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-rw-r--r--arch/arm/Kconfig20
-rw-r--r--arch/arm/include/asm/paravirt.h20
-rw-r--r--arch/arm/include/asm/xen/hypercall.h7
-rw-r--r--arch/arm/include/asm/xen/interface.h3
-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/paravirt.c25
-rw-r--r--arch/arm/xen/enlighten.c95
-rw-r--r--arch/arm/xen/hypercall.S1
8 files changed, 172 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b0e7ff176028..426115f7cb63 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1824,6 +1824,25 @@ config SWIOTLB
config IOMMU_HELPER
def_bool SWIOTLB
+config PARAVIRT
+ bool "Enable paravirtualization code"
+ help
+ This changes the kernel so it can modify itself when it is run
+ under a hypervisor, potentially improving performance significantly
+ over full virtualization.
+
+config PARAVIRT_TIME_ACCOUNTING
+ bool "Paravirtual steal time accounting"
+ select PARAVIRT
+ default n
+ help
+ Select this option to enable fine granularity task steal time
+ accounting. Time spent executing other tasks in parallel with
+ the current vCPU is discounted from the vCPU power. To account for
+ that, there can be a small performance impact.
+
+ If in doubt, say N here.
+
config XEN_DOM0
def_bool y
depends on XEN
@@ -1837,6 +1856,7 @@ config XEN
select ARCH_DMA_ADDR_T_64BIT
select ARM_PSCI
select SWIOTLB_XEN
+ select PARAVIRT
help
Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
diff --git a/arch/arm/include/asm/paravirt.h b/arch/arm/include/asm/paravirt.h
new file mode 100644
index 000000000000..8435ff591386
--- /dev/null
+++ b/arch/arm/include/asm/paravirt.h
@@ -0,0 +1,20 @@
+#ifndef _ASM_ARM_PARAVIRT_H
+#define _ASM_ARM_PARAVIRT_H
+
+#ifdef CONFIG_PARAVIRT
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops {
+ unsigned long long (*steal_clock)(int cpu);
+};
+extern struct pv_time_ops pv_time_ops;
+
+static inline u64 paravirt_steal_clock(int cpu)
+{
+ return pv_time_ops.steal_clock(cpu);
+}
+#endif
+
+#endif
diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h
index 712b50e0a6dc..d769972db8cb 100644
--- a/arch/arm/include/asm/xen/hypercall.h
+++ b/arch/arm/include/asm/xen/hypercall.h
@@ -35,6 +35,7 @@
#include <xen/interface/xen.h>
#include <xen/interface/sched.h>
+#include <xen/interface/platform.h>
long privcmd_call(unsigned call, unsigned long a1,
unsigned long a2, unsigned long a3,
@@ -49,6 +50,12 @@ int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
int HYPERVISOR_physdev_op(int cmd, void *arg);
int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
int HYPERVISOR_tmem_op(void *arg);
+int HYPERVISOR_platform_op_raw(void *arg);
+static inline int HYPERVISOR_platform_op(struct xen_platform_op *op)
+{
+ op->interface_version = XENPF_INTERFACE_VERSION;
+ return HYPERVISOR_platform_op_raw(op);
+}
int HYPERVISOR_multicall(struct multicall_entry *calls, uint32_t nr);
static inline int
diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h
index 50066006e6bd..75d596862892 100644
--- a/arch/arm/include/asm/xen/interface.h
+++ b/arch/arm/include/asm/xen/interface.h
@@ -27,6 +27,8 @@
(hnd).p = val; \
} while (0)
+#define __HYPERVISOR_platform_op_raw __HYPERVISOR_platform_op
+
#ifndef __ASSEMBLY__
/* Explicitly size integers that represent pfns in the interface with
* Xen so that we can have one ABI that works for 32 and 64 bit guests.
