--- /dev/null
+/*
+ * PCI Backend Operations - respond to PCI requests from Frontend
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <xen/events.h>
+#include <linux/sched.h>
+#include "pciback.h"
+
+int verbose_request;
+module_param(verbose_request, int, 0644);
+
+static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
+
+/* Ensure a device is has the fake IRQ handler "turned on/off" and is
+ * ready to be exported. This MUST be run after xen_pcibk_reset_device
+ * which does the actual PCI device enable/disable.
+ */
+static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
+{
+ struct xen_pcibk_dev_data *dev_data;
+ int rc;
+ int enable = 0;
+
+ dev_data = pci_get_drvdata(dev);
+ if (!dev_data)
+ return;
+
+ /* We don't deal with bridges */
+ if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
+ return;
+
+ if (reset) {
+ dev_data->enable_intx = 0;
+ dev_data->ack_intr = 0;
+ }
+ enable = dev_data->enable_intx;
+
+ /* Asked to disable, but ISR isn't runnig */
+ if (!enable && !dev_data->isr_on)
+ return;
+
+ /* Squirrel away the IRQs in the dev_data. We need this
+ * b/c when device transitions to MSI, the dev->irq is
+ * overwritten with the MSI vector.
+ */
+ if (enable)
+ dev_data->irq = dev->irq;
+
+ /*
+ * SR-IOV devices in all use MSI-X and have no legacy
+ * interrupts, so inhibit creating a fake IRQ handler for them.
+ */
+ if (dev_data->irq == 0)
+ goto out;
+
+ dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
+ dev_data->irq_name,
+ dev_data->irq,
+ pci_is_enabled(dev) ? "on" : "off",
+ dev->msi_enabled ? "MSI" : "",
+ dev->msix_enabled ? "MSI/X" : "",
+ dev_data->isr_on ? "enable" : "disable",
+ enable ? "enable" : "disable");
+
+ if (enable) {
+ rc = request_irq(dev_data->irq,
+ xen_pcibk_guest_interrupt, IRQF_SHARED,
+ dev_data->irq_name, dev);
+ if (rc) {
+ dev_err(&dev->dev, "%s: failed to install fake IRQ " \
+ "handler for IRQ %d! (rc:%d)\n",
+ dev_data->irq_name, dev_data->irq, rc);
+ goto out;
+ }
+ } else {
+ free_irq(dev_data->irq, dev);
+ dev_data->irq = 0;
+ }
+ dev_data->isr_on = enable;
+ dev_data->ack_intr = enable;
+out:
+ dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
+ dev_data->irq_name,
+ dev_data->irq,
+ pci_is_enabled(dev) ? "on" : "off",
+ dev->msi_enabled ? "MSI" : "",
+ dev->msix_enabled ? "MSI/X" : "",
+ enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
+ (dev_data->isr_on ? "failed to disable" : "disabled"));
+}
+
+/* Ensure a device is "turned off" and ready to be exported.
+ * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
+ * ready to be re-exported)
+ */
+void xen_pcibk_reset_device(struct pci_dev *dev)
+{
+ u16 cmd;
+
+ xen_pcibk_control_isr(dev, 1 /* reset device */);
+
+ /* Disable devices (but not bridges) */
+ if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
+#ifdef CONFIG_PCI_MSI
+ /* The guest could have been abruptly killed without
+ * disabling MSI/MSI-X interrupts.*/
+ if (dev->msix_enabled)
+ pci_disable_msix(dev);
+ if (dev->msi_enabled)
+ pci_disable_msi(dev);
+#endif
+ if (pci_is_enabled(dev))
+ pci_disable_device(dev);
+
+ pci_write_config_word(dev, PCI_COMMAND, 0);
+
+ dev->is_busmaster = 0;
+ } else {
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ if (cmd & (PCI_COMMAND_INVALIDATE)) {
+ cmd &= ~(PCI_COMMAND_INVALIDATE);
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+
+ dev->is_busmaster = 0;
+ }
+ }
+}
+
+#ifdef CONFIG_PCI_MSI
+static
+int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
+ struct pci_dev *dev, struct xen_pci_op *op)
+{
+ struct xen_pcibk_dev_data *dev_data;
+ int status;
+
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
+
+ status = pci_enable_msi(dev);
+
+ if (status) {
+ pr_warn_ratelimited("%s: error enabling MSI for guest %u: err %d\n",
+ pci_name(dev), pdev->xdev->otherend_id,
+ status);
+ op->value = 0;
+ return XEN_PCI_ERR_op_failed;
+ }
+
+ /* The value the guest needs is actually the IDT vector, not the
+ * the local domain's IRQ number. */
+
+ op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
+ op->value);
+
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ dev_data->ack_intr = 0;
+
+ return 0;
+}
+
+static
+int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
+ struct pci_dev *dev, struct xen_pci_op *op)
+{
+ struct xen_pcibk_dev_data *dev_data;
+
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
+ pci_name(dev));
+ pci_disable_msi(dev);
+
+ op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
+ op->value);
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ dev_data->ack_intr = 1;
+ return 0;
+}
+
+static
+int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
+ struct pci_dev *dev, struct xen_pci_op *op)
+{
+ struct xen_pcibk_dev_data *dev_data;
+ int i, result;
+ struct msix_entry *entries;
+
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
+ pci_name(dev));
+ if (op->value > SH_INFO_MAX_VEC)
+ return -EINVAL;
+
+ entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
+ if (entries == NULL)
+ return -ENOMEM;
+
+ for (i = 0; i < op->value; i++) {
+ entries[i].entry = op->msix_entries[i].entry;
+ entries[i].vector = op->msix_entries[i].vector;
+ }
+
+ result = pci_enable_msix_exact(dev, entries, op->value);
+ if (result == 0) {
+ for (i = 0; i < op->value; i++) {
+ op->msix_entries[i].entry = entries[i].entry;
+ if (entries[i].vector) {
+ op->msix_entries[i].vector =
+ xen_pirq_from_irq(entries[i].vector);
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: " \
+ "MSI-X[%d]: %d\n",
+ pci_name(dev), i,
+ op->msix_entries[i].vector);
+ }
+ }
+ } else
+ pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: err %d!\n",
+ pci_name(dev), pdev->xdev->otherend_id,
+ result);
+ kfree(entries);
+
+ op->value = result;
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ dev_data->ack_intr = 0;
+
+ return result > 0 ? 0 : result;
+}
+
+static
+int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
+ struct pci_dev *dev, struct xen_pci_op *op)
+{
+ struct xen_pcibk_dev_data *dev_data;
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
+ pci_name(dev));
+ pci_disable_msix(dev);
+
+ /*
+ * SR-IOV devices (which don't have any legacy IRQ) have
+ * an undefined IRQ value of zero.
