kernel_optimize_test/arch/arm/xen/enlighten.c
Julien Grall 24d5373dda arm/xen: Use alloc_percpu rather than __alloc_percpu
The function xen_guest_init is using __alloc_percpu with an alignment
which are not power of two.

However, the percpu allocator never supported alignments which are not power
of two and has always behaved incorectly in thise case.

Commit 3ca45a4 "percpu: ensure requested alignment is power of two"
introduced a check which trigger a warning [1] when booting linux-next
on Xen. But in reality this bug was always present.

This can be fixed by replacing the call to __alloc_percpu with
alloc_percpu. The latter will use an alignment which are a power of two.

[1]

[    0.023921] illegal size (48) or align (48) for percpu allocation
[    0.024167] ------------[ cut here ]------------
[    0.024344] WARNING: CPU: 0 PID: 1 at linux/mm/percpu.c:892 pcpu_alloc+0x88/0x6c0
[    0.024584] Modules linked in:
[    0.024708]
[    0.024804] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
4.9.0-rc7-next-20161128 #473
[    0.025012] Hardware name: Foundation-v8A (DT)
[    0.025162] task: ffff80003d870000 task.stack: ffff80003d844000
[    0.025351] PC is at pcpu_alloc+0x88/0x6c0
[    0.025490] LR is at pcpu_alloc+0x88/0x6c0
[    0.025624] pc : [<ffff00000818e678>] lr : [<ffff00000818e678>]
pstate: 60000045
[    0.025830] sp : ffff80003d847cd0
[    0.025946] x29: ffff80003d847cd0 x28: 0000000000000000
[    0.026147] x27: 0000000000000000 x26: 0000000000000000
[    0.026348] x25: 0000000000000000 x24: 0000000000000000
[    0.026549] x23: 0000000000000000 x22: 00000000024000c0
[    0.026752] x21: ffff000008e97000 x20: 0000000000000000
[    0.026953] x19: 0000000000000030 x18: 0000000000000010
[    0.027155] x17: 0000000000000a3f x16: 00000000deadbeef
[    0.027357] x15: 0000000000000006 x14: ffff000088f79c3f
[    0.027573] x13: ffff000008f79c4d x12: 0000000000000041
[    0.027782] x11: 0000000000000006 x10: 0000000000000042
[    0.027995] x9 : ffff80003d847a40 x8 : 6f697461636f6c6c
[    0.028208] x7 : 6120757063726570 x6 : ffff000008f79c84
[    0.028419] x5 : 0000000000000005 x4 : 0000000000000000
[    0.028628] x3 : 0000000000000000 x2 : 000000000000017f
[    0.028840] x1 : ffff80003d870000 x0 : 0000000000000035
[    0.029056]
[    0.029152] ---[ end trace 0000000000000000 ]---
[    0.029297] Call trace:
[    0.029403] Exception stack(0xffff80003d847b00 to
                               0xffff80003d847c30)
[    0.029621] 7b00: 0000000000000030 0001000000000000
ffff80003d847cd0 ffff00000818e678
[    0.029901] 7b20: 0000000000000002 0000000000000004
ffff000008f7c060 0000000000000035
[    0.030153] 7b40: ffff000008f79000 ffff000008c4cd88
ffff80003d847bf0 ffff000008101778
[    0.030402] 7b60: 0000000000000030 0000000000000000
ffff000008e97000 00000000024000c0
[    0.030647] 7b80: 0000000000000000 0000000000000000
0000000000000000 0000000000000000
[    0.030895] 7ba0: 0000000000000035 ffff80003d870000
000000000000017f 0000000000000000
[    0.031144] 7bc0: 0000000000000000 0000000000000005
ffff000008f79c84 6120757063726570
[    0.031394] 7be0: 6f697461636f6c6c ffff80003d847a40
0000000000000042 0000000000000006
[    0.031643] 7c00: 0000000000000041 ffff000008f79c4d
ffff000088f79c3f 0000000000000006
[    0.031877] 7c20: 00000000deadbeef 0000000000000a3f
[    0.032051] [<ffff00000818e678>] pcpu_alloc+0x88/0x6c0
[    0.032229] [<ffff00000818ece8>] __alloc_percpu+0x18/0x20
[    0.032409] [<ffff000008d9606c>] xen_guest_init+0x174/0x2f4
[    0.032591] [<ffff0000080830f8>] do_one_initcall+0x38/0x130
[    0.032783] [<ffff000008d90c34>] kernel_init_freeable+0xe0/0x248
[    0.032995] [<ffff00000899a890>] kernel_init+0x10/0x100
[    0.033172] [<ffff000008082ec0>] ret_from_fork+0x10/0x50

