Commit d271ab29 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen updates from Juergen Gross:

 - fix a bug introduced in 5.5 in the Xen gntdev driver

 - fix the Xen balloon driver when running on ancient Xen versions

 - allow Xen stubdoms to control interrupt enable flags of
   passed-through PCI cards

 - release resources in Xen backends under memory pressure

* tag 'for-linus-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/blkback: Consistently insert one empty line between functions
  xen/blkback: Remove unnecessary static variable name prefixes
  xen/blkback: Squeeze page pools if a memory pressure is detected
  xenbus/backend: Protect xenbus callback with lock
  xenbus/backend: Add memory pressure handler callback
  xen/gntdev: Do not use mm notifiers with autotranslating guests
  xen/balloon: Support xend-based toolstack take two
  xen-pciback: optionally allow interrupt enable flag writes
parents 2634744b 8557bbe5

Documentation/ABI/testing/sysfs-driver-pciback

+13 −0
Original line number Diff line number Diff line
@@ -11,3 +11,16 @@ Description: 
                #echo 00:19.0-E0:2:FF > /sys/bus/pci/drivers/pciback/quirks

                will allow the guest to read and write to the configuration

                register 0x0E.



What:           /sys/bus/pci/drivers/pciback/allow_interrupt_control

Date:           Jan 2020

KernelVersion:  5.6

Contact:        xen-devel@lists.xenproject.org

Description:

                List of devices which can have interrupt control flag (INTx,

                MSI, MSI-X) set by a connected guest. It is meant to be set

                only when the guest is a stubdomain hosting device model (qemu)

                and the actual device is assigned to a HVM. It is not safe

                (similar to permissive attribute) to set for a devices assigned

                to a PV guest. The device is automatically removed from this

                list when the connected pcifront terminates.

Documentation/ABI/testing/sysfs-driver-xen-blkback

+10 −0
Original line number Diff line number Diff line
@@ -25,3 +25,13 @@ Description: 
                allocated without being in use. The time is in

                seconds, 0 means indefinitely long.

                The default is 60 seconds.



What:           /sys/module/xen_blkback/parameters/buffer_squeeze_duration_ms

Date:           December 2019

KernelVersion:  5.6

Contact:        SeongJae Park <sjpark@amazon.de>

Description:

                When memory pressure is reported to blkback this option

                controls the duration in milliseconds that blkback will not

                cache any page not backed by a grant mapping.

                The default is 10ms.

drivers/block/xen-blkback/blkback.c

+21 −21
Original line number Diff line number Diff line
@@ -62,8 +62,8 @@ 
 * IO workloads.

 */



static int xen_blkif_max_buffer_pages = 1024;

module_param_named(max_buffer_pages, xen_blkif_max_buffer_pages, int, 0644);

static int max_buffer_pages = 1024;

module_param_named(max_buffer_pages, max_buffer_pages, int, 0644);

MODULE_PARM_DESC(max_buffer_pages,

"Maximum number of free pages to keep in each block backend buffer");
@@ -78,8 +78,8 @@ MODULE_PARM_DESC(max_buffer_pages, 
 * algorithm.

 */



static int xen_blkif_max_pgrants = 1056;

module_param_named(max_persistent_grants, xen_blkif_max_pgrants, int, 0644);

static int max_pgrants = 1056;

module_param_named(max_persistent_grants, max_pgrants, int, 0644);

MODULE_PARM_DESC(max_persistent_grants,

                 "Maximum number of grants to map persistently");
@@ -88,8 +88,8 @@ MODULE_PARM_DESC(max_persistent_grants, 
 * use. The time is in seconds, 0 means indefinitely long.

 */



static unsigned int xen_blkif_pgrant_timeout = 60;

module_param_named(persistent_grant_unused_seconds, xen_blkif_pgrant_timeout,

static unsigned int pgrant_timeout = 60;

module_param_named(persistent_grant_unused_seconds, pgrant_timeout,

		   uint, 0644);

MODULE_PARM_DESC(persistent_grant_unused_seconds,

		 "Time in seconds an unused persistent grant is allowed to "
@@ -137,9 +137,8 @@ module_param(log_stats, int, 0644); 


static inline bool persistent_gnt_timeout(struct persistent_gnt *persistent_gnt)

{

	return xen_blkif_pgrant_timeout &&

	       (jiffies - persistent_gnt->last_used >=

		HZ * xen_blkif_pgrant_timeout);

	return pgrant_timeout && (jiffies - persistent_gnt->last_used >=

			HZ * pgrant_timeout);

}



static inline int get_free_page(struct xen_blkif_ring *ring, struct page **page)
@@ -234,7 +233,7 @@ static int add_persistent_gnt(struct xen_blkif_ring *ring, 
	struct persistent_gnt *this;

	struct xen_blkif *blkif = ring->blkif;



	if (ring->persistent_gnt_c >= xen_blkif_max_pgrants) {

	if (ring->persistent_gnt_c >= max_pgrants) {

		if (!blkif->vbd.overflow_max_grants)

			blkif->vbd.overflow_max_grants = 1;

		return -EBUSY;
@@ -397,14 +396,13 @@ static void purge_persistent_gnt(struct xen_blkif_ring *ring) 
		goto out;

	}



	if (ring->persistent_gnt_c < xen_blkif_max_pgrants ||

	    (ring->persistent_gnt_c == xen_blkif_max_pgrants &&

	if (ring->persistent_gnt_c < max_pgrants ||

	    (ring->persistent_gnt_c == max_pgrants &&

	    !ring->blkif->vbd.overflow_max_grants)) {

		num_clean = 0;

