Merge tag 'v4.19-rc6' into for-4.20/block

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>

8 files changed, 63 insertions, 30 deletions

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index b459edfacff3..90d387b50ab7 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -79,15 +79,19 @@ config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
 	  This value is used to allocate enough space in internal
 	  tables needed for physical memory administration.
 
-config XEN_SCRUB_PAGES
-	bool "Scrub pages before returning them to system"
+config XEN_SCRUB_PAGES_DEFAULT
+	bool "Scrub pages before returning them to system by default"
 	depends on XEN_BALLOON
 	default y
 	help
 	  Scrub pages before returning them to the system for reuse by
 	  other domains.  This makes sure that any confidential data
 	  is not accidentally visible to other domains.  Is it more
-	  secure, but slightly less efficient.
+	  secure, but slightly less efficient. This can be controlled with
+	  xen_scrub_pages=0 parameter and
+	  /sys/devices/system/xen_memory/xen_memory0/scrub_pages.
+	  This option only sets the default value.
+
 	  If in doubt, say yes.
 
 config XEN_DEV_EVTCHN
diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index d4265c8ebb22..b1357aa4bc55 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -19,15 +19,16 @@ static void enable_hotplug_cpu(int cpu)
 
 static void disable_hotplug_cpu(int cpu)
 {
-	if (cpu_online(cpu)) {
-		lock_device_hotplug();
+	if (!cpu_is_hotpluggable(cpu))
+		return;
+	lock_device_hotplug();
+	if (cpu_online(cpu))
 		device_offline(get_cpu_device(cpu));
-		unlock_device_hotplug();
-	}
-	if (cpu_present(cpu))
+	if (!cpu_online(cpu) && cpu_present(cpu)) {
 		xen_arch_unregister_cpu(cpu);
-
-	set_cpu_present(cpu, false);
+		set_cpu_present(cpu, false);
+	}
+	unlock_device_hotplug();
 }
 
 static int vcpu_online(unsigned int cpu)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 08e4af04d6f2..e6c1934734b7 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -138,7 +138,7 @@ static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
 		clear_evtchn_to_irq_row(row);
 	}
 
-	evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq;
+	evtchn_to_irq[row][col] = irq;
 	return 0;
 }
 
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 57390c7666e5..b0b02a501167 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -492,12 +492,19 @@ static bool in_range(struct gntdev_grant_map *map,
 	return true;
 }
 
-static void unmap_if_in_range(struct gntdev_grant_map *map,
-			      unsigned long start, unsigned long end)
+static int unmap_if_in_range(struct gntdev_grant_map *map,
+			      unsigned long start, unsigned long end,
+			      bool blockable)
 {
 	unsigned long mstart, mend;
 	int err;
 
+	if (!in_range(map, start, end))
+		return 0;
+
+	if (!blockable)
+		return -EAGAIN;
+
 	mstart = max(start, map->vma->vm_start);
 	mend   = min(end,   map->vma->vm_end);
 	pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
@@ -508,6 +515,8 @@ static void unmap_if_in_range(struct gntdev_grant_map *map,
 				(mstart - map->vma->vm_start) >> PAGE_SHIFT,
 				(mend - mstart) >> PAGE_SHIFT);
 	WARN_ON(err);
+
+	return 0;
 }
 
 static int mn_invl_range_start(struct mmu_notifier *mn,
@@ -519,25 +528,20 @@ static int mn_invl_range_start(struct mmu_notifier *mn,
 	struct gntdev_grant_map *map;
 	int ret = 0;
 
