Merge tag 'for-linus-5.3a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
"Fixes and features:

- A series to introduce a common command line parameter for disabling
paravirtual extensions when running as a guest in virtualized
environment

- A fix for int3 handling in Xen pv guests

- Removal of the Xen-specific tmem driver as support of tmem in Xen
has been dropped (and it was experimental only)

- A security fix for running as Xen dom0 (XSA-300)

- A fix for IRQ handling when offlining cpus in Xen guests

- Some small cleanups"

* tag 'for-linus-5.3a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: let alloc_xenballooned_pages() fail if not enough memory free
xen/pv: Fix a boot up hang revealed by int3 self test
x86/xen: Add "nopv" support for HVM guest
x86/paravirt: Remove const mark from x86_hyper_xen_hvm variable
xen: Map "xen_nopv" parameter to "nopv" and mark it obsolete
x86: Add "nopv" parameter to disable PV extensions
x86/xen: Mark xen_hvm_need_lapic() and xen_x2apic_para_available() as __init
xen: remove tmem driver
Revert "x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized"
xen/events: fix binding user event channels to cpus

Documentation/admin-guide/kernel-parameters.txt

···
 			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
···
 	xen_nopv	[X86]
 			Disables the PV optimizations forcing the HVM guest to
 			run as generic HVM guest with no PV drivers.
+			This option is obsoleted by the "nopv" option, which
+			has equivalent effect for XEN platform.
 
 	xen_scrub_pages=	[XEN]
 			Boolean option to control scrubbing pages before giving them back
···
 			delta of virtualized Xen timers, where lower values
 			improve timer resolution at the expense of processing
 			more timer interrupts.
+
+	nopv=		[X86,XEN,KVM,HYPER_V,VMWARE]
+			Disables the PV optimizations forcing the guest to run
+			as generic guest with no PV drivers. Currently support
+			XEN HVM, KVM, HYPER_V and VMWARE guest.
 
 	xirc2ps_cs=	[NET,PCMCIA]
 			Format:

arch/x86/entry/entry_64.S

···
 #ifdef CONFIG_XEN_PV
 idtentry xennmi			do_nmi			has_error_code=0
 idtentry xendebug		do_debug		has_error_code=0
-idtentry xenint3		do_int3			has_error_code=0
 #endif
 
 idtentry general_protection	do_general_protection	has_error_code=1

arch/x86/include/asm/hypervisor.h

···
 
 	/* runtime callbacks */
 	struct x86_hyper_runtime runtime;
+
+	/* ignore nopv parameter */
+	bool ignore_nopv;
 };
 
+extern const struct hypervisor_x86 x86_hyper_vmware;
+extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
+extern const struct hypervisor_x86 x86_hyper_xen_pv;
+extern const struct hypervisor_x86 x86_hyper_kvm;
+extern const struct hypervisor_x86 x86_hyper_jailhouse;
+extern const struct hypervisor_x86 x86_hyper_acrn;
+extern struct hypervisor_x86 x86_hyper_xen_hvm;
+
+extern bool nopv;
 extern enum x86_hypervisor_type x86_hyper_type;
 extern void init_hypervisor_platform(void);
 static inline bool hypervisor_is_type(enum x86_hypervisor_type type)

arch/x86/include/asm/traps.h

···
 asmlinkage void xen_divide_error(void);
 asmlinkage void xen_xennmi(void);
 asmlinkage void xen_xendebug(void);
-asmlinkage void xen_xenint3(void);
+asmlinkage void xen_int3(void);
 asmlinkage void xen_overflow(void);
 asmlinkage void xen_bounds(void);
 asmlinkage void xen_invalid_op(void);

arch/x86/include/asm/x86_init.h

···
 extern void x86_early_init_platform_quirks(void);
 extern void x86_init_noop(void);
 extern void x86_init_uint_noop(unsigned int unused);
+extern bool bool_x86_init_noop(void);
+extern void x86_op_int_noop(int cpu);
 extern bool x86_pnpbios_disabled(void);
 
 #endif

arch/x86/include/asm/xen/hypervisor.h

···
 }
 
 #ifdef CONFIG_XEN
-extern bool xen_hvm_need_lapic(void);
+extern bool __init xen_hvm_need_lapic(void);
 
