[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH 08/10] ARM: vGIC: move target vcpu from irq_rank to struct pending_irq
So far we kept the target VCPU for SPIs in the rank structure. Move that information over into pending_irq. This changes vgic_get_target_vcpu(), which now takes only a domain and a struct pending_irq to get the target vCPU, in a way that does not necessarily require the pending_irq lock to be held. Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> --- xen/arch/arm/gic.c | 3 +- xen/arch/arm/vgic-v2.c | 57 ++++++++++++++--------------------- xen/arch/arm/vgic-v3.c | 71 ++++++++++++++++++++++---------------------- xen/arch/arm/vgic.c | 74 ++++++++++++++++++++-------------------------- xen/include/asm-arm/vgic.h | 15 ++++------ 5 files changed, 97 insertions(+), 123 deletions(-) diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index e175e9b..737da6b 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -492,7 +492,8 @@ static void gic_update_one_lr(struct vcpu *v, int i) smp_wmb(); if ( test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) ) { - struct vcpu *v_target = vgic_get_target_vcpu(v, irq); + struct vcpu *v_target = vgic_get_target_vcpu(v->domain, p); + irq_set_affinity(p->desc, cpumask_of(v_target->processor)); clear_bit(GIC_IRQ_GUEST_MIGRATING, &p->status); } diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c index 22c679c..bf755ae 100644 --- a/xen/arch/arm/vgic-v2.c +++ b/xen/arch/arm/vgic-v2.c @@ -66,19 +66,21 @@ void vgic_v2_setup_hw(paddr_t dbase, paddr_t cbase, paddr_t csize, * * Note the byte offset will be aligned to an ITARGETSR<n> boundary. */ -static uint32_t vgic_fetch_itargetsr(struct vgic_irq_rank *rank, - unsigned int offset) +static uint32_t vgic_fetch_itargetsr(struct vcpu *v, unsigned int offset) { uint32_t reg = 0; unsigned int i; - ASSERT(spin_is_locked(&rank->lock)); - - offset &= INTERRUPT_RANK_MASK; offset &= ~(NR_TARGETS_PER_ITARGETSR - 1); for ( i = 0; i < NR_TARGETS_PER_ITARGETSR; i++, offset++ ) - reg |= (1 << read_atomic(&rank->vcpu[offset])) << (i * NR_BITS_PER_TARGET); + { + struct pending_irq *p = irq_to_pending(v, offset); + + spin_lock(&p->lock); + reg |= (1 << p->vcpu_id) << (i * NR_BITS_PER_TARGET); + spin_unlock(&p->lock); + } return reg; } @@ -89,32 +91,28 @@ static uint32_t vgic_fetch_itargetsr(struct vgic_irq_rank *rank, * * Note the byte offset will be aligned to an ITARGETSR<n> boundary. */ -static void vgic_store_itargetsr(struct domain *d, struct vgic_irq_rank *rank, +static void vgic_store_itargetsr(struct domain *d, unsigned int offset, uint32_t itargetsr) { unsigned int i; unsigned int virq; - ASSERT(spin_is_locked(&rank->lock)); - /* * The ITARGETSR0-7, used for SGIs/PPIs, are implemented RO in the * emulation and should never call this function. * - * They all live in the first rank. + * They all live in the first four bytes of ITARGETSR. */ - BUILD_BUG_ON(NR_INTERRUPT_PER_RANK != 32); - ASSERT(rank->index >= 1); + ASSERT(offset >= 4); - offset &= INTERRUPT_RANK_MASK; + virq = offset; offset &= ~(NR_TARGETS_PER_ITARGETSR - 1); - virq = rank->index * NR_INTERRUPT_PER_RANK + offset; - for ( i = 0; i < NR_TARGETS_PER_ITARGETSR; i++, offset++, virq++ ) { unsigned int new_target, old_target; uint8_t new_mask; + struct pending_irq *p = spi_to_pending(d, virq); /* * Don't need to mask as we rely on new_mask to fit for only one @@ -151,16 +149,17 @@ static void vgic_store_itargetsr(struct domain *d, struct vgic_irq_rank *rank, /* The vCPU ID always starts from 0 */ new_target--; - old_target = read_atomic(&rank->vcpu[offset]); + spin_lock(&p->lock); + + old_target = p->vcpu_id; /* Only migrate the vIRQ if the target vCPU has changed */ if ( new_target != old_target ) { - if ( vgic_migrate_irq(d->vcpu[old_target], - d->vcpu[new_target], - virq) ) - write_atomic(&rank->vcpu[offset], new_target); + if ( vgic_migrate_irq(p, d->vcpu[old_target], d->vcpu[new_target]) ) + p->vcpu_id = new_target; } + spin_unlock(&p->lock); } } @@ -168,9 +167,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info, register_t *r, void *priv) { struct hsr_dabt dabt = info->dabt; - struct vgic_irq_rank *rank; int gicd_reg = (int)(info->gpa - v->domain->arch.vgic.dbase); - unsigned long flags; unsigned int irq; perfc_incr(vgicd_reads); @@ -259,11 +256,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info, uint32_t itargetsr; if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width; - rank = vgic_rank_offset(v, 8, gicd_reg - GICD_ITARGETSR, DABT_WORD); - if ( rank == NULL) goto read_as_zero; - vgic_lock_rank(v, rank, flags); - itargetsr = vgic_fetch_itargetsr(rank, gicd_reg - GICD_ITARGETSR); - vgic_unlock_rank(v, rank, flags); + itargetsr = vgic_fetch_itargetsr(v, gicd_reg - GICD_ITARGETSR); *r = vgic_reg32_extract(itargetsr, info); return 1; @@ -385,10 +378,8 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info, register_t r, void *priv) { struct hsr_dabt dabt = info->dabt; - struct vgic_irq_rank *rank; int gicd_reg = (int)(info->gpa - v->domain->arch.vgic.dbase); uint32_t tr; - unsigned long flags; unsigned int irq; perfc_incr(vgicd_writes); @@ -492,14 +483,10 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info, uint32_t itargetsr; if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width; - rank = vgic_rank_offset(v, 8, gicd_reg - GICD_ITARGETSR, DABT_WORD); - if ( rank == NULL) goto write_ignore; - vgic_lock_rank(v, rank, flags); - itargetsr = vgic_fetch_itargetsr(rank, gicd_reg - GICD_ITARGETSR); + itargetsr = vgic_fetch_itargetsr(v, gicd_reg - GICD_ITARGETSR); vgic_reg32_update(&itargetsr, r, info); - vgic_store_itargetsr(v->domain, rank, gicd_reg - GICD_ITARGETSR, + vgic_store_itargetsr(v->domain, gicd_reg - GICD_ITARGETSR, itargetsr); - vgic_unlock_rank(v, rank, flags); return 1; } diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c index 01764c9..15a512a 100644 --- a/xen/arch/arm/vgic-v3.c +++ b/xen/arch/arm/vgic-v3.c @@ -97,18 +97,20 @@ static struct vcpu *vgic_v3_irouter_to_vcpu(struct domain *d, uint64_t irouter) * * Note the byte offset will be aligned to an IROUTER<n> boundary. */ -static uint64_t vgic_fetch_irouter(struct vgic_irq_rank *rank, - unsigned int offset) +static uint64_t vgic_fetch_irouter(struct vcpu *v, unsigned int offset) { - ASSERT(spin_is_locked(&rank->lock)); + struct pending_irq *p; + uint64_t aff; /* There is exactly 1 vIRQ per IROUTER */ offset /= NR_BYTES_PER_IROUTER; - /* Get the index in the rank */ - offset &= INTERRUPT_RANK_MASK; + p = irq_to_pending(v, offset); + spin_lock(&p->lock); + aff = vcpuid_to_vaffinity(p->vcpu_id); + spin_unlock(&p->lock); - return vcpuid_to_vaffinity(read_atomic(&rank->vcpu[offset])); + return aff; } /* @@ -117,11 +119,13 @@ static uint64_t vgic_fetch_irouter(struct vgic_irq_rank *rank, * * Note the offset will be aligned to the appropriate boundary. */ -static void vgic_store_irouter(struct domain *d, struct vgic_irq_rank *rank, +static void vgic_store_irouter(struct domain *d, unsigned int offset, uint64_t irouter) { struct vcpu *new_vcpu, *old_vcpu; + struct pending_irq *p; unsigned int virq; + bool reinject; /* There is 1 vIRQ per IROUTER */ virq = offset / NR_BYTES_PER_IROUTER; @@ -132,11 +136,11 @@ static void vgic_store_irouter(struct domain *d, struct vgic_irq_rank *rank, */ ASSERT(virq >= 32); - /* Get the index in the rank */ - offset &= virq & INTERRUPT_RANK_MASK; + p = spi_to_pending(d, virq); + spin_lock(&p->lock); new_vcpu = vgic_v3_irouter_to_vcpu(d, irouter); - old_vcpu = d->vcpu[read_atomic(&rank->vcpu[offset])]; + old_vcpu = d->vcpu[p->vcpu_id]; /* * From the spec (see 8.9.13 in IHI 0069A), any write with an @@ -146,16 +150,21 @@ static void vgic_store_irouter(struct domain *d, struct vgic_irq_rank *rank, * invalid vCPU. So for now, just ignore the write. * * TODO: Respect the spec + * + * Only migrate the IRQ if the target vCPU has changed */ - if ( !new_vcpu ) - return; - - /* Only migrate the IRQ if the target vCPU has changed */ - if ( new_vcpu != old_vcpu ) + if ( !new_vcpu || new_vcpu == old_vcpu ) { - if ( vgic_migrate_irq(old_vcpu, new_vcpu, virq) ) - write_atomic(&rank->vcpu[offset], new_vcpu->vcpu_id); + spin_unlock(&p->lock); + return; } + + reinject = vgic_migrate_irq(p, old_vcpu, new_vcpu); + + spin_unlock(&p->lock); + + if ( reinject ) + vgic_vcpu_inject_irq(new_vcpu, virq); } static inline bool vgic_reg64_check_access(struct hsr_dabt dabt) @@ -869,8 +878,6 @@ static int vgic_v3_distr_mmio_read(struct vcpu *v, mmio_info_t *info, register_t *r, void *priv) { struct hsr_dabt dabt = info->dabt; - struct vgic_irq_rank *rank; - unsigned long flags; int gicd_reg = (int)(info->gpa - v->domain->arch.vgic.dbase); perfc_incr(vgicd_reads); @@ -996,15 +1003,12 @@ static int vgic_v3_distr_mmio_read(struct vcpu *v, mmio_info_t *info, case VRANGE64(GICD_IROUTER32, GICD_IROUTER1019): { uint64_t irouter; + unsigned int irq; if ( !vgic_reg64_check_access(dabt) ) goto bad_width; - rank = vgic_rank_offset(v, 64, gicd_reg - GICD_IROUTER, - DABT_DOUBLE_WORD); - if ( rank == NULL ) goto read_as_zero; - vgic_lock_rank(v, rank, flags); - irouter = vgic_fetch_irouter(rank, gicd_reg - GICD_IROUTER); - vgic_unlock_rank(v, rank, flags); - + irq = (gicd_reg - GICD_IROUTER) / 8; + if ( irq >= v->domain->arch.vgic.nr_spis + 32 ) goto read_as_zero; + irouter = vgic_fetch_irouter(v, gicd_reg - GICD_IROUTER); *r = vgic_reg64_extract(irouter, info); return 1; @@ -1070,8 +1074,6 @@ static int vgic_v3_distr_mmio_write(struct vcpu *v, mmio_info_t *info, register_t r, void *priv) { struct hsr_dabt dabt = info->dabt; - struct vgic_irq_rank *rank; - unsigned long flags; int gicd_reg = (int)(info->gpa - v->domain->arch.vgic.dbase); perfc_incr(vgicd_writes); @@ -1185,16 +1187,15 @@ static int vgic_v3_distr_mmio_write(struct vcpu *v, mmio_info_t *info, case VRANGE64(GICD_IROUTER32, GICD_IROUTER1019): { uint64_t irouter; + unsigned int irq; if ( !vgic_reg64_check_access(dabt) ) goto bad_width; - rank = vgic_rank_offset(v, 64, gicd_reg - GICD_IROUTER, - DABT_DOUBLE_WORD); - if ( rank == NULL ) goto write_ignore; - vgic_lock_rank(v, rank, flags); - irouter = vgic_fetch_irouter(rank, gicd_reg - GICD_IROUTER); + irq = (gicd_reg - GICD_IROUTER) / 8; + if ( irq >= v->domain->arch.vgic.nr_spis + 32 ) goto write_ignore; + + irouter = vgic_fetch_irouter(v, gicd_reg - GICD_IROUTER); vgic_reg64_update(&irouter, r, info); - vgic_store_irouter(v->domain, rank, gicd_reg - GICD_IROUTER, irouter); - vgic_unlock_rank(v, rank, flags); + vgic_store_irouter(v->domain, gicd_reg - GICD_IROUTER, irouter); return 1; } diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c index a23079a..530ac55 100644 --- a/xen/arch/arm/vgic.c +++ b/xen/arch/arm/vgic.c @@ -60,32 +60,22 @@ struct vgic_irq_rank *vgic_rank_irq(struct vcpu *v, unsigned int irq) return vgic_get_rank(v, rank); } -static void vgic_init_pending_irq(struct pending_irq *p, unsigned int virq) +static void vgic_init_pending_irq(struct pending_irq *p, unsigned int virq, + int vcpu_id) { INIT_LIST_HEAD(&p->inflight); INIT_LIST_HEAD(&p->lr_queue); spin_lock_init(&p->lock); p->irq = virq; + p->vcpu_id = vcpu_id; } static void vgic_rank_init(struct vgic_irq_rank *rank, uint8_t index, unsigned int vcpu) { - unsigned