[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 11/11] x86/vpt: introduce a per-vPT lock
Introduce a per virtual timer lock that replaces the existing per-vCPU and per-domain vPT locks. Since virtual timers are no longer assigned or migrated between vCPUs the locking can be simplified to a in-structure spinlock that protects all the fields. This requires introducing a helper to initialize the spinlock, and that could be used to initialize other virtual timer fields in the future. Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> --- Changes since v1: - New in his version. --- xen/arch/x86/emul-i8254.c | 1 + xen/arch/x86/hvm/hpet.c | 8 +++++- xen/arch/x86/hvm/hvm.c | 4 --- xen/arch/x86/hvm/rtc.c | 1 + xen/arch/x86/hvm/vlapic.c | 1 + xen/arch/x86/hvm/vpt.c | 48 +++++++++++++++------------------- xen/include/asm-x86/hvm/vcpu.h | 3 --- xen/include/asm-x86/hvm/vpt.h | 9 ++----- 8 files changed, 33 insertions(+), 42 deletions(-) diff --git a/xen/arch/x86/emul-i8254.c b/xen/arch/x86/emul-i8254.c index 73be4188ad4..a47138cbab7 100644 --- a/xen/arch/x86/emul-i8254.c +++ b/xen/arch/x86/emul-i8254.c @@ -484,6 +484,7 @@ void pit_init(struct domain *d, unsigned long cpu_khz) { register_portio_handler(d, PIT_BASE, 4, handle_pit_io); register_portio_handler(d, 0x61, 1, handle_speaker_io); + init_periodic_timer(&pit->pt0); } pit_reset(d); diff --git a/xen/arch/x86/hvm/hpet.c b/xen/arch/x86/hvm/hpet.c index ca94e8b4538..20593c3862d 100644 --- a/xen/arch/x86/hvm/hpet.c +++ b/xen/arch/x86/hvm/hpet.c @@ -739,12 +739,18 @@ static void hpet_set(HPETState *h) void hpet_init(struct domain *d) { + HPETState *h = domain_vhpet(d); + unsigned int i; + if ( !has_vhpet(d) ) return; - hpet_set(domain_vhpet(d)); + hpet_set(h); register_mmio_handler(d, &hpet_mmio_ops); d->arch.hvm.params[HVM_PARAM_HPET_ENABLED] = 1; + + for ( i = 0; i < HPET_TIMER_NUM; i++ ) + init_periodic_timer(&h->pt[i]); } void hpet_deinit(struct domain *d) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 3a72da67ef2..1c014fc26c3 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -665,8 +665,6 @@ int hvm_domain_initialise(struct domain *d) /* need link to containing domain */ d->arch.hvm.pl_time->domain = d; - rwlock_init(&d->arch.hvm.pl_time->pt_migrate); - /* Set the default IO Bitmap. */ if ( is_hardware_domain(d) ) { @@ -1556,8 +1554,6 @@ int hvm_vcpu_initialise(struct vcpu *v) hvm_asid_flush_vcpu(v); - spin_lock_init(&v->arch.hvm.tm_lock); - rc = hvm_vcpu_cacheattr_init(v); /* teardown: vcpu_cacheattr_destroy */ if ( rc != 0 ) goto fail1; diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c index 3150f5f1479..2d540b16acd 100644 --- a/xen/arch/x86/hvm/rtc.c +++ b/xen/arch/x86/hvm/rtc.c @@ -846,6 +846,7 @@ void rtc_init(struct domain *d) init_timer(&s->update_timer, rtc_update_timer, s, smp_processor_id()); init_timer(&s->update_timer2, rtc_update_timer2, s, smp_processor_id()); init_timer(&s->alarm_timer, rtc_alarm_cb, s, smp_processor_id()); + init_periodic_timer(&s->pt); register_portio_handler(d, RTC_PORT(0), 2, handle_rtc_io); diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c index 8091b6d8925..688ff85e710 100644 --- a/xen/arch/x86/hvm/vlapic.c +++ b/xen/arch/x86/hvm/vlapic.c @@ -1651,6 +1651,7 @@ int vlapic_init(struct vcpu *v) return 0; } + init_periodic_timer(&vlapic->pt); vlapic->pt.source = PTSRC_lapic; vlapic->regs_page = alloc_domheap_page(v->domain, MEMF_no_owner); diff --git a/xen/arch/x86/hvm/vpt.c b/xen/arch/x86/hvm/vpt.c index 84d49c1b25c..9cb0b8a0a82 100644 --- a/xen/arch/x86/hvm/vpt.c +++ b/xen/arch/x86/hvm/vpt.c @@ -126,23 +126,6 @@ static int pt_irq_masked(struct periodic_time *pt) return 1; } -static void pt_lock(struct periodic_time *pt) -{ - /* - * We cannot use pt_vcpu_lock here, because we need to acquire the - * per-domain lock first and then (re-)fetch the value of pt->vcpu, or - * else we might be using a stale value of pt->vcpu. - */ - read_lock(&pt->vcpu->domain->arch.hvm.pl_time->pt_migrate); - spin_lock(&pt->vcpu->arch.hvm.tm_lock); -} - -static void pt_unlock(struct periodic_time *pt) -{ - spin_unlock(&pt->vcpu->arch.hvm.tm_lock); - read_unlock(&pt->vcpu->domain->arch.hvm.pl_time->pt_migrate); -} - static void pt_process_missed_ticks(struct periodic_time *pt) { s_time_t