On Fri, Feb 8, 2019 at 1:15 AM Vitaly Kuznetsov <vkuzn...@redhat.com> wrote: > > lantianyu1...@gmail.com writes: > > > From: Lan Tianyu <tianyu....@microsoft.com> > > > > On the bare metal, enabling X2APIC mode requires interrupt remapping > > function which helps to deliver irq to cpu with 32-bit APIC ID. > > Hyper-V doesn't provide interrupt remapping function so far and Hyper-V > > MSI protocol already supports to deliver interrupt to the CPU whose > > virtual processor index is more than 255. IO-APIC interrupt still has > > 8-bit APIC ID limitation. > > > > This patch is to add Hyper-V stub IOMMU driver in order to enable > > X2APIC mode successfully in Hyper-V Linux guest. The driver returns X2APIC > > interrupt remapping capability when X2APIC mode is available. Otherwise, > > it creates a Hyper-V irq domain to limit IO-APIC interrupts' affinity > > and make sure cpus assigned with IO-APIC interrupt have 8-bit APIC ID. > > > > Define 24 IO-APIC remapping entries because Hyper-V only expose one > > single IO-APIC and one IO-APIC has 24 pins according IO-APIC spec( > > https://pdos.csail.mit.edu/6.828/2016/readings/ia32/ioapic.pdf). > > > > Signed-off-by: Lan Tianyu <tianyu....@microsoft.com> > > --- > > Change since v2: > > - Improve comment about why save IO-APIC entry in the irq chip data. > > - Some code improvement. > > - Improve statement in the IOMMU Kconfig. > > > > Change since v1: > > - Remove unused pr_fmt > > - Make ioapic_ir_domain as static variable > > - Remove unused variables cfg and entry in the > > hyperv_irq_remapping_alloc() > > - Fix comments > > --- > > drivers/iommu/Kconfig | 8 ++ > > drivers/iommu/Makefile | 1 + > > drivers/iommu/hyperv-iommu.c | 194 > > ++++++++++++++++++++++++++++++++++++++++++ > > drivers/iommu/irq_remapping.c | 3 + > > drivers/iommu/irq_remapping.h | 1 + > > 5 files changed, 207 insertions(+) > > create mode 100644 drivers/iommu/hyperv-iommu.c > > > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > > index 45d7021..6090935 100644 > > --- a/drivers/iommu/Kconfig > > +++ b/drivers/iommu/Kconfig > > @@ -437,4 +437,12 @@ config QCOM_IOMMU > > help > > Support for IOMMU on certain Qualcomm SoCs. > > > > +config HYPERV_IOMMU > > + bool "Hyper-V x2APIC IRQ Handling" > > + depends on HYPERV > > + select IOMMU_API > > + help > > + Stub IOMMU driver to handle IRQs as to allow Hyper-V Linux > > + guests to run with x2APIC mode enabled. > > + > > endif # IOMMU_SUPPORT > > diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile > > index a158a68..8c71a15 100644 > > --- a/drivers/iommu/Makefile > > +++ b/drivers/iommu/Makefile > > @@ -32,3 +32,4 @@ obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o > > obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o > > obj-$(CONFIG_S390_IOMMU) += s390-iommu.o > > obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o > > +obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o > > diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c > > new file mode 100644 > > index 0000000..d8572c5 > > --- /dev/null > > +++ b/drivers/iommu/hyperv-iommu.c > > @@ -0,0 +1,194 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > + > > +/* > > + * Hyper-V stub IOMMU driver. > > + * > > + * Copyright (C) 2019, Microsoft, Inc. > > + * > > + * Author : Lan Tianyu <tianyu....