# HG changeset patch # User George Dunlap # Date 1315231215 -3600 # Node ID 32814ad7458dc842a7c588eee13e5c4ee11709a3 # Parent f1349a968a5ac5577d67ad4a3f3490c580dbe264 xen: Add global irq_vector_map option, set if using AMD global intremap tables As mentioned in previous changesets, AMD IOMMU interrupt remapping tables only look at the vector, not the destination id of an interrupt. This means that all IRQs going through the same interrupt remapping table need to *not* share vectors. The irq "vector map" functionality was originally introduced after a patch which disabled global AMD IOMMUs entirely. That patch has since been reverted, meaning that AMD intremap tables can either be per-device or global. This patch therefore introduces a global irq vector map option, and enables it if we're using an AMD IOMMU with a global interrupt remapping table. This patch removes the "irq-perdev-vector-map" boolean command-line optino and replaces it with "irq_vector_map", which can have one of three values: none, global, or per-device. Setting the irq_vector_map to any value will override the default that the AMD code sets. Signed-off-by: George Dunlap diff -r 6fc00d52c179 docs/src/user.tex --- a/docs/src/user.tex Mon Aug 22 16:15:33 2011 +0100 +++ b/docs/src/user.tex Fri Oct 21 15:21:23 2011 -0400 @@ -4197,6 +4197,10 @@ \item [ vcpu\_migration\_delay=$<$minimum\_time$>$] Set minimum time of vcpu migration in microseconds (default 0). This parameter avoids agressive vcpu migration. For example, the linux kernel uses 0.5ms by default. +\item [ irq_vector_map=xxx ] Enable irq vector non-sharing maps. Setting 'global' + will ensure that no IRQs will share vectors. Setting 'per-device' will ensure + that no IRQs from the same device will share vectors. Setting to 'none' will + disable it entirely, overriding any defaults the IOMMU code may set. \end{description} In addition, the following options may be specified on the Xen command diff -r 6fc00d52c179 xen/arch/x86/irq.c --- a/xen/arch/x86/irq.c Mon Aug 22 16:15:33 2011 +0100 +++ b/xen/arch/x86/irq.c Fri Oct 21 15:21:23 2011 -0400 @@ -24,6 +24,8 @@ #include #include +static void parse_irq_vector_map_param(char *s); + /* opt_noirqbalance: If true, software IRQ balancing/affinity is disabled. */ bool_t __read_mostly opt_noirqbalance = 0; boolean_param("noirqbalance", opt_noirqbalance); @@ -33,8 +35,10 @@ integer_param("nr_irqs", nr_irqs); /* This default may be changed by the AMD IOMMU code */ -bool_t __read_mostly opt_irq_perdev_vector_map = 0; -boolean_param("irq-perdev-vector-map", opt_irq_perdev_vector_map); +int __read_mostly opt_irq_vector_map = OPT_IRQ_VECTOR_MAP_DEFAULT; +custom_param("irq_vector_map", parse_irq_vector_map_param); + +vmask_t global_used_vector_map; u8 __read_mostly *irq_vector; struct irq_desc __read_mostly *irq_desc = NULL; @@ -63,6 +67,26 @@ /* irq_ratelimit: the max irq rate allowed in every 10ms, set 0 to disable */ static unsigned int __read_mostly irq_ratelimit_threshold = 10000; integer_param("irq_ratelimit", irq_ratelimit_threshold); + +static void __init parse_irq_vector_map_param(char *s) +{ + char *ss; + + do { + ss = strchr(s, ','); + if ( ss ) + *ss = '\0'; + + if ( !strcmp(s, "none")) + opt_irq_vector_map=OPT_IRQ_VECTOR_MAP_NONE; + else if ( !strcmp(s, "global")) + opt_irq_vector_map=OPT_IRQ_VECTOR_MAP_GLOBAL; + else if ( !strcmp(s, "per-device")) + opt_irq_vector_map=OPT_IRQ_VECTOR_MAP_PERDEV; + + s = ss + 1; + } while ( ss ); +} /* Must be called when irq disabled */ void lock_vector_lock(void) @@ -348,6 +372,41 @@ end_none }; +static vmask_t *irq_get_used_vector_mask(int irq) +{ + vmask_t *ret = NULL; + + if ( opt_irq_vector_map == OPT_IRQ_VECTOR_MAP_GLOBAL ) + { + struct irq_desc *desc = irq_to_desc(irq); + + ret = &global_used_vector_map; + + if ( desc->chip_data->used_vectors ) + { + printk(XENLOG_INFO "%s: Strange, unassigned irq %d already has used_vectors!\n", + __func__, irq); + } + else + { + int vector; + + vector = irq_to_vector(irq); + if ( vector > 0 ) + { + printk(XENLOG_INFO "%s: Strange, irq %d already assigned vector %d!