#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
|
#include <linux/bootmem.h>
|
#endif
|
#include <linux/cpu.h>
|
#include <linux/kexec.h>
|
#include <linux/slab.h>
|
|
#include <xen/features.h>
|
#include <xen/page.h>
|
|
#include <asm/xen/hypercall.h>
|
#include <asm/xen/hypervisor.h>
|
#include <asm/cpu.h>
|
#include <asm/e820/api.h>
|
|
#include "xen-ops.h"
|
#include "smp.h"
|
#include "pmu.h"
|
|
EXPORT_SYMBOL_GPL(hypercall_page);
|
|
/*
|
* Pointer to the xen_vcpu_info structure or
|
* &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
|
* and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
|
* but if the hypervisor supports VCPUOP_register_vcpu_info then it can point
|
* to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to
|
* acknowledge pending events.
|
* Also more subtly it is used by the patched version of irq enable/disable
|
* e.g. xen_irq_enable_direct and xen_iret in PV mode.
|
*
|
* The desire to be able to do those mask/unmask operations as a single
|
* instruction by using the per-cpu offset held in %gs is the real reason
|
* vcpu info is in a per-cpu pointer and the original reason for this
|
* hypercall.
|
*
|
*/
|
DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
|
|
/*
|
* Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info
|
* hypercall. This can be used both in PV and PVHVM mode. The structure
|
* overrides the default per_cpu(xen_vcpu, cpu) value.
|
*/
|
DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
|
|
/* Linux <-> Xen vCPU id mapping */
|
DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
|
EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
|
|
enum xen_domain_type xen_domain_type = XEN_NATIVE;
|
EXPORT_SYMBOL_GPL(xen_domain_type);
|
|
unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
|
EXPORT_SYMBOL(machine_to_phys_mapping);
|
unsigned long machine_to_phys_nr;
|
EXPORT_SYMBOL(machine_to_phys_nr);
|
|
struct start_info *xen_start_info;
|
EXPORT_SYMBOL_GPL(xen_start_info);
|
|
struct shared_info xen_dummy_shared_info;
|
|
__read_mostly int xen_have_vector_callback;
|
EXPORT_SYMBOL_GPL(xen_have_vector_callback);
|
|
/*
|
* NB: needs to live in .data because it's used by xen_prepare_pvh which runs
|
* before clearing the bss.
|
*/
|
uint32_t xen_start_flags __attribute__((section(".data"))) = 0;
|
EXPORT_SYMBOL(xen_start_flags);
|
|
/*
|
* Point at some empty memory to start with. We map the real shared_info
|
* page as soon as fixmap is up and running.
|
*/
|
struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
|
|
/*
|
* Flag to determine whether vcpu info placement is available on all
|
* VCPUs. We assume it is to start with, and then set it to zero on
|
* the first failure. This is because it can succeed on some VCPUs
|
* and not others, since it can involve hypervisor memory allocation,
|
* or because the guest failed to guarantee all the appropriate
|
* constraints on all VCPUs (ie buffer can't cross a page boundary).
|
*
|
* Note that any particular CPU may be using a placed vcpu structure,
|
* but we can only optimise if the all are.
|
*
|
* 0: not available, 1: available
|
*/
|
int xen_have_vcpu_info_placement = 1;
|
|
static int xen_cpu_up_online(unsigned int cpu)
|
{
|
xen_init_lock_cpu(cpu);
|
return 0;
|
}
|
|
int xen_cpuhp_setup(int (*cpu_up_prepare_cb)(unsigned int),
|
int (*cpu_dead_cb)(unsigned int))
|
{
|
int rc;
|
|
rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE,
|
"x86/xen/guest:prepare",
|
cpu_up_prepare_cb, cpu_dead_cb);
|
if (rc >= 0) {
|
rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
|
"x86/xen/guest:online",
|
xen_cpu_up_online, NULL);
|
if (rc < 0)
|
cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE);
|
}
|
|
return rc >= 0 ? 0 : rc;
|
}
|
|
static int xen_vcpu_setup_restore(int cpu)
|
{
|
int rc = 0;
|
|
/* Any per_cpu(xen_vcpu) is stale, so reset it */
|
xen_vcpu_info_reset(cpu);
|
|
/*
|
* For PVH and PVHVM, setup online VCPUs only. The rest will
|
* be handled by hotplug.
|
*/
|
if (xen_pv_domain() ||
|
(xen_hvm_domain() && cpu_online(cpu))) {
|
rc = xen_vcpu_setup(cpu);
|
}
|
|
return rc;
|
}
|
|
/*
|
* On restore, set the vcpu placement up again.
|
* If it fails, then we're in a bad state, since
|
* we can't back out from using it...
|
*/
|
void xen_vcpu_restore(void)
|
{
|
int cpu, rc;
|
|
for_each_possible_cpu(cpu) {
|
bool other_cpu = (cpu != smp_processor_id());
|
bool is_up;
|
|
if (xen_vcpu_nr(cpu) == XEN_VCPU_ID_INVALID)
|
continue;
|
|
/* Only Xen 4.5 and higher support this. */
|
is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up,
|
xen_vcpu_nr(cpu), NULL) > 0;
|
|
if (other_cpu && is_up &&
|
HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
|
BUG();
|
|
if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
|
xen_setup_runstate_info(cpu);
|
|
rc = xen_vcpu_setup_restore(cpu);
|
if (rc)
|
pr_emerg_once("vcpu restore failed for cpu=%d err=%d. "
|
"System will hang.\n", cpu, rc);
|
/*
|
* In case xen_vcpu_setup_restore() fails, do not bring up the
|
* VCPU. This helps us avoid the resulting OOPS when the VCPU
|
* accesses pvclock_vcpu_time via xen_vcpu (which is NULL.)
