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+/******************************************************************************
+ *
+ * Copyright 2019 (C) Alistair Francis <alistair.francis@wdc.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include <xen/bitops.h>
+#include <xen/errno.h>
+#include <xen/grant_table.h>
+#include <xen/hypercall.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+#include <xen/livepatch.h>
+#include <xen/sched.h>
+#include <xen/softirq.h>
+#include <xen/wait.h>
+
+DEFINE_PER_CPU(struct vcpu *, curr_vcpu);
+
+static void do_idle(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ sched_tick_suspend();
+ /* sched_tick_suspend() can raise TIMER_SOFTIRQ. Process it now. */
+ process_pending_softirqs();
+
+ local_irq_disable();
+ if ( cpu_is_haltable(cpu) )
+ {
+ wait_for_interrupt();
+ }
+ local_irq_enable();
+
+ sched_tick_resume();
+}
+
+void idle_loop(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ for ( ; ; )
+ {
+ if ( cpu_is_offline(cpu) )
+ stop_cpu();
+
+ /* Are we here for running vcpu context tasklets, or for idling? */
+ if ( unlikely(tasklet_work_to_do(cpu)) )
+ do_tasklet();
+ /*
+ * Test softirqs twice --- first to see if should even try scrubbing
+ * and then, after it is done, whether softirqs became pending
+ * while we were scrubbing.
+ */
+ else if ( !softirq_pending(cpu) && !scrub_free_pages() &&
+ !softirq_pending(cpu) )
+ do_idle();
+
+ do_softirq();
+ /*
+ * We MUST be last (or before dsb, wfi). Otherwise after we get the
+ * softirq we would execute dsb,wfi (and sleep) and not patch.
+ */
+ check_for_livepatch_work();
+ }
+}
+
+
+void context_switch(struct vcpu *prev, struct vcpu *next)
+{
+ ASSERT(local_irq_is_enabled());
+ ASSERT(prev != next);
+ ASSERT(!vcpu_cpu_dirty(next));
+
+ local_irq_disable();
+
+ /* TODO */
+
+ set_current(next);
+}
+
+void continue_running(struct vcpu *same)
+{
+ /* Nothing to do */
+}
+
+void sync_local_execstate(void)
+{
+ /* Nothing to do -- no lazy switching */
+}
+
+void sync_vcpu_execstate(struct vcpu *v)
+{
+ /* Nothing to do -- no lazy switching */
+}
+
+unsigned long hypercall_create_continuation(
+ unsigned int op, const char *format, ...)
+{
+ /* TODO */
+
+ return 0;
+}
+
+void startup_cpu_idle_loop(void)
+{
+ struct vcpu *v = current;
+
+ ASSERT(is_idle_vcpu(v));
+
+ reset_stack_and_jump(idle_loop);
+}
+
+struct domain *alloc_domain_struct(void)
+{
+ struct domain *d;
+ BUILD_BUG_ON(sizeof(*d) > PAGE_SIZE);
+ d = alloc_xenheap_pages(0, 0);
+ if ( d == NULL )
+ return NULL;
+
+ clear_page(d);
+ return d;
+}
+
+void free_domain_struct(struct domain *d)
+{
+ free_xenheap_page(d);
+}
+
+void dump_pageframe_info(struct domain *d)
+{
+
+}
+
+int arch_sanitise_domain_config(struct xen_domctl_createdomain *config)
+{
+ /* TODO */
+
+ return 0;
+}
+
+
+int arch_domain_create(struct domain *d,
+ struct xen_domctl_createdomain *config)
+{
+ /* TODO */
+
+ return 0;
+}
+
+void arch_domain_destroy(struct domain *d)
+{
+}
+
+void arch_domain_shutdown(struct domain *d)
+{
+}
+
+void arch_domain_pause(struct domain *d)
+{
+}
+
+void arch_domain_unpause(struct domain *d)
+{
+}
+
+int arch_domain_soft_reset(struct domain *d)
+{
+ return -ENOSYS;
+}
+
+void arch_domain_creation_finished(struct domain *d)
+{
+ /* TODO */
+}
+
+int domain_relinquish_resources(struct domain *d)
+{
+ /* TODO */
+
+ return 0;
+}
+
+void arch_dump_domain_info(struct domain *d)
+{
+ p2m_dump_info(d);
+}
+
+long arch_do_vcpu_op(int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
+{
+ return -ENOSYS;
+}
+
+void arch_dump_vcpu_info(struct vcpu *v)
+{
+ /* TODO */
+}
+
+int arch_set_info_guest(
+ struct vcpu *v, vcpu_guest_context_u c)
+{
+ /* TODO */
+
+ return 0;
+}
+
+#define MAX_PAGES_PER_VCPU 2
+
+struct vcpu *alloc_vcpu_struct(const struct domain *d)
+{
+ struct vcpu *v;
+
+ BUILD_BUG_ON(sizeof(*v) > MAX_PAGES_PER_VCPU * PAGE_SIZE);
+ v = alloc_xenheap_pages(get_order_from_bytes(sizeof(*v)), 0);
+ if ( v != NULL )
+ {
+ unsigned int i;
+
+ for ( i = 0; i < DIV_ROUND_UP(sizeof(*v), PAGE_SIZE); i++ )
+ clear_page((void *)v + i * PAGE_SIZE);
+ }
+
+ return v;
+}
+
+void free_vcpu_struct(struct vcpu *v)
+{
+ free_xenheap_pages(v, get_order_from_bytes(sizeof(*v)));
+}
+
+int arch_initialise_vcpu(struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
+{
+ return default_initialise_vcpu(v, arg);
+}
+
+int arch_vcpu_reset(struct vcpu *v)
+{
+ /* TODO */
+ return 0;
+}
+
+int arch_vcpu_create(struct vcpu *v)
+{
+ int rc = 0;
+
+ /* TODO */
+
+ return rc;
+}
+
+void arch_vcpu_destroy(struct vcpu *v)
+{
+ /* TODO */
+}