This patch enables irqfd on arm/arm64. Both irqfd and resamplefd are supported. Injection is implemented in vgic.c without routing.
This patch enables CONFIG_HAVE_KVM_EVENTFD and CONFIG_HAVE_KVM_IRQFD. KVM_CAP_IRQFD is now advertised. KVM_CAP_IRQFD_RESAMPLE capability automatically is advertised as soon as CONFIG_HAVE_KVM_IRQFD is set. Irqfd injection is restricted to SPI. The rationale behind not supporting PPI irqfd injection is that any device using a PPI would be a private-to-the-CPU device (timer for instance), so its state would have to be context-switched along with the VCPU and would require in-kernel wiring anyhow. It is not a relevant use case for irqfds. Signed-off-by: Eric Auger <eric.au...@linaro.org> Reviewed-by: Christoffer Dall <christoffer.d...@linaro.org> --- v5 -> v6: - KVM_CAP_IRQFD support depends on vgic_present - add Christoffer's Reviewed-by v4 -> v5: - squash [PATCH v4 3/3] KVM: arm64: add irqfd support into this patch - some rewording in Documentation/virtual/kvm/api.txt and in vgic vgic_process_maintenance unlock comment. - move explanation of why not supporting PPI into commit message - in case of injection before gic readiness, -ENODEV is returned. It is up to the user space to avoid this situation. v3 -> v4: - reword commit message - explain why we unlock the distributor before calling kvm_notify_acked_irq - rename is_assigned_irq into has_notifier - change EOI and injection kvm_debug format string - remove error local variable in kvm_set_irq - Move HAVE_KVM_IRQCHIP unset in a separate patch - handle case were the irqfd injection is attempted before the vgic is ready. in such a case the notifier, if any, is called immediatly - use nr_irqs to test spi is within correct range v2 -> v3: - removal of irq.h from eventfd.c put in a separate patch to increase visibility - properly expose KVM_CAP_IRQFD capability in arm.c - remove CONFIG_HAVE_KVM_IRQCHIP meaningfull only if irq_comm.c is used v1 -> v2: - rebase on 3.17rc1 - move of the dist unlock in process_maintenance - remove of dist lock in __kvm_vgic_sync_hwstate - rewording of the commit message (add resamplefd reference) - remove irq.h --- Documentation/virtual/kvm/api.txt | 6 +++- arch/arm/include/uapi/asm/kvm.h | 3 ++ arch/arm/kvm/Kconfig | 2 ++ arch/arm/kvm/Makefile | 2 +- arch/arm/kvm/arm.c | 5 ++++ arch/arm64/include/uapi/asm/kvm.h | 3 ++ arch/arm64/kvm/Kconfig | 2 ++ arch/arm64/kvm/Makefile | 2 +- virt/kvm/arm/vgic.c | 63 ++++++++++++++++++++++++++++++++++++--- 9 files changed, 81 insertions(+), 7 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 0007fef..5ed8088 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2231,7 +2231,7 @@ into the hash PTE second double word). 4.75 KVM_IRQFD Capability: KVM_CAP_IRQFD -Architectures: x86 s390 +Architectures: x86 s390 arm arm64 Type: vm ioctl Parameters: struct kvm_irqfd (in) Returns: 0 on success, -1 on error @@ -2257,6 +2257,10 @@ Note that closing the resamplefd is not sufficient to disable the irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. +On ARM/ARM64, the gsi field in the kvm_irqfd struct specifies the Shared +Peripheral Interrupt (SPI) index, such that the GIC interrupt ID is +given by gsi + 32. + 4.76 KVM_PPC_ALLOCATE_HTAB Capability: KVM_CAP_PPC_ALLOC_HTAB diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 09ee408..77547bb 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -196,6 +196,9 @@ struct kvm_arch_memory_slot { /* Highest supported SPI, from VGIC_NR_IRQS */ #define KVM_ARM_IRQ_GIC_MAX 127 +/* One single KVM irqchip, ie. the VGIC */ +#define KVM_NR_IRQCHIPS 1 + /* PSCI interface */ #define KVM_PSCI_FN_BASE 0x95c1ba5e #define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n)) diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig index 9f581b1..e519a40 100644 --- a/arch/arm/kvm/Kconfig +++ b/arch/arm/kvm/Kconfig @@ -24,6 +24,7 @@ config KVM select KVM_MMIO select KVM_ARM_HOST depends on ARM_VIRT_EXT && ARM_LPAE + select HAVE_KVM_EVENTFD ---help--- Support hosting virtualized guest machines. You will also need to select one or more of the processor modules below. @@ -55,6 +56,7 @@ config KVM_ARM_MAX_VCPUS config KVM_ARM_VGIC bool "KVM support for Virtual GIC" depends on KVM_ARM_HOST && OF + select HAVE_KVM_IRQFD default y ---help--- Adds support for a hardware assisted, in-kernel GIC emulation. diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile index f7057ed..859db09 100644 --- a/arch/arm/kvm/Makefile +++ b/arch/arm/kvm/Makefile @@ -15,7 +15,7 @@ AFLAGS_init.o := -Wa,-march=armv7-a$(plus_virt) AFLAGS_interrupts.o := -Wa,-march=armv7-a$(plus_virt) KVM := ../../../virt/kvm -kvm-arm-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o +kvm-arm-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o obj-y += kvm-arm.o init.o interrupts.o obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 9c905b4..8f8c1da 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -172,6 +172,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_IRQCHIP: r = vgic_present; break; +#ifdef CONFIG_HAVE_KVM_IRQFD + case KVM_CAP_IRQFD: + r = vgic_present; + break; +#endif case KVM_CAP_DEVICE_CTRL: case KVM_CAP_USER_MEMORY: case KVM_CAP_SYNC_MMU: diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 8e38878..1ed4417 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -182,6 +182,9 @@ struct kvm_arch_memory_slot { /* Highest supported SPI, from VGIC_NR_IRQS */ #define KVM_ARM_IRQ_GIC_MAX 127 +/* One single KVM irqchip, ie. the VGIC */ +#define KVM_NR_IRQCHIPS 1 + /* PSCI interface */ #define KVM_PSCI_FN_BASE 0x95c1ba5e #define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n)) diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 279e1a0..09c25c2 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -26,6 +26,7 @@ config KVM select KVM_ARM_HOST select KVM_ARM_VGIC select KVM_ARM_TIMER + select HAVE_KVM_EVENTFD ---help--- Support hosting virtualized guest machines. @@ -50,6 +51,7 @@ config KVM_ARM_MAX_VCPUS config KVM_ARM_VGIC bool depends on KVM_ARM_HOST && OF + select HAVE_KVM_IRQFD ---help--- Adds support for a hardware assisted, in-kernel GIC emulation. diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 32a0961..2e6b827 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -11,7 +11,7 @@ ARM=../../../arch/arm/kvm obj-$(CONFIG_KVM_ARM_HOST) += kvm.o -kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/arm.o $(ARM)/mmu.o $(ARM)/mmio.o kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/psci.o $(ARM)/perf.o diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 03affc7..d1a5c70 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1447,7 +1447,10 @@ epilog: static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) { u32 status = vgic_get_interrupt_status(vcpu); + struct vgic_dist *dist = &vcpu->kvm->arch.vgic; bool level_pending = false; + struct kvm *kvm = vcpu->kvm; + bool has_notifier; kvm_debug("STATUS = %08x\n", status); @@ -1464,6 +1467,7 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) struct vgic_lr vlr = vgic_get_lr(vcpu, lr); WARN_ON(vgic_irq_is_edge(vcpu, vlr.irq)); + spin_lock(&dist->lock); vgic_irq_clear_queued(vcpu, vlr.irq); WARN_ON(vlr.state & LR_STATE_MASK); vlr.state = 0; @@ -1482,6 +1486,24 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) */ vgic_dist_irq_clear_soft_pend(vcpu, vlr.irq); + /* + * kvm_notify_acked_irq calls kvm_set_irq() + * to reset the IRQ level. Need to release the + * lock for kvm_set_irq to grab it. + */ + spin_unlock(&dist->lock); + + has_notifier = kvm_irq_has_notifier(kvm, 0, + vlr.irq - VGIC_NR_PRIVATE_IRQS); + + if (has_notifier) { + kvm_debug("Guest EOIed vIRQ %d on CPU %d\n", + vlr.irq, vcpu->vcpu_id); + kvm_notify_acked_irq(kvm, 0, + vlr.irq - VGIC_NR_PRIVATE_IRQS); + } + spin_lock(&dist->lock); + /* Any additional pending interrupt? */ if (vgic_dist_irq_get_level(vcpu, vlr.irq)) { vgic_cpu_irq_set(vcpu, vlr.irq); @@ -1491,6 +1513,8 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) vgic_cpu_irq_clear(vcpu, vlr.irq); } + spin_unlock(&dist->lock); + /* * Despite being EOIed, the LR may not have * been marked as empty. @@ -1555,14 +1579,10 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu) { - struct vgic_dist *dist = &vcpu->kvm->arch.vgic; - if (!irqchip_in_kernel(vcpu->kvm)) return; - spin_lock(&dist->lock); __kvm_vgic_sync_hwstate(vcpu); - spin_unlock(&dist->lock); } int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu) @@ -2481,3 +2501,38 @@ out_free_irq: free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus()); return ret; } + +int kvm_irq_map_gsi(struct kvm *kvm, + struct kvm_kernel_irq_routing_entry *entries, + int gsi) +{ + return gsi; +} + +int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin) +{ + return pin; +} + +int kvm_set_irq(struct kvm *kvm, int irq_source_id, + u32 irq, int level, bool line_status) +{ + unsigned int spi = irq + VGIC_NR_PRIVATE_IRQS; + + kvm_debug("irqfd sets vIRQ %d to %d\n", irq, level); + + if (likely(vgic_initialized(kvm))) { + if (spi > kvm->arch.vgic.nr_irqs) + return -EINVAL; + return kvm_vgic_inject_irq(kvm, 0, spi, level); + } else + return -ENODEV; +} + +/* MSI not implemented yet */ +int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, + struct kvm *kvm, int irq_source_id, + int level, bool line_status) +{ + return 0; +} -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html