-static inline bool xen_x2apic_para_available(void)
+static inline bool __init xen_x2apic_para_available(void)
 {
 	return xen_hvm_need_lapic();
 }
 #else
-static inline bool xen_x2apic_para_available(void)
+static inline bool __init xen_x2apic_para_available(void)
 {
 	return (xen_cpuid_base() != 0);
 }

arch/x86/kernel/cpu/hypervisor.c

···
 #include <asm/processor.h>
 #include <asm/hypervisor.h>
 
-extern const struct hypervisor_x86 x86_hyper_vmware;
-extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
-extern const struct hypervisor_x86 x86_hyper_xen_pv;
-extern const struct hypervisor_x86 x86_hyper_xen_hvm;
-extern const struct hypervisor_x86 x86_hyper_kvm;
-extern const struct hypervisor_x86 x86_hyper_jailhouse;
-extern const struct hypervisor_x86 x86_hyper_acrn;
-
 static const __initconst struct hypervisor_x86 * const hypervisors[] =
 {
 #ifdef CONFIG_XEN_PV
···
 enum x86_hypervisor_type x86_hyper_type;
 EXPORT_SYMBOL(x86_hyper_type);
 
+bool __initdata nopv;
+static __init int parse_nopv(char *arg)
+{
+	nopv = true;
+	return 0;
+}
+early_param("nopv", parse_nopv);
+
 static inline const struct hypervisor_x86 * __init
 detect_hypervisor_vendor(void)
 {
···
 	uint32_t pri, max_pri = 0;
 
 	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
+		if (unlikely(nopv) && !(*p)->ignore_nopv)
+			continue;
+
 		pri = (*p)->detect();
 		if (pri > max_pri) {
 			max_pri = pri;

arch/x86/kernel/jailhouse.c

···
 	.detect			= jailhouse_detect,
 	.init.init_platform	= jailhouse_init_platform,
 	.init.x2apic_available	= jailhouse_x2apic_available,
+	.ignore_nopv		= true,
 };

arch/x86/kernel/smpboot.c

···
 	pr_info("CPU0: ");
 	print_cpu_info(&cpu_data(0));
 
-	native_pv_lock_init();
-
 	uv_system_init();
 
 	set_mtrr_aps_delayed_init();
···
 	/* already set me in cpu_online_mask in boot_cpu_init() */
 	cpumask_set_cpu(me, cpu_callout_mask);
 	cpu_set_state_online(me);
+	native_pv_lock_init();
 }
 
 void __init calculate_max_logical_packages(void)

arch/x86/kernel/x86_init.c

···
 void __init x86_init_uint_noop(unsigned int unused) { }
 static int __init iommu_init_noop(void) { return 0; }
 static void iommu_shutdown_noop(void) { }
-static bool __init bool_x86_init_noop(void) { return false; }
-static void x86_op_int_noop(int cpu) { }
+bool __init bool_x86_init_noop(void) { return false; }
+void x86_op_int_noop(int cpu) { }
 
 /*
  * The platform setup functions are preset with the default functions

arch/x86/xen/enlighten_hvm.c

···
 #endif
 }
 
-static bool xen_nopv;
 static __init int xen_parse_nopv(char *arg)
 {
-       xen_nopv = true;
-       return 0;
+	pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n");
+
+	if (xen_cpuid_base())
+		nopv = true;
+	return 0;
 }
 early_param("xen_nopv", xen_parse_nopv);
 
-bool xen_hvm_need_lapic(void)
+bool __init xen_hvm_need_lapic(void)
 {
-	if (xen_nopv)
-		return false;
 	if (xen_pv_domain())
 		return false;
 	if (!xen_hvm_domain())
···
 	if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
 		return false;
 	return true;
-}
-EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
-
-static uint32_t __init xen_platform_hvm(void)
-{
-	if (xen_pv_domain() || xen_nopv)
-		return 0;
-
-	return xen_cpuid_base();
 }
 
 static __init void xen_hvm_guest_late_init(void)
···
 	/* PVH detected. */
 	xen_pvh = true;
 
+	if (nopv)
+		panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
+
 	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
 	if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
 		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
···
 #endif
 }
 
