diff options
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 41 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 | ||||
| -rw-r--r-- | include/linux/kvm.h | 6 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 2 | ||||
| -rw-r--r-- | virt/kvm/assigned-dev.c | 209 |
5 files changed, 230 insertions, 29 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 59a3826..6386f8c 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1169,6 +1169,14 @@ following flags are specified: /* Depends on KVM_CAP_IOMMU */ #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) +/* The following two depend on KVM_CAP_PCI_2_3 */ +#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1) +#define KVM_DEV_ASSIGN_MASK_INTX (1 << 2) + +If KVM_DEV_ASSIGN_PCI_2_3 is set, the kernel will manage legacy INTx interrupts +via the PCI-2.3-compliant device-level mask, thus enable IRQ sharing with other +assigned devices or host devices. KVM_DEV_ASSIGN_MASK_INTX specifies the +guest's view on the INTx mask, see KVM_ASSIGN_SET_INTX_MASK for details. The KVM_DEV_ASSIGN_ENABLE_IOMMU flag is a mandatory option to ensure isolation of the device. Usages not specifying this flag are deprecated. @@ -1441,6 +1449,39 @@ The "num_dirty" field is a performance hint for KVM to determine whether it should skip processing the bitmap and just invalidate everything. It must be set to the number of set bits in the bitmap. +4.60 KVM_ASSIGN_SET_INTX_MASK + +Capability: KVM_CAP_PCI_2_3 +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_assigned_pci_dev (in) +Returns: 0 on success, -1 on error + +Allows userspace to mask PCI INTx interrupts from the assigned device. The +kernel will not deliver INTx interrupts to the guest between setting and +clearing of KVM_ASSIGN_SET_INTX_MASK via this interface. This enables use of +and emulation of PCI 2.3 INTx disable command register behavior. + +This may be used for both PCI 2.3 devices supporting INTx disable natively and +older devices lacking this support. Userspace is responsible for emulating the +read value of the INTx disable bit in the guest visible PCI command register. +When modifying the INTx disable state, userspace should precede updating the +physical device command register by calling this ioctl to inform the kernel of +the new intended INTx mask state. + +Note that the kernel uses the device INTx disable bit to internally manage the +device interrupt state for PCI 2.3 devices. Reads of this register may +therefore not match the expected value. Writes should always use the guest +intended INTx disable value rather than attempting to read-copy-update the +current physical device state. Races between user and kernel updates to the +INTx disable bit are handled lazily in the kernel. It's possible the device +may generate unintended interrupts, but they will not be injected into the +guest. + +See KVM_ASSIGN_DEV_IRQ for the data structure. The target device is specified +by assigned_dev_id. In the flags field, only KVM_DEV_ASSIGN_MASK_INTX is +evaluated. + 4.62 KVM_CREATE_SPAPR_TCE Capability: KVM_CAP_SPAPR_TCE diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9477dc6..6866083 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2143,6 +2143,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_XSAVE: case KVM_CAP_ASYNC_PF: case KVM_CAP_GET_TSC_KHZ: + case KVM_CAP_PCI_2_3: r = 1; break; case KVM_CAP_COALESCED_MMIO: diff --git a/include/linux/kvm.h b/include/linux/kvm.h index acbe429..6c322a9 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -588,6 +588,7 @@ struct kvm_ppc_pvinfo { #define KVM_CAP_TSC_DEADLINE_TIMER 72 #define KVM_CAP_S390_UCONTROL 73 #define KVM_CAP_SYNC_REGS 74 +#define KVM_CAP_PCI_2_3 75 #ifdef KVM_CAP_IRQ_ROUTING @@ -784,6 +785,9 @@ struct kvm_s390_ucas_mapping { /* Available with KVM_CAP_TSC_CONTROL */ #define KVM_SET_TSC_KHZ _IO(KVMIO, 0xa2) #define KVM_GET_TSC_KHZ _IO(KVMIO, 0xa3) +/* Available with KVM_CAP_PCI_2_3 */ +#define KVM_ASSIGN_SET_INTX_MASK _IOW(KVMIO, 0xa4, \ + struct kvm_assigned_pci_dev) /* * ioctls for vcpu fds @@ -857,6 +861,8 @@ struct kvm_s390_ucas_mapping { #define KVM_SET_ONE_REG _IOW(KVMIO, 0xac, struct kvm_one_reg) #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) +#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1) +#define KVM_DEV_ASSIGN_MASK_INTX (1 << 2) struct kvm_assigned_pci_dev { __u32 assigned_dev_id; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index e42d85a..ec171c1 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -546,6 +546,7 @@ struct kvm_assigned_dev_kernel { unsigned int entries_nr; int host_irq; bool host_irq_disabled; + bool pci_2_3; struct msix_entry *host_msix_entries; int guest_irq; struct msix_entry *guest_msix_entries; @@ -555,6 +556,7 @@ struct kvm_assigned_dev_kernel { struct pci_dev *dev; struct kvm *kvm; spinlock_t intx_lock; + struct mutex