@microsoft.com> > > + */ > > + > > +#include <linux/types.h> > > +#include <linux/interrupt.h> > > +#include <linux/irq.h> > > +#include <linux/iommu.h> > > +#include <linux/module.h> > > + > > +#include <asm/hw_irq.h> > > +#include <asm/io_apic.h> > > +#include <asm/irq_remapping.h> > > +#include <asm/hypervisor.h> > > + > > +#include "irq_remapping.h" > > + > > +#ifdef CONFIG_IRQ_REMAP > > + > > +/* > > + * According 82093AA IO-APIC spec , IO APIC has a 24-entry Interrupt > > + * Redirection Table. Hyper-V exposes one single IO-APIC and so define > > + * 24 IO APIC remmapping entries. > > + */ > > +#define IOAPIC_REMAPPING_ENTRY 24 > > + > > +static cpumask_t ioapic_max_cpumask = { CPU_BITS_NONE }; > > +static struct irq_domain *ioapic_ir_domain; > > + > > +static int hyperv_ir_set_affinity(struct irq_data *data, > > + const struct cpumask *mask, bool force) > > +{ > > + struct irq_data *parent = data->parent_data; > > + struct irq_cfg *cfg = irqd_cfg(data); > > + struct IO_APIC_route_entry *entry; > > + int ret; > > + > > + /* Return error If new irq affinity is out of ioapic_max_cpumask. */ > > + if (!cpumask_subset(mask, &ioapic_max_cpumask)) > > + return -EINVAL; > > + > > + ret = parent->chip->irq_set_affinity(parent, mask, force); > > + if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE) > > + return ret; > > + > > + entry = data->chip_data; > > + entry->dest = cfg->dest_apicid; > > + entry->vector = cfg->vector; > > + send_cleanup_vector(cfg); > > + > > + return 0; > > +} > > + > > +static struct irq_chip hyperv_ir_chip = { > > + .name = "HYPERV-IR", > > + .irq_ack = apic_ack_irq, > > + .irq_set_affinity = hyperv_ir_set_affinity, > > +}; > > + > > +static int hyperv_irq_remapping_alloc(struct irq_domain *domain, > > + unsigned int virq, unsigned int nr_irqs, > > + void *arg) > > +{ > > + struct irq_alloc_info *info = arg; > > + struct irq_data *irq_data; > > + struct irq_desc *desc; > > + int ret = 0; > > + > > + if (!info || info->type != X86_IRQ_ALLOC_TYPE_IOAPIC || nr_irqs > 1) > > + return -EINVAL; > > + > > + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg); > > + if (ret < 0) > > + return ret; > > + > > + irq_data = irq_domain_get_irq_data(domain, virq); > > + if (!irq_data) { > > + irq_domain_free_irqs_common(domain, virq, nr_irqs); > > + return -EINVAL; > > + } > > + > > + irq_data->chip = &hyperv_ir_chip; > > + > > + /* > > + * If there is interrupt remapping function of IOMMU, setting irq > > + * affinity only needs to change IRTE of IOMMU. But Hyper-V doesn't > > + * support interrupt remapping function, setting irq affinity of > > IO-APIC > > + * interrupts still needs to change IO-APIC registers. But ioapic_ > > + * configure_entry() will ignore value of cfg->vector and cfg-> > > + * dest_apicid when IO-APIC's parent irq domain is not the vector > > + * domain.(See ioapic_configure_entry()) In order to setting vector > > + * and dest_apicid to IO-APIC register, IO-APIC entry pointer is saved > > + * in the chip_data and hyperv_irq_remapping_activate()/hyperv_ir_set_ > > + * affinity() set vector and dest_apicid directly into IO-APIC entry. > > + */ > > + irq_data->chip_data = info->ioapic_entry; > > + > > + /* > > + * Hypver-V IO APIC irq affinity should be in the scope of > > + * ioapic_max_cpumask because no irq remapping support. > > + */ > > + desc = irq_data_to_desc(irq_data); > > + cpumask_copy(desc->irq_common_data.affinity, &ioapic_max_cpumask); > > + > > + return 0; > > +} > > + > > +static void hyperv_irq_remapping_free(struct irq_domain *domain, > > + unsigned int virq, unsigned int nr_irqs) > > +{ > > + irq_domain_free_irqs_common(domain, virq, nr_irqs); > > +} > > + > > +static