-const __initconst struct hypervisor_x86 x86_hyper_xen_hvm = {
+static uint32_t __init xen_platform_hvm(void)
+{
+	uint32_t xen_domain = xen_cpuid_base();
+	struct x86_hyper_init *h = &x86_hyper_xen_hvm.init;
+
+	if (xen_pv_domain())
+		return 0;
+
+	if (xen_pvh_domain() && nopv) {
+		/* Guest booting via the Xen-PVH boot entry goes here */
+		pr_info("\"nopv\" parameter is ignored in PVH guest\n");
+		nopv = false;
+	} else if (nopv && xen_domain) {
+		/*
+		 * Guest booting via normal boot entry (like via grub2) goes
+		 * here.
+		 *
+		 * Use interface functions for bare hardware if nopv,
+		 * xen_hvm_guest_late_init is an exception as we need to
+		 * detect PVH and panic there.
+		 */
+		h->init_platform = x86_init_noop;
+		h->x2apic_available = bool_x86_init_noop;
+		h->init_mem_mapping = x86_init_noop;
+		h->init_after_bootmem = x86_init_noop;
+		h->guest_late_init = xen_hvm_guest_late_init;
+		x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop;
+	}
+	return xen_domain;
+}
+
+struct hypervisor_x86 x86_hyper_xen_hvm __initdata = {
 	.name                   = "Xen HVM",
 	.detect                 = xen_platform_hvm,
 	.type			= X86_HYPER_XEN_HVM,
···
 	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
 	.init.guest_late_init	= xen_hvm_guest_late_init,
 	.runtime.pin_vcpu       = xen_pin_vcpu,
+	.ignore_nopv            = true,
 };

arch/x86/xen/enlighten_pv.c

···
 
 static struct trap_array_entry trap_array[] = {
 	{ debug,                       xen_xendebug,                    true },
-	{ int3,                        xen_xenint3,                     true },
 	{ double_fault,                xen_double_fault,                true },
 #ifdef CONFIG_X86_MCE
 	{ machine_check,               xen_machine_check,               true },
 #endif
 	{ nmi,                         xen_xennmi,                      true },
+	{ int3,                        xen_int3,                        false },
 	{ overflow,                    xen_overflow,                    false },
 #ifdef CONFIG_IA32_EMULATION
 	{ entry_INT80_compat,          xen_entry_INT80_compat,          false },
···
 	.detect                 = xen_platform_pv,
 	.type			= X86_HYPER_XEN_PV,
 	.runtime.pin_vcpu       = xen_pin_vcpu,
+	.ignore_nopv		= true,
 };

arch/x86/xen/spinlock.c

···
 	int irq;
 	char *name;
 
-	if (!xen_pvspin) {
-		if (cpu == 0)
-			static_branch_disable(&virt_spin_lock_key);
+	if (!xen_pvspin)
 		return;
-	}
 
 	WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n",
 	     cpu, per_cpu(lock_kicker_irq, cpu));
···
 
 	if (!xen_pvspin) {
 		printk(KERN_DEBUG "xen: PV spinlocks disabled\n");
+		static_branch_disable(&virt_spin_lock_key);
 		return;
 	}
 	printk(KERN_DEBUG "xen: PV spinlocks enabled\n");

arch/x86/xen/xen-asm_64.S

···
 xen_pv_trap debug
 xen_pv_trap xendebug
 xen_pv_trap int3
-xen_pv_trap xenint3
 xen_pv_trap xennmi
 xen_pv_trap overflow
 xen_pv_trap bounds

drivers/xen/Kconfig

···
 	  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
···
 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"

drivers/xen/Makefile

···
 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/balloon.c

···
 				state = reserve_additional_memory();
 		}
 
-		if (credit < 0)
-			state = decrease_reservation(-credit, GFP_BALLOON);
+		if (credit < 0) {
+			long n_pages;
+
+			n_pages = min(-credit, si_mem_available());
+			state = decrease_reservation(n_pages, GFP_BALLOON);
+			if (state == BP_DONE && n_pages != -credit &&
+			    n_pages < totalreserve_pages)
+				state = BP_EAGAIN;
+		}
 
 		state = update_schedule(state);
 
···
 			return 0;
 		}
 	}
+
+	if (si_mem_available() < nr_pages)
+		return -ENOMEM;
 
 	st = decrease_reservation(nr_pages, GFP_USER);
 	if (st != BP_DONE)
···
 	balloon_stats.schedule_delay = 1;
 	balloon_stats.max_schedule_delay = 32;
 	balloon_stats.retry_count = 1;
-	balloon_stats.max_retry_count = RETRY_UNLIMITED;
+	balloon_stats.max_retry_count = 4;
 
 #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
 	set_online_page_callback(&xen_online_page);

drivers/xen/events/events_base.c

···
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu)
+static int xen_rebind_evtchn_to_cpu(int evtchn, unsigned int tcpu)
 {
 	struct evtchn_bind_vcpu bind_vcpu;
 	int masked;
···
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(xen_rebind_evtchn_to_cpu);
 
