diff options
-rw-r--r-- | hw/vfio_pci.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c index 0473ae8..4e9c2dd 100644 --- a/hw/vfio_pci.c +++ b/hw/vfio_pci.c @@ -185,6 +185,21 @@ static void vfio_unmask_intx(VFIODevice *vdev) ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set); } +#ifdef CONFIG_KVM /* Unused outside of CONFIG_KVM code */ +static void vfio_mask_intx(VFIODevice *vdev) +{ + struct vfio_irq_set irq_set = { + .argsz = sizeof(irq_set), + .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_MASK, + .index = VFIO_PCI_INTX_IRQ_INDEX, + .start = 0, + .count = 1, + }; + + ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set); +} +#endif + /* * Disabling BAR mmaping can be slow, but toggling it around INTx can * also be a huge overhead. We try to get the best of both worlds by @@ -248,6 +263,161 @@ static void vfio_eoi(VFIODevice *vdev) vfio_unmask_intx(vdev); } +static void vfio_enable_intx_kvm(VFIODevice *vdev) +{ +#ifdef CONFIG_KVM + struct kvm_irqfd irqfd = { + .fd = event_notifier_get_fd(&vdev->intx.interrupt), + .gsi = vdev->intx.route.irq, + .flags = KVM_IRQFD_FLAG_RESAMPLE, + }; + struct vfio_irq_set *irq_set; + int ret, argsz; + int32_t *pfd; + + if (!kvm_irqchip_in_kernel() || + vdev->intx.route.mode != PCI_INTX_ENABLED || + !kvm_check_extension(kvm_state, KVM_CAP_IRQFD_RESAMPLE)) { + return; + } + + /* Get to a known interrupt state */ + qemu_set_fd_handler(irqfd.fd, NULL, NULL, vdev); + vfio_mask_intx(vdev); + vdev->intx.pending = false; + qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 0); + + /* Get an eventfd for resample/unmask */ + if (event_notifier_init(&vdev->intx.unmask, 0)) { + error_report("vfio: Error: event_notifier_init failed eoi\n"); + goto fail; + } + + /* KVM triggers it, VFIO listens for it */ + irqfd.resamplefd = event_notifier_get_fd(&vdev->intx.unmask); + + if (kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd)) { + error_report("vfio: Error: Failed to setup resample irqfd: %m\n"); + goto fail_irqfd; + } + + argsz = sizeof(*irq_set) + sizeof(*pfd); + + irq_set = g_malloc0(argsz); + irq_set->argsz = argsz; + irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_UNMASK; + irq_set->index = VFIO_PCI_INTX_IRQ_INDEX; + irq_set->start = 0; + irq_set->count = 1; + pfd = (int32_t *)&irq_set->data; + + *pfd = irqfd.resamplefd; + + ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set); + g_free(irq_set); + if (ret) { + error_report("vfio: Error: Failed to setup INTx unmask fd: %m\n"); + goto fail_vfio; + } + + /* Let'em rip */ + vfio_unmask_intx(vdev); + + vdev->intx.kvm_accel = true; + + DPRINTF("%s(%04x:%02x:%02x.%x) KVM INTx accel enabled\n", + __func__, vdev->host.domain, vdev->host.bus, + vdev->host.slot, vdev->host.function); + + return; + +fail_vfio: + irqfd.flags = KVM_IRQFD_FLAG_DEASSIGN; + kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd); +fail_irqfd: + event_notifier_cleanup(&vdev->intx.unmask); +fail: + qemu_set_fd_handler(irqfd.fd, vfio_intx_interrupt, NULL, vdev); + vfio_unmask_intx(vdev); +#endif +} + +static void vfio_disable_intx_kvm(VFIODevice *vdev) +{ +#ifdef CONFIG_KVM + struct kvm_irqfd irqfd = { + .fd = event_notifier_get_fd(&vdev->intx.interrupt), + .gsi = vdev->intx.route.irq, + .flags = KVM_IRQFD_FLAG_DEASSIGN, + }; + + if (!vdev->intx.kvm_accel) { + return; + } + + /* + * Get to a known state, hardware masked, QEMU ready to accept new + * interrupts, QEMU IRQ de-asserted. + */ + vfio_mask_intx(vdev); + vdev->intx.pending = false; + qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 0); + + /* Tell KVM to stop listening for an INTx irqfd */ + if (kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd)) { + error_report("vfio: Error: Failed to disable INTx irqfd: %m\n"); + } + + /* We only need to close the eventfd for VFIO to cleanup the kernel side */ + event_notifier_cleanup(&vdev->intx.unmask); + + /* QEMU starts listening for interrupt events. */ + qemu_set_fd_handler(irqfd.fd, vfio_intx_interrupt, NULL, vdev); + + vdev->intx.kvm_accel = false; + + /* If we've missed an event, let it re-fire through QEMU */ + vfio_unmask_intx(vdev); + + DPRINTF("%s(%04x:%02x:%02x.%x) KVM INTx accel disabled\n", + __func__, vdev->host.domain, vdev->host.bus, + vdev->host.slot, vdev->host.function); +#endif +} + +static void vfio_update_irq(PCIDevice *pdev) +{ + VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev); + PCIINTxRoute route; + + if (vdev->interrupt != VFIO_INT_INTx) { + return; + } + + route = pci_device_route_intx_to_irq(&vdev->pdev, vdev->intx.pin); + + if (!pci_intx_route_changed(&vdev->intx.route, &route)) { + return; /* Nothing changed */ + } + + DPRINTF("%s(%04x:%02x:%02x.%x) IRQ moved %d -> %d\n", __func__, + vdev->host.domain, vdev->host.bus, vdev->host.slot, + vdev->host.function, vdev->intx.route.irq, route.irq); + + vfio_disable_intx_kvm(vdev); + + vdev->intx.route = route; + + if (route.mode != PCI_INTX_ENABLED) { + return; + } + + vfio_enable_intx_kvm(vdev); + + /* Re-enable the interrupt in cased we missed an EOI */ + vfio_eoi(vdev); +} + static int vfio_enable_intx(VFIODevice *vdev) { uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1); @@ -262,6 +432,18 @@ static int vfio_enable_intx(VFIODevice *vdev) vfio_disable_interrupts(vdev); vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */ + +#ifdef CONFIG_KVM + /* + * Only conditional to avoid generating error messages on platforms + * where we won't actually use the result anyway. + */ + if (kvm_check_extension(kvm_state, KVM_CAP_IRQFD_RESAMPLE)) { + vdev->intx.route = pci_device_route_intx_to_irq(&vdev->pdev, + vdev->intx.pin); + } +#endif + ret = event_notifier_init(&vdev->intx.interrupt, 0); if (ret) { error_report("vfio: Error: event_notifier_init failed\n"); @@ -290,6 +472,8 @@ static int vfio_enable_intx(VFIODevice *vdev) return -errno; } + vfio_enable_intx_kvm(vdev); + vdev->interrupt = VFIO_INT_INTx; DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain, @@ -303,6 +487,7 @@ static void vfio_disable_intx(VFIODevice *vdev) int fd; qemu_del_timer(vdev->intx.mmap_timer); + vfio_disable_intx_kvm(vdev); vfio_disable_irqindex(vdev, VFIO_PCI_INTX_IRQ_INDEX); vdev->intx.pending = false; qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 0); @@ -1839,6 +2024,7 @@ static int vfio_initfn(PCIDevice *pdev) if (vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1)) { vdev->intx.mmap_timer = qemu_new_timer_ms(vm_clock, vfio_intx_mmap_enable, vdev); + pci_device_set_intx_routing_notifier(&vdev->pdev, vfio_update_irq); ret = vfio_enable_intx(vdev); if (ret) { goto out_teardown; |