Merge tag 'for-linus-4.4-rc5-tag' of git://git.kernel.org/pub/scm/lin…

…ux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:
 - XSA-155 security fixes to backend drivers.
 - XSA-157 security fixes to pciback.

* tag 'for-linus-4.4-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-pciback: fix up cleanup path when alloc fails
  xen/pciback: Don't allow MSI-X ops if PCI_COMMAND_MEMORY is not set.
  xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled.
  xen/pciback: Do not install an IRQ handler for MSI interrupts.
  xen/pciback: Return error on XEN_PCI_OP_enable_msix when device has MSI or MSI-X enabled
  xen/pciback: Return error on XEN_PCI_OP_enable_msi when device has MSI or MSI-X enabled
  xen/pciback: Save xen_pci_op commands before processing it
  xen-scsiback: safely copy requests
  xen-blkback: read from indirect descriptors only once
  xen-blkback: only read request operation from shared ring once
  xen-netback: use RING_COPY_REQUEST() throughout
  xen-netback: don't use last request to determine minimum Tx credit
  xen: Add RING_COPY_REQUEST()
  xen/x86/pvh: Use HVM's flush_tlb_others op
  xen: Resume PMU from non-atomic context
  xen/events/fifo: Consume unprocessed events when a CPU dies

arch/x86/xen/mmu.c

@@ -2495,14 +2495,9 @@ void __init xen_init_mmu_ops(void)
 {
 	x86_init.paging.pagetable_init = xen_pagetable_init;
 
-	/* Optimization - we can use the HVM one but it has no idea which
-	 * VCPUs are descheduled - which means that it will needlessly IPI
-	 * them. Xen knows so let it do the job.
-	 */
-	if (xen_feature(XENFEAT_auto_translated_physmap)) {
-		pv_mmu_ops.flush_tlb_others = xen_flush_tlb_others;
+	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return;
-	}
+
 	pv_mmu_ops = xen_mmu_ops;
 
 	memset(dummy_mapping, 0xff, PAGE_SIZE);

arch/x86/xen/suspend.c

@@ -68,26 +68,16 @@ static void xen_pv_post_suspend(int suspend_cancelled)
 
 void xen_arch_pre_suspend(void)
 {
-	int cpu;
-
-	for_each_online_cpu(cpu)
-		xen_pmu_finish(cpu);
-
 	if (xen_pv_domain())
 		xen_pv_pre_suspend();
 }
 
 void xen_arch_post_suspend(int cancelled)
 {
-	int cpu;
-
 	if (xen_pv_domain())
 		xen_pv_post_suspend(cancelled);
 	else
 		xen_hvm_post_suspend(cancelled);
-
-	for_each_online_cpu(cpu)
-		xen_pmu_init(cpu);
 }
 
 static void xen_vcpu_notify_restore(void *data)
@@ -106,10 +96,20 @@ static void xen_vcpu_notify_suspend(void *data)
 
 void xen_arch_resume(void)
 {
+	int cpu;
+
 	on_each_cpu(xen_vcpu_notify_restore, NULL, 1);
+
+	for_each_online_cpu(cpu)
+		xen_pmu_init(cpu);
 }
 
 void xen_arch_suspend(void)
 {
+	int cpu;
+
+	for_each_online_cpu(cpu)
+		xen_pmu_finish(cpu);
+
 	on_each_cpu(xen_vcpu_notify_suspend, NULL, 1);
 }

drivers/block/xen-blkback/blkback.c

@@ -950,22 +950,27 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
 		goto unmap;
 
