--- /dev/null
+/*
+ * VFIO PCI interrupt handling
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
+ * Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc. All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/eventfd.h>
+#include <linux/msi.h>
+#include <linux/pci.h>
+#include <linux/file.h>
+#include <linux/vfio.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+
+#include "vfio_pci_private.h"
+
+/*
+ * INTx
+ */
+static void vfio_send_intx_eventfd(void *opaque, void *unused)
+{
+ struct vfio_pci_device *vdev = opaque;
+
+ if (likely(is_intx(vdev) && !vdev->virq_disabled))
+ eventfd_signal(vdev->ctx[0].trigger, 1);
+}
+
+void vfio_pci_intx_mask(struct vfio_pci_device *vdev)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vdev->irqlock, flags);
+
+ /*
+ * Masking can come from interrupt, ioctl, or config space
+ * via INTx disable. The latter means this can get called
+ * even when not using intx delivery. In this case, just
+ * try to have the physical bit follow the virtual bit.
+ */
+ if (unlikely(!is_intx(vdev))) {
+ if (vdev->pci_2_3)
+ pci_intx(pdev, 0);
+ } else if (!vdev->ctx[0].masked) {
+ /*
+ * Can't use check_and_mask here because we always want to
+ * mask, not just when something is pending.
+ */
+ if (vdev->pci_2_3)
+ pci_intx(pdev, 0);
+ else
+ disable_irq_nosync(pdev->irq);
+
+ vdev->ctx[0].masked = true;
+ }
+
+ spin_unlock_irqrestore(&vdev->irqlock, flags);
+}
+
+/*
+ * 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
+ * a signal is necessary, which can then be handled via a work queue
+ * or directly depending on the caller.
+ */
+static int vfio_pci_intx_unmask_handler(void *opaque, void *unused)
+{
+ struct vfio_pci_device *vdev = opaque;
+ struct pci_dev *pdev = vdev->pdev;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&vdev->irqlock, flags);
+
+ /*
+ * Unmasking comes from ioctl or config, so again, have the
+ * physical bit follow the virtual even when not using INTx.
+ */
+ if (unlikely(!is_intx(vdev))) {
+ if (vdev->pci_2_3)
+ pci_intx(pdev, 1);
+ } else if (vdev->ctx[0].masked && !vdev->virq_disabled) {
+ /*
+ * A pending interrupt here would immediately trigger,
+ * but we can avoid that overhead by just re-sending
+ * the interrupt to the user.
+ */
+ if (vdev->pci_2_3) {
+ if (!pci_check_and_unmask_intx(pdev))
+ ret = 1;
+ } else
+ enable_irq(pdev->irq);
+
+ vdev->ctx[0].masked = (ret > 0);
+ }
+
+ spin_unlock_irqrestore(&vdev->irqlock, flags);
+
+ return ret;
+}
+
+void vfio_pci_intx_unmask(struct vfio_pci_device *vdev)
+{
+ if (vfio_pci_intx_unmask_handler(vdev, NULL) > 0)
+ vfio_send_intx_eventfd(vdev, NULL);
+}
+
+static irqreturn_t vfio_intx_handler(int irq, void *dev_id)
+{
+ struct vfio_pci_device *vdev = dev_id;
+ unsigned long flags;
+ int ret = IRQ_NONE;
+
+ spin_lock_irqsave(&vdev->irqlock, flags);
+
+ if (!vdev->pci_2_3) {
+ disable_irq_nosync(vdev->pdev->irq);
+ vdev->ctx[0].masked = true;
+ ret = IRQ_HANDLED;
+ } else if (!vdev->ctx[0].masked && /* may be shared */
+ pci_check_and_mask_intx(vdev->pdev)) {
+ vdev->ctx[0].masked = true;
+ ret = IRQ_HANDLED;
+ }
+
+ spin_unlock_irqrestore(&vdev->irqlock, flags);
+
+ if (ret == IRQ_HANDLED)
+ vfio_send_intx_eventfd(vdev, NULL);
+
+ return ret;
+}
+
+static int vfio_intx_enable(struct vfio_pci_device *vdev)
+{
+ if (!is_irq_none(vdev))
+ return -EINVAL;
+
+ if (!vdev->pdev->irq)
+ return -ENODEV;
+
+ vdev->ctx = kzalloc(sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
+ if (!vdev->ctx)
+ return -ENOMEM;
+
+ vdev->num_ctx = 1;
+
+ /*
+ * 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.
