On Tue, 2014-11-25 at 20:23 +0800, Feng Wu wrote:
> This patch adds the kvm-vfio interface for VT-d Posted-Interrrupts.
> When guests updates MSI/MSI-x information for an assigned-device,
> QEMU will use KVM_DEV_VFIO_DEVICE_POSTING_IRQ attribute to setup
> IRTE for VT-d PI. This patch implement this IRQ attribute.
>
> Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
> ---
> virt/kvm/vfio.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 115 insertions(+), 0 deletions(-)
>
> diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
> index 6bc7001..435adf4 100644
> --- a/virt/kvm/vfio.c
> +++ b/virt/kvm/vfio.c
> @@ -446,6 +446,115 @@ out:
> return ret;
> }
>
> +static int kvm_update_pi_irte(struct kvm *kvm, int host_irq, int guest_irq)
> +{
> + /*
> + * TODO: need to add the real code to update the related IRTE,
> + * Basically, This fucntion will do the following things:
> + * - Get struