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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 7/7] xen: Enable event channel of PV extension of HVM
On Tuesday 09 March 2010 01:00:52 Stefano Stabellini wrote:
> Have you actually tried booting a guest with 2 vcpus?
> Are you sure it works for you?
I mostly tested my patches with 4 vcpus, so that I can know if the SMP code
works well.
--
regards
Yang, Sheng
>
> On Mon, 8 Mar 2010, Sheng Yang wrote:
> > We mapped each IOAPIC pin to a VIRQ, so that we can deliver interrupt
> > through these VIRQs.
> >
> > We used X86_PLATFORM_IPI_VECTOR as the notification vector for hypervisor
> > to notify guest about the event.
> >
> > The patch also enabled SMP support, then we can support IPI through
> > evtchn as well.
> >
> > When this feature is enabled, we would relay on Xen PV timer for
> > clockevent, rather than other hardware emulated ones.
> >
> > Then we don't use IOAPIC/LAPIC, eliminated the overhead brought by
> > unnecessary VMExit caused by LAPIC.
> >
> > PV evtchn depends on PV clocksource. To enable it, put following line in
> > the HVM configure file:
> >
> > cpuid = [ '0x40000002:edx=0x7' ]
> >
> > It would enable PV extension framework(bit 0), PV clocksource(bit 1), as
> > well as PV evtchn(bit 2).
> >
> > Notice if you try to enable PV evtchn without other two bits set, the
> > setting would be ignored.
> >
> > Signed-off-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
> > ---
> > arch/x86/xen/enlighten.c | 6 ++--
> > arch/x86/xen/hvmpv.c | 70
> > +++++++++++++++++++++++++++++++++++++++- arch/x86/xen/irq.c |
> > 28 ++++++++++++++++
> > arch/x86/xen/smp.c | 76
> > ++++++++++++++++++++++++++++++++++++++++-- arch/x86/xen/xen-ops.h |
> > 16 +++++++++
> > drivers/xen/events.c | 74
> > ++++++++++++++++++++++++++++++++++++++--- include/xen/events.h |
> > 4 ++
> > include/xen/hvm.h | 5 +++
> > include/xen/interface/xen.h | 6 +++-
> > 9 files changed, 270 insertions(+), 15 deletions(-)
> >
> > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> > index 36daccb..2d60e70 100644
> > --- a/arch/x86/xen/enlighten.c
> > +++ b/arch/x86/xen/enlighten.c
> > @@ -717,7 +717,7 @@ static u32 xen_safe_apic_wait_icr_idle(void)
> > return 0;
> > }
> >
> > -static void set_xen_basic_apic_ops(void)
> > +void xen_set_basic_apic_ops(void)
> > {
> > apic->read = xen_apic_read;
> > apic->write = xen_apic_write;
> > @@ -1026,7 +1026,7 @@ static void xen_crash_shutdown(struct pt_regs
> > *regs) xen_reboot(SHUTDOWN_crash);
> > }
> >
> > -static const struct machine_ops __initdata xen_machine_ops = {
> > +const struct machine_ops __initdata xen_machine_ops = {
> > .restart = xen_restart,
> > .halt = xen_machine_halt,
> > .power_off = xen_machine_halt,
> > @@ -1116,7 +1116,7 @@ asmlinkage void __init xen_start_kernel(void)
> > /*
> > * set up the basic apic ops.
> > */
> > - set_xen_basic_apic_ops();
> > + xen_set_basic_apic_ops();
> > #endif
> >
> > if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
> > diff --git a/arch/x86/xen/hvmpv.c b/arch/x86/xen/hvmpv.c
> > index e944caf..97d148d 100644
> > --- a/arch/x86/xen/hvmpv.c
> > +++ b/arch/x86/xen/hvmpv.c
> > @@ -17,6 +17,7 @@
> > #include <xen/interface/version.h>
> > #include <xen/interface/memory.h>
> >
> > +#include <asm/reboot.h>
> > #include <asm/xen/cpuid.h>
> > #include <asm/xen/hypercall.h>
> > #include <asm/xen/hypervisor.h>
> > @@ -45,6 +46,8 @@ static void __init xen_hvm_pv_banner(void)
> > version >> 16, version & 0xffff, extra.extraversion);
> > if (xen_hvm_pv_clock_enabled())
> > printk(KERN_INFO "PV feature: PV clocksource enabled\n");
> > + if (xen_hvm_pv_evtchn_enabled())
> > + printk(KERN_INFO "PV feature: Event channel enabled\n");
> > }
> >
> > static int __init xen_para_available(void)
> > @@ -84,9 +87,14 @@ static int __init init_hvm_pv_info(void)
> > if (!(edx & XEN_CPUID_FEAT2_HVM_PV))
> > return -ENODEV;
> >
> > - if (edx & XEN_CPUID_FEAT2_HVM_PV_CLOCK)
> > + if (edx & XEN_CPUID_FEAT2_HVM_PV_CLOCK) {
> > xen_hvm_pv_features |= XEN_HVM_PV_CLOCK_ENABLED;
> >
> > + /* Evtchn depends on PV clocksource */
> > + if (edx & XEN_CPUID_FEAT2_HVM_PV_EVTCHN)
> > + xen_hvm_pv_features |= XEN_HVM_PV_EVTCHN_ENABLED;
> > + }
> > +
> > if (pages < 1)
> > return -ENODEV;
> >
> > @@ -134,6 +142,64 @@ static void __init init_pv_clocksource(void)
> > xen_register_clocksource();
> > }
> >
> > +static int set_callback_via(uint64_t via)
> > +{
> > + struct xen_hvm_param a;
> > +
> > + a.domid = DOMID_SELF;
> > + a.index = HVM_PARAM_CALLBACK_IRQ;
> > + a.value = via;
> > + return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
> > +}
> > +
> > +void do_hvm_pv_evtchn_intr(void)
> > +{
> > + per_cpu(irq_count, smp_processor_id())++;
> > + xen_hvm_evtchn_do_upcall(get_irq_regs());
> > + per_cpu(irq_count, smp_processor_id())--;
> > +}
> > +
> > +#ifdef CONFIG_X86_LOCAL_APIC
> > +static void xen_hvm_pv_evtchn_apic_write(u32 reg, u32 val)
> > +{
> > + /* The only one reached here should be EOI */
> > + WARN_ON(reg != APIC_EOI);
> > +}
> > +#endif
> > +
> > +static void __init init_pv_evtchn(void)
> > +{
> > + uint64_t callback_via;
> > +
> > + if (!xen_hvm_pv_evtchn_enabled())
> > + return;
> > +
> > + xen_hvm_pv_init_irq_ops();
> > +
> > + x86_init.timers.timer_init = xen_time_init;
> > + x86_init.timers.setup_percpu_clockev = x86_init_noop;
> > + x86_cpuinit.setup_percpu_clockev = x86_init_noop;
> > +
> > + pv_apic_ops.startup_ipi_hook = paravirt_nop;
> > +#ifdef CONFIG_X86_LOCAL_APIC
> > + /*
> > + * set up the basic apic ops.
> > + */
> > + xen_set_basic_apic_ops();
> > + apic->write = xen_hvm_pv_evtchn_apic_write;
> > +#endif
> > +
> > + callback_via = HVM_CALLBACK_VECTOR(X86_PLATFORM_IPI_VECTOR);
> > + set_callback_via(callback_via);
> > +
> > + x86_platform_ipi_callback = do_hvm_pv_evtchn_intr;
> > +
> > + disable_acpi();
> > +
> > + xen_hvm_pv_smp_init();
> > + machine_ops = xen_machine_ops;
> > +}
> > +
> > void __init xen_guest_init(void)
> > {
> > int r;
> > @@ -158,4 +224,6 @@ void __init xen_guest_init(void)
> > xen_domain_type = XEN_HVM_DOMAIN;
> >
> > init_pv_clocksource();
> > +
> > + init_pv_evtchn();
> > }
> > diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
> > index 9d30105..e325640 100644
> > --- a/arch/x86/xen/irq.c
> > +++ b/arch/x86/xen/irq.c
> > @@ -2,6 +2,7 @@
> >
> > #include <asm/x86_init.h>
> >
> > +#include <xen/xen.h>
> > #include <xen/interface/xen.h>
> > #include <xen/interface/sched.h>
> > #include <xen/interface/vcpu.h>
> > @@ -131,3 +132,30 @@ void __init xen_init_irq_ops()
> > pv_irq_ops = xen_irq_ops;
> > x86_init.irqs.intr_init = xen_init_IRQ;
> > }
> > +
> > +#ifdef CONFIG_XEN_HVM_PV
> > +static void xen_hvm_pv_evtchn_disable(void)
> > +{
> > + native_irq_disable();
> > + xen_irq_disable();
> > +}
> > +PV_CALLEE_SAVE_REGS_THUNK(xen_hvm_pv_evtchn_disable);
> > +
> > +static void xen_hvm_pv_evtchn_enable(void)
> > +{
> > + native_irq_enable();
> > + xen_irq_enable();
> > +}
> > +PV_CALLEE_SAVE_REGS_THUNK(xen_hvm_pv_evtchn_enable);
> > +
> > +void __init xen_hvm_pv_init_irq_ops(void)
> > +{
> > + if (xen_hvm_pv_evtchn_enabled()) {
> > + pv_irq_ops.irq_disable =
> > + PV_CALLEE_SAVE(xen_hvm_pv_evtchn_disable);
> > + pv_irq_ops.irq_enable =
> > + PV_CALLEE_SAVE(xen_hvm_pv_evtchn_enable);
> > + x86_init.irqs.intr_init = xen_hvm_pv_evtchn_init_IRQ;
> > + }
> > +}
> > +#endif
> > diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
> > index 563d205..a9fd12d 100644
> > --- a/arch/x86/xen/smp.c
> > +++ b/arch/x86/xen/smp.c
> > @@ -15,18 +15,24 @@
> > #include <linux/sched.h>
> > #include <linux/err.h>
> > #include <linux/smp.h>
> > +#include <linux/nmi.h>
> >
> > #include <asm/paravirt.h>
> > #include <asm/desc.h>
> > #include <asm/pgtable.h>
> > #include <asm/cpu.h>
> > +#include <asm/trampoline.h>
> > +#include <asm/tlbflush.h>
> > +#include <asm/mtrr.h>
> >
> > #include <xen/interface/xen.h>
> > #include <xen/interface/vcpu.h>
> >
> > #include <asm/xen/interface.h>
> > #include <asm/xen/hypercall.h>
> > +#include <asm/xen/hypervisor.h>
> >
> > +#include <xen/xen.h>
> > #include <xen/page.h>
> > #include <xen/events.h>
> >
> > @@ -63,8 +69,12 @@ static __cpuinit void cpu_bringup(void)
> > touch_softlockup_watchdog();
> > preempt_disable();
> >
> > - xen_enable_sysenter();
> > - xen_enable_syscall();
> > + if (xen_pv_domain()) {
> > + xen_enable_sysenter();
> > + xen_enable_syscall();
> > + }
> > +
> > + set_mtrr_aps_delayed_init();
> >
> > cpu = smp_processor_id();
> > smp_store_cpu_info(cpu);
> > @@ -171,7 +181,8 @@ static void __init xen_smp_prepare_boot_cpu(void)
> >