int i; - - /* - * Make sure that the type chosen to store the target is able to - * store an VCPU ID between 0 and the maximum of virtual CPUs - * supported. - */ - BUILD_BUG_ON((1 << (sizeof(rank->vcpu[0]) * 8)) < MAX_VIRT_CPUS); - spin_lock_init(&rank->lock); rank->index = index; - - for ( i = 0; i < NR_INTERRUPT_PER_RANK; i++ ) - write_atomic(&rank->vcpu[i], vcpu); } int domain_vgic_register(struct domain *d, int *mmio_count) @@ -136,8 +126,9 @@ int domain_vgic_init(struct domain *d, unsigned int nr_spis) if ( d->arch.vgic.pending_irqs == NULL ) return -ENOMEM; + /* SPIs are routed to VCPU0 by default */ for (i=0; i<d->arch.vgic.nr_spis; i++) - vgic_init_pending_irq(&d->arch.vgic.pending_irqs[i], i + 32); + vgic_init_pending_irq(&d->arch.vgic.pending_irqs[i], i + 32, 0); /* SPIs are routed to VCPU0 by default */ for ( i = 0; i < DOMAIN_NR_RANKS(d); i++ ) @@ -202,8 +193,9 @@ int vcpu_vgic_init(struct vcpu *v) v->domain->arch.vgic.handler->vcpu_init(v); memset(&v->arch.vgic.pending_irqs, 0, sizeof(v->arch.vgic.pending_irqs)); + /* SGIs/PPIs are always routed to this VCPU */ for (i = 0; i < 32; i++) - vgic_init_pending_irq(&v->arch.vgic.pending_irqs[i], i); + vgic_init_pending_irq(&v->arch.vgic.pending_irqs[i], i, v->vcpu_id); INIT_LIST_HEAD(&v->arch.vgic.inflight_irqs); INIT_LIST_HEAD(&v->arch.vgic.lr_pending); @@ -218,11 +210,11 @@ int vcpu_vgic_free(struct vcpu *v) return 0; } -struct vcpu *vgic_get_target_vcpu(struct vcpu *v, unsigned int virq) +struct vcpu *vgic_get_target_vcpu(struct domain *d, struct pending_irq *p) { - struct vgic_irq_rank *rank = vgic_rank_irq(v, virq); - int target = read_atomic(&rank->vcpu[virq & INTERRUPT_RANK_MASK]); - return v->domain->vcpu[target]; + uint16_t vcpu_id = read_atomic(&p->vcpu_id); + + return d->vcpu[vcpu_id]; } static uint8_t extract_priority(struct pending_irq *p) @@ -289,31 +281,29 @@ DEFINE_GATHER_IRQ_INFO(enabled, extract_enabled, 1) DEFINE_GATHER_IRQ_INFO(config, extract_config, 2) DEFINE_SCATTER_IRQ_INFO(config, set_config, 2) -bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq) +bool vgic_migrate_irq(struct pending_irq *p, struct vcpu *old, struct vcpu *new) { - unsigned long flags; - struct pending_irq *p = irq_to_pending(old, irq); - - /* nothing to do for virtual interrupts */ - if ( p->desc == NULL ) - return true; + ASSERT(spin_is_locked(&p->lock)); /* migration already in progress, no need to do anything */ if ( test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) ) { - gprintk(XENLOG_WARNING, "irq %u migration failed: requested while in progress\n", irq); + gprintk(XENLOG_WARNING, "irq %u migration failed: requested while in progress\n", p->irq); return false; } - perfc_incr(vgic_irq_migrates); + p->vcpu_id = new->vcpu_id; + + /* nothing to do for virtual interrupts */ + if ( p->desc == NULL ) + return false; - spin_lock_irqsave(&old->arch.vgic.lock, flags); + perfc_incr(vgic_irq_migrates); if ( list_empty(&p->inflight) ) { irq_set_affinity(p->desc, cpumask_of(new->processor)); - spin_unlock_irqrestore(&old->arch.vgic.lock, flags); - return true; + return false; } /* If the IRQ is still lr_pending, re-inject it to the new vcpu */ if ( !list_empty(&p->lr_queue) ) @@ -322,8 +312,6 @@ bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq) list_del_init(&p->lr_queue); list_del_init(&p->inflight); irq_set_affinity(p->desc, cpumask_of(new->processor)); - spin_unlock_irqrestore(&old->arch.vgic.lock, flags); - vgic_vcpu_inject_irq(new, irq); return true; } /* if the IRQ is in a GICH_LR register, set GIC_IRQ_GUEST_MIGRATING @@ -331,8 +319,7 @@ bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq) if ( !list_empty(&p->inflight) ) set_bit(GIC_IRQ_GUEST_MIGRATING, &p->status); - spin_unlock_irqrestore(&old->arch.vgic.lock, flags); - return