Re: [Xen-devel] [PATCH v2 12/25] arm: domain

[Keir Fraser <keir.xen@xxxxxxxxx>]

On 09/12/2011 13:13, "stefano.stabellini@xxxxxxxxxxxxx"
<stefano.stabellini@xxxxxxxxxxxxx> wrote:

> From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> 
> Domain creation and destruction, vcpu initialization and destruction,
> arch specific scheduling functions called by common code.

It would be nice if xen-arm had per-vcpu stacks (and, optionally, per-cpu
irq stacks) off the bat. However I won't make it a strict requirement while
xen-x86 is lagging in this area. That's where you cribbed this logic from
after all.

 -- Keir

> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxx>
> ---
>  xen/arch/arm/domain.c        |  253
> ++++++++++++++++++++++++++++++++++++++++++
>  xen/include/asm-arm/domain.h |   43 +++++++
>  2 files changed, 296 insertions(+), 0 deletions(-)
>  create mode 100644 xen/arch/arm/domain.c
>  create mode 100644 xen/include/asm-arm/domain.h
> 
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> new file mode 100644
> index 0000000..d706b5f
> --- /dev/null
> +++ b/xen/arch/arm/domain.c
> @@ -0,0 +1,253 @@
> +#include <xen/config.h>
> +#include <xen/init.h>
> +#include <xen/lib.h>
> +#include <xen/sched.h>
> +#include <xen/softirq.h>
> +#include <xen/wait.h>
> +#include <xen/errno.h>
> +
> +#include <asm/current.h>
> +#include <asm/regs.h>
> +#include <asm/p2m.h>
> +#include <asm/irq.h>
> +
> +DEFINE_PER_CPU(struct vcpu *, curr_vcpu);
> +
> +static void continue_idle_domain(struct vcpu *v)
> +{
> +    reset_stack_and_jump(idle_loop);
> +}
> +
> +static void continue_nonidle_domain(struct vcpu *v)
> +{
> +    /* check_wakeup_from_wait(); */
> +    reset_stack_and_jump(return_from_trap);
> +}
> +
> +void idle_loop(void)
> +{
> +    for ( ; ; )
> +    {
> +  /* TODO
> +     if ( cpu_is_offline(smp_processor_id()) )
> +     play_dead();
> +     (*pm_idle)();
> +     BUG();
> +  */
> +        do_tasklet();
> +        do_softirq();
> +    }
> +}
> +
> +static void ctxt_switch_from(struct vcpu *p)
> +{
> +
> +}
> +
> +static void ctxt_switch_to(struct vcpu *n)
> +{
> +    p2m_load_VTTBR(n->domain);
> +}
> +
> +static void __context_switch(void)
> +{
> +    struct cpu_user_regs *stack_regs = guest_cpu_user_regs();
> +    unsigned int          cpu = smp_processor_id();
> +    struct vcpu          *p = per_cpu(curr_vcpu, cpu);
> +    struct vcpu          *n = current;
> +
> +    ASSERT(p != n);
> +    ASSERT(cpumask_empty(n->vcpu_dirty_cpumask));
> +
> +    if ( !is_idle_vcpu(p) )
> +    {
> +        memcpy(&p->arch.user_regs, stack_regs, CTXT_SWITCH_STACK_BYTES);
> +        ctxt_switch_from(p);
> +    }
> +
> +    if ( !is_idle_vcpu(n) )
> +    {
> +        memcpy(stack_regs, &n->arch.user_regs, CTXT_SWITCH_STACK_BYTES);
> +        ctxt_switch_to(n);
> +    }
> +
> +    per_cpu(curr_vcpu, cpu) = n;
> +
> +}
> +
> +static void schedule_tail(struct vcpu *v)
> +{
> +    if ( is_idle_vcpu(v) )
> +        continue_idle_domain(v);
> +    else
> +        continue_nonidle_domain(v);
> +}
> +
> +void context_switch(struct vcpu *prev, struct vcpu *next)
> +{
> +    unsigned int cpu = smp_processor_id();
> +
> +    ASSERT(local_irq_is_enabled());
> +
> +    printk("context switch %d:%d%s -> %d:%d%s\n",
> +           prev->domain->domain_id, prev->vcpu_id, is_idle_vcpu(prev) ? "
> (idle)" : "",
> +           next->domain->domain_id, next->vcpu_id, is_idle_vcpu(next) ? "
> (idle)" : "");
> +
> + /* TODO
> +    if (prev != next)
> +    update_runstate_area(prev);
> + */
> +
> +    local_irq_disable();
> +
> +    set_current(next);
> +
> +    if ( (per_cpu(curr_vcpu, cpu) == next) ||