 	for (n = 0, i = 0; n < nseg; n++) {
+		uint8_t first_sect, last_sect;
+
 		if ((n % SEGS_PER_INDIRECT_FRAME) == 0) {
 			/* Map indirect segments */
 			if (segments)
 				kunmap_atomic(segments);
 			segments = kmap_atomic(pages[n/SEGS_PER_INDIRECT_FRAME]->page);
 		}
 		i = n % SEGS_PER_INDIRECT_FRAME;
+
 		pending_req->segments[n]->gref = segments[i].gref;
-		seg[n].nsec = segments[i].last_sect -
-			segments[i].first_sect + 1;
-		seg[n].offset = (segments[i].first_sect << 9);
-		if ((segments[i].last_sect >= (XEN_PAGE_SIZE >> 9)) ||
-		    (segments[i].last_sect < segments[i].first_sect)) {
+
+		first_sect = READ_ONCE(segments[i].first_sect);
+		last_sect = READ_ONCE(segments[i].last_sect);
+		if (last_sect >= (XEN_PAGE_SIZE >> 9) || last_sect < first_sect) {
 			rc = -EINVAL;
 			goto unmap;
 		}
+
+		seg[n].nsec = last_sect - first_sect + 1;
+		seg[n].offset = first_sect << 9;
 		preq->nr_sects += seg[n].nsec;
 	}
 

drivers/block/xen-blkback/common.h

@@ -408,8 +408,8 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst,
 					struct blkif_x86_32_request *src)
 {
 	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
-	dst->operation = src->operation;
-	switch (src->operation) {
+	dst->operation = READ_ONCE(src->operation);
+	switch (dst->operation) {
 	case BLKIF_OP_READ:
 	case BLKIF_OP_WRITE:
 	case BLKIF_OP_WRITE_BARRIER:
@@ -456,8 +456,8 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst,
 					struct blkif_x86_64_request *src)
 {
 	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
-	dst->operation = src->operation;
-	switch (src->operation) {
+	dst->operation = READ_ONCE(src->operation);
+	switch (dst->operation) {
 	case BLKIF_OP_READ:
 	case BLKIF_OP_WRITE:
 	case BLKIF_OP_WRITE_BARRIER:

drivers/net/xen-netback/netback.c

@@ -258,18 +258,18 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
 						 struct netrx_pending_operations *npo)
 {
 	struct xenvif_rx_meta *meta;
-	struct xen_netif_rx_request *req;
+	struct xen_netif_rx_request req;
 
-	req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+	RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 
 	meta = npo->meta + npo->meta_prod++;
 	meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
 	meta->gso_size = 0;
 	meta->size = 0;
-	meta->id = req->id;
+	meta->id = req.id;
 
 	npo->copy_off = 0;
-	npo->copy_gref = req->gref;
+	npo->copy_gref = req.gref;
 
 	return meta;
 }
@@ -424,7 +424,7 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 	struct xenvif *vif = netdev_priv(skb->dev);
 	int nr_frags = skb_shinfo(skb)->nr_frags;
 	int i;
-	struct xen_netif_rx_request *req;
+	struct xen_netif_rx_request req;
 	struct xenvif_rx_meta *meta;
 	unsigned char *data;
 	int head = 1;
@@ -443,15 +443,15 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 
 	/* Set up a GSO prefix descriptor, if necessary */
 	if ((1 << gso_type) & vif->gso_prefix_mask) {
-		req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+		RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 		meta = npo->meta + npo->meta_prod++;
 		meta->gso_type = gso_type;
 		meta->gso_size = skb_shinfo(skb)->gso_size;
 		meta->size = 0;
-		meta->id = req->id;
+		meta->id = req.id;
 	}
 
-	req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+	RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 	meta = npo->meta + npo->meta_prod++;
 
 	if ((1 << gso_type) & vif->gso_mask) {
@@ -463,9 +463,9 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 	}
 
 	meta->size = 0;
-	meta->id = req->id;
+	meta->id = req.id;
 	npo->copy_off = 0;
-	npo->copy_gref = req->gref;
+	npo->copy_gref = req.gref;
 
 	data = skb->data;
 	while (data < skb_tail_pointer(skb)) {
@@ -679,9 +679,7 @@ static void tx_add_credit(struct xenvif_queue *queue)
 	 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
 	 * Otherwise the interface can seize up due to insufficient credit.
 	 */
-	max_burst = RING_GET_REQUEST(&queue->tx, queue->tx.req_cons)->size;
-	max_burst = min(max_burst, 131072UL);
-	max_burst = max(max_burst, queue->credit_bytes);
+	max_burst = max(131072UL, queue->credit_bytes);
 
