diff --git a/arch/powerpc/kvm/book3s_xive_template.c b/arch/powerpc/kvm/book3s_xive_template.c index c7a5deadd1cc..99c3620b40d9 100644 --- a/arch/powerpc/kvm/book3s_xive_template.c +++ b/arch/powerpc/kvm/book3s_xive_template.c @@ -11,6 +11,9 @@ #define XGLUE(a,b) a##b #define GLUE(a,b) XGLUE(a,b) +/* Dummy interrupt used when taking interrupts out of a queue in H_CPPR */ +#define XICS_DUMMY 1 + static void GLUE(X_PFX,ack_pending)(struct kvmppc_xive_vcpu *xc) { u8 cppr; @@ -205,6 +208,10 @@ static u32 GLUE(X_PFX,scan_interrupts)(struct kvmppc_xive_vcpu *xc, goto skip_ipi; } + /* If it's the dummy interrupt, continue searching */ + if (hirq == XICS_DUMMY) + goto skip_ipi; + /* If fetching, update queue pointers */ if (scan_type == scan_fetch) { q->idx = idx; @@ -385,9 +392,76 @@ static void GLUE(X_PFX,push_pending_to_hw)(struct kvmppc_xive_vcpu *xc) __x_writeb(prio, __x_tima + TM_SPC_SET_OS_PENDING); } +static void GLUE(X_PFX,scan_for_rerouted_irqs)(struct kvmppc_xive *xive, + struct kvmppc_xive_vcpu *xc) +{ + unsigned int prio; + + /* For each priority that is now masked */ + for (prio = xc->cppr; prio < KVMPPC_XIVE_Q_COUNT; prio++) { + struct xive_q *q = &xc->queues[prio]; + struct kvmppc_xive_irq_state *state; + struct kvmppc_xive_src_block *sb; + u32 idx, toggle, entry, irq, hw_num; + struct xive_irq_data *xd; + __be32 *qpage; + u16 src; + + idx = q->idx; + toggle = q->toggle; + qpage = READ_ONCE(q->qpage); + if (!qpage) + continue; + + /* For each interrupt in the queue */ + for (;;) { + entry = be32_to_cpup(qpage + idx); + + /* No more ? */ + if ((entry >> 31) == toggle) + break; + irq = entry & 0x7fffffff; + + /* Skip dummies and IPIs */ + if (irq == XICS_DUMMY || irq == XICS_IPI) + goto next; + sb = kvmppc_xive_find_source(xive, irq, &src); + if (!sb) + goto next; + state = &sb->irq_state[src]; + + /* Has it been rerouted ? */ + if (xc->server_num == state->act_server) + goto next; + + /* + * Allright, it *has* been re-routed, kill it from + * the queue. + */ + qpage[idx] = cpu_to_be32((entry & 0x80000000) | XICS_DUMMY); + + /* Find the HW interrupt */ + kvmppc_xive_select_irq(state, &hw_num, &xd); + + /* If it's not an LSI, set PQ to 11 the EOI will force a resend */ + if (!(xd->flags & XIVE_IRQ_FLAG_LSI)) + GLUE(X_PFX,esb_load)(xd, XIVE_ESB_SET_PQ_11); + + /* EOI the source */ + GLUE(X_PFX,source_eoi)(hw_num, xd); + + next: + idx = (idx + 1) & q->msk; + if (idx == 0) + toggle ^= 1; + } + } +} + X_STATIC int GLUE(X_PFX,h_cppr)(struct kvm_vcpu *vcpu, unsigned long cppr) { struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu; + struct kvmppc_xive *xive = vcpu->kvm->arch.xive; u8 old_cppr; pr_devel("H_CPPR(cppr=%ld)\n", cppr); @@ -407,14 +481,34 @@ X_STATIC int GLUE(X_PFX,h_cppr)(struct kvm_vcpu *vcpu, unsigned long cppr) */ smp_mb(); - /* - * We are masking less, we need to look for pending things - * to deliver and set VP pending bits accordingly to trigger - * a new interrupt otherwise we might miss MFRR changes for - * which we have optimized out sending an IPI signal. - */ - if (cppr > old_cppr) + if (cppr > old_cppr) { + /* + * We are masking less, we need to look for pending things + * to deliver and set VP pending bits accordingly to trigger + * a new interrupt otherwise we might miss MFRR changes for + * which we have optimized out sending an IPI signal. + */ GLUE(X_PFX,push_pending_to_hw)(xc); + } else { + /* + * We are masking more, we need to check the queue for any + * interrupt that has been routed to another CPU, take + * it out (replace it with the dummy) and retrigger it. + * + * This is necessary since those interrupts may otherwise + * never be processed, at least not until this CPU restores + * its CPPR. + * + * This is in theory racy vs. HW adding new interrupts to + * the queue. In practice this works because the interesting + * cases are when the guest has done a set_xive() to move the + * interrupt away, which flushes the xive, followed by the + * target CPU doing a H_CPPR. So any new interrupt coming into + * the queue must still be routed to us and isn't a source + * of concern. + */ + GLUE(X_PFX,scan_for_rerouted_irqs)(xive, xc); + } /* Apply new CPPR */ xc->hw_cppr = cppr;