From 7c0639a3af697d4ae7a5db4d2ecc09eed43cad35 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 20:47:50 +0200 Subject: Merging upstream version 6.7.12. Signed-off-by: Daniel Baumann --- drivers/vfio/pci/vfio_pci_intrs.c | 186 +++++++++++++++++++++++--------------- 1 file changed, 111 insertions(+), 75 deletions(-) (limited to 'drivers/vfio/pci/vfio_pci_intrs.c') diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index cbb4bcbfbf..fb5392b749 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -90,22 +90,28 @@ static void vfio_send_intx_eventfd(void *opaque, void *unused) if (likely(is_intx(vdev) && !vdev->virq_disabled)) { struct vfio_pci_irq_ctx *ctx; + struct eventfd_ctx *trigger; ctx = vfio_irq_ctx_get(vdev, 0); if (WARN_ON_ONCE(!ctx)) return; - eventfd_signal(ctx->trigger, 1); + + trigger = READ_ONCE(ctx->trigger); + if (likely(trigger)) + eventfd_signal(trigger); } } /* Returns true if the INTx vfio_pci_irq_ctx.masked value is changed. */ -bool vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) +static bool __vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) { struct pci_dev *pdev = vdev->pdev; struct vfio_pci_irq_ctx *ctx; unsigned long flags; bool masked_changed = false; + lockdep_assert_held(&vdev->igate); + spin_lock_irqsave(&vdev->irqlock, flags); /* @@ -143,6 +149,17 @@ out_unlock: return masked_changed; } +bool vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) +{ + bool mask_changed; + + mutex_lock(&vdev->igate); + mask_changed = __vfio_pci_intx_mask(vdev); + mutex_unlock(&vdev->igate); + + return mask_changed; +} + /* * If this is triggered by an eventfd, we can't call eventfd_signal * or else we'll deadlock on the eventfd wait queue. Return >0 when @@ -194,12 +211,21 @@ out_unlock: return ret; } -void vfio_pci_intx_unmask(struct vfio_pci_core_device *vdev) +static void __vfio_pci_intx_unmask(struct vfio_pci_core_device *vdev) { + lockdep_assert_held(&vdev->igate); + if (vfio_pci_intx_unmask_handler(vdev, NULL) > 0) vfio_send_intx_eventfd(vdev, NULL); } +void vfio_pci_intx_unmask(struct vfio_pci_core_device *vdev) +{ + mutex_lock(&vdev->igate); + __vfio_pci_intx_unmask(vdev); + mutex_unlock(&vdev->igate); +} + static irqreturn_t vfio_intx_handler(int irq, void *dev_id) { struct vfio_pci_core_device *vdev = dev_id; @@ -231,97 +257,100 @@ static irqreturn_t vfio_intx_handler(int irq, void *dev_id) return ret; } -static int vfio_intx_enable(struct vfio_pci_core_device *vdev) +static int vfio_intx_enable(struct vfio_pci_core_device *vdev, + struct eventfd_ctx *trigger) { + struct pci_dev *pdev = vdev->pdev; struct vfio_pci_irq_ctx *ctx; + unsigned long irqflags; + char *name; + int ret; if (!is_irq_none(vdev)) return -EINVAL; - if (!vdev->pdev->irq) + if (!pdev->irq) return -ENODEV; + name = kasprintf(GFP_KERNEL_ACCOUNT, "vfio-intx(%s)", pci_name(pdev)); + if (!name) + return -ENOMEM; + ctx = vfio_irq_ctx_alloc(vdev, 0); if (!ctx) return -ENOMEM; + ctx->name = name; + ctx->trigger = trigger; + /* - * If the virtual interrupt is masked, restore it. Devices - * supporting DisINTx can be masked at the hardware level - * here, non-PCI-2.3 devices will have to wait until the - * interrupt is enabled. + * Fill the initial masked state based on virq_disabled. After + * enable, changing the DisINTx bit in vconfig directly changes INTx + * masking. igate prevents races during setup, once running masked + * is protected via irqlock. + * + * Devices supporting DisINTx also reflect the current mask state in + * the physical DisINTx bit, which is not affected during IRQ setup. + * + * Devices without DisINTx support require an exclusive interrupt. + * IRQ masking is performed at the IRQ chip. Again, igate protects + * against races during setup and IRQ handlers and irqfds are not + * yet active, therefore masked is stable and can be used to + * conditionally auto-enable the IRQ. + * + * irq_type must be stable while the IRQ handler is registered, + * therefore it must be set before request_irq(). */ ctx->masked = vdev->virq_disabled; - if (vdev->pci_2_3) - pci_intx(vdev->pdev, !ctx->masked); + if (vdev->pci_2_3) { + pci_intx(pdev, !ctx->masked); + irqflags = IRQF_SHARED; + } else { + irqflags = ctx->masked ? IRQF_NO_AUTOEN : 0; + } vdev->irq_type = VFIO_PCI_INTX_IRQ_INDEX; + ret = request_irq(pdev->irq, vfio_intx_handler, + irqflags, ctx->name, vdev); + if (ret) { + vdev->irq_type = VFIO_PCI_NUM_IRQS; + kfree(name); + vfio_irq_ctx_free(vdev, ctx, 0); + return ret; + } + return 0; } -static int vfio_intx_set_signal(struct vfio_pci_core_device *vdev, int fd) +static int vfio_intx_set_signal(struct vfio_pci_core_device *vdev, + struct eventfd_ctx *trigger) { struct pci_dev *pdev = vdev->pdev; - unsigned