 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
 			    bool force)
···
 
 	return ret;
 }
+
+/* To be called with desc->lock held. */
+int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu)
+{
+	struct irq_data *d = irq_desc_get_irq_data(desc);
+
+	return set_affinity_irq(d, cpumask_of(tcpu), false);
+}
+EXPORT_SYMBOL_GPL(xen_set_affinity_evtchn);
 
 static void enable_dynirq(struct irq_data *data)
 {

drivers/xen/evtchn.c

···
 	this_cpu_write(bind_last_selected_cpu, selected_cpu);
 
 	/* unmask expects irqs to be disabled */
-	xen_rebind_evtchn_to_cpu(evtchn, selected_cpu);
+	xen_set_affinity_evtchn(desc, selected_cpu);
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
 

drivers/xen/tmem.c

···
-// 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 <[e-mail]>");
-MODULE_DESCRIPTION("Shim to Xen transcendent memory");

drivers/xen/xen-balloon.c

···
 {
 	register_balloon(&balloon_dev);
 
-	register_xen_selfballooning(&balloon_dev);
-
 	register_xenstore_notifier(&xenstore_notifier);
 }
 EXPORT_SYMBOL_GPL(xen_balloon_init);

drivers/xen/xen-selfballoon.c

···
-// SPDX-License-Identifier: GPL-2.0
-/******************************************************************************
- * Xen selfballoon driver (and optional frontswap self-shrinking driver)
- *
- * Copyright (c) 2009-2011, Dan Magenheimer, Oracle Corp.
- *
- * This code complements the cleancache and frontswap patchsets to optimize
- * support for Xen Transcendent Memory ("tmem").  The policy it implements
- * is rudimentary and will likely improve over time, but it does work well
- * enough today.
- *
- * Two functionalities are implemented here which both use "control theory"
- * (feedback) to optimize memory utilization. In a virtualized environment
- * such as Xen, RAM is often a scarce resource and we would like to ensure
- * that each of a possibly large number of virtual machines is using RAM
- * efficiently, i.e. using as little as possible when under light load
- * and obtaining as much as possible when memory demands are high.
- * Since RAM needs vary highly dynamically and sometimes dramatically,
- * "hysteresis" is used, that is, memory target is determined not just
- * on current data but also on past data stored in the system.
- *
- * "Selfballooning" creates memory pressure by managing the Xen balloon
- * driver to decrease and increase available kernel memory, driven
- * largely by the target value of "Committed_AS" (see /proc/meminfo).
- * Since Committed_AS does not account for clean mapped pages (i.e. pages
- * in RAM that are identical to pages on disk), selfballooning has the
- * affect of pushing less frequently used clean pagecache pages out of
- * kernel RAM and, presumably using cleancache, into Xen tmem where
- * Xen can more efficiently optimize RAM utilization for such pages.
- *
- * When kernel memory demand unexpectedly increases faster than Xen, via
- * the selfballoon driver, is able to (or chooses to) provide usable RAM,
- * the kernel may invoke swapping.  In most cases, frontswap is able
- * to absorb this swapping into Xen tmem.  However, due to the fact
- * that the kernel swap subsystem assumes swapping occurs to a disk,
- * swapped pages may sit on the disk for a very long time; even if
- * the kernel knows the page will never be used again.  This is because
- * the disk space costs very little and can be overwritten when
- * necessary.  When such stale pages are in frontswap, however, they
- * are taking up valuable real estate.  "Frontswap selfshrinking" works
- * to resolve this:  When frontswap activity is otherwise stable
- * and the guest kernel is not under memory pressure, the "frontswap
- * selfshrinking" accounts for this by providing pressure to remove some
- * pages from frontswap and return them to kernel memory.
- *
- * For both "selfballooning" and "frontswap-selfshrinking", a worker
- * thread is used and sysfs tunables are provided to adjust the frequency
- * and rate of adjustments to achieve the goal, as well as to disable one
- * or both functions independently.
- *
- * While some argue that this functionality can and should be implemented
- * in userspace, it has been observed that bad things happen (e.g. OOMs).
- *
- * System configuration note: Selfballooning should not be enabled on
- * systems without a sufficiently large swap device configured; for best
- * results, it is recommended that total swap be increased by the size
- * of the guest memory. Note, that selfballooning should be disabled by default
- * if frontswap is not configured.  Similarly selfballooning should be enabled
- * by default if frontswap is configured and can be disabled with the
- * "tmem.selfballooning=0" kernel boot option.  Finally, when frontswap is