missed_ticks, now = NOW(); @@ -213,7 +196,7 @@ static void pt_timer_fn(void *data) void *cb_priv; unsigned int irq; - pt_lock(pt); + spin_lock(&pt->lock); v = pt->vcpu; irq = pt->irq; @@ -228,7 +211,7 @@ static void pt_timer_fn(void *data) cb_priv = pt->priv; } - pt_unlock(pt); + spin_unlock(&pt->lock); if ( cb ) cb(v, cb_priv); @@ -245,7 +228,7 @@ static void eoi_callback(unsigned int unused, void *data) time_cb *cb = NULL; void *cb_priv; - pt_lock(pt); + spin_lock(&pt->lock); pt_irq_fired(pt->vcpu, pt); if ( pt->pending_intr_nr && inject_interrupt(pt) ) @@ -256,7 +239,7 @@ static void eoi_callback(unsigned int unused, void *data) v = pt->vcpu; } - pt_unlock(pt); + spin_unlock(&pt->lock); if ( cb ) cb(v, cb_priv); @@ -312,6 +295,11 @@ static bool inject_interrupt(struct periodic_time *pt) return true; } +void init_periodic_timer(struct periodic_time *pt) +{ + spin_lock_init(&pt->lock); +} + void create_periodic_time( struct vcpu *v, struct periodic_time *pt, uint64_t delta, uint64_t period, uint8_t irq, time_cb *cb, void *data, bool level) @@ -328,7 +316,7 @@ void create_periodic_time( destroy_periodic_time(pt); - write_lock(&v->domain->arch.hvm.pl_time->pt_migrate); + spin_lock(&pt->lock); pt->pending_intr_nr = 0; @@ -391,18 +379,21 @@ void create_periodic_time( init_timer(&pt->timer, pt_timer_fn, pt, v->processor); set_timer(&pt->timer, pt->scheduled); - write_unlock(&v->domain->arch.hvm.pl_time->pt_migrate); + spin_unlock(&pt->lock); } void destroy_periodic_time(struct periodic_time *pt) { unsigned int gsi; + spin_lock(&pt->lock); /* Was this structure previously initialised by create_periodic_time()? */ if ( pt->vcpu == NULL ) + { + spin_unlock(&pt->lock); return; + } - pt_lock(pt); pt->pending_intr_nr = 0; gsi = pt->irq; @@ -415,7 +406,7 @@ void destroy_periodic_time(struct periodic_time *pt) hvm_gsi_unregister_callback(pt->vcpu->domain, gsi, &pt->eoi_cb); break; } - pt_unlock(pt); + spin_unlock(&pt->lock); /* * pt_timer_fn() can run until this kill_timer() returns. We must do this @@ -430,10 +421,13 @@ static void pt_resume(struct periodic_time *pt) time_cb *cb = NULL; void *cb_priv; + spin_lock(&pt->lock); if ( pt->vcpu == NULL ) + { + spin_unlock(&pt->lock); return; + } - pt_lock(pt); if ( pt->pending_intr_nr && inject_interrupt(pt) ) { pt->pending_intr_nr--; @@ -441,7 +435,7 @@ static void pt_resume(struct periodic_time *pt) cb_priv = pt->priv; v = pt->vcpu; } - pt_unlock(pt); + spin_unlock(&pt->lock); if ( cb ) cb(v, cb_priv); diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h index 9a756964fb0..fe3d0e10426 100644 --- a/xen/include/asm-x86/hvm/vcpu.h +++ b/xen/include/asm-x86/hvm/vcpu.h @@ -148,9 +148,6 @@ struct hvm_vcpu { s64 cache_tsc_offset; u64 guest_time; - /* Lock for virtual platform timers. */ - spinlock_t tm_lock; - bool flag_dr_dirty; bool debug_state_latch; bool single_step; diff --git a/xen/include/asm-x86/hvm/vpt.h b/xen/include/asm-x86/hvm/vpt.h index af04efa5e01..5628cff8f7a 100644 --- a/xen/include/asm-x86/hvm/vpt.h +++ b/xen/include/asm-x86/hvm/vpt.h @@ -48,6 +48,7 @@ struct periodic_time { time_cb *cb; void *priv; /* point back to platform time source */ struct hvm_gsi_eoi_callback eoi_cb; /* EOI callback registration data */ + spinlock_t lock; }; @@ -126,13 +127,6 @@ struct pl_time { /* platform time */ struct RTCState vrtc; struct HPETState vhpet; struct PMTState vpmt; - /* - * rwlock to prevent periodic_time vCPU migration. Take the lock in read - * mode in order to prevent the vcpu field of periodic_time from changing. - * Lock must be taken in write mode when changes to the vcpu field are - * performed, as it allows exclusive access to all the timers of a domain. - */ - rwlock_t pt_migrate; /* guest_time = Xen sys time + stime_offset */ int64_t stime_offset; /* Ensures monotonicity in appropriate timer modes. */ @@ -167,6 +161,7 @@ void create_periodic_time( struct vcpu *v, struct periodic_time *pt, uint64_t delta, uint64_t period, uint8_t irq, time_cb *cb, void *data, bool level); void destroy_periodic_time(struct periodic_time *pt); +void init_periodic_timer(struct periodic_time *pt); int pv_pit_handler(int port, int data, int write); void pit_reset(struct domain *d); -- 2.30.1
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