> > /* We've switched to the "real" per-cpu gdt, so make sure the
> > old memory can be recycled */
> > - make_lowmem_page_readwrite(xen_initial_gdt);
> > + if (xen_feature(XENFEAT_writable_descriptor_tables))
> > + make_lowmem_page_readwrite(xen_initial_gdt);
> >
> > xen_setup_vcpu_info_placement();
> > }
> > @@ -282,6 +293,39 @@ cpu_initialize_context(unsigned int cpu, struct
> > task_struct *idle) return 0;
> > }
> >
> > +static __cpuinit int
> > +hvm_pv_cpu_initialize_context(unsigned int cpu, struct task_struct
> > *idle) +{
> > + struct vcpu_guest_context *ctxt;
> > + unsigned long start_ip;
> > +
> > + if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
> > + return 0;
> > +
> > + ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
> > + if (ctxt == NULL)
> > + return -ENOMEM;
> > +
> > + early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
> > + initial_code = (unsigned long)cpu_bringup_and_idle;
> > + stack_start.sp = (void *) idle->thread.sp;
> > +
> > + /* start_ip had better be page-aligned! */
> > + start_ip = setup_trampoline();
> > +
> > + /* only start_ip is what we want */
> > + ctxt->flags = VGCF_HVM_GUEST;
> > + ctxt->user_regs.eip = start_ip;
> > +
> > + printk(KERN_INFO "Booting processor %d ip 0x%lx\n", cpu,
> > start_ip); +
> > + if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
> > + BUG();
> > +
> > + kfree(ctxt);
> > + return 0;
> > +}
> > +
> > static int __cpuinit xen_cpu_up(unsigned int cpu)
> > {
> > struct task_struct *idle = idle_task(cpu);
> > @@ -292,6 +336,7 @@ static int __cpuinit xen_cpu_up(unsigned int cpu)
> > irq_ctx_init(cpu);
> > #else
> > clear_tsk_thread_flag(idle, TIF_FORK);
> > + initial_gs = per_cpu_offset(cpu);
> > per_cpu(kernel_stack, cpu) =
> > (unsigned long)task_stack_page(idle) -
> > KERNEL_STACK_OFFSET + THREAD_SIZE;
> > @@ -305,7 +350,13 @@ static int __cpuinit xen_cpu_up(unsigned int cpu)
> > /* make sure interrupts start blocked */
> > per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
> >
> > - rc = cpu_initialize_context(cpu, idle);
> > + if (xen_pv_domain())
> > + rc = cpu_initialize_context(cpu, idle);
> > + else if (xen_hvm_pv_evtchn_enabled())
> > + rc = hvm_pv_cpu_initialize_context(cpu, idle);
> > + else
> > + BUG();
> > +
> > if (rc)
> > return rc;
> >
> > @@ -480,3 +531,20 @@ void __init xen_smp_init(void)
> > xen_fill_possible_map();
> > xen_init_spinlocks();
> > }
> > +
> > +#ifdef CONFIG_XEN_HVM_PV
> > +static void xen_hvm_pv_flush_tlb_others(const struct cpumask *cpumask,
> > + struct mm_struct *mm, unsigned
> > long va) +{
> > + /* TODO Make it more specific */
> > + flush_tlb_all();
> > +}
> > +
> > +void __init xen_hvm_pv_smp_init(void)
> > +{
> > + if (xen_hvm_pv_evtchn_enabled()) {
> > + smp_ops = xen_smp_ops;
> > + pv_mmu_ops.flush_tlb_others =
> > xen_hvm_pv_flush_tlb_others; + }
> > +}
> > +#endif
> > diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
> > index d56b660..4de9874 100644
> > --- a/arch/x86/xen/xen-ops.h
> > +++ b/arch/x86/xen/xen-ops.h
> > @@ -52,6 +52,12 @@ void xen_register_clocksource(void);
