3 files changed, 16 insertions, 17 deletions

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 6284538a8184..42a48ac763ee 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -122,7 +122,7 @@ config VIRTIO_BALLOON
 
 config VIRTIO_MEM
 	tristate "Virtio mem driver"
-	depends on X86_64 || ARM64
+	depends on X86_64 || ARM64 || RISCV
 	depends on VIRTIO
 	depends on MEMORY_HOTPLUG
 	depends on MEMORY_HOTREMOVE
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 835cfbcb59c8..bc1f962e483b 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -82,7 +82,7 @@ static inline int virtio_id_match(const struct virtio_device *dev,
 
 /* This looks through all the IDs a driver claims to support.  If any of them
  * match, we return 1 and the kernel will call virtio_dev_probe(). */
-static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
+static int virtio_dev_match(struct device *_dv, const struct device_driver *_dr)
 {
 	unsigned int i;
 	struct virtio_device *dev = dev_to_virtio(_dv);
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index a3857bacc844..b0b871441578 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -1146,12 +1146,16 @@ static void virtio_mem_set_fake_offline(unsigned long pfn,
 	for (; nr_pages--; pfn++) {
 		struct page *page = pfn_to_page(pfn);
 
-		__SetPageOffline(page);
-		if (!onlined) {
+		if (!onlined)
+			/*
+			 * Pages that have not been onlined yet were initialized
+			 * to PageOffline(). Remember that we have to route them
+			 * through generic_online_page().
+			 */
 			SetPageDirty(page);
-			/* FIXME: remove after cleanups */
-			ClearPageReserved(page);
-		}
+		else
+			__SetPageOffline(page);
+		VM_WARN_ON_ONCE(!PageOffline(page));
 	}
 	page_offline_end();
 }
@@ -1166,9 +1170,11 @@ static void virtio_mem_clear_fake_offline(unsigned long pfn,
 	for (; nr_pages--; pfn++) {
 		struct page *page = pfn_to_page(pfn);
 
-		__ClearPageOffline(page);
 		if (!onlined)
+			/* generic_online_page() will clear PageOffline(). */
 			ClearPageDirty(page);
+		else
+			__ClearPageOffline(page);
 	}
 }
 
@@ -1263,12 +1269,6 @@ static void virtio_mem_fake_offline_going_offline(unsigned long pfn,
 	struct page *page;
 	unsigned long i;
 
-	/*
-	 * Drop our reference to the pages so the memory can get offlined
-	 * and add the unplugged pages to the managed page counters (so
-	 * offlining code can correctly subtract them again).
-	 */
-	adjust_managed_page_count(pfn_to_page(pfn), nr_pages);
 	/* Drop our reference to the pages so the memory can get offlined. */
 	for (i = 0; i < nr_pages; i++) {
 		page = pfn_to_page(pfn + i);
@@ -1287,10 +1287,9 @@ static void virtio_mem_fake_offline_cancel_offline(unsigned long pfn,
 	unsigned long i;
 
 	/*
-	 * Get the reference we dropped when going offline and subtract the
-	 * unplugged pages from the managed page counters.
+	 * Get the reference again that we dropped via page_ref_dec_and_test()
+	 * when going offline.
 	 */
-	adjust_managed_page_count(pfn_to_page(pfn), -nr_pages);
 	for (i = 0; i < nr_pages; i++)
 		page_ref_inc(pfn_to_page(pfn + i));
 }