long irqflags = IRQF_SHARED; struct vfio_pci_irq_ctx *ctx; - struct eventfd_ctx *trigger; - unsigned long flags; - int ret; + struct eventfd_ctx *old; ctx = vfio_irq_ctx_get(vdev, 0); if (WARN_ON_ONCE(!ctx)) return -EINVAL; - if (ctx->trigger) { - free_irq(pdev->irq, vdev); - kfree(ctx->name); - eventfd_ctx_put(ctx->trigger); - ctx->trigger = NULL; - } - - if (fd < 0) /* Disable only */ - return 0; + old = ctx->trigger; - ctx->name = kasprintf(GFP_KERNEL_ACCOUNT, "vfio-intx(%s)", - pci_name(pdev)); - if (!ctx->name) - return -ENOMEM; + WRITE_ONCE(ctx->trigger, trigger); - trigger = eventfd_ctx_fdget(fd); - if (IS_ERR(trigger)) { - kfree(ctx->name); - return PTR_ERR(trigger); + /* Releasing an old ctx requires synchronizing in-flight users */ + if (old) { + synchronize_irq(pdev->irq); + vfio_virqfd_flush_thread(&ctx->unmask); + eventfd_ctx_put(old); } - ctx->trigger = trigger; - - if (!vdev->pci_2_3) - irqflags = 0; - - ret = request_irq(pdev->irq, vfio_intx_handler, - irqflags, ctx->name, vdev); - if (ret) { - ctx->trigger = NULL; - kfree(ctx->name); - eventfd_ctx_put(trigger); - return ret; - } - - /* - * INTx disable will stick across the new irq setup, - * disable_irq won't. - */ - spin_lock_irqsave(&vdev->irqlock, flags); - if (!vdev->pci_2_3 && ctx->masked) - disable_irq_nosync(pdev->irq); - spin_unlock_irqrestore(&vdev->irqlock, flags); - return 0; } static void vfio_intx_disable(struct vfio_pci_core_device *vdev) { + struct pci_dev *pdev = vdev->pdev; struct vfio_pci_irq_ctx *ctx; ctx = vfio_irq_ctx_get(vdev, 0); @@ -329,10 +358,13 @@ static void vfio_intx_disable(struct vfio_pci_core_device *vdev) if (ctx) { vfio_virqfd_disable(&ctx->unmask); vfio_virqfd_disable(&ctx->mask); + free_irq(pdev->irq, vdev); + if (ctx->trigger) + eventfd_ctx_put(ctx->trigger); + kfree(ctx->name); + vfio_irq_ctx_free(vdev, ctx, 0); } - vfio_intx_set_signal(vdev, -1); vdev->irq_type = VFIO_PCI_NUM_IRQS; - vfio_irq_ctx_free(vdev, ctx, 0); } /* @@ -342,7 +374,7 @@ static irqreturn_t vfio_msihandler(int irq, void *arg) { struct eventfd_ctx *trigger = arg; - eventfd_signal(trigger, 1); + eventfd_signal(trigger); return IRQ_HANDLED; } @@ -560,11 +592,11 @@ static int vfio_pci_set_intx_unmask(struct vfio_pci_core_device *vdev, return -EINVAL; if (flags & VFIO_IRQ_SET_DATA_NONE) { - vfio_pci_intx_unmask(vdev); + __vfio_pci_intx_unmask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t unmask = *(uint8_t *)data; if (unmask) - vfio_pci_intx_unmask(vdev); + __vfio_pci_intx_unmask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { struct vfio_pci_irq_ctx *ctx = vfio_irq_ctx_get(vdev, 0); int32_t fd = *(int32_t *)data; @@ -591,11 +623,11 @@ static int vfio_pci_set_intx_mask(struct vfio_pci_core_device *vdev, return -EINVAL; if (flags & VFIO_IRQ_SET_DATA_NONE) { - vfio_pci_intx_mask(vdev); + __vfio_pci_intx_mask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t mask = *(uint8_t *)data; if (mask) - vfio_pci_intx_mask(vdev); + __vfio_pci_intx_mask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { return -ENOTTY; /* XXX implement me */ } @@ -616,19 +648,23 @@ static int vfio_pci_set_intx_trigger(struct vfio_pci_core_device *vdev, return -EINVAL; if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { + struct eventfd_ctx *trigger = NULL; int32_t fd = *(int32_t *)data; int ret; - if (is_intx(vdev)) - return vfio_intx_set_signal(vdev, fd); + if (fd >= 0) { + trigger = eventfd_ctx_fdget(fd); + if (IS_ERR(trigger)) + return PTR_ERR(trigger); + } - ret = vfio_intx_enable(vdev); - if (ret) - return ret; + if (is_intx(vdev)) + ret = vfio_intx_set_signal(vdev, trigger); + else + ret = vfio_intx_enable(vdev, trigger); - ret = vfio_intx_set_signal(vdev, fd); - if (ret) - vfio_intx_disable(vdev); + if (ret && trigger) + eventfd_ctx_put(trigger); return ret; } @@ -689,11 +725,11 @@ static int vfio_pci_set_msi_trigger(struct vfio_pci_core_device *vdev, if (!ctx) continue; if (flags & VFIO_IRQ_SET_DATA_NONE) { - eventfd_signal(ctx->trigger, 1); + eventfd_signal(ctx->trigger); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t *bools = data; if (bools[i - start]) - eventfd_signal(ctx->trigger, 1); + eventfd_signal(ctx->trigger); } } return 0; @@ -707,7 +743,7 @@ static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx, if (flags & VFIO_IRQ_SET_DATA_NONE) { if (*ctx) { if (count) { - eventfd_signal(*ctx, 1); + eventfd_signal(*ctx); } else { eventfd_ctx_put(*ctx); *ctx = NULL; @@ -722,7 +758,7 @@ static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx, trigger = *(uint8_t *)data; if (trigger && *ctx) - eventfd_signal(*ctx, 1); + eventfd_signal(*ctx); return 0; } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { -- cgit v1.2.3