> > unsigned long xen_get_wallclock(void);
> > int xen_set_wallclock(unsigned long time);
> > unsigned long long xen_sched_clock(void);
> > +void xen_set_basic_apic_ops(void);
> > +
> > +#ifdef CONFIG_XEN_HVM_PV
> > +void __init xen_hvm_pv_init_irq_ops(void);
> > +void __init xen_hvm_pv_evtchn_init_IRQ(void);
> > +#endif /* CONFIG_XEN_HVM_PV */
> >
> > irqreturn_t xen_debug_interrupt(int irq, void *dev_id);
> >
> > @@ -62,9 +68,17 @@ void xen_setup_vcpu_info_placement(void);
> > #ifdef CONFIG_SMP
> > void xen_smp_init(void);
> >
> > +#ifdef CONFIG_XEN_HVM_PV
> > +void xen_hvm_pv_smp_init(void);
> > +#endif /* CONFIG_XEN_HVM_PV */
> > +
> > extern cpumask_var_t xen_cpu_initialized_map;
> > #else
> > static inline void xen_smp_init(void) {}
> > +#ifdef CONFIG_XEN_HVM_PV
> > +static inline void xen_hvm_pv_smp_init(void) {}
> > +#endif /* CONFIG_XEN_HVM_PV */
> > +
> > #endif
> >
> > #ifdef CONFIG_PARAVIRT_SPINLOCKS
> > @@ -102,4 +116,6 @@ void xen_sysret32(void);
> > void xen_sysret64(void);
> > void xen_adjust_exception_frame(void);
> >
> > +extern const struct machine_ops xen_machine_ops;
> > +
> > #endif /* XEN_OPS_H */
> > diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> > index ce602dd..e4b9de6 100644
> > --- a/drivers/xen/events.c
> > +++ b/drivers/xen/events.c
> > @@ -32,14 +32,17 @@
> > #include <asm/irq.h>
> > #include <asm/idle.h>
> > #include <asm/sync_bitops.h>
> > +#include <asm/desc.h>
> > #include <asm/xen/hypercall.h>
> > #include <asm/xen/hypervisor.h>
> >
> > +#include <xen/xen.h>
> > #include <xen/xen-ops.h>
> > #include <xen/events.h>
> > #include <xen/interface/xen.h>
> > #include <xen/interface/event_channel.h>
> >
> > +
> > /*
> > * This lock protects updates to the following mapping and
> > reference-count * arrays. The lock does not need to be acquired to read
> > the mapping tables. @@ -616,17 +619,13 @@ static DEFINE_PER_CPU(unsigned,
> > xed_nesting_count); * a bitset of words which contain pending event bits.
> > The second * level is a bitset of pending events themselves.
> > */
> > -void xen_evtchn_do_upcall(struct pt_regs *regs)
> > +void __xen_evtchn_do_upcall(struct pt_regs *regs)
> > {
> > int cpu = get_cpu();
> > - struct pt_regs *old_regs = set_irq_regs(regs);
> > struct shared_info *s = HYPERVISOR_shared_info;
> > struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
> > unsigned count;
> >
> > - exit_idle();
> > - irq_enter();
> > -
> > do {
> > unsigned long pending_words;
> >
> > @@ -662,10 +661,25 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
> > } while(count != 1);
> >
> > out:
> > + put_cpu();
> > +}
> > +
> > +void xen_evtchn_do_upcall(struct pt_regs *regs)
> > +{
> > + struct pt_regs *old_regs = set_irq_regs(regs);
> > +
> > + exit_idle();
> > + irq_enter();
> > +
> > + __xen_evtchn_do_upcall(regs);
> > +
> > irq_exit();
> > set_irq_regs(old_regs);
> > +}
> >
> > - put_cpu();
> > +void xen_hvm_evtchn_do_upcall(struct pt_regs *regs)
> > +{
> > + __xen_evtchn_do_upcall(regs);
> > }
> >
> > /* Rebind a new event channel to an existing irq. */