-	/* TODO do we really need a mutex here? */
 	if (blockable)
 		mutex_lock(&priv->lock);
 	else if (!mutex_trylock(&priv->lock))
 		return -EAGAIN;
 
 	list_for_each_entry(map, &priv->maps, next) {
-		if (in_range(map, start, end)) {
-			ret = -EAGAIN;
+		ret = unmap_if_in_range(map, start, end, blockable);
+		if (ret)
 			goto out_unlock;
-		}
-		unmap_if_in_range(map, start, end);
 	}
 	list_for_each_entry(map, &priv->freeable_maps, next) {
-		if (in_range(map, start, end)) {
-			ret = -EAGAIN;
+		ret = unmap_if_in_range(map, start, end, blockable);
+		if (ret)
 			goto out_unlock;
-		}
-		unmap_if_in_range(map, start, end);
 	}
 
 out_unlock:
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 7bafa703a992..84575baceebc 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -1040,18 +1040,33 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 		return ret;
 
 	for (i = 0; i < count; i++) {
-		/* Retry eagain maps */
-		if (map_ops[i].status == GNTST_eagain)
-			gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
-						&map_ops[i].status, __func__);
-
-		if (map_ops[i].status == GNTST_okay) {
+		switch (map_ops[i].status) {
+		case GNTST_okay:
+		{
 			struct xen_page_foreign *foreign;
 
 			SetPageForeign(pages[i]);
 			foreign = xen_page_foreign(pages[i]);
 			foreign->domid = map_ops[i].dom;
 			foreign->gref = map_ops[i].ref;
+			break;
+		}
+
+		case GNTST_no_device_space:
+			pr_warn_ratelimited("maptrack limit reached, can't map all guest pages\n");
+			break;
+
+		case GNTST_eagain:
+			/* Retry eagain maps */
+			gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref,
+						map_ops + i,
+						&map_ops[i].status, __func__);
+			/* Test status in next loop iteration. */
+			i--;
+			break;
+
+		default:
+			break;
 		}
 	}
 
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c93d8ef8df34..5bb01a62f214 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -280,9 +280,11 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path,
 		/*
 		 * The Xenstore watch fires directly after registering it and
 		 * after a suspend/resume cycle. So ENOENT is no error but
-		 * might happen in those cases.
+		 * might happen in those cases. ERANGE is observed when we get
+		 * an empty value (''), this happens when we acknowledge the
+		 * request by writing '\0' below.
 		 */
-		if (err != -ENOENT)
+		if (err != -ENOENT && err != -ERANGE)
 			pr_err("Error %d reading sysrq code in control/sysrq\n",
 			       err);
 		xenbus_transaction_end(xbt, 1);
diff --git a/drivers/xen/mem-reservation.c b/drivers/xen/mem-reservation.c
index 084799c6180e..3782cf070338 100644
--- a/drivers/xen/mem-reservation.c
+++ b/drivers/xen/mem-reservation.c
@@ -14,6 +14,10 @@
 
 #include <xen/interface/memory.h>
 #include <xen/mem-reservation.h>
+#include <linux/moduleparam.h>
+
+bool __read_mostly xen_scrub_pages = IS_ENABLED(CONFIG_XEN_SCRUB_PAGES_DEFAULT);
+core_param(xen_scrub_pages, xen_scrub_pages, bool, 0);
 
 /*
  * Use one extent per PAGE_SIZE to avoid to break down the page into
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index 294f35ce9e46..63c1494a8d73 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -44,6 +44,7 @@
 #include <xen/xenbus.h>
 #include <xen/features.h>
 #include <xen/page.h>
+#include <xen/mem-reservation.h>
 
 #define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))
 
@@ -137,6 +138,7 @@ static DEVICE_ULONG_ATTR(schedule_delay, 0444, balloon_stats.schedule_delay);
 static DEVICE_ULONG_ATTR(max_schedule_delay, 0644, balloon_stats.max_schedule_delay);
 static DEVICE_ULONG_ATTR(retry_count, 0444, balloon_stats.retry_count);
 static DEVICE_ULONG_ATTR(max_retry_count, 0644, balloon_stats.max_retry_count);
+static DEVICE_BOOL_ATTR(scrub_pages, 0644, xen_scrub_pages);
 
 static ssize_t show_target_kb(struct device *dev, struct device_attribute *attr,
 			      char *buf)
@@ -203,6 +205,7 @@ static struct attribute *balloon_attrs[] = {
 	&dev_attr_max_schedule_delay.attr.attr,
 	&dev_attr_retry_count.attr.attr,
 	&dev_attr_max_retry_count.attr.attr,
+	&dev_attr_scrub_pages.attr.attr,
 	NULL
 };