Commit 814bbf49 authored by Juergen Gross's avatar Juergen Gross
Browse files

xen: remove tmem driver 



The Xen tmem (transcendent memory) driver can be removed, as the
related Xen hypervisor feature never made it past the "experimental"
state and will be removed in future Xen versions (>= 4.13).

The xen-selfballoon driver depends on tmem, so it can be removed, too.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Acked-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 090d54bc

Documentation/admin-guide/kernel-parameters.txt

+0 −21
Original line number Diff line number Diff line
@@ -4674,27 +4674,6 @@ 
			Force threading of all interrupt handlers except those

			marked explicitly IRQF_NO_THREAD.



	tmem		[KNL,XEN]

			Enable the Transcendent memory driver if built-in.



	tmem.cleancache=0|1 [KNL, XEN]

			Default is on (1). Disable the usage of the cleancache

			API to send anonymous pages to the hypervisor.



	tmem.frontswap=0|1 [KNL, XEN]

			Default is on (1). Disable the usage of the frontswap

			API to send swap pages to the hypervisor. If disabled

			the selfballooning and selfshrinking are force disabled.



	tmem.selfballooning=0|1 [KNL, XEN]

			Default is on (1). Disable the driving of swap pages

			to the hypervisor.



	tmem.selfshrinking=0|1 [KNL, XEN]

			Default is on (1). Partial swapoff that immediately

			transfers pages from Xen hypervisor back to the

			kernel based on different criteria.



	topology=	[S390]

			Format: {off | on}

			Specify if the kernel should make use of the cpu

drivers/xen/Kconfig

+0 −23
Original line number Diff line number Diff line
@@ -10,21 +10,6 @@ config XEN_BALLOON 
	  the system to expand the domain's memory allocation, or alternatively

	  return unneeded memory to the system.



config XEN_SELFBALLOONING

	bool "Dynamically self-balloon kernel memory to target"

	depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP && XEN_TMEM

	help

	  Self-ballooning dynamically balloons available kernel memory driven

	  by the current usage of anonymous memory ("committed AS") and

	  controlled by various sysfs-settable parameters.  Configuring

	  FRONTSWAP is highly recommended; if it is not configured, self-

	  ballooning is disabled by default. If FRONTSWAP is configured,

	  frontswap-selfshrinking is enabled by default but can be disabled

	  with the 'tmem.selfshrink=0' kernel boot parameter; and self-ballooning

	  is enabled by default but can be disabled with the 'tmem.selfballooning=0'

	  kernel boot parameter.  Note that systems without a sufficiently

	  large swap device should not enable self-ballooning.



config XEN_BALLOON_MEMORY_HOTPLUG

	bool "Memory hotplug support for Xen balloon driver"

	depends on XEN_BALLOON && MEMORY_HOTPLUG
@@ -191,14 +176,6 @@ config SWIOTLB_XEN 
	def_bool y

	select SWIOTLB



config XEN_TMEM

	tristate

	depends on !ARM && !ARM64

	default m if (CLEANCACHE || FRONTSWAP)

	help

	  Shim to interface in-kernel Transcendent Memory hooks

	  (e.g. cleancache and frontswap) to Xen tmem hypercalls.



config XEN_PCIDEV_BACKEND

	tristate "Xen PCI-device backend driver"

	depends on PCI && X86 && XEN

drivers/xen/Makefile

+0 −2
Original line number Diff line number Diff line
@@ -17,14 +17,12 @@ dom0-$(CONFIG_X86) += pcpu.o 
obj-$(CONFIG_XEN_DOM0)			+= $(dom0-y)

obj-$(CONFIG_BLOCK)			+= biomerge.o

obj-$(CONFIG_XEN_BALLOON)		+= xen-balloon.o

obj-$(CONFIG_XEN_SELFBALLOONING)	+= xen-selfballoon.o

obj-$(CONFIG_XEN_DEV_EVTCHN)		+= xen-evtchn.o

obj-$(CONFIG_XEN_GNTDEV)		+= xen-gntdev.o

obj-$(CONFIG_XEN_GRANT_DEV_ALLOC)	+= xen-gntalloc.o

obj-$(CONFIG_XENFS)			+= xenfs/

obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o

obj-$(CONFIG_XEN_PVHVM)			+= platform-pci.o

obj-$(CONFIG_XEN_TMEM)			+= tmem.o

obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o

obj-$(CONFIG_XEN_MCE_LOG)		+= mcelog.o

obj-$(CONFIG_XEN_PCIDEV_BACKEND)	+= xen-pciback/

drivers/xen/tmem.c

deleted100644 → 0
+0 −419
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Xen implementation for transcendent memory (tmem)

 *

 * Copyright (C) 2009-2011 Oracle Corp.  All rights reserved.

