diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h index e4016985764e..efb0e597b272 100644 --- a/arch/powerpc/include/asm/xive.h +++ b/arch/powerpc/include/asm/xive.h @@ -46,7 +46,15 @@ struct xive_irq_data { /* Setup/used by frontend */ int target; + /* + * saved_p means that there is a queue entry for this interrupt + * in some CPU's queue (not including guest vcpu queues), even + * if P is not set in the source ESB. + * stale_p means that there is no queue entry for this interrupt + * in some CPU's queue, even if P is set in the source ESB. + */ bool saved_p; + bool stale_p; }; #define XIVE_IRQ_FLAG_STORE_EOI 0x01 #define XIVE_IRQ_FLAG_LSI 0x02 diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c index 586867e46e51..591bfb4bfd0f 100644 --- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -166,6 +166,9 @@ static irqreturn_t xive_esc_irq(int irq, void *data) */ vcpu->arch.xive_esc_on = false; + /* This orders xive_esc_on = false vs. subsequent stale_p = true */ + smp_wmb(); /* goes with smp_mb() in cleanup_single_escalation */ + return IRQ_HANDLED; } @@ -1119,6 +1122,31 @@ void kvmppc_xive_disable_vcpu_interrupts(struct kvm_vcpu *vcpu) vcpu->arch.xive_esc_raddr = 0; } +/* + * In single escalation mode, the escalation interrupt is marked so + * that EOI doesn't re-enable it, but just sets the stale_p flag to + * indicate that the P bit has already been dealt with. However, the + * assembly code that enters the guest sets PQ to 00 without clearing + * stale_p (because it has no easy way to address it). Hence we have + * to adjust stale_p before shutting down the interrupt. + */ +void xive_cleanup_single_escalation(struct kvm_vcpu *vcpu, + struct kvmppc_xive_vcpu *xc, int irq) +{ + struct irq_data *d = irq_get_irq_data(irq); + struct xive_irq_data *xd = irq_data_get_irq_handler_data(d); + + /* + * This slightly odd sequence gives the right result + * (i.e. stale_p set if xive_esc_on is false) even if + * we race with xive_esc_irq() and xive_irq_eoi(). + */ + xd->stale_p = false; + smp_mb(); /* paired with smb_wmb in xive_esc_irq */ + if (!vcpu->arch.xive_esc_on) + xd->stale_p = true; +} + void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu) { struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu; @@ -1143,6 +1171,9 @@ void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu) /* Free escalations */ for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) { if (xc->esc_virq[i]) { + if (xc->xive->single_escalation) + xive_cleanup_single_escalation(vcpu, xc, + xc->esc_virq[i]); free_irq(xc->esc_virq[i], vcpu); irq_dispose_mapping(xc->esc_virq[i]); kfree(xc->esc_virq_names[i]); diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h index 50494d0ee375..955b820ffd6d 100644 --- a/arch/powerpc/kvm/book3s_xive.h +++ b/arch/powerpc/kvm/book3s_xive.h @@ -282,6 +282,8 @@ int kvmppc_xive_select_target(struct kvm *kvm, u32 *server, u8 prio); int kvmppc_xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio, bool single_escalation); struct kvmppc_xive *kvmppc_xive_get_device(struct kvm *kvm, u32 type); +void xive_cleanup_single_escalation(struct kvm_vcpu *vcpu, + struct kvmppc_xive_vcpu *xc, int irq); #endif /* CONFIG_KVM_XICS */ #endif /* _KVM_PPC_BOOK3S_XICS_H */ diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c index 11b91b46fc39..f0cab43e6f4b 100644 --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -71,6 +71,9 @@ void kvmppc_xive_native_cleanup_vcpu(struct kvm_vcpu *vcpu) for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) { /* Free the escalation irq */ if (xc->esc_virq[i]) { + if (xc->xive->single_escalation) + xive_cleanup_single_escalation(vcpu, xc, + xc->esc_virq[i]); free_irq(xc->esc_virq[i], vcpu); irq_dispose_mapping(xc->esc_virq[i]); kfree(xc->esc_virq_names[i]); diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c index 1cdb39575eae..be86fce1a84e 100644 --- a/arch/powerpc/sysdev/xive/common.c +++ b/arch/powerpc/sysdev/xive/common.c @@ -135,7 +135,7 @@ static u32 xive_read_eq(struct xive_q *q, bool just_peek) static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek) { u32 irq = 0; - u8 prio; + u8 prio = 0; /* Find highest pending priority */ while (xc->pending_prio != 0) { @@ -148,8 +148,19 @@ static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek) irq = xive_read_eq(&xc->queue[prio], just_peek); /* Found something ? That's it */ - if (irq) - break; + if (irq) { + if (just_peek || irq_to_desc(irq)) + break; + /* + * We should never get here; if we do then we must + * have failed to synchronize the interrupt properly + * when shutting it down. + */ + pr_crit("xive: got interrupt %d without descriptor, dropping\n", + irq); + WARN_ON(1); + continue; + } /* Clear pending bits */ xc->pending_prio &= ~(1 << prio); @@ -307,6 +318,7 @@ static void xive_do_queue_eoi(struct xive_cpu *xc) */ static void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd) { + xd->stale_p = false; /* If the XIVE supports the new "store EOI facility, use it */ if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI) xive_esb_write(xd, XIVE_ESB_STORE_EOI, 0); @@ -350,7 +362,7 @@ static void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd) } } -/* irq_chip eoi callback */ +/* irq_chip eoi callback, called with irq descriptor lock held */ static void xive_irq_eoi(struct irq_data *d) { struct xive_irq_data *xd = irq_data_get_irq_handler_data(d); @@ -366,6 +378,8 @@ static void xive_irq_eoi(struct irq_data *d) if (!irqd_irq_disabled(d) && !irqd_is_forwarded_to_vcpu(d) && !