\n", + __func__, irq, vector); + + ASSERT(!test_bit(vector, ret)); + + set_bit(vector, ret); + } + } + } + + return ret; +} + int __assign_irq_vector(int irq, struct irq_cfg *cfg, const cpumask_t *mask) { /* @@ -366,6 +425,7 @@ int cpu, err; unsigned long flags; cpumask_t tmp_mask; + vmask_t *irq_used_vectors = NULL; old_vector = irq_to_vector(irq); if (old_vector) { @@ -380,6 +440,17 @@ return -EAGAIN; err = -ENOSPC; + + /* This is the only place normal IRQs are ever marked + * as "in use". If they're not in use yet, check to see + * if we need to assign a global vector mask. */ + if ( irq_status[irq] == IRQ_USED ) + { + irq_used_vectors = cfg->used_vectors; + } + else + irq_used_vectors = irq_get_used_vector_mask(irq); + for_each_cpu_mask(cpu, *mask) { int new_cpu; int vector, offset; @@ -405,8 +476,8 @@ if (test_bit(vector, used_vectors)) goto next; - if (cfg->used_vectors - && test_bit(vector, cfg->used_vectors) ) + if (irq_used_vectors + && test_bit(vector, irq_used_vectors) ) goto next; for_each_cpu_mask(new_cpu, tmp_mask) @@ -424,15 +495,22 @@ per_cpu(vector_irq, new_cpu)[vector] = irq; cfg->vector = vector; cpus_copy(cfg->cpu_mask, tmp_mask); + + irq_status[irq] = IRQ_USED; + ASSERT((cfg->used_vectors == NULL) + || (cfg->used_vectors == irq_used_vectors)); + cfg->used_vectors = irq_used_vectors; + + if (IO_APIC_IRQ(irq)) + irq_vector[irq] = vector; + if ( cfg->used_vectors ) { ASSERT(!test_bit(vector, cfg->used_vectors)); + set_bit(vector, cfg->used_vectors); } - irq_status[irq] = IRQ_USED; - if (IO_APIC_IRQ(irq)) - irq_vector[irq] = vector; err = 0; local_irq_restore(flags); break; @@ -1521,7 +1599,7 @@ if ( !IS_PRIV(current->domain) && !(IS_PRIV_FOR(current->domain, d) && - irq_access_permitted(current->domain, pirq))) + irq_access_permitted(current->domain, pirq))) return -EPERM; if ( pirq < 0 || pirq >= d->nr_pirqs || irq < 0 || irq >= nr_irqs ) @@ -1569,11 +1647,21 @@ if ( desc->handler != &no_irq_type ) dprintk(XENLOG_G_ERR, "dom%d: irq %d in use\n", - d->domain_id, irq); + d->domain_id, irq); desc->handler = &pci_msi_type; - if ( opt_irq_perdev_vector_map + if ( opt_irq_vector_map == OPT_IRQ_VECTOR_MAP_PERDEV && !desc->chip_data->used_vectors ) + { desc->chip_data->used_vectors = &pdev->info.used_vectors; + if ( desc->chip_data->vector != IRQ_VECTOR_UNASSIGNED ) + { + int vector = desc->chip_data->vector; + ASSERT(!test_bit(vector, desc->chip_data->used_vectors)); + + set_bit(vector, desc->chip_data->used_vectors); + } + } + d->arch.pirq_irq[pirq] = irq; d->arch.irq_pirq[irq] = pirq; setup_msi_irq(pdev, msi_desc, irq); @@ -1584,9 +1672,12 @@ d->arch.pirq_irq[pirq] = irq; d->arch.irq_pirq[irq] = pirq; spin_unlock_irqrestore(&desc->lock, flags); + + if ( opt_irq_vector_map == OPT_IRQ_VECTOR_MAP_PERDEV ) + printk(XENLOG_INFO "Per-device vector maps for GSIs not implemented yet.\n"); } - done: +done: return ret; } diff -r 6fc00d52c179 xen/drivers/passthrough/amd/pci_amd_iommu.c --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c Mon Aug 22 16:15:33 2011 +0100 +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c Fri Oct 21 15:21:23 2011 -0400 @@ -169,18 +169,35 @@ return -ENODEV; } - /* Enable use of per-device vector map unless otherwise - * specified */ - if ( iommu_amd_perdev_vector_map ) + /* + * AMD IOMMUs don't distinguish between vectors destined for + * different cpus when doing interrupt remapping. This means + * that interrupts going through the same intremap table + * can't share the same vector. + * + * If irq_vector_map isn't specified, choose a sensible default: + * - If we're using per-device interemap tables, per-device + * vector non-sharing maps + * - If we're using a global interemap table, global vector + * non-sharing map + */ + if ( opt_irq_vector_map == OPT_IRQ_VECTOR_MAP_DEFAULT ) { - printk("AMD-Vi: Enabling per-device vector maps\n"); - opt_irq_perdev_vector_map=1; + if ( amd_iommu_perdev_intremap ) + { + printk("AMD-Vi: Enabling per-device vector maps\n"); + opt_irq_vector_map = OPT_IRQ_VECTOR_MAP_PERDEV; + } + else + { + printk("AMD-Vi: Enabling global vector map\n"); + opt_irq_vector_map = OPT_IRQ_VECTOR_MAP_GLOBAL; + } } else { - printk("AMD-Vi: WARNING - not enabling per-device vector maps\n"); + printk("AMD-Vi: Not overriding irq_vector_map setting\n"); } - return scan_pci_devices(); } diff -r 6fc00d52c179 xen/include/asm-x86/irq.h --- a/xen/include/asm-x86/irq.h Mon Aug 22 16:15:33 2011 +0100 +++ b/xen/include/asm-x86/irq.h Fri Oct 21 15:21:23 2011 -0400 @@ -44,6 +44,13 @@ extern u8 *irq_vector; extern bool_t opt_noirqbalance; + +#define OPT_IRQ_VECTOR_MAP_DEFAULT 0 /* Do the default thing */ +#define OPT_IRQ_VECTOR_MAP_NONE 1 /* None */ +#define OPT_IRQ_VECTOR_MAP_GLOBAL 2 /* One global vector map (no vector sharing) */ +#define OPT_IRQ_VECTOR_MAP_PERDEV 3 /* Per-device vetor map (no vector sharing w/in a device) */ + +extern int opt_irq_vector_map; /* * Per-cpu current frame pointer - the location of the last exception frame on