 	/* Take care that adding a new chunk of credit doesn't wrap to zero. */
 	max_credit = queue->remaining_credit + queue->credit_bytes;
@@ -711,7 +709,7 @@ static void xenvif_tx_err(struct xenvif_queue *queue,
 		spin_unlock_irqrestore(&queue->response_lock, flags);
 		if (cons == end)
 			break;
-		txp = RING_GET_REQUEST(&queue->tx, cons++);
+		RING_COPY_REQUEST(&queue->tx, cons++, txp);
 	} while (1);
 	queue->tx.req_cons = cons;
 }
@@ -778,8 +776,7 @@ static int xenvif_count_requests(struct xenvif_queue *queue,
 		if (drop_err)
 			txp = &dropped_tx;
 
-		memcpy(txp, RING_GET_REQUEST(&queue->tx, cons + slots),
-		       sizeof(*txp));
+		RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
 
 		/* If the guest submitted a frame >= 64 KiB then
 		 * first->size overflowed and following slots will
@@ -1112,8 +1109,7 @@ static int xenvif_get_extras(struct xenvif_queue *queue,
 			return -EBADR;
 		}
 
-		memcpy(&extra, RING_GET_REQUEST(&queue->tx, cons),
-		       sizeof(extra));
+		RING_COPY_REQUEST(&queue->tx, cons, &extra);
 		if (unlikely(!extra.type ||
 			     extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
 			queue->tx.req_cons = ++cons;
@@ -1322,7 +1318,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
 		idx = queue->tx.req_cons;
 		rmb(); /* Ensure that we see the request before we copy it. */
-		memcpy(&txreq, RING_GET_REQUEST(&queue->tx, idx), sizeof(txreq));
+		RING_COPY_REQUEST(&queue->tx, idx, &txreq);
 
 		/* Credit-based scheduling. */
 		if (txreq.size > queue->remaining_credit &&

drivers/xen/events/events_fifo.c

@@ -281,7 +281,8 @@ static void handle_irq_for_port(unsigned port)
 
 static void consume_one_event(unsigned cpu,
 			      struct evtchn_fifo_control_block *control_block,
-			      unsigned priority, unsigned long *ready)
+			      unsigned priority, unsigned long *ready,
+			      bool drop)
 {
 	struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
 	uint32_t head;
@@ -313,13 +314,17 @@ static void consume_one_event(unsigned cpu,
 	if (head == 0)
 		clear_bit(priority, ready);
 
-	if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port))
-		handle_irq_for_port(port);
+	if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) {
+		if (unlikely(drop))
+			pr_warn("Dropping pending event for port %u\n", port);
+		else
+			handle_irq_for_port(port);
+	}
 
 	q->head[priority] = head;
 }
 
-static void evtchn_fifo_handle_events(unsigned cpu)
+static void __evtchn_fifo_handle_events(unsigned cpu, bool drop)
 {
 	struct evtchn_fifo_control_block *control_block;
 	unsigned long ready;
@@ -331,11 +336,16 @@ static void evtchn_fifo_handle_events(unsigned cpu)
 
 	while (ready) {
 		q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES);
-		consume_one_event(cpu, control_block, q, &ready);
+		consume_one_event(cpu, control_block, q, &ready, drop);
 		ready |= xchg(&control_block->ready, 0);
 	}
 }
 
+static void evtchn_fifo_handle_events(unsigned cpu)
+{
+	__evtchn_fifo_handle_events(cpu, false);
+}
+
 static void evtchn_fifo_resume(void)
 {
 	unsigned cpu;
@@ -420,6 +430,9 @@ static int evtchn_fifo_cpu_notification(struct notifier_block *self,
 		if (!per_cpu(cpu_control_block, cpu))
 			ret = evtchn_fifo_alloc_control_block(cpu);
 		break;
+	case CPU_DEAD:
+		__evtchn_fifo_handle_events(cpu, true);
+		break;
 	default:
 		break;
 	}

drivers/xen/xen-pciback/pciback.h

@@ -37,6 +37,7 @@ struct xen_pcibk_device {
 	struct xen_pci_sharedinfo *sh_info;
 	unsigned long flags;
 	struct work_struct op_work;
+	struct xen_pci_op op;
 };
 
 struct xen_pcibk_dev_data {