intx_mask_lock; char irq_name[32]; struct pci_saved_state *pci_saved_state; }; diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c index ece8061..08e0571 100644 --- a/virt/kvm/assigned-dev.c +++ b/virt/kvm/assigned-dev.c @@ -55,22 +55,66 @@ static int find_index_from_host_irq(struct kvm_assigned_dev_kernel return index; } -static irqreturn_t kvm_assigned_dev_thread(int irq, void *dev_id) +static irqreturn_t kvm_assigned_dev_intx(int irq, void *dev_id) { struct kvm_assigned_dev_kernel *assigned_dev = dev_id; + int ret; - if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_INTX) { - spin_lock(&assigned_dev->intx_lock); + spin_lock(&assigned_dev->intx_lock); + if (pci_check_and_mask_intx(assigned_dev->dev)) { + assigned_dev->host_irq_disabled = true; + ret = IRQ_WAKE_THREAD; + } else + ret = IRQ_NONE; + spin_unlock(&assigned_dev->intx_lock); + + return ret; +} + +static void +kvm_assigned_dev_raise_guest_irq(struct kvm_assigned_dev_kernel *assigned_dev, + int vector) +{ + if (unlikely(assigned_dev->irq_requested_type & + KVM_DEV_IRQ_GUEST_INTX)) { + mutex_lock(&assigned_dev->intx_mask_lock); + if (!(assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX)) + kvm_set_irq(assigned_dev->kvm, + assigned_dev->irq_source_id, vector, 1); + mutex_unlock(&assigned_dev->intx_mask_lock); + } else + kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, + vector, 1); +} + +static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id) +{ + struct kvm_assigned_dev_kernel *assigned_dev = dev_id; + + if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) { + spin_lock_irq(&assigned_dev->intx_lock); disable_irq_nosync(irq); assigned_dev->host_irq_disabled = true; - spin_unlock(&assigned_dev->intx_lock); + spin_unlock_irq(&assigned_dev->intx_lock); } - kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, - assigned_dev->guest_irq, 1); + kvm_assigned_dev_raise_guest_irq(assigned_dev, + assigned_dev->guest_irq); + + return IRQ_HANDLED; +} + +#ifdef __KVM_HAVE_MSI +static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id) +{ + struct kvm_assigned_dev_kernel *assigned_dev = dev_id; + + kvm_assigned_dev_raise_guest_irq(assigned_dev, + assigned_dev->guest_irq); return IRQ_HANDLED; } +#endif #ifdef __KVM_HAVE_MSIX static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id) @@ -81,8 +125,7 @@ static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id) if (index >= 0) { vector = assigned_dev->guest_msix_entries[index].vector; - kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, - vector, 1); + kvm_assigned_dev_raise_guest_irq(assigned_dev, vector); } return IRQ_HANDLED; @@ -98,15 +141,31 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian) kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0); - /* The guest irq may be shared so this ack may be - * from another device. - */ - spin_lock(&dev->intx_lock); - if (dev->host_irq_disabled) { - enable_irq(dev->host_irq); - dev->host_irq_disabled = false; + mutex_lock(&dev->intx_mask_lock); + + if (!(dev->flags & KVM_DEV_ASSIGN_MASK_INTX)) { + bool reassert = false; + + spin_lock_irq(&dev->intx_lock); + /* + * The guest IRQ may be shared so this ack can come from an + * IRQ for another guest device. + */ + if (dev->host_irq_disabled) { + if (!(dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) + enable_irq(dev->host_irq); + else if (!pci_check_and_unmask_intx(dev->dev)) + reassert = true; + dev->host_irq_disabled = reassert; + } + spin_unlock_irq(&dev->intx_lock); + + if (reassert) + kvm_set_irq(dev->kvm, dev->irq_source_id, + dev->guest_irq, 1); } - spin_unlock(&dev->intx_lock); + + mutex_unlock(&dev->intx_mask_lock); } static void deassign_guest_irq(struct kvm *kvm, @@ -154,7 +213,15 @@ static void deassign_host_irq(struct kvm *kvm, pci_disable_msix(assigned_dev->dev); } else { /* Deal with MSI and INTx */ - disable_irq(assigned_dev->host_irq); + if ((assigned_dev->irq_requested_type & + KVM_DEV_IRQ_HOST_INTX) && + (assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) { + spin_lock_irq(&assigned_dev->intx_lock); + pci_intx(assigned_dev->dev, false); + spin_unlock_irq(&assigned_dev->intx_lock); + synchronize_irq(assigned_dev->host_irq); + } else + disable_irq(assigned_dev->host_irq); free_irq(assigned_dev->host_irq, assigned_dev); @@ -235,15 +302,34 @@ void kvm_free_all_assigned_devices(struct kvm *kvm) static int assigned_device_enable_host_intx(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev) { + irq_handler_t irq_handler; + unsigned long flags; + dev->host_irq = dev->dev->irq; - /* Even though this is PCI, we don't want to use shared - * interrupts. Sharing host devices with guest-assigned devices - * on the same interrupt line is not a happy situation: there - * are going to be long delays in accepting, acking, etc. + + /* + * We can only share the IRQ line with other host devices