 * Author: Dan Magenheimer

 */



#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt



#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/types.h>

#include <linux/init.h>

#include <linux/pagemap.h>

#include <linux/cleancache.h>

#include <linux/frontswap.h>



#include <xen/xen.h>

#include <xen/interface/xen.h>

#include <xen/page.h>

#include <asm/xen/hypercall.h>

#include <asm/xen/hypervisor.h>

#include <xen/tmem.h>



#ifndef CONFIG_XEN_TMEM_MODULE

bool __read_mostly tmem_enabled = false;



static int __init enable_tmem(char *s)

{

	tmem_enabled = true;

	return 1;

}

__setup("tmem", enable_tmem);

#endif



#ifdef CONFIG_CLEANCACHE

static bool cleancache __read_mostly = true;

module_param(cleancache, bool, S_IRUGO);

static bool selfballooning __read_mostly = true;

module_param(selfballooning, bool, S_IRUGO);

#endif /* CONFIG_CLEANCACHE */



#ifdef CONFIG_FRONTSWAP

static bool frontswap __read_mostly = true;

module_param(frontswap, bool, S_IRUGO);

#else /* CONFIG_FRONTSWAP */

#define frontswap (0)

#endif /* CONFIG_FRONTSWAP */



#ifdef CONFIG_XEN_SELFBALLOONING

static bool selfshrinking __read_mostly = true;

module_param(selfshrinking, bool, S_IRUGO);

#endif /* CONFIG_XEN_SELFBALLOONING */



#define TMEM_CONTROL               0

#define TMEM_NEW_POOL              1

#define TMEM_DESTROY_POOL          2

#define TMEM_NEW_PAGE              3

#define TMEM_PUT_PAGE              4

#define TMEM_GET_PAGE              5

#define TMEM_FLUSH_PAGE            6

#define TMEM_FLUSH_OBJECT          7

#define TMEM_READ                  8

#define TMEM_WRITE                 9

#define TMEM_XCHG                 10



/* Bits for HYPERVISOR_tmem_op(TMEM_NEW_POOL) */

#define TMEM_POOL_PERSIST          1

#define TMEM_POOL_SHARED           2

#define TMEM_POOL_PAGESIZE_SHIFT   4

#define TMEM_VERSION_SHIFT        24





struct tmem_pool_uuid {

	u64 uuid_lo;

	u64 uuid_hi;

};



struct tmem_oid {

	u64 oid[3];

};



#define TMEM_POOL_PRIVATE_UUID	{ 0, 0 }



/* flags for tmem_ops.new_pool */

#define TMEM_POOL_PERSIST          1

#define TMEM_POOL_SHARED           2



/* xen tmem foundation ops/hypercalls */



static inline int xen_tmem_op(u32 tmem_cmd, u32 tmem_pool, struct tmem_oid oid,

	u32 index, unsigned long gmfn, u32 tmem_offset, u32 pfn_offset, u32 len)

{

	struct tmem_op op;

	int rc = 0;



	op.cmd = tmem_cmd;

	op.pool_id = tmem_pool;

	op.u.gen.oid[0] = oid.oid[0];

	op.u.gen.oid[1] = oid.oid[1];

	op.u.gen.oid[2] = oid.oid[2];

	op.u.gen.index = index;

	op.u.gen.tmem_offset = tmem_offset;

	op.u.gen.pfn_offset = pfn_offset;

	op.u.gen.len = len;

	set_xen_guest_handle(op.u.gen.gmfn, (void *)gmfn);

	rc = HYPERVISOR_tmem_op(&op);

	return rc;

}



static int xen_tmem_new_pool(struct tmem_pool_uuid uuid,

				u32 flags, unsigned long pagesize)

{

	struct tmem_op op;

	int rc = 0, pageshift;



	for (pageshift = 0; pagesize != 1; pageshift++)

		pagesize >>= 1;

	flags |= (pageshift - 12) << TMEM_POOL_PAGESIZE_SHIFT;

	flags |= TMEM_SPEC_VERSION << TMEM_VERSION_SHIFT;

	op.cmd = TMEM_NEW_POOL;

	op.u.new.uuid[0] = uuid.uuid_lo;

	op.u.new.uuid[1] = uuid.uuid_hi;

	op.u.new.flags = flags;

	rc = HYPERVISOR_tmem_op(&op);

	return rc;

}



/* xen generic tmem ops */



static int xen_tmem_put_page(u32 pool_id, struct tmem_oid oid,

			     u32 index, struct page *page)

{

	return xen_tmem_op(TMEM_PUT_PAGE, pool_id, oid, index,

			   xen_page_to_gfn(page), 0, 0, 0);

}



static int xen_tmem_get_page(u32 pool_id, struct tmem_oid oid,

			     u32 index, struct page *page)