> +         (is_idle_vcpu(next) && cpu_online(cpu)) )
> +    {
> +        local_irq_enable();
> +    }
> +    else
> +    {
> +        __context_switch();
> +
> +        /* Re-enable interrupts before restoring state which may fault. */
> +        local_irq_enable();
> +    }
> +
> +    context_saved(prev);
> +
> + /* TODO
> +    if (prev != next)
> +    update_runstate_area(next);
> + */
> +
> +    schedule_tail(next);
> +    BUG();
> +
> +}
> +
> +void continue_running(struct vcpu *same)
> +{
> +    schedule_tail(same);
> +    BUG();
> +}
> +
> +int __sync_local_execstate(void)
> +{
> +    unsigned long flags;
> +    int switch_required;
> +
> +    local_irq_save(flags);
> +
> +    switch_required = (this_cpu(curr_vcpu) != current);
> +
> +    if ( switch_required )
> +    {
> +        ASSERT(current == idle_vcpu[smp_processor_id()]);
> +        __context_switch();
> +    }
> +
> +    local_irq_restore(flags);
> +
> +    return switch_required;
> +}
> +
> +void sync_local_execstate(void)
> +{
> +    (void)__sync_local_execstate();
> +}
> +
> +void startup_cpu_idle_loop(void)
> +{
> +        struct vcpu *v = current;
> +
> +        ASSERT(is_idle_vcpu(v));
> +  /* TODO
> +     cpumask_set_cpu(v->processor, v->domain->domain_dirty_cpumask);
> +     cpumask_set_cpu(v->processor, v->vcpu_dirty_cpumask);
> +  */
> +
> +        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 )
> +        clear_page(d);
> +    return d;
> +}
> +
> +void free_domain_struct(struct domain *d)
> +{
> +    free_xenheap_page(d);
> +}
> +
> +void dump_pageframe_info(struct domain *d)
> +{
> +
> +}
> +
> +struct vcpu *alloc_vcpu_struct(void)
> +{
> +    struct vcpu *v;
> +    BUILD_BUG_ON(sizeof(*v) > PAGE_SIZE);
> +    v = alloc_xenheap_pages(0, 0);
> +    if ( v != NULL )
> +        clear_page(v);
> +    return v;
> +}
> +
> +void free_vcpu_struct(struct vcpu *v)
> +{
> +    free_xenheap_page(v);
> +}
> +
> +int vcpu_initialise(struct vcpu *v)
> +{
> +    int rc = 0;
> +
> +    return rc;
> +}
> +
> +void vcpu_destroy(struct vcpu *v)
> +{
> +
> +}
> +
> +int arch_domain_create(struct domain *d, unsigned int domcr_flags)
> +{
> +    int rc;
> +
> +    d->max_vcpus = 8;
> +
> +    rc = 0;
> +fail:
> +    return rc;
> +}
> +
> +void arch_domain_destroy(struct domain *d)
> +{
> +    /* p2m_destroy */
> +    /* domain_vgic_destroy */
> +}
> +
> +void arch_dump_domain_info(struct domain *d)
> +{
> +}
> +
> +void arch_dump_vcpu_info(struct vcpu *v)
> +{
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-set-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> new file mode 100644
> index 0000000..c226bdf
> --- /dev/null
> +++ b/xen/include/asm-arm/domain.h
> @@ -0,0 +1,43 @@
> +#ifndef __ASM_DOMAIN_H__
> +#define __ASM_DOMAIN_H__
> +
> +#include <xen/config.h>
> +#include <xen/cache.h>
> +#include <asm/page.h>
> +#include <asm/p2m.h>
> +
> +struct pending_irq
> +{
> +    int irq;
> +    struct irq_desc *desc; /* only set it the irq corresponds to a physical
> irq */
> +    uint8_t priority;
> +    struct list_head link;
> +};
> +
> +struct arch_domain
> +{
> +}  __cacheline_aligned;
> +
> +struct arch_vcpu
> +{
> +    struct cpu_user_regs user_regs;
> +
> +    uint32_t sctlr;
> +    uint32_t ttbr0, ttbr1, ttbcr;
> +
> +}  __cacheline_aligned;
> +
> +void vcpu_show_execution_state(struct vcpu *);
> +void vcpu_show_registers(const struct vcpu *);
> +
> +#endif /* __ASM_DOMAIN_H__ */
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-set-style: "BSD"
> + * c-basic-offset: 4
> + * tab-width: 4
> + * indent-tabs-mode: nil
> + * End:
> + */



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