- * configured, frontswap-selfshrinking can be disabled  with the
- * "tmem.selfshrink=0" kernel boot option.
- *
- * Selfballooning is disallowed in domain0 and force-disabled.
- *
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/kernel.h>
-#include <linux/memblock.h>
-#include <linux/swap.h>
-#include <linux/mm.h>
-#include <linux/mman.h>
-#include <linux/workqueue.h>
-#include <linux/device.h>
-#include <xen/balloon.h>
-#include <xen/tmem.h>
-#include <xen/xen.h>
-
-/* Enable/disable with sysfs. */
-static int xen_selfballooning_enabled __read_mostly;
-
-/*
- * Controls rate at which memory target (this iteration) approaches
- * ultimate goal when memory need is increasing (up-hysteresis) or
- * decreasing (down-hysteresis). Higher values of hysteresis cause
- * slower increases/decreases. The default values for the various
- * parameters were deemed reasonable by experimentation, may be
- * workload-dependent, and can all be adjusted via sysfs.
- */
-static unsigned int selfballoon_downhysteresis __read_mostly = 8;
-static unsigned int selfballoon_uphysteresis __read_mostly = 1;
-
-/* In HZ, controls frequency of worker invocation. */
-static unsigned int selfballoon_interval __read_mostly = 5;
-
-/*
- * Minimum usable RAM in MB for selfballooning target for balloon.
- * If non-zero, it is added to totalreserve_pages and self-ballooning
- * will not balloon below the sum.  If zero, a piecewise linear function
- * is calculated as a minimum and added to totalreserve_pages.  Note that
- * setting this value indiscriminately may cause OOMs and crashes.
- */
-static unsigned int selfballoon_min_usable_mb;
-
-/*
- * Amount of RAM in MB to add to the target number of pages.
- * Can be used to reserve some more room for caches and the like.
- */
-static unsigned int selfballoon_reserved_mb;
-
-static void selfballoon_process(struct work_struct *work);
-static DECLARE_DELAYED_WORK(selfballoon_worker, selfballoon_process);
-
-#ifdef CONFIG_FRONTSWAP
-#include <linux/frontswap.h>
-
-/* Enable/disable with sysfs. */
-static bool frontswap_selfshrinking __read_mostly;
-
-/*
- * The default values for the following parameters were deemed reasonable
- * by experimentation, may be workload-dependent, and can all be
- * adjusted via sysfs.
- */
-
-/* Control rate for frontswap shrinking. Higher hysteresis is slower. */
-static unsigned int frontswap_hysteresis __read_mostly = 20;
-
-/*
- * Number of selfballoon worker invocations to wait before observing that
- * frontswap selfshrinking should commence. Note that selfshrinking does
- * not use a separate worker thread.
- */
-static unsigned int frontswap_inertia __read_mostly = 3;
-
-/* Countdown to next invocation of frontswap_shrink() */
-static unsigned long frontswap_inertia_counter;
-
-/*
- * Invoked by the selfballoon worker thread, uses current number of pages
- * in frontswap (frontswap_curr_pages()), previous status, and control
- * values (hysteresis and inertia) to determine if frontswap should be
- * shrunk and what the new frontswap size should be.  Note that
- * frontswap_shrink is essentially a partial swapoff that immediately
- * transfers pages from the "swap device" (frontswap) back into kernel
- * RAM; despite the name, frontswap "shrinking" is very different from
- * the "shrinker" interface used by the kernel MM subsystem to reclaim
- * memory.
- */
-static void frontswap_selfshrink(void)
-{
-	static unsigned long cur_frontswap_pages;
-	unsigned long last_frontswap_pages;
-	unsigned long tgt_frontswap_pages;
-
-	last_frontswap_pages = cur_frontswap_pages;
-	cur_frontswap_pages = frontswap_curr_pages();
-	if (!cur_frontswap_pages ||
-			(cur_frontswap_pages > last_frontswap_pages)) {
-		frontswap_inertia_counter = frontswap_inertia;
-		return;
-	}
-	if (frontswap_inertia_counter && --frontswap_inertia_counter)
-		return;
-	if (cur_frontswap_pages <= frontswap_hysteresis)
-		tgt_frontswap_pages = 0;
-	else
-		tgt_frontswap_pages = cur_frontswap_pages -
-			(cur_frontswap_pages / frontswap_hysteresis);
-	frontswap_shrink(tgt_frontswap_pages);
-	frontswap_inertia_counter = frontswap_inertia;
-}
-
-#endif /* CONFIG_FRONTSWAP */
-
-#define MB2PAGES(mb)	((mb) << (20 - PAGE_SHIFT))
-#define PAGES2MB(pages) ((pages) >> (20 - PAGE_SHIFT))
-
-/*
- * Use current balloon size, the goal (vm_committed_as), and hysteresis
- * parameters to set a new target balloon size
- */
-static void selfballoon_process(struct work_struct *work)
-{
-	unsigned long cur_pages, goal_pages, tgt_pages, floor_pages;
-	unsigned long useful_pages;
-	bool reset_timer = false;
-
-	if (xen_selfballooning_enabled) {
-		cur_pages = totalram_pages();
-		tgt_pages = cur_pages; /* default is no change */