Reported-by: Wei Chen <wei.chen@arm.com>
Link: https://lkml.org/lkml/2016/11/28/669
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: stable@vger.kernel.org
2016-12-07 13:23:15 -08:00

461 lines
12 KiB
C

#include <xen/xen.h>
#include <xen/events.h>
#include <xen/grant_table.h>
#include <xen/hvm.h>
#include <xen/interface/vcpu.h>
#include <xen/interface/xen.h>
#include <xen/interface/memory.h>
#include <xen/interface/hvm/params.h>
#include <xen/features.h>
#include <xen/platform_pci.h>
#include <xen/xenbus.h>
#include <xen/page.h>
#include <xen/interface/sched.h>
#include <xen/xen-ops.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/xen-ops.h>
#include <asm/system_misc.h>
#include <asm/efi.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/cpuidle.h>
#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/acpi.h>
#include <linux/mm.h>
struct start_info _xen_start_info;
struct start_info *xen_start_info = &_xen_start_info;
EXPORT_SYMBOL(xen_start_info);
enum xen_domain_type xen_domain_type = XEN_NATIVE;
EXPORT_SYMBOL(xen_domain_type);
struct shared_info xen_dummy_shared_info;
struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
static struct vcpu_info __percpu *xen_vcpu_info;
/* Linux <-> Xen vCPU id mapping */
DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
/* These are unused until we support booting "pre-ballooned" */
unsigned long xen_released_pages;
struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
static __read_mostly unsigned int xen_events_irq;
int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t *gfn, int nr,
int *err_ptr, pgprot_t prot,
unsigned domid,
struct page **pages)
{
return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
prot, domid, pages);
}
EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
/* Not used by XENFEAT_auto_translated guests. */
int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t gfn, int nr,
pgprot_t prot, unsigned domid,
struct page **pages)
{
return -ENOSYS;
}
EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
int nr, struct page **pages)
{
return xen_xlate_unmap_gfn_range(vma, nr, pages);
}
EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
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 int xen_starting_cpu(unsigned int cpu)
{
struct vcpu_register_vcpu_info info;
struct vcpu_info *vcpup;
int err;
/*
* VCPUOP_register_vcpu_info cannot be called twice for the same
* vcpu, so if vcpu_info is already registered, just get out. This
* can happen with cpu-hotplug.
*/
if (per_cpu(xen_vcpu, cpu) != NULL)
goto after_register_vcpu_info;
pr_info("Xen: initializing cpu%d\n", cpu);
vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
info.mfn = virt_to_gfn(vcpup);
info.offset = xen_offset_in_page(vcpup);
err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
&info);
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);
return 0;
}
static int xen_dying_cpu(unsigned int cpu)
{
disable_percpu_irq(xen_events_irq);
return 0;
}
static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
{
struct sched_shutdown r = { .reason = SHUTDOWN_reboot };
int rc;
rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
BUG_ON(rc);
}
static void xen_power_off(void)
{
struct sched_shutdown r = { .reason = SHUTDOWN_poweroff };
int rc;
rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
BUG_ON(rc);
}
static irqreturn_t xen_arm_callback(int irq, void *arg)
{
xen_hvm_evtchn_do_upcall();
return IRQ_HANDLED;
}
static __initdata struct {
const char *compat;
const char *prefix;
const char *version;
bool found;
} hyper_node = {"xen,xen", "xen,xen-", NULL, false};
static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
int depth, void *data)
{
const void *s = NULL;
int len;
if (depth != 1 || strcmp(uname, "hypervisor") != 0)
return 0;
if (of_flat_dt_is_compatible(node, hyper_node.compat))
hyper_node.found = true;
s = of_get_flat_dt_prop(node, "compatible", &len);
if (strlen(hyper_node.prefix) + 3 < len &&
!strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
hyper_node.version = s + strlen(hyper_node.prefix);
/*
* Check if Xen supports EFI by checking whether there is the
* "/hypervisor/uefi" node in DT. If so, runtime services are available
* through proxy functions (e.g. in case of Xen dom0 EFI implementation
* they call special hypercall which executes relevant EFI functions)
* and that is why they are always enabled.
*/
if (IS_ENABLED(CONFIG_XEN_EFI)) {
