Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752135AbaKWR6j (ORCPT ); Sun, 23 Nov 2014 12:58:39 -0500 Received: from mail-wg0-f44.google.com ([74.125.82.44]:61227 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752085AbaKWR6g (ORCPT ); Sun, 23 Nov 2014 12:58:36 -0500 From: Eric Auger To: eric.auger@st.com, eric.auger@linaro.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, alex.williamson@redhat.com, joel.schopp@amd.com, kim.phillips@freescale.com, paulus@samba.org, gleb@kernel.org, pbonzini@redhat.com Cc: linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com, ming.lei@canonical.com, feng.wu@intel.com Subject: [PATCH v4 2/3] KVM: arm: add irqfd support Date: Sun, 23 Nov 2014 18:56:59 +0100 Message-Id: <1416765420-12057-3-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1416765420-12057-1-git-send-email-eric.auger@linaro.org> References: <1416765420-12057-1-git-send-email-eric.auger@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch enables irqfd on arm. 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. Signed-off-by: Eric Auger --- 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 - 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. - 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 | 5 ++- arch/arm/include/uapi/asm/kvm.h | 3 ++ arch/arm/kvm/Kconfig | 2 ++ arch/arm/kvm/Makefile | 2 +- arch/arm/kvm/arm.c | 3 ++ virt/kvm/arm/vgic.c | 72 ++++++++++++++++++++++++++++++++++++--- 6 files changed, 81 insertions(+), 6 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 7610eaa..4deccc0 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2206,7 +2206,7 @@ into the hash PTE second double word). 4.75 KVM_IRQFD Capability: KVM_CAP_IRQFD -Architectures: x86 s390 +Architectures: x86 s390 arm Type: vm ioctl Parameters: struct kvm_irqfd (in) Returns: 0 on success, -1 on error @@ -2232,6 +2232,9 @@ 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, the gsi must be a shared peripheral interrupt (SPI). +This means the corresponding programmed GIC interrupt ID is 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 9e193c8..fb75af2 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -172,6 +172,9 @@ 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: +#endif case KVM_CAP_DEVICE_CTRL: case KVM_CAP_USER_MEMORY: case KVM_CAP_SYNC_MMU: diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 3aaca49..3417776 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1446,7 +1446,10 @@ 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); @@ -1463,6 +1466,7 @@ 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; @@ -1481,6 +1485,24 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) */ vgic_dist_irq_clear_soft_pend(vcpu, vlr.irq); + /* + * Unlock the distributor since kvm_notify_acked_irq + * will call kvm_set_irq to reset the IRQ level. + * This latter attempts to grab dist->lock + */ + 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); @@ -1490,6 +1512,8 @@ 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. @@ -1554,14 +1578,10 @@ 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) @@ -2477,3 +2497,47 @@ 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 if (level && kvm_irq_has_notifier(kvm, 0, irq)) { + /* + * any IRQ injected before vgic readiness is + * ignored and the notifier, if any, is called + * immediately as if the virtual IRQ were completed + * by the guest + */ + kvm_notify_acked_irq(kvm, 0, irq); + return -EAGAIN; + } + return 0; +} + +/* 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 linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/