-		goal_pages = vm_memory_committed() +
-				totalreserve_pages +
-				MB2PAGES(selfballoon_reserved_mb);
-#ifdef CONFIG_FRONTSWAP
-		/* allow space for frontswap pages to be repatriated */
-		if (frontswap_selfshrinking)
-			goal_pages += frontswap_curr_pages();
-#endif
-		if (cur_pages > goal_pages)
-			tgt_pages = cur_pages -
-				((cur_pages - goal_pages) /
-				  selfballoon_downhysteresis);
-		else if (cur_pages < goal_pages)
-			tgt_pages = cur_pages +
-				((goal_pages - cur_pages) /
-				  selfballoon_uphysteresis);
-		/* else if cur_pages == goal_pages, no change */
-		useful_pages = max_pfn - totalreserve_pages;
-		if (selfballoon_min_usable_mb != 0)
-			floor_pages = totalreserve_pages +
-					MB2PAGES(selfballoon_min_usable_mb);
-		/* piecewise linear function ending in ~3% slope */
-		else if (useful_pages < MB2PAGES(16))
-			floor_pages = max_pfn; /* not worth ballooning */
-		else if (useful_pages < MB2PAGES(64))
-			floor_pages = totalreserve_pages + MB2PAGES(16) +
-					((useful_pages - MB2PAGES(16)) >> 1);
-		else if (useful_pages < MB2PAGES(512))
-			floor_pages = totalreserve_pages + MB2PAGES(40) +
-					((useful_pages - MB2PAGES(40)) >> 3);
-		else /* useful_pages >= MB2PAGES(512) */
-			floor_pages = totalreserve_pages + MB2PAGES(99) +
-					((useful_pages - MB2PAGES(99)) >> 5);
-		if (tgt_pages < floor_pages)
-			tgt_pages = floor_pages;
-		balloon_set_new_target(tgt_pages +
-			balloon_stats.current_pages - totalram_pages());
-		reset_timer = true;
-	}
-#ifdef CONFIG_FRONTSWAP
-	if (frontswap_selfshrinking) {
-		frontswap_selfshrink();
-		reset_timer = true;
-	}
-#endif
-	if (reset_timer)
-		schedule_delayed_work(&selfballoon_worker,
-			selfballoon_interval * HZ);
-}
-
-#ifdef CONFIG_SYSFS
-
-#include <linux/capability.h>
-
-#define SELFBALLOON_SHOW(name, format, args...)				\
-	static ssize_t show_##name(struct device *dev,	\
-					  struct device_attribute *attr, \
-					  char *buf) \
-	{ \
-		return sprintf(buf, format, ##args); \
-	}
-
-SELFBALLOON_SHOW(selfballooning, "%d\n", xen_selfballooning_enabled);
-
-static ssize_t store_selfballooning(struct device *dev,
-			    struct device_attribute *attr,
-			    const char *buf,
-			    size_t count)
-{
-	bool was_enabled = xen_selfballooning_enabled;
-	unsigned long tmp;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	err = kstrtoul(buf, 10, &tmp);
-	if (err)
-		return err;
-	if ((tmp != 0) && (tmp != 1))
-		return -EINVAL;
-
-	xen_selfballooning_enabled = !!tmp;
-	if (!was_enabled && xen_selfballooning_enabled)
-		schedule_delayed_work(&selfballoon_worker,
-			selfballoon_interval * HZ);
-
-	return count;
-}
-
-static DEVICE_ATTR(selfballooning, S_IRUGO | S_IWUSR,
-		   show_selfballooning, store_selfballooning);
-
-SELFBALLOON_SHOW(selfballoon_interval, "%d\n", selfballoon_interval);
-
-static ssize_t store_selfballoon_interval(struct device *dev,
-					  struct device_attribute *attr,
-					  const char *buf,
-					  size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	selfballoon_interval = val;
-	return count;
-}
-
-static DEVICE_ATTR(selfballoon_interval, S_IRUGO | S_IWUSR,
-		   show_selfballoon_interval, store_selfballoon_interval);
-
-SELFBALLOON_SHOW(selfballoon_downhys, "%d\n", selfballoon_downhysteresis);
-
-static ssize_t store_selfballoon_downhys(struct device *dev,
-					 struct device_attribute *attr,
-					 const char *buf,
-					 size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	selfballoon_downhysteresis = val;
-	return count;
-}
-
-static DEVICE_ATTR(selfballoon_downhysteresis, S_IRUGO | S_IWUSR,
-		   show_selfballoon_downhys, store_selfballoon_downhys);
-
-
-SELFBALLOON_SHOW(selfballoon_uphys, "%d\n", selfballoon_uphysteresis);
-
-static ssize_t store_selfballoon_uphys(struct device *dev,
-				       struct device_attribute *attr,
-				       const char *buf,
-				       size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	selfballoon_uphysteresis = val;
-	return count;
-}
-
-static DEVICE_ATTR(selfballoon_uphysteresis, S_IRUGO | S_IWUSR,
-		   show_selfballoon_uphys, store_selfballoon_uphys);
-
-SELFBALLOON_SHOW(selfballoon_min_usable_mb, "%d\n",
-				selfballoon_min_usable_mb);
-
-static ssize_t store_selfballoon_min_usable_mb(struct device *dev,
-					       struct device_attribute *attr,
-					       const char *buf,
-					       size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	selfballoon_min_usable_mb = val;
-	return count;
-}
-
-static DEVICE_ATTR(selfballoon_min_usable_mb, S_IRUGO | S_IWUSR,
-		   show_selfballoon_min_usable_mb,
-		   store_selfballoon_min_usable_mb);
-
-SELFBALLOON_SHOW(selfballoon_reserved_mb, "%d\n",
-				selfballoon_reserved_mb);
-
-static ssize_t store_selfballoon_reserved_mb(struct device *dev,