(xd->flags & XIVE_IRQ_NO_EOI)) xive_do_source_eoi(irqd_to_hwirq(d), xd); + else + xd->stale_p = true; /* * Clear saved_p to indicate that it's no longer occupying @@ -397,11 +411,16 @@ static void xive_do_source_set_mask(struct xive_irq_data *xd, */ if (mask) { val = xive_esb_read(xd, XIVE_ESB_SET_PQ_01); - xd->saved_p = !!(val & XIVE_ESB_VAL_P); - } else if (xd->saved_p) + if (!xd->stale_p && !!(val & XIVE_ESB_VAL_P)) + xd->saved_p = true; + xd->stale_p = false; + } else if (xd->saved_p) { xive_esb_read(xd, XIVE_ESB_SET_PQ_10); - else + xd->saved_p = false; + } else { xive_esb_read(xd, XIVE_ESB_SET_PQ_00); + xd->stale_p = false; + } } /* @@ -541,6 +560,8 @@ static unsigned int xive_irq_startup(struct irq_data *d) unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); int target, rc; + xd->saved_p = false; + xd->stale_p = false; pr_devel("xive_irq_startup: irq %d [0x%x] data @%p\n", d->irq, hw_irq, d); @@ -587,6 +608,7 @@ static unsigned int xive_irq_startup(struct irq_data *d) return 0; } +/* called with irq descriptor lock held */ static void xive_irq_shutdown(struct irq_data *d) { struct xive_irq_data *xd = irq_data_get_irq_handler_data(d); @@ -601,16 +623,6 @@ static void xive_irq_shutdown(struct irq_data *d) /* Mask the interrupt at the source */ xive_do_source_set_mask(xd, true); - /* - * The above may have set saved_p. We clear it otherwise it - * will prevent re-enabling later on. It is ok to forget the - * fact that the interrupt might be in a queue because we are - * accounting that already in xive_dec_target_count() and will - * be re-routing it to a new queue with proper accounting when - * it's started up again - */ - xd->saved_p = false; - /* * Mask the interrupt in HW in the IVT/EAS and set the number * to be the "bad" IRQ number @@ -797,6 +809,10 @@ static int xive_irq_retrigger(struct irq_data *d) return 1; } +/* + * Caller holds the irq descriptor lock, so this won't be called + * concurrently with xive_get_irqchip_state on the same interrupt. + */ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state) { struct xive_irq_data *xd = irq_data_get_irq_handler_data(d); @@ -820,6 +836,10 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state) /* Set it to PQ=10 state to prevent further sends */ pq = xive_esb_read(xd, XIVE_ESB_SET_PQ_10); + if (!xd->stale_p) { + xd->saved_p = !!(pq & XIVE_ESB_VAL_P); + xd->stale_p = !xd->saved_p; + } /* No target ? nothing to do */ if (xd->target == XIVE_INVALID_TARGET) { @@ -827,7 +847,7 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state) * An untargetted interrupt should have been * also masked at the source */ - WARN_ON(pq & 2); + WARN_ON(xd->saved_p); return 0; } @@ -847,9 +867,8 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state) * This saved_p is cleared by the host EOI, when we know * for sure the queue slot is no longer in use. */ - if (pq & 2) { - pq = xive_esb_read(xd, XIVE_ESB_SET_PQ_11); - xd->saved_p = true; + if (xd->saved_p) { + xive_esb_read(xd, XIVE_ESB_SET_PQ_11); /* * Sync the XIVE source HW to ensure the interrupt @@ -862,8 +881,7 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state) */ if (xive_ops->sync_source) xive_ops->sync_source(hw_irq); - } else - xd->saved_p = false; + } } else { irqd_clr_forwarded_to_vcpu(d); @@ -914,6 +932,23 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state) return 0; } +/* Called with irq descriptor lock held. */ +static int xive_get_irqchip_state(struct irq_data *data, + enum irqchip_irq_state which, bool *state) +{ + struct xive_irq_data *xd = irq_data_get_irq_handler_data(data); + + switch (which) { + case IRQCHIP_STATE_ACTIVE: + *state = !xd->stale_p && + (xd->saved_p || + !!(xive_esb_read(xd, XIVE_ESB_GET) & XIVE_ESB_VAL_P)); + return 0; + default: + return -EINVAL; + } +} + static struct irq_chip xive_irq_chip = { .name = "XIVE-IRQ", .irq_startup = xive_irq_startup, @@ -925,6 +960,7 @@ static struct irq_chip xive_irq_chip = { .irq_set_type = xive_irq_set_type, .irq_retrigger = xive_irq_retrigger, .irq_set_vcpu_affinity = xive_irq_set_vcpu_affinity, + .irq_get_irqchip_state = xive_get_irqchip_state, }; bool is_xive_irq(struct irq_chip *chip) @@ -1337,6 +1373,11 @@ static void xive_flush_cpu_queue(unsigned int cpu, struct xive_cpu *xc) raw_spin_lock(&desc->lock); xd = irq_desc_get_handler_data(desc); + /* + * Clear saved_p to indicate that it's no longer pending + */ + xd->saved_p = false; + /* * For LSIs, we EOI, this will cause a resend if it's * still asserted. Otherwise do an MSI retrigger.