if we are + * able to disable the IRQ source at device-level - independently of + * the guest driver. Otherwise host devices may suffer from unbounded + * IRQ latencies when the guest keeps the line asserted. */ - if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread, - IRQF_ONESHOT, dev->irq_name, dev)) + if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) { + irq_handler = kvm_assigned_dev_intx; + flags = IRQF_SHARED; + } else { + irq_handler = NULL; + flags = IRQF_ONESHOT; + } + if (request_threaded_irq(dev->host_irq, irq_handler, + kvm_assigned_dev_thread_intx, flags, + dev->irq_name, dev)) return -EIO; + + if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) { + spin_lock_irq(&dev->intx_lock); + pci_intx(dev->dev, true); + spin_unlock_irq(&dev->intx_lock); + } return 0; } @@ -260,8 +346,9 @@ static int assigned_device_enable_host_msi(struct kvm *kvm, } dev->host_irq = dev->dev->irq; - if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread, - 0, dev->irq_name, dev)) { + if (request_threaded_irq(dev->host_irq, NULL, + kvm_assigned_dev_thread_msi, 0, + dev->irq_name, dev)) { pci_disable_msi(dev->dev); return -EIO; } @@ -319,7 +406,6 @@ static int assigned_device_enable_guest_msi(struct kvm *kvm, { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = -1; - dev->host_irq_disabled = false; return 0; } #endif @@ -331,7 +417,6 @@ static int assigned_device_enable_guest_msix(struct kvm *kvm, { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = -1; - dev->host_irq_disabled = false; return 0; } #endif @@ -365,6 +450,7 @@ static int assign_host_irq(struct kvm *kvm, default: r = -EINVAL; } + dev->host_irq_disabled = false; if (!r) dev->irq_requested_type |= host_irq_type; @@ -466,6 +552,7 @@ static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm, { int r = -ENODEV; struct kvm_assigned_dev_kernel *match; + unsigned long irq_type; mutex_lock(&kvm->lock); @@ -474,7 +561,9 @@ static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm, if (!match) goto out; - r = kvm_deassign_irq(kvm, match, assigned_irq->flags); + irq_type = assigned_irq->flags & (KVM_DEV_IRQ_HOST_MASK | + KVM_DEV_IRQ_GUEST_MASK); + r = kvm_deassign_irq(kvm, match, irq_type); out: mutex_unlock(&kvm->lock); return r; @@ -607,6 +696,10 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, if (!match->pci_saved_state) printk(KERN_DEBUG "%s: Couldn't store %s saved state\n", __func__, dev_name(&dev->dev)); + + if (!pci_intx_mask_supported(dev)) + assigned_dev->flags &= ~KVM_DEV_ASSIGN_PCI_2_3; + match->assigned_dev_id = assigned_dev->assigned_dev_id; match->host_segnr = assigned_dev->segnr; match->host_busnr = assigned_dev->busnr; @@ -614,6 +707,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, match->flags = assigned_dev->flags; match->dev = dev; spin_lock_init(&match->intx_lock); + mutex_init(&match->intx_mask_lock); match->irq_source_id = -1; match->kvm = kvm; match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq; @@ -759,6 +853,55 @@ msix_entry_out: } #endif +static int kvm_vm_ioctl_set_pci_irq_mask(struct kvm *kvm, + struct kvm_assigned_pci_dev *assigned_dev) +{ + int r = 0; + struct kvm_assigned_dev_kernel *match; + + mutex_lock(&kvm->lock); + + match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, + assigned_dev->assigned_dev_id); + if (!match) { + r = -ENODEV; + goto out; + } + + mutex_lock(&match->intx_mask_lock); + + match->flags &= ~KVM_DEV_ASSIGN_MASK_INTX; + match->flags |= assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX; + + if (match->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) { + if (assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX) { + kvm_set_irq(match->kvm, match->irq_source_id, + match->guest_irq, 0); + /* + * Masking at hardware-level is performed on demand, + * i.e. when an IRQ actually arrives at the host. + */ + } else if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) { + /* + * Unmask the IRQ line if required. Unmasking at + * device level will be performed by user space. + */ + spin_lock_irq(&match->intx_lock); + if (match->host_irq_disabled) { + enable_irq(match->host_irq); + match->host_irq_disabled = false; + } + spin_unlock_irq(&match->intx_lock); + } + } + + mutex_unlock(&match->intx_mask_lock); + +out: + mutex_unlock(&kvm->lock); + return r; +} + long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl, unsigned long arg) { @@ -866,6 +1009,15 @@ long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl, break; } #endif + case KVM_ASSIGN_SET_INTX_MASK: { + struct kvm_assigned_pci_dev assigned_dev; + + r = -EFAULT; + if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev)) + goto out; + r = kvm_vm_ioctl_set_pci_irq_mask(kvm, &assigned_dev); + break; + } default: r = -ENOTTY; break; @@ -873,4 +1025,3 @@ long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl, out: return r; } - |