+ */
+ vdev->ctx[0].masked = vdev->virq_disabled;
+ if (vdev->pci_2_3)
+ pci_intx(vdev->pdev, !vdev->ctx[0].masked);
+
+ vdev->irq_type = VFIO_PCI_INTX_IRQ_INDEX;
+
+ return 0;
+}
+
+static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ unsigned long irqflags = IRQF_SHARED;
+ struct eventfd_ctx *trigger;
+ unsigned long flags;
+ int ret;
+
+ if (vdev->ctx[0].trigger) {
+ free_irq(pdev->irq, vdev);
+ kfree(vdev->ctx[0].name);
+ eventfd_ctx_put(vdev->ctx[0].trigger);
+ vdev->ctx[0].trigger = NULL;
+ }
+
+ if (fd < 0) /* Disable only */
+ return 0;
+
+ vdev->ctx[0].name = kasprintf(GFP_KERNEL, "vfio-intx(%s)",
+ pci_name(pdev));
+ if (!vdev->ctx[0].name)
+ return -ENOMEM;
+
+ trigger = eventfd_ctx_fdget(fd);
+ if (IS_ERR(trigger)) {
+ kfree(vdev->ctx[0].name);
+ return PTR_ERR(trigger);
+ }
+
+ vdev->ctx[0].trigger = trigger;
+
+ if (!vdev->pci_2_3)
+ irqflags = 0;
+
+ ret = request_irq(pdev->irq, vfio_intx_handler,
+ irqflags, vdev->ctx[0].name, vdev);
+ if (ret) {
+ vdev->ctx[0].trigger = NULL;
+ kfree(vdev->ctx[0].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 && vdev->ctx[0].masked)
+ disable_irq_nosync(pdev->irq);
+ spin_unlock_irqrestore(&vdev->irqlock, flags);
+
+ return 0;
+}
+
+static void vfio_intx_disable(struct vfio_pci_device *vdev)
+{
+ vfio_intx_set_signal(vdev, -1);
+ vfio_virqfd_disable(&vdev->ctx[0].unmask);
+ vfio_virqfd_disable(&vdev->ctx[0].mask);
+ vdev->irq_type = VFIO_PCI_NUM_IRQS;
+ vdev->num_ctx = 0;
+ kfree(vdev->ctx);
+}
+
+/*
+ * MSI/MSI-X
+ */
+static irqreturn_t vfio_msihandler(int irq, void *arg)
+{
+ struct eventfd_ctx *trigger = arg;
+
+ eventfd_signal(trigger, 1);
+ return IRQ_HANDLED;
+}
+
+static int vfio_msi_enable(struct vfio_pci_device *vdev, int nvec, bool msix)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ int ret;
+
+ if (!is_irq_none(vdev))
+ return -EINVAL;
+
+ vdev->ctx = kzalloc(nvec * sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
+ if (!vdev->ctx)
+ return -ENOMEM;
+
+ if (msix) {
+ int i;
+
+ vdev->msix = kzalloc(nvec * sizeof(struct msix_entry),
+ GFP_KERNEL);
+ if (!vdev->msix) {
+ kfree(vdev->ctx);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < nvec; i++)
+ vdev->msix[i].entry = i;
+
+ ret = pci_enable_msix_range(pdev, vdev->msix, 1, nvec);
+ if (ret < nvec) {
+ if (ret > 0)
+ pci_disable_msix(pdev);
+ kfree(vdev->msix);
+ kfree(vdev->ctx);
+ return ret;
+ }
+ } else {
+ ret = pci_enable_msi_range(pdev, 1, nvec);
+ if (ret < nvec) {
+ if (ret > 0)
+ pci_disable_msi(pdev);
+ kfree(vdev->ctx);
+ return ret;
+ }
+ }
+
+ vdev->num_ctx = nvec;
+ vdev->irq_type = msix ? VFIO_PCI_MSIX_IRQ_INDEX :
+ VFIO_PCI_MSI_IRQ_INDEX;
+
+ if (!msix) {
+ /*
+ * Compute the virtual hardware field for max msi vectors -
+ * it is the log base 2 of the number of vectors.