+ */
+ op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
+ op->value);
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ dev_data->ack_intr = 1;
+ return 0;
+}
+#endif
+/*
+* Now the same evtchn is used for both pcifront conf_read_write request
+* as well as pcie aer front end ack. We use a new work_queue to schedule
+* xen_pcibk conf_read_write service for avoiding confict with aer_core
+* do_recovery job which also use the system default work_queue
+*/
+void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
+{
+ /* Check that frontend is requesting an operation and that we are not
+ * already processing a request */
+ if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
+ && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
+ queue_work(xen_pcibk_wq, &pdev->op_work);
+ }
+ /*_XEN_PCIB_active should have been cleared by pcifront. And also make
+ sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
+ if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
+ && test_bit(_PCIB_op_pending, &pdev->flags)) {
+ wake_up(&xen_pcibk_aer_wait_queue);
+ }
+}
+
+/* Performing the configuration space reads/writes must not be done in atomic
+ * context because some of the pci_* functions can sleep (mostly due to ACPI
+ * use of semaphores). This function is intended to be called from a work
+ * queue in process context taking a struct xen_pcibk_device as a parameter */
+
+void xen_pcibk_do_op(struct work_struct *data)
+{
+ struct xen_pcibk_device *pdev =
+ container_of(data, struct xen_pcibk_device, op_work);
+ struct pci_dev *dev;
+ struct xen_pcibk_dev_data *dev_data = NULL;
+ struct xen_pci_op *op = &pdev->sh_info->op;
+ int test_intx = 0;
+
+ dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
+
+ if (dev == NULL)
+ op->err = XEN_PCI_ERR_dev_not_found;
+ else {
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ test_intx = dev_data->enable_intx;
+ switch (op->cmd) {
+ case XEN_PCI_OP_conf_read:
+ op->err = xen_pcibk_config_read(dev,
+ op->offset, op->size, &op->value);
+ break;
+ case XEN_PCI_OP_conf_write:
+ op->err = xen_pcibk_config_write(dev,
+ op->offset, op->size, op->value);
+ break;
+#ifdef CONFIG_PCI_MSI
+ case XEN_PCI_OP_enable_msi:
+ op->err = xen_pcibk_enable_msi(pdev, dev, op);
+ break;
+ case XEN_PCI_OP_disable_msi:
+ op->err = xen_pcibk_disable_msi(pdev, dev, op);
+ break;
+ case XEN_PCI_OP_enable_msix:
+ op->err = xen_pcibk_enable_msix(pdev, dev, op);
+ break;
+ case XEN_PCI_OP_disable_msix:
+ op->err = xen_pcibk_disable_msix(pdev, dev, op);
+ break;
+#endif
+ default:
+ op->err = XEN_PCI_ERR_not_implemented;
+ break;
+ }
+ }
+ if (!op->err && dev && dev_data) {
+ /* Transition detected */
+ if ((dev_data->enable_intx != test_intx))
+ xen_pcibk_control_isr(dev, 0 /* no reset */);
+ }
+ /* Tell the driver domain that we're done. */
+ wmb();
+ clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
+ notify_remote_via_irq(pdev->evtchn_irq);
+
+ /* Mark that we're done. */
+ smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
+ clear_bit(_PDEVF_op_active, &pdev->flags);
+ smp_mb__after_atomic(); /* /before/ final check for work */
+
+ /* Check to see if the driver domain tried to start another request in
+ * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
+ */
+ xen_pcibk_test_and_schedule_op(pdev);
+}
+
+irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
+{
+ struct xen_pcibk_device *pdev = dev_id;
+
+ xen_pcibk_test_and_schedule_op(pdev);
+
+ return IRQ_HANDLED;
+}
+static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
+{
+ struct pci_dev *dev = (struct pci_dev *)dev_id;
+ struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
+
+ if (dev_data->isr_on && dev_data->ack_intr) {
+ dev_data->handled++;
+ if ((dev_data->handled % 1000) == 0) {
+ if (xen_test_irq_shared(irq)) {
+ pr_info("%s IRQ line is not shared "
+ "with other domains. Turning ISR off\n",
+ dev_data->irq_name);
+ dev_data->ack_intr = 0;
+ }
+ }
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
Code Review / kvmfornfv.git / blobdiff