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xen: fixes and features for 5.3-rc1 

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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
This commit is contained in:
Linus Torvalds 2019-07-19 11:41:26 -07:00
parent 26473f8370 a1078e821b
commit b5d72dda89
25 changed files with 112 additions and 1120 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
Documentation/admin-guide/kernel-parameters.txt
View File

@ -4698,27 +4698,6 @@
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
@ -5288,6 +5267,8 @@
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
@ -5302,6 +5283,11 @@
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:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]

1
arch/x86/entry/entry_64.S
View File

@ -1176,7 +1176,6 @@ idtentry stack_segment do_stack_segment has_error_code=1
#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

12
arch/x86/include/asm/hypervisor.h
View File

@ -53,8 +53,20 @@ struct hypervisor_x86 {
/* 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)

2
arch/x86/include/asm/traps.h
View File

@ -40,7 +40,7 @@ asmlinkage void simd_coprocessor_error(void);
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);

2
arch/x86/include/asm/x86_init.h
View File

@ -301,6 +301,8 @@ extern struct x86_apic_ops x86_apic_ops;
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

6
arch/x86/include/asm/xen/hypervisor.h
View File

@ -44,14 +44,14 @@ static inline uint32_t xen_cpuid_base(void)
}
#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);
}

19
arch/x86/kernel/cpu/hypervisor.c
View File

@ -26,14 +26,6 @@
#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
@ -58,6 +50,14 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
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)
{
@ -65,6 +65,9 @@ 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;

1
arch/x86/kernel/jailhouse.c
View File

@ -217,4 +217,5 @@ const struct hypervisor_x86 x86_hyper_jailhouse __refconst = {
.detect = jailhouse_detect,
.init.init_platform = jailhouse_init_platform,
.init.x2apic_available = jailhouse_x2apic_available,
.ignore_nopv = true,
};

3
arch/x86/kernel/smpboot.c
View File

@ -1368,8 +1368,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
pr_info("CPU0: ");
print_cpu_info(&cpu_data(0));
native_pv_lock_init();
uv_system_init();
set_mtrr_aps_delayed_init();
@ -1399,6 +1397,7 @@ void __init native_smp_prepare_boot_cpu(void)
/* 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)

4
arch/x86/kernel/x86_init.c
View File

@ -29,8 +29,8 @@ void x86_init_noop(void) { }
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

58
arch/x86/xen/enlighten_hvm.c
View File

@ -210,18 +210,18 @@ static void __init xen_hvm_guest_init(void)
#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())
@ -230,15 +230,6 @@ bool xen_hvm_need_lapic(void)
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)
{
@ -251,6 +242,9 @@ 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;
@ -260,7 +254,38 @@ static __init void xen_hvm_guest_late_init(void)
#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,
@ -269,4 +294,5 @@ const __initconst struct hypervisor_x86 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,
};

3
arch/x86/xen/enlighten_pv.c
View File

@ -596,12 +596,12 @@ struct trap_array_entry {
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 },
@ -1463,4 +1463,5 @@ const __initconst struct hypervisor_x86 x86_hyper_xen_pv = {
.detect = xen_platform_pv,
.type = X86_HYPER_XEN_PV,
.runtime.pin_vcpu = xen_pin_vcpu,
.ignore_nopv = true,
};

6
arch/x86/xen/spinlock.c
View File

@ -68,11 +68,8 @@ void xen_init_lock_cpu(int cpu)
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));
@ -124,6 +121,7 @@ void __init xen_init_spinlocks(void)
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");

1
arch/x86/xen/xen-asm_64.S
View File

@ -32,7 +32,6 @@ xen_pv_trap divide_error
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

23
drivers/xen/Kconfig
View File

@ -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

2
drivers/xen/Makefile
View File

@ -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/

16
drivers/xen/balloon.c
View File

@ -535,8 +535,15 @@ static void balloon_process(struct work_struct *work)
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);
@ -575,6 +582,9 @@ static int add_ballooned_pages(int nr_pages)
}
}
if (si_mem_available() < nr_pages)
return -ENOMEM;
st = decrease_reservation(nr_pages, GFP_USER);
if (st != BP_DONE)
return -ENOMEM;
@ -707,7 +717,7 @@ static int __init balloon_init(void)
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);

12
drivers/xen/events/events_base.c
View File

@ -1294,7 +1294,7 @@ void rebind_evtchn_irq(int evtchn, int irq)
}
/* 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;
@ -1328,7 +1328,6 @@ int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu)
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)
@ -1342,6 +1341,15 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
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)
{
int evtchn = evtchn_from_irq(data->irq);

2
drivers/xen/evtchn.c
View File

@ -447,7 +447,7 @@ static void evtchn_bind_interdom_next_vcpu(int evtchn)
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);
}

419
drivers/xen/tmem.c
View File

@ -1,419 +0,0 @@
// 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");

2
drivers/xen/xen-balloon.c
View File

@ -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);

579
drivers/xen/xen-selfballoon.c
View File

@ -1,579 +0,0 @@
// 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);

10
include/xen/balloon.h
View File

@ -27,16 +27,6 @@ void balloon_set_new_target(unsigned long target);
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

3
include/xen/events.h
View File

@ -3,6 +3,7 @@
#define _XEN_EVENTS_H
#include <linux/interrupt.h>
#include <linux/irq.h>
#ifdef CONFIG_PCI_MSI
#include <linux/msi.h>
#endif
@ -59,7 +60,7 @@ void evtchn_put(unsigned int evtchn);
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)
{

18
include/xen/tmem.h
View File

@ -1,18 +0,0 @@
/* 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 */