-					     struct device_attribute *attr,
-					     const char *buf,
-					     size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	selfballoon_reserved_mb = val;
-	return count;
-}
-
-static DEVICE_ATTR(selfballoon_reserved_mb, S_IRUGO | S_IWUSR,
-		   show_selfballoon_reserved_mb,
-		   store_selfballoon_reserved_mb);
-
-
-#ifdef CONFIG_FRONTSWAP
-SELFBALLOON_SHOW(frontswap_selfshrinking, "%d\n", frontswap_selfshrinking);
-
-static ssize_t store_frontswap_selfshrinking(struct device *dev,
-					     struct device_attribute *attr,
-					     const char *buf,
-					     size_t count)
-{
-	bool was_enabled = frontswap_selfshrinking;
-	unsigned long tmp;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &tmp);
-	if (err)
-		return err;
-	if ((tmp != 0) && (tmp != 1))
-		return -EINVAL;
-	frontswap_selfshrinking = !!tmp;
-	if (!was_enabled && !xen_selfballooning_enabled &&
-	     frontswap_selfshrinking)
-		schedule_delayed_work(&selfballoon_worker,
-			selfballoon_interval * HZ);
-
-	return count;
-}
-
-static DEVICE_ATTR(frontswap_selfshrinking, S_IRUGO | S_IWUSR,
-		   show_frontswap_selfshrinking, store_frontswap_selfshrinking);
-
-SELFBALLOON_SHOW(frontswap_inertia, "%d\n", frontswap_inertia);
-
-static ssize_t store_frontswap_inertia(struct device *dev,
-				       struct device_attribute *attr,
-				       const char *buf,
-				       size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	frontswap_inertia = val;
-	frontswap_inertia_counter = val;
-	return count;
-}
-
-static DEVICE_ATTR(frontswap_inertia, S_IRUGO | S_IWUSR,
-		   show_frontswap_inertia, store_frontswap_inertia);
-
-SELFBALLOON_SHOW(frontswap_hysteresis, "%d\n", frontswap_hysteresis);
-
-static ssize_t store_frontswap_hysteresis(struct device *dev,
-					  struct device_attribute *attr,
-					  const char *buf,
-					  size_t count)
-{
-	unsigned long val;
-	int err;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	err = kstrtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val == 0)
-		return -EINVAL;
-	frontswap_hysteresis = val;
-	return count;
-}
-
-static DEVICE_ATTR(frontswap_hysteresis, S_IRUGO | S_IWUSR,
-		   show_frontswap_hysteresis, store_frontswap_hysteresis);
-
-#endif /* CONFIG_FRONTSWAP */
-
-static struct attribute *selfballoon_attrs[] = {
-	&dev_attr_selfballooning.attr,
-	&dev_attr_selfballoon_interval.attr,
-	&dev_attr_selfballoon_downhysteresis.attr,
-	&dev_attr_selfballoon_uphysteresis.attr,
-	&dev_attr_selfballoon_min_usable_mb.attr,
-	&dev_attr_selfballoon_reserved_mb.attr,
-#ifdef CONFIG_FRONTSWAP
-	&dev_attr_frontswap_selfshrinking.attr,
-	&dev_attr_frontswap_hysteresis.attr,
-	&dev_attr_frontswap_inertia.attr,
-#endif
-	NULL
-};
-
-static const struct attribute_group selfballoon_group = {
-	.name = "selfballoon",
-	.attrs = selfballoon_attrs
-};
-#endif
-
-int register_xen_selfballooning(struct device *dev)
-{
-	int error = -1;
-
-#ifdef CONFIG_SYSFS
-	error = sysfs_create_group(&dev->kobj, &selfballoon_group);
-#endif
-	return error;
-}
-EXPORT_SYMBOL(register_xen_selfballooning);
-
-int xen_selfballoon_init(bool use_selfballooning, bool use_frontswap_selfshrink)
-{
-	bool enable = false;
-	unsigned long reserve_pages;
-
-	if (!xen_domain())
-		return -ENODEV;
-
-	if (xen_initial_domain()) {
-		pr_info("Xen selfballooning driver disabled for domain0\n");
-		return -ENODEV;
-	}
-
-	xen_selfballooning_enabled = tmem_enabled && use_selfballooning;
-	if (xen_selfballooning_enabled) {
-		pr_info("Initializing Xen selfballooning driver\n");
-		enable = true;
-	}
-#ifdef CONFIG_FRONTSWAP
-	frontswap_selfshrinking = tmem_enabled && use_frontswap_selfshrink;
-	if (frontswap_selfshrinking) {
-		pr_info("Initializing frontswap selfshrinking driver\n");
-		enable = true;
-	}
-#endif
-	if (!enable)
-		return -ENODEV;
-
-	/*
-	 * Give selfballoon_reserved_mb a default value(10% of total ram pages)
-	 * to make selfballoon not so aggressive.
-	 *
-	 * There are mainly two reasons:
-	 * 1) The original goal_page didn't consider some pages used by kernel
-	 *    space, like slab pages and memory used by device drivers.
-	 *
-	 * 2) The balloon driver may not give back memory to guest OS fast
-	 *    enough when the workload suddenly aquries a lot of physical memory.
-	 *
-	 * In both cases, the guest OS will suffer from memory pressure and
-	 * OOM killer may be triggered.
-	 * By reserving extra 10% of total ram pages, we can keep the system
-	 * much more reliably and response faster in some cases.
-	 */
-	if (!selfballoon_reserved_mb) {
-		reserve_pages = totalram_pages() / 10;
-		selfballoon_reserved_mb = PAGES2MB(reserve_pages);
-	}
-	schedule_delayed_work(&selfballoon_worker, selfballoon_interval * HZ);
-
-	return 0;
-}
-EXPORT_SYMBOL(xen_selfballoon_init);