@@ -76,6 +78,7 @@ struct pvclock_wall_clock {
u32 version;
u32 sec;
u32 nsec;
+ u32 sec_hi;
} __attribute__((__packed__));
#endif
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index f729085ece28..2c5f160be65e 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_EFI) += efi.o
ifneq ($(CONFIG_ARCH_EBSA110),y)
obj-y += io.o
endif
+obj-$(CONFIG_PARAVIRT) += paravirt.o
head-y := head$(MMUEXT).o
obj-$(CONFIG_DEBUG_LL) += debug.o
diff --git a/arch/arm/kernel/paravirt.c b/arch/arm/kernel/paravirt.c
new file mode 100644
index 000000000000..53f371ed4568
--- /dev/null
+++ b/arch/arm/kernel/paravirt.c
@@ -0,0 +1,25 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2013 Citrix Systems
+ *
+ * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+ */
+
+#include <linux/export.h>
+#include <linux/jump_label.h>
+#include <linux/types.h>
+#include <asm/paravirt.h>
+
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops pv_time_ops;
+EXPORT_SYMBOL_GPL(pv_time_ops);
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index fc7ea529f462..75cd7345c654 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -12,6 +12,7 @@
#include <xen/page.h>
#include <xen/interface/sched.h>
#include <xen/xen-ops.h>
+#include <asm/paravirt.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <asm/system_misc.h>
@@ -25,6 +26,10 @@
#include <linux/cpufreq.h>
#include <linux/cpu.h>
#include <linux/console.h>
+#include <linux/pvclock_gtod.h>
+#include <linux/time64.h>
+#include <linux/timekeeping.h>
+#include <linux/timekeeper_internal.h>
#include <linux/mm.h>
@@ -79,6 +84,83 @@ int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
}
EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
+static unsigned long long xen_stolen_accounting(int cpu)
+{
+ struct vcpu_runstate_info state;
+
+ BUG_ON(cpu != smp_processor_id());
+
+ xen_get_runstate_snapshot(&state);
+
+ WARN_ON(state.state != RUNSTATE_running);
+
+ return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline];
+}
+
+static void xen_read_wallclock(struct timespec64 *ts)
+{
+ u32 version;
+ struct timespec64 now, ts_monotonic;
+ struct shared_info *s = HYPERVISOR_shared_info;
+ struct pvclock_wall_clock *wall_clock = &(s->wc);
+
+ /* get wallclock at system boot */
+ do {
+ version = wall_clock->version;
+ rmb(); /* fetch version before time */
+ now.tv_sec = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
+ now.tv_nsec = wall_clock->nsec;
+ rmb(); /* fetch time before checking version */
+ } while ((wall_clock->version & 1) || (version != wall_clock->version));
+
+ /* time since system boot */
+ ktime_get_ts64(&ts_monotonic);
+ *ts = timespec64_add(now, ts_monotonic);
+}
+
+static int xen_pvclock_gtod_notify(struct notifier_block *nb,
+ unsigned long was_set, void *priv)
+{
+ /* Protected by the calling core code serialization */
+ static struct timespec64 next_sync;
+
+ struct xen_platform_op op;
+ struct timespec64 now, system_time;
+ struct timekeeper *tk = priv;
+
+ now.tv_sec = tk->xtime_sec;
+ now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
+ system_time = timespec64_add(now, tk->wall_to_monotonic);
+
+ /*
+ * We only take the expensive HV call when the clock was set
+ * or when the 11 minutes RTC synchronization time elapsed.
+ */
+ if (!was_set && timespec64_compare(&now, &next_sync) < 0)
+ return NOTIFY_OK;
+
+ op.cmd = XENPF_settime64;
+ op.u.settime64.mbz = 0;
+ op.u.settime64.secs = now.tv_sec;
+ op.u.settime64.nsecs = now.tv_nsec;
+ op.u.settime64.system_time = timespec64_to_ns(&system_time);
+ (void)HYPERVISOR_platform_op(&op);
+
+ /*
+ * Move the next drift compensation time 11 minutes
+ * ahead. That's emulating the sync_cmos_clock() update for
+ * the hardware RTC.
+ */
+ next_sync = now;
+ next_sync.tv_sec += 11 * 60;
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block xen_pvclock_gtod_notifier = {
+ .notifier_call = xen_pvclock_gtod_notify,
+};
+
static void xen_percpu_init(void)
{
struct vcpu_register_vcpu_info info;
@@ -104,6 +186,8 @@ static void xen_percpu_init(void)
BUG_ON(err);
per_cpu(xen_vcpu, cpu) = vcpup;
+ xen_setup_runstate_info(cpu);
+
after_register_vcpu_info:
enable_percpu_irq(xen_events_irq, 0);
put_cpu();
@@ -271,6 +355,11 @@ static int __init xen_guest_init(void)
register_cpu_notifier(&xen_cpu_notifier);
+ pv_time_ops.steal_clock = xen_stolen_accounting;
+ static_key_slow_inc(&paravirt_steal_enabled);
+ if (xen_initial_domain())
+ pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
+
return 0;
}
early_initcall(xen_guest_init);
@@ -282,6 +371,11 @@ static int __init xen_pm_init(void)
pm_power_off = xen_power_off;
arm_pm_restart = xen_restart;
+ if (!xen_initial_domain()) {
+ struct timespec64 ts;
+ xen_read_wallclock(&ts);
+ do_settimeofday64(&ts);
+ }
return 0;
}
@@ -307,5 +401,6 @@ EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
EXPORT_SYMBOL_GPL(privcmd_call);
diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
index 10fd99c568c6..9a36f4f49c10 100644
--- a/arch/arm/xen/hypercall.S
+++ b/arch/arm/xen/hypercall.S
@@ -89,6 +89,7 @@ HYPERCALL2(memory_op);
HYPERCALL2(physdev_op);
HYPERCALL3(vcpu_op);
HYPERCALL1(tmem_op);
+HYPERCALL1(platform_op_raw);
HYPERCALL2(multicall);
ENTRY(privcmd_call)