true; + return false; } void arch_move_irqs(struct vcpu *v) @@ -345,11 +332,13 @@ void arch_move_irqs(struct vcpu *v) for ( i = 32; i < vgic_num_irqs(d); i++ ) { - v_target = vgic_get_target_vcpu(v, i); - p = irq_to_pending(v_target, i); + p = irq_to_pending(d->vcpu[0], i); + spin_lock(&p->lock); + v_target = vgic_get_target_vcpu(d, p); if ( v_target == v && !test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) ) irq_set_affinity(p->desc, cpu_mask); + spin_unlock(&p->lock); } } @@ -362,8 +351,8 @@ void vgic_disable_irqs(struct vcpu *v, unsigned int irq, uint32_t r) struct vcpu *v_target; while ( (i = find_next_bit(&mask, 32, i)) < 32 ) { - v_target = vgic_get_target_vcpu(v, irq + i); - p = irq_to_pending(v_target, irq + i); + p = irq_to_pending(v, irq + i); + v_target = vgic_get_target_vcpu(v->domain, p); clear_bit(GIC_IRQ_GUEST_ENABLED, &p->status); gic_remove_from_queues(v_target, irq + i); if ( p->desc != NULL ) @@ -387,10 +376,10 @@ void vgic_enable_irqs(struct vcpu *v, unsigned int irq, uint32_t r) struct domain *d = v->domain; while ( (i = find_next_bit(&mask, 32, i)) < 32 ) { - v_target = vgic_get_target_vcpu(v, irq + i); + p = irq_to_pending(v, irq + i); + v_target = vgic_get_target_vcpu(d, p); spin_lock_irqsave(&v_target->arch.vgic.lock, flags); - p = irq_to_pending(v_target, irq + i); spin_lock(&p->lock); set_bit(GIC_IRQ_GUEST_ENABLED, &p->status); @@ -561,11 +550,12 @@ out: void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq) { struct vcpu *v; + struct pending_irq *p = irq_to_pending(d->vcpu[0], virq); /* the IRQ needs to be an SPI */ ASSERT(virq >= 32 && virq <= vgic_num_irqs(d)); - v = vgic_get_target_vcpu(d->vcpu[0], virq); + v = vgic_get_target_vcpu(d, p); vgic_vcpu_inject_irq(v, virq); } diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h index fe09fb8..186e6df 100644 --- a/xen/include/asm-arm/vgic.h +++ b/xen/include/asm-arm/vgic.h @@ -76,6 +76,7 @@ struct pending_irq uint8_t lr; uint8_t priority; /* the priority of the currently inflight IRQ */ uint8_t new_priority; /* the priority of newly triggered IRQs */ + uint8_t vcpu_id; /* inflight is used to append instances of pending_irq to * vgic.inflight_irqs */ struct list_head inflight; @@ -103,14 +104,6 @@ struct vgic_irq_rank { spinlock_t lock; /* Covers access to all other members of this struct */ uint8_t index; - - /* - * It's more convenient to store a target VCPU per vIRQ - * than the register ITARGETSR/IROUTER itself. - * Use atomic operations to read/write the vcpu fields to avoid - * taking the rank lock. - */ - uint8_t vcpu[32]; }; struct sgi_target { @@ -301,7 +294,8 @@ enum gic_sgi_mode; extern int domain_vgic_init(struct domain *d, unsigned int nr_spis); extern void domain_vgic_free(struct domain *d); extern int vcpu_vgic_init(struct vcpu *v); -extern struct vcpu *vgic_get_target_vcpu(struct vcpu *v, unsigned int virq); +extern struct vcpu *vgic_get_target_vcpu(struct domain *d, + struct pending_irq *p); extern void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq); extern void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq); extern void vgic_clear_pending_irqs(struct vcpu *v); @@ -321,7 +315,8 @@ extern int vcpu_vgic_free(struct vcpu *v); extern bool vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode, int virq, const struct sgi_target *target); -extern bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq); +extern bool vgic_migrate_irq(struct pending_irq *p, + struct vcpu *old, struct vcpu *new); /* Reserve a specific guest vIRQ */ extern bool vgic_reserve_virq(struct domain *d, unsigned int virq); -- 2.9.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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