include/xen/balloon.h

···
 int alloc_xenballooned_pages(int nr_pages, struct page **pages);
 void free_xenballooned_pages(int nr_pages, struct page **pages);
 
-struct device;
-#ifdef CONFIG_XEN_SELFBALLOONING
-extern int register_xen_selfballooning(struct device *dev);
-#else
-static inline int register_xen_selfballooning(struct device *dev)
-{
-	return -ENOSYS;
-}
-#endif
-
 #ifdef CONFIG_XEN_BALLOON
 void xen_balloon_init(void);
 #else

include/xen/events.h

···
 #define _XEN_EVENTS_H
 
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #ifdef CONFIG_PCI_MSI
 #include <linux/msi.h>
 #endif
···
 
 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector);
 void rebind_evtchn_irq(int evtchn, int irq);
-int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu);
+int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu);
 
 static inline void notify_remote_via_evtchn(int port)
 {

include/xen/tmem.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _XEN_TMEM_H
-#define _XEN_TMEM_H
-
-#include <linux/types.h>
-
-#ifdef CONFIG_XEN_TMEM_MODULE
-#define tmem_enabled true
-#else
-/* defined in drivers/xen/tmem.c */
-extern bool tmem_enabled;
-#endif
-
-#ifdef CONFIG_XEN_SELFBALLOONING
-extern int xen_selfballoon_init(bool, bool);
-#endif
-
-#endif /* _XEN_TMEM_H */