int hyperv_irq_remapping_activate(struct irq_domain *domain, > > + struct irq_data *irq_data, bool reserve) > > +{ > > + struct irq_cfg *cfg = irqd_cfg(irq_data); > > + struct IO_APIC_route_entry *entry = irq_data->chip_data; > > + > > + entry->dest = cfg->dest_apicid; > > + entry->vector = cfg->vector; > > + > > + return 0; > > +} > > + > > +static struct irq_domain_ops hyperv_ir_domain_ops = { > > + .alloc = hyperv_irq_remapping_alloc, > > + .free = hyperv_irq_remapping_free, > > + .activate = hyperv_irq_remapping_activate, > > +}; > > + > > +static int __init hyperv_prepare_irq_remapping(void) > > +{ > > + struct fwnode_handle *fn; > > + int i; > > + > > + if (!hypervisor_is_type(x86_hyper_type) || > > I think this should be > > if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
Sorry for oops and will fix in the next version. Thanks. > > > + !x2apic_supported()) > > + return -ENODEV; > > + > > + fn = irq_domain_alloc_named_id_fwnode("HYPERV-IR", 0); > > + if (!fn) > > + return -ENOMEM; > > + > > + ioapic_ir_domain = > > + irq_domain_create_hierarchy(arch_get_ir_parent_domain(), > > + 0, IOAPIC_REMAPPING_ENTRY, fn, > > + &hyperv_ir_domain_ops, NULL); > > + > > + irq_domain_free_fwnode(fn); > > + > > + /* > > + * Hyper-V doesn't provide irq remapping function for > > + * IO-APIC and so IO-APIC only accepts 8-bit APIC ID. > > + * Cpu's APIC ID is read from ACPI MADT table and APIC IDs > > + * in the MADT table on Hyper-v are sorted monotonic increasingly. > > + * APIC ID reflects cpu topology. There maybe some APIC ID > > + * gaps when cpu number in a socket is not power of two. Prepare > > + * max cpu affinity for IOAPIC irqs. Scan cpu 0-255 and set cpu > > + * into ioapic_max_cpumask if its APIC ID is less than 256. > > + */ > > + for (i = 0; i < 256; i++) > > + if (cpu_physical_id(i) < 256) > > + cpumask_set_cpu(i, &ioapic_max_cpumask); > > + > > + return 0; > > +} > > + > > +static int __init hyperv_enable_irq_remapping(void) > > +{ > > + return IRQ_REMAP_X2APIC_MODE; > > +} > > + > > +static struct irq_domain *hyperv_get_ir_irq_domain(struct irq_alloc_info > > *info) > > +{ > > + if (info->type == X86_IRQ_ALLOC_TYPE_IOAPIC) > > + return ioapic_ir_domain; > > + else > > + return NULL; > > +} > > + > > +struct irq_remap_ops hyperv_irq_remap_ops = { > > + .prepare = hyperv_prepare_irq_remapping, > > + .enable = hyperv_enable_irq_remapping, > > + .get_ir_irq_domain = hyperv_get_ir_irq_domain, > > +}; > > + > > +#endif > > diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c > > index b94ebd4..81cf290 100644 > > --- a/drivers/iommu/irq_remapping.c > > +++ b/drivers/iommu/irq_remapping.c > > @@ -103,6 +103,9 @@ int __init irq_remapping_prepare(void) > > else if (IS_ENABLED(CONFIG_AMD_IOMMU) && > > amd_iommu_irq_ops.prepare() == 0) > > remap_ops = &amd_iommu_irq_ops; > > + else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) && > > + hyperv_irq_remap_ops.prepare() == 0) > > + remap_ops = &hyperv_irq_remap_ops; > > else > > return -ENOSYS; > > > > diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h > > index 0afef6e..f8609e9 100644 > > --- a/drivers/iommu/irq_remapping.h > > +++ b/drivers/iommu/irq_remapping.h > > @@ -64,6 +64,7 @@ struct irq_remap_ops { > > > > extern struct irq_remap_ops intel_irq_remap_ops; > > extern struct irq_remap_ops amd_iommu_irq_ops; > > +extern struct irq_remap_ops hyperv_irq_remap_ops; > > > > #else /* CONFIG_IRQ_REMAP */ > > -- > Vitaly -- Best regards Tianyu Lan