if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
!efi_runtime_disabled())
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
}
return 0;
}
/*
* see Documentation/devicetree/bindings/arm/xen.txt for the
* documentation of the Xen Device Tree format.
*/
#define GRANT_TABLE_PHYSADDR 0
void __init xen_early_init(void)
{
of_scan_flat_dt(fdt_find_hyper_node, NULL);
if (!hyper_node.found) {
pr_debug("No Xen support\n");
return;
}
if (hyper_node.version == NULL) {
pr_debug("Xen version not found\n");
return;
}
pr_info("Xen %s support found\n", hyper_node.version);
xen_domain_type = XEN_HVM_DOMAIN;
xen_setup_features();
if (xen_feature(XENFEAT_dom0))
xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
else
xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
if (!console_set_on_cmdline && !xen_initial_domain())
add_preferred_console("hvc", 0, NULL);
}
static void __init xen_acpi_guest_init(void)
{
#ifdef CONFIG_ACPI
struct xen_hvm_param a;
int interrupt, trigger, polarity;
a.domid = DOMID_SELF;
a.index = HVM_PARAM_CALLBACK_IRQ;
if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
|| (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
xen_events_irq = 0;
return;
}
interrupt = a.value & 0xff;
trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
: ACPI_LEVEL_SENSITIVE;
polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
: ACPI_ACTIVE_HIGH;
xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
#endif
}
static void __init xen_dt_guest_init(void)
{
struct device_node *xen_node;
xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
if (!xen_node) {
pr_err("Xen support was detected before, but it has disappeared\n");
return;
}
xen_events_irq = irq_of_parse_and_map(xen_node, 0);
}
static int __init xen_guest_init(void)
{
struct xen_add_to_physmap xatp;
struct shared_info *shared_info_page = NULL;
int cpu;
if (!xen_domain())
return 0;
if (!acpi_disabled)
xen_acpi_guest_init();
else
xen_dt_guest_init();
if (!xen_events_irq) {
pr_err("Xen event channel interrupt not found\n");
return -ENODEV;
}
/*
* The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
* parameters are found. Force enable runtime services.
*/
if (efi_enabled(EFI_RUNTIME_SERVICES))
xen_efi_runtime_setup();
shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
if (!shared_info_page) {
pr_err("not enough memory\n");
return -ENOMEM;
}
xatp.domid = DOMID_SELF;
xatp.idx = 0;
xatp.space = XENMAPSPACE_shared_info;
xatp.gpfn = virt_to_gfn(shared_info_page);
if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
BUG();
HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
* page, we use it in the event channel upcall and in some pvclock
* related functions.
* The shared info contains exactly 1 CPU (the boot CPU). The guest
* is required to use VCPUOP_register_vcpu_info to place vcpu info
* for secondary CPUs as they are brought up.
* For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
*/
xen_vcpu_info = alloc_percpu(struct vcpu_info);
if (xen_vcpu_info == NULL)
return -ENOMEM;
/* Direct vCPU id mapping for ARM guests. */
for_each_possible_cpu(cpu)
per_cpu(xen_vcpu_id, cpu) = cpu;
xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
&xen_auto_xlat_grant_frames.vaddr,
xen_auto_xlat_grant_frames.count)) {
free_percpu(xen_vcpu_info);
return -ENOMEM;
}
gnttab_init();
if (!xen_initial_domain())
xenbus_probe(NULL);
/*
* Making sure board specific code will not set up ops for
* cpu idle and cpu freq.
*/
disable_cpuidle();
disable_cpufreq();
xen_init_IRQ();
if (request_percpu_irq(xen_events_irq, xen_arm_callback,
"events", &xen_vcpu)) {
pr_err("Error request IRQ %d\n", xen_events_irq);
return -EINVAL;
}
xen_time_setup_guest();
if (xen_initial_domain())
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
"AP_ARM_XEN_STARTING", xen_starting_cpu,
xen_dying_cpu);
}
early_initcall(xen_guest_init);
static int __init xen_pm_init(void)
{
if (!xen_domain())
return -ENODEV;
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;
}
late_initcall(xen_pm_init);
/* empty stubs */
void xen_arch_pre_suspend(void) { }
void xen_arch_post_suspend(int suspend_cancelled) { }
void xen_timer_resume(void) { }
void xen_arch_resume(void) { }
void xen_arch_suspend(void) { }
/* In the hypercall.S file. */
EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
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(HYPERVISOR_vm_assist);
EXPORT_SYMBOL_GPL(privcmd_call);