> > @@ -944,3 +958,51 @@ void __init xen_init_IRQ(void)
> >
> > irq_ctx_init(smp_processor_id());
> > }
> > +
> > +void __init xen_hvm_pv_evtchn_init_IRQ(void)
> > +{
> > + int i;
> > +
> > + xen_init_IRQ();
> > + for (i = 0; i < NR_IRQS_LEGACY; i++) {
> > + struct evtchn_bind_virq bind_virq;
> > + struct irq_desc *desc = irq_to_desc(i);
> > + int virq, evtchn;
> > +
> > + virq = i + VIRQ_EMUL_PIN_START;
> > + bind_virq.virq = virq;
> > + bind_virq.vcpu = 0;
> > +
> > + if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
> > + &bind_virq) != 0)
> > + BUG();
> > +
> > + evtchn = bind_virq.port;
> > + evtchn_to_irq[evtchn] = i;
> > + irq_info[i] = mk_virq_info(evtchn, virq);
> > +
> > + desc->status = IRQ_DISABLED;
> > + desc->action = NULL;
> > + desc->depth = 1;
> > +
> > + /*
> > + * 16 old-style INTA-cycle interrupts:
> > + */
> > + set_irq_chip_and_handler_name(i, &xen_dynamic_chip,
> > + handle_level_irq, "event");
> > + }
> > +
> > + /*
> > + * Cover the whole vector space, no vector can escape
> > + * us. (some of these will be overridden and become
> > + * 'special' SMP interrupts)
> > + */
> > + for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
> > + int vector = FIRST_EXTERNAL_VECTOR + i;
> > + if (vector != IA32_SYSCALL_VECTOR)
> > + set_intr_gate(vector, interrupt[i]);
> > + }
> > +
> > + /* generic IPI for platform specific use, now used for HVM evtchn
> > */ + alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi); +}
> > diff --git a/include/xen/events.h b/include/xen/events.h
> > index e68d59a..b9fbb3b 100644
> > --- a/include/xen/events.h
> > +++ b/include/xen/events.h
> > @@ -56,4 +56,8 @@ void xen_poll_irq(int irq);
> > /* Determine the IRQ which is bound to an event channel */
> > unsigned irq_from_evtchn(unsigned int evtchn);
> >
> > +#ifdef CONFIG_XEN_HVM_PV
> > +void xen_hvm_evtchn_do_upcall(struct pt_regs *regs);
> > +#endif
> > +
> > #endif /* _XEN_EVENTS_H */
> > diff --git a/include/xen/hvm.h b/include/xen/hvm.h
> > index 4ea8887..c66d788 100644
> > --- a/include/xen/hvm.h
> > +++ b/include/xen/hvm.h
> > @@ -20,4 +20,9 @@ static inline unsigned long hvm_get_parameter(int idx)
> > return xhv.value;
> > }
> >
> > +#define HVM_CALLBACK_VIA_TYPE_VECTOR 0x2
> > +#define HVM_CALLBACK_VIA_TYPE_SHIFT 56
> > +#define HVM_CALLBACK_VECTOR(x)
> > (((uint64_t)HVM_CALLBACK_VIA_TYPE_VECTOR)<<\ +
> > HVM_CALLBACK_VIA_TYPE_SHIFT | (x)) +
> > #endif /* XEN_HVM_H__ */
> > diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
> > index 2befa3e..70a6c6e 100644
> > --- a/include/xen/interface/xen.h
> > +++ b/include/xen/interface/xen.h
> > @@ -90,7 +90,11 @@
> > #define VIRQ_ARCH_6 22
> > #define VIRQ_ARCH_7 23
> >
> > -#define NR_VIRQS 24
> > +#define VIRQ_EMUL_PIN_START 24
> > +#define VIRQ_EMUL_PIN_NUM 16
> > +
> > +#define NR_VIRQS (VIRQ_EMUL_PIN_START + VIRQ_EMUL_PIN_NUM)
> > +
> > /*
> > * MMU-UPDATE REQUESTS
> > *
> > --
> > 1.5.4.5
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
>
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