|
* Note that this does not improve the situation much -- now the
|
* VM hangs instead of OOPSing -- with the VCPUs that did not
|
* fail, spinning in stop_machine(), waiting for the failed
|
* VCPUs to come up.
|
*/
|
if (other_cpu && is_up && (rc == 0) &&
|
HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
|
BUG();
|
}
|
}
|
|
void xen_vcpu_info_reset(int cpu)
|
{
|
if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS) {
|
per_cpu(xen_vcpu, cpu) =
|
&HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
|
} else {
|
/* Set to NULL so that if somebody accesses it we get an OOPS */
|
per_cpu(xen_vcpu, cpu) = NULL;
|
}
|
}
|
|
int xen_vcpu_setup(int cpu)
|
{
|
struct vcpu_register_vcpu_info info;
|
int err;
|
struct vcpu_info *vcpup;
|
|
BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
|
|
/*
|
* This path is called on PVHVM at bootup (xen_hvm_smp_prepare_boot_cpu)
|
* and at restore (xen_vcpu_restore). Also called for hotplugged
|
* VCPUs (cpu_init -> xen_hvm_cpu_prepare_hvm).
|
* However, the hypercall can only be done once (see below) so if a VCPU
|
* is offlined and comes back online then let's not redo the hypercall.
|
*
|
* For PV it is called during restore (xen_vcpu_restore) and bootup
|
* (xen_setup_vcpu_info_placement). The hotplug mechanism does not
|
* use this function.
|
*/
|
if (xen_hvm_domain()) {
|
if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
|
return 0;
|
}
|
|
if (xen_have_vcpu_info_placement) {
|
vcpup = &per_cpu(xen_vcpu_info, cpu);
|
info.mfn = arbitrary_virt_to_mfn(vcpup);
|
info.offset = offset_in_page(vcpup);
|
|
/*
|
* Check to see if the hypervisor will put the vcpu_info
|
* structure where we want it, which allows direct access via
|
* a percpu-variable.
|
* N.B. This hypercall can _only_ be called once per CPU.
|
* Subsequent calls will error out with -EINVAL. This is due to
|
* the fact that hypervisor has no unregister variant and this
|
* hypercall does not allow to over-write info.mfn and
|
* info.offset.
|
*/
|
err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info,
|
xen_vcpu_nr(cpu), &info);
|
|
if (err) {
|
pr_warn_once("register_vcpu_info failed: cpu=%d err=%d\n",
|
cpu, err);
|
xen_have_vcpu_info_placement = 0;
|
} else {
|
/*
|
* This cpu is using the registered vcpu info, even if
|
* later ones fail to.
|
*/
|
per_cpu(xen_vcpu, cpu) = vcpup;
|
}
|
}
|
|
if (!xen_have_vcpu_info_placement)
|
xen_vcpu_info_reset(cpu);
|
|
return ((per_cpu(xen_vcpu, cpu) == NULL) ? -ENODEV : 0);
|
}
|
|
void xen_reboot(int reason)
|
{
|
struct sched_shutdown r = { .reason = reason };
|
int cpu;
|
|
for_each_online_cpu(cpu)
|
xen_pmu_finish(cpu);
|
|
if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
|
BUG();
|
}
|
|
static int reboot_reason = SHUTDOWN_reboot;
|
static bool xen_legacy_crash;
|
void xen_emergency_restart(void)
|
{
|
xen_reboot(reboot_reason);
|
}
|
|
static int
|
xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
|
{
|
if (!kexec_crash_loaded()) {
|
if (xen_legacy_crash)
|
xen_reboot(SHUTDOWN_crash);
|
|
reboot_reason = SHUTDOWN_crash;
|
|
/*
|
* If panic_timeout==0 then we are supposed to wait forever.
|
* However, to preserve original dom0 behavior we have to drop
|
* into hypervisor. (domU behavior is controlled by its
|
* config file)
|
*/
|
if (panic_timeout == 0)
|
panic_timeout = -1;
|
}
|
return NOTIFY_DONE;
|
}
|
|
static int __init parse_xen_legacy_crash(char *arg)
|
{
|
xen_legacy_crash = true;
|
return 0;
|
}
|
early_param("xen_legacy_crash", parse_xen_legacy_crash);
|
|
static struct notifier_block xen_panic_block = {
|
.notifier_call = xen_panic_event,
|
.priority = INT_MIN
|
};
|
|
int xen_panic_handler_init(void)
|
{
|
atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
|
return 0;
|
}
|
|
void xen_pin_vcpu(int cpu)
|
{
|
static bool disable_pinning;
|
struct sched_pin_override pin_override;
|
int ret;
|
|
if (disable_pinning)
|
return;
|
|
pin_override.pcpu = cpu;
|
ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override);
|
|
/* Ignore errors when removing override. */
|
if (cpu < 0)
|
return;
|
|
switch (ret) {
|
case -ENOSYS:
|
pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n",
|
cpu);
|
disable_pinning = true;
|
break;
|
case -EPERM:
|
WARN(1, "Trying to pin vcpu without having privilege to do so\n");
|
disable_pinning = true;
|
break;
|
case -EINVAL:
|
case -EBUSY:
|
pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n",
|
cpu);
|
break;
|
case 0:
|
break;
|
default:
|
WARN(1, "rc %d while trying to pin vcpu\n", ret);
|
disable_pinning = true;
|
}
|
}
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
void xen_arch_register_cpu(int num)
|
{
|
arch_register_cpu(num);
|
}
|
EXPORT_SYMBOL(xen_arch_register_cpu);
|
|
void xen_arch_unregister_cpu(int num)
|
{
|
arch_unregister_cpu(num);
|
}
|
EXPORT_SYMBOL(xen_arch_unregister_cpu);
|
#endif
|