+ */
+ vdev->msi_qmax = fls(nvec * 2 - 1) - 1;
+ }
+
+ return 0;
+}
+
+static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev,
+ int vector, int fd, bool msix)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ int irq = msix ? vdev->msix[vector].vector : pdev->irq + vector;
+ char *name = msix ? "vfio-msix" : "vfio-msi";
+ struct eventfd_ctx *trigger;
+ int ret;
+
+ if (vector >= vdev->num_ctx)
+ return -EINVAL;
+
+ if (vdev->ctx[vector].trigger) {
+ free_irq(irq, vdev->ctx[vector].trigger);
+ kfree(vdev->ctx[vector].name);
+ eventfd_ctx_put(vdev->ctx[vector].trigger);
+ vdev->ctx[vector].trigger = NULL;
+ }
+
+ if (fd < 0)
+ return 0;
+
+ vdev->ctx[vector].name = kasprintf(GFP_KERNEL, "%s[%d](%s)",
+ name, vector, pci_name(pdev));
+ if (!vdev->ctx[vector].name)
+ return -ENOMEM;
+
+ trigger = eventfd_ctx_fdget(fd);
+ if (IS_ERR(trigger)) {
+ kfree(vdev->ctx[vector].name);
+ return PTR_ERR(trigger);
+ }
+
+ /*
+ * The MSIx vector table resides in device memory which may be cleared
+ * via backdoor resets. We don't allow direct access to the vector
+ * table so even if a userspace driver attempts to save/restore around
+ * such a reset it would be unsuccessful. To avoid this, restore the
+ * cached value of the message prior to enabling.
+ */
+ if (msix) {
+ struct msi_msg msg;
+
+ get_cached_msi_msg(irq, &msg);
+ pci_write_msi_msg(irq, &msg);
+ }
+
+ ret = request_irq(irq, vfio_msihandler, 0,
+ vdev->ctx[vector].name, trigger);
+ if (ret) {
+ kfree(vdev->ctx[vector].name);
+ eventfd_ctx_put(trigger);
+ return ret;
+ }
+
+ vdev->ctx[vector].trigger = trigger;
+
+ return 0;
+}
+
+static int vfio_msi_set_block(struct vfio_pci_device *vdev, unsigned start,
+ unsigned count, int32_t *fds, bool msix)
+{
+ int i, j, ret = 0;
+
+ if (start + count > vdev->num_ctx)
+ return -EINVAL;
+
+ for (i = 0, j = start; i < count && !ret; i++, j++) {
+ int fd = fds ? fds[i] : -1;
+ ret = vfio_msi_set_vector_signal(vdev, j, fd, msix);
+ }
+
+ if (ret) {
+ for (--j; j >= start; j--)
+ vfio_msi_set_vector_signal(vdev, j, -1, msix);
+ }
+
+ return ret;
+}
+
+static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ int i;
+
+ vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
+
+ for (i = 0; i < vdev->num_ctx; i++) {
+ vfio_virqfd_disable(&vdev->ctx[i].unmask);
+ vfio_virqfd_disable(&vdev->ctx[i].mask);
+ }
+
+ if (msix) {
+ pci_disable_msix(vdev->pdev);
+ kfree(vdev->msix);
+ } else
+ pci_disable_msi(pdev);
+
+ vdev->irq_type = VFIO_PCI_NUM_IRQS;
+ vdev->num_ctx = 0;
+ kfree(vdev->ctx);
+}
+
+/*
+ * IOCTL support
+ */
+static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (!is_intx(vdev) || start != 0 || count != 1)
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ 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);
+ } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ int32_t fd = *(int32_t *)data;
+ if (fd >= 0)
+ return vfio_virqfd_enable((void *) vdev,
+ vfio_pci_intx_unmask_handler,
+ vfio_send_intx_eventfd, NULL,
+ &vdev->ctx[0].unmask, fd);
+
+ vfio_virqfd_disable(&vdev->ctx[0].unmask);
+ }
+
+ return 0;
+}
+
+static int vfio_pci_set_intx_mask(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (!is_intx(vdev) || start != 0 || count != 1)
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ 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);
+ } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ return -ENOTTY; /* XXX implement me */
+ }
+
+ return 0;
+}
+
+static int vfio_pci_set_intx_trigger(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (is_intx(vdev) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
+ vfio_intx_disable(vdev);
+ return 0;
+ }
+
+ if (!(is_intx(vdev) || is_irq_none(vdev)) || start != 0 || count != 1)
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ int32_t fd = *(int32_t *)data;
+ int ret;
+
+ if (is_intx(vdev))
+ return vfio_intx_set_signal(vdev, fd);
+
+ ret = vfio_intx_enable(vdev);
+ if (ret)
+ return ret;
+
+ ret = vfio_intx_set_signal(vdev, fd);
+ if (ret)
+ vfio_intx_disable(vdev);
+
+ return ret;
+ }
+
+ if (!is_intx(vdev))