	} else {

		num_clean = (xen_blkif_max_pgrants / 100) * LRU_PERCENT_CLEAN;

		num_clean = ring->persistent_gnt_c - xen_blkif_max_pgrants +

			    num_clean;

		num_clean = (max_pgrants / 100) * LRU_PERCENT_CLEAN;

		num_clean = ring->persistent_gnt_c - max_pgrants + num_clean;

		num_clean = min(ring->persistent_gnt_c, num_clean);

		pr_debug("Going to purge at least %u persistent grants\n",

			 num_clean);
@@ -599,8 +597,7 @@ static void print_stats(struct xen_blkif_ring *ring) 
		 current->comm, ring->st_oo_req,

		 ring->st_rd_req, ring->st_wr_req,

		 ring->st_f_req, ring->st_ds_req,

		 ring->persistent_gnt_c,

		 xen_blkif_max_pgrants);

		 ring->persistent_gnt_c, max_pgrants);

	ring->st_print = jiffies + msecs_to_jiffies(10 * 1000);

	ring->st_rd_req = 0;

	ring->st_wr_req = 0;
@@ -656,8 +653,11 @@ purge_gnt_list: 
			ring->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL);

		}



		/* Shrink if we have more than xen_blkif_max_buffer_pages */

		shrink_free_pagepool(ring, xen_blkif_max_buffer_pages);

		/* Shrink the free pages pool if it is too large. */

		if (time_before(jiffies, blkif->buffer_squeeze_end))

			shrink_free_pagepool(ring, 0);

		else

			shrink_free_pagepool(ring, max_buffer_pages);



		if (log_stats && time_after(jiffies, ring->st_print))

			print_stats(ring);
@@ -884,7 +884,7 @@ again: 
			continue;

		}

		if (use_persistent_gnts &&

		    ring->persistent_gnt_c < xen_blkif_max_pgrants) {

		    ring->persistent_gnt_c < max_pgrants) {

			/*

			 * We are using persistent grants, the grant is

			 * not mapped but we might have room for it.
@@ -911,7 +911,7 @@ again: 
			pages[seg_idx]->persistent_gnt = persistent_gnt;

			pr_debug("grant %u added to the tree of persistent grants, using %u/%u\n",

				 persistent_gnt->gnt, ring->persistent_gnt_c,

				 xen_blkif_max_pgrants);

				 max_pgrants);

			goto next;

		}

		if (use_persistent_gnts && !blkif->vbd.overflow_max_grants) {

drivers/block/xen-blkback/common.h

+1 −0
Original line number Diff line number Diff line
@@ -319,6 +319,7 @@ struct xen_blkif { 
	/* All rings for this device. */

	struct xen_blkif_ring	*rings;

	unsigned int		nr_rings;

	unsigned long		buffer_squeeze_end;

};



struct seg_buf {

drivers/block/xen-blkback/xenbus.c

+22 −4
Original line number Diff line number Diff line
@@ -467,7 +467,6 @@ static void xenvbd_sysfs_delif(struct xenbus_device *dev) 
	device_remove_file(&dev->dev, &dev_attr_physical_device);

}





static void xen_vbd_free(struct xen_vbd *vbd)

{

	if (vbd->bdev)
@@ -524,6 +523,7 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle, 
		handle, blkif->domid);

	return 0;

}



static int xen_blkbk_remove(struct xenbus_device *dev)

{

	struct backend_info *be = dev_get_drvdata(&dev->dev);
@@ -607,6 +607,7 @@ static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info 
	if (err)

		dev_warn(&dev->dev, "writing feature-discard (%d)", err);

}



int xen_blkbk_barrier(struct xenbus_transaction xbt,

		      struct backend_info *be, int state)

{
@@ -691,7 +692,6 @@ fail: 
	return err;

}





/*

 * Callback received when the hotplug scripts have placed the physical-device

 * node.  Read it and the mode node, and create a vbd.  If the frontend is
@@ -783,7 +783,6 @@ static void backend_changed(struct xenbus_watch *watch, 
	}

}





/*

 * Callback received when the frontend's state changes.

 */
@@ -858,9 +857,27 @@ static void frontend_changed(struct xenbus_device *dev, 
	}

}



/* Once a memory pressure is detected, squeeze free page pools for a while. */

static unsigned int buffer_squeeze_duration_ms = 10;

module_param_named(buffer_squeeze_duration_ms,

		buffer_squeeze_duration_ms, int, 0644);

MODULE_PARM_DESC(buffer_squeeze_duration_ms,

"Duration in ms to squeeze pages buffer when a memory pressure is detected");



/* ** Connection ** */

/*

 * Callback received when the memory pressure is detected.

 */

static void reclaim_memory(struct xenbus_device *dev)

{

	struct backend_info *be = dev_get_drvdata(&dev->dev);



	if (!be)

		return;

	be->blkif->buffer_squeeze_end = jiffies +

		msecs_to_jiffies(buffer_squeeze_duration_ms);

}



/* ** Connection ** */



/*

 * Write the physical details regarding the block device to the store, and
@@ -1152,6 +1169,7 @@ static struct xenbus_driver xen_blkbk_driver = { 
	.remove = xen_blkbk_remove,

	.otherend_changed = frontend_changed,

	.allow_rebind = true,

	.reclaim_memory = reclaim_memory,

};



int xen_blkif_xenbus_init(void)

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