAIN; break; } - __SetPageOffline(page); adjust_managed_page_count(page, -1); xenmem_reservation_scrub_page(page); list_add(&page->lru, &pages); @@ -648,10 +648,8 @@ void free_xenballooned_pages(int nr_pages, struct page **pages) mutex_lock(&balloon_mutex); for (i = 0; i < nr_pages; i++) { - if (pages[i]) { - __SetPageOffline(pages[i]); + if (pages[i]) balloon_append(pages[i]); - } } balloon_stats.target_unpopulated -= nr_pages; @@ -669,7 +667,6 @@ static void __init balloon_add_region(unsigned long start_pfn, unsigned long pages) { unsigned long pfn, extra_pfn_end; - struct page *page; /* * If the amount of usable memory has been limited (e.g., with @@ -679,12 +676,10 @@ static void __init balloon_add_region(unsigned long start_pfn, extra_pfn_end = min(max_pfn, start_pfn + pages); for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) { - page = pfn_to_page(pfn); /* totalram_pages and totalhigh_pages do not include the boot-time balloon extension, so don't subtract from it. */ - __SetPageOffline(page); - balloon_append(page); + balloon_append(pfn_to_page(pfn)); } balloon_stats.total_pages += extra_pfn_end - start_pfn; -- cgit v1.2.1 From 04ccbdc390b14d8fdc4612abbf023ff49cdc5cd8 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 1 Oct 2019 11:01:52 +0200 Subject: xen/balloon: Clear PG_offline in balloon_retrieve() Let's move the clearing to balloon_retrieve(). In bp_state increase_reservation(), we now clear the flag a little earlier than before, however, this should not matter for XEN. Suggested-by: Boris Ostrovsky Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Signed-off-by: David Hildenbrand Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- drivers/xen/balloon.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 8c245e99bb06..5bae515c8e25 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -189,6 +189,7 @@ static struct page *balloon_retrieve(bool require_lowmem) else balloon_stats.balloon_low--; + __ClearPageOffline(page); return page; } @@ -440,7 +441,6 @@ static enum bp_state increase_reservation(unsigned long nr_pages) xenmem_reservation_va_mapping_update(1, &page, &frame_list[i]); /* Relinquish the page back to the allocator. */ - __ClearPageOffline(page); free_reserved_page(page); } @@ -606,7 +606,6 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) while (pgno < nr_pages) { page = balloon_retrieve(true); if (page) { - __ClearPageOffline(page); pages[pgno++] = page; #ifdef CONFIG_XEN_HAVE_PVMMU /* -- cgit v1.2.1