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ vfio_send_intx_eventfd(vdev, NULL);
+ } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
+ uint8_t trigger = *(uint8_t *)data;
+ if (trigger)
+ vfio_send_intx_eventfd(vdev, NULL);
+ }
+ return 0;
+}
+
+static int vfio_pci_set_msi_trigger(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ int i;
+ bool msix = (index == VFIO_PCI_MSIX_IRQ_INDEX) ? true : false;
+
+ if (irq_is(vdev, index) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
+ vfio_msi_disable(vdev, msix);
+ return 0;
+ }
+
+ if (!(irq_is(vdev, index) || is_irq_none(vdev)))
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ int32_t *fds = data;
+ int ret;
+
+ if (vdev->irq_type == index)
+ return vfio_msi_set_block(vdev, start, count,
+ fds, msix);
+
+ ret = vfio_msi_enable(vdev, start + count, msix);
+ if (ret)
+ return ret;
+
+ ret = vfio_msi_set_block(vdev, start, count, fds, msix);
+ if (ret)
+ vfio_msi_disable(vdev, msix);
+
+ return ret;
+ }
+
+ if (!irq_is(vdev, index) || start + count > vdev->num_ctx)
+ return -EINVAL;
+
+ for (i = start; i < start + count; i++) {
+ if (!vdev->ctx[i].trigger)
+ continue;
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ eventfd_signal(vdev->ctx[i].trigger, 1);
+ } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
+ uint8_t *bools = data;
+ if (bools[i - start])
+ eventfd_signal(vdev->ctx[i].trigger, 1);
+ }
+ }
+ return 0;
+}
+
+static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx,
+ uint32_t flags, void *data)
+{
+ int32_t fd = *(int32_t *)data;
+
+ if (!(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
+ return -EINVAL;
+
+ /* DATA_NONE/DATA_BOOL enables loopback testing */
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ if (*ctx)
+ eventfd_signal(*ctx, 1);
+ return 0;
+ } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
+ uint8_t trigger = *(uint8_t *)data;
+ if (trigger && *ctx)
+ eventfd_signal(*ctx, 1);
+ return 0;
+ }
+
+ /* Handle SET_DATA_EVENTFD */
+ if (fd == -1) {
+ if (*ctx)
+ eventfd_ctx_put(*ctx);
+ *ctx = NULL;
+ return 0;
+ } else if (fd >= 0) {
+ struct eventfd_ctx *efdctx;
+ efdctx = eventfd_ctx_fdget(fd);
+ if (IS_ERR(efdctx))
+ return PTR_ERR(efdctx);
+ if (*ctx)
+ eventfd_ctx_put(*ctx);
+ *ctx = efdctx;
+ return 0;
+ } else
+ return -EINVAL;
+}
+
+static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (index != VFIO_PCI_ERR_IRQ_INDEX)
+ return -EINVAL;
+
+ /*
+ * We should sanitize start & count, but that wasn't caught
+ * originally, so this IRQ index must forever ignore them :-(
+ */
+
+ return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger, flags, data);
+}
+
+static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count != 1)
+ return -EINVAL;
+
+ return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger, flags, data);
+}
+
+int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
+ unsigned index, unsigned start, unsigned count,
+ void *data)
+{
+ int (*func)(struct vfio_pci_device *vdev, unsigned index,
+ unsigned start, unsigned count, uint32_t flags,
+ void *data) = NULL;
+
+ switch (index) {
+ case VFIO_PCI_INTX_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_MASK:
+ func = vfio_pci_set_intx_mask;
+ break;
+ case VFIO_IRQ_SET_ACTION_UNMASK:
+ func = vfio_pci_set_intx_unmask;
+ break;
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ func = vfio_pci_set_intx_trigger;
+ break;
+ }
+ break;
+ case VFIO_PCI_MSI_IRQ_INDEX:
+ case VFIO_PCI_MSIX_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_MASK:
+ case VFIO_IRQ_SET_ACTION_UNMASK:
+ /* XXX Need masking support exported */
+ break;
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ func = vfio_pci_set_msi_trigger;
+ break;
+ }
+ break;
+ case VFIO_PCI_ERR_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ if (pci_is_pcie(vdev->pdev))
+ func = vfio_pci_set_err_trigger;
+ break;
+ }
+ break;
+ case VFIO_PCI_REQ_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ func = vfio_pci_set_req_trigger;
+ break;
+ }
+ break;
+ }
+
+ if (!func)
+ return -ENOTTY;
+
+ return func(vdev, index, start, count, flags, data);
+}
Code Review / kvmfornfv.git / blobdiff