On 08/01/2012 08:18 AM, Alex Williamson wrote:
> This adds the core of the QEMU VFIO-based PCI device assignment driver.
> To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> and CONFIG_VFIO_PCI in your host Linux kernel config. Load the vfio-pci
> module. To assign device 0000:05:00.0 to a guest, do the following:
>
> for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
> vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
> device=$(cat /sys/bus/pci/devices/$dev/device)
> if [ -e /sys/bus/pci/devices/$dev/driver ]; then
> echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
> fi
> echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> done
>
> See Documentation/vfio.txt in the Linux kernel tree for further
> description of IOMMU groups and VFIO.
>
> Then launch qemu including the option:
>
> -device vfio-pci,host=0000:05:00.0
>
> Support for legacy PCI interrupts (INTx) is not yet included and will
> be added in a future update. Both MSI and MSI-X are supported here.
> +
> +static void vfio_update_irq(PCIDevice *pdev)
> +{
> + VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> + PCIINTxRoute route;
> +
> + if (vdev->interrupt != INT_INTx) {
> + return;
> + }
> +
> + route = pci_device_route_intx_to_irq(&vdev->pdev, vdev->intx.pin);
> + if (!memcmp(&route, &vdev->intx.route, sizeof(route))) {
> + return; /* Nothing changed */
> + }
You can't memcmp() structures, the compiler may add uninitialized holes
that will miscompare. It's probably harmless here since it's an
optimization.
Unrelated nit: memcmp() doesn't return a boolean or a count, so
!memcmp() is really unintuitive, at least to me.
> +
> +static int vfio_enable_intx(VFIODevice *vdev)
> +{
> + struct vfio_irq_set_fd irq_set_fd = {
> + .irq_set = {
> + .argsz = sizeof(irq_set_fd),
> + .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
> + .index = VFIO_PCI_INTX_IRQ_INDEX,
> + .start = 0,
> + .count = 1,
> + },
> + };
> + uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
> +
> + if (!pin) {
> + return 0;
> + }
> +
> + vfio_disable_interrupts(vdev);
> +
> + vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */
> + vdev->intx.route = pci_device_route_intx_to_irq(&vdev->pdev,
> + vdev->intx.pin);
> + /* TBD - Enable QEMU eoi notifier */
> +
> + if (event_notifier_init(&vdev->intx.interrupt, 0)) {
> + error_report("vfio: Error: event_notifier_init failed\n");
> + return -1;
return -error is better.
> + }
> +
> + irq_set_fd.fd = event_notifier_get_fd(&vdev->intx.interrupt);
> + qemu_set_fd_handler(irq_set_fd.fd, vfio_intx_interrupt, NULL, vdev);
> +
> + if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd)) {
> + error_report("vfio: Error: Failed to setup INTx fd: %s\n",
> + strerror(errno));
> + return -1;
> + }
> +
> + vfio_enable_intx_kvm(vdev);
> +
> + vdev->interrupt = INT_INTx;
> +
> + DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> + vdev->host.bus, vdev->host.slot, vdev->host.function);
> +
> + return 0;
> +}
> +
> +
> +
> +/* XXX This should move to msi.c */
Well?
> +static MSIMessage msi_get_msg(PCIDevice *pdev, unsigned int vector)
> +{
> + uint16_t flags = pci_get_word(pdev->config + pdev->msi_cap + PCI_MSI_FLAGS);
> + bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
> + MSIMessage msg;
> +
> + if (msi64bit) {
> + msg.address = pci_get_quad(pdev->config +
> + pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> + } else {
> + msg.address = pci_get_long(pdev->config +
> + pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> + }
> +
> + msg.data = pci_get_word(pdev->config + pdev->msi_cap +
> + (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32));
> + msg.data += vector;
> +
> + return msg;
> +}
> +
> +
> +/*
> + * IO Port/MMIO - Beware of the endians, VFIO is always little endian
> + */
> +static void vfio_bar_write(void *opaque, target_phys_addr_t addr,
> + uint64_t data, unsigned size)
> +{
> + VFIOBAR *bar = opaque;
> + uint8_t buf[8];
> +
> + switch (size) {
> + case 1:
> + *buf = data & 0xff;
> + break;
> + case 2:
> + *(uint16_t *)buf = cpu_to_le16(data);
> + break;
> + case 4:
> + *(uint32_t *)buf = cpu_to_le32(data);
> + break;
This works accidentally on machines that require alignment, since
there's no requirement from the compiler to align buf. You can use a
union to align it.
> + default:
> + hw_error("vfio: unsupported write size, %d bytes\n", size);
> + break;
> + }
> +
> + if (pwrite(bar->fd, buf, size, bar->fd_offset + addr) != size) {
> + error_report("%s(,0x%"PRIx64", 0x%"PRIx64", %d) failed: %s\n",
> + __func__, addr, data, size, strerror(errno));
> + }
> +
> + DPRINTF("%s(BAR%d+0x%"PRIx64", 0x%"PRIx64", %d)\n",
> + __func__, bar->nr, addr, data, size);
> +}
> +
> +
> +static void vfio_listener_region_add(MemoryListener *listener,
> + MemoryRegionSection *section)
> +{
> + VFIOContainer *container = container_of(listener, VFIOContainer,
> + iommu_data.listener);
> + target_phys_addr_t iova, end;
> + void *vaddr;
> + int ret;
> +
> + if (vfio_listener_skipped_section(section)) {
> + DPRINTF("vfio: SKIPPING region_add %016lx - %016lx\n",
> + section->offset_within_address_space,
> + section->offset_within_address_space + section->size - 1);
> + return;
> + }
> +
> + if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> + (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> + error_report("%s received unaligned region\n", __func__);
Is it really an error? I think you can just add the condition to
skipped_section.
> + return;
> + }
> +
> +
--
error compiling committee.c: too many arguments to function
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