{

	return xen_tmem_op(TMEM_GET_PAGE, pool_id, oid, index,

			   xen_page_to_gfn(page), 0, 0, 0);

}



static int xen_tmem_flush_page(u32 pool_id, struct tmem_oid oid, u32 index)

{

	return xen_tmem_op(TMEM_FLUSH_PAGE, pool_id, oid, index,

		0, 0, 0, 0);

}



static int xen_tmem_flush_object(u32 pool_id, struct tmem_oid oid)

{

	return xen_tmem_op(TMEM_FLUSH_OBJECT, pool_id, oid, 0, 0, 0, 0, 0);

}





#ifdef CONFIG_CLEANCACHE

static int xen_tmem_destroy_pool(u32 pool_id)

{

	struct tmem_oid oid = { { 0 } };



	return xen_tmem_op(TMEM_DESTROY_POOL, pool_id, oid, 0, 0, 0, 0, 0);

}



/* cleancache ops */



static void tmem_cleancache_put_page(int pool, struct cleancache_filekey key,

				     pgoff_t index, struct page *page)

{

	u32 ind = (u32) index;

	struct tmem_oid oid = *(struct tmem_oid *)&key;



	if (pool < 0)

		return;

	if (ind != index)

		return;

	mb(); /* ensure page is quiescent; tmem may address it with an alias */

	(void)xen_tmem_put_page((u32)pool, oid, ind, page);

}



static int tmem_cleancache_get_page(int pool, struct cleancache_filekey key,

				    pgoff_t index, struct page *page)

{

	u32 ind = (u32) index;

	struct tmem_oid oid = *(struct tmem_oid *)&key;

	int ret;



	/* translate return values to linux semantics */

	if (pool < 0)

		return -1;

	if (ind != index)

		return -1;

	ret = xen_tmem_get_page((u32)pool, oid, ind, page);

	if (ret == 1)

		return 0;

	else

		return -1;

}



static void tmem_cleancache_flush_page(int pool, struct cleancache_filekey key,

				       pgoff_t index)

{

	u32 ind = (u32) index;

	struct tmem_oid oid = *(struct tmem_oid *)&key;



	if (pool < 0)

		return;

	if (ind != index)

		return;

	(void)xen_tmem_flush_page((u32)pool, oid, ind);

}



static void tmem_cleancache_flush_inode(int pool, struct cleancache_filekey key)

{

	struct tmem_oid oid = *(struct tmem_oid *)&key;



	if (pool < 0)

		return;

	(void)xen_tmem_flush_object((u32)pool, oid);

}



static void tmem_cleancache_flush_fs(int pool)

{

	if (pool < 0)

		return;

	(void)xen_tmem_destroy_pool((u32)pool);

}



static int tmem_cleancache_init_fs(size_t pagesize)

{

	struct tmem_pool_uuid uuid_private = TMEM_POOL_PRIVATE_UUID;



	return xen_tmem_new_pool(uuid_private, 0, pagesize);

}



static int tmem_cleancache_init_shared_fs(uuid_t *uuid, size_t pagesize)

{

	struct tmem_pool_uuid shared_uuid;



	shared_uuid.uuid_lo = *(u64 *)&uuid->b[0];

	shared_uuid.uuid_hi = *(u64 *)&uuid->b[8];

	return xen_tmem_new_pool(shared_uuid, TMEM_POOL_SHARED, pagesize);

}



static const struct cleancache_ops tmem_cleancache_ops = {

	.put_page = tmem_cleancache_put_page,

	.get_page = tmem_cleancache_get_page,

	.invalidate_page = tmem_cleancache_flush_page,

	.invalidate_inode = tmem_cleancache_flush_inode,

	.invalidate_fs = tmem_cleancache_flush_fs,

	.init_shared_fs = tmem_cleancache_init_shared_fs,

	.init_fs = tmem_cleancache_init_fs

};

#endif



#ifdef CONFIG_FRONTSWAP

/* frontswap tmem operations */



/* a single tmem poolid is used for all frontswap "types" (swapfiles) */

static int tmem_frontswap_poolid;



/*

 * Swizzling increases objects per swaptype, increasing tmem concurrency

 * for heavy swaploads.  Later, larger nr_cpus -> larger SWIZ_BITS

 */

#define SWIZ_BITS		4

#define SWIZ_MASK		((1 << SWIZ_BITS) - 1)

#define _oswiz(_type, _ind)	((_type << SWIZ_BITS) | (_ind & SWIZ_MASK))

#define iswiz(_ind)		(_ind >> SWIZ_BITS)



static inline struct tmem_oid oswiz(unsigned type, u32 ind)

{

	struct tmem_oid oid = { .oid = { 0 } };

	oid.oid[0] = _oswiz(type, ind);

	return oid;

}



/* returns 0 if the page was successfully put into frontswap, -1 if not */

static int tmem_frontswap_store(unsigned type, pgoff_t offset,

				   struct page *page)

{

	u64 ind64 = (u64)offset;

	u32 ind = (u32)offset;

	int pool = tmem_frontswap_poolid;

	int ret;



	/* THP isn't supported */

	if (PageTransHuge(page))

		return -1;



	if (pool < 0)

		return -1;

	if (ind64 != ind)

		return -1;

	mb(); /* ensure page is quiescent; tmem may address it with an alias */

	ret = xen_tmem_put_page(pool, oswiz(type, ind), iswiz(ind), page);

	/* translate Xen tmem return values to linux semantics */

	if (ret == 1)

		return 0;

	else

		return -1;

}



/*

 * returns 0 if the page was successfully gotten from frontswap, -1 if

 * was not present (should never happen!)

 */

static int tmem_frontswap_load(unsigned type, pgoff_t offset,

				   struct page *page)

{

	u64 ind64 = (u64)offset;

	u32 ind = (u32)offset;

	int pool = tmem_frontswap_poolid;

	int ret;



	if (pool < 0)

		return -1;

	if (ind64 != ind)

		return -1;

	ret = xen_tmem_get_page(pool, oswiz(type, ind), iswiz(ind), page);

	/* translate Xen tmem return values to linux semantics */

	if (ret == 1)

		return 0;

	else

		return -1;

}



/* flush a single page from frontswap */

static void tmem_frontswap_flush_page(unsigned type, pgoff_t offset)

{

	u64 ind64 = (u64)offset;

	u32 ind = (u32)offset;

	int pool = tmem_frontswap_poolid;



	if (pool < 0)

		return;

	if (ind64 != ind)

		return;

	(void) xen_tmem_flush_page(pool, oswiz(type, ind), iswiz(ind));

}



/* flush all pages from the passed swaptype */

static void tmem_frontswap_flush_area(unsigned type)

{

	int pool = tmem_frontswap_poolid;

	int ind;



	if (pool < 0)

		return;

	for (ind = SWIZ_MASK; ind >= 0; ind--)

		(void)xen_tmem_flush_object(pool, oswiz(type, ind));

}



static void tmem_frontswap_init(unsigned ignored)

{

	struct tmem_pool_uuid private = TMEM_POOL_PRIVATE_UUID;



	/* a single tmem poolid is used for all frontswap "types" (swapfiles) */

	if (tmem_frontswap_poolid < 0)

		tmem_frontswap_poolid =

		    xen_tmem_new_pool(private, TMEM_POOL_PERSIST, PAGE_SIZE);

}



static struct frontswap_ops tmem_frontswap_ops = {

	.store = tmem_frontswap_store,

	.load = tmem_frontswap_load,

	.invalidate_page = tmem_frontswap_flush_page,

	.invalidate_area = tmem_frontswap_flush_area,

	.init = tmem_frontswap_init

};

#endif



static int __init xen_tmem_init(void)

{

	if (!xen_domain())

		return 0;

#ifdef CONFIG_FRONTSWAP

	if (tmem_enabled && frontswap) {

		char *s = "";



		tmem_frontswap_poolid = -1;

		frontswap_register_ops(&tmem_frontswap_ops);

		pr_info("frontswap enabled, RAM provided by Xen Transcendent Memory%s\n",

			s);

	}

#endif

#ifdef CONFIG_CLEANCACHE

	BUILD_BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid));

	if (tmem_enabled && cleancache) {

		int err;



		err = cleancache_register_ops(&tmem_cleancache_ops);

		if (err)

			pr_warn("xen-tmem: failed to enable cleancache: %d\n",

				err);

		else

			pr_info("cleancache enabled, RAM provided by "

				"Xen Transcendent Memory\n");

	}

#endif

#ifdef CONFIG_XEN_SELFBALLOONING

	/*

	 * There is no point of driving pages to the swap system if they

	 * aren't going anywhere in tmem universe.

	 */

	if (!frontswap) {

		selfshrinking = false;

		selfballooning = false;

	}

	xen_selfballoon_init(selfballooning, selfshrinking);

#endif

	return 0;

}



module_init(xen_tmem_init)

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Dan Magenheimer <dan.magenheimer@oracle.com>");

MODULE_DESCRIPTION("Shim to Xen transcendent memory");

drivers/xen/xen-balloon.c

+0 −2
Original line number Diff line number Diff line
@@ -129,8 +129,6 @@ void xen_balloon_init(void) 
{

	register_balloon(&balloon_dev);



	register_xen_selfballooning(&balloon_dev);



	register_xenstore_notifier(&xenstore_notifier);

}

EXPORT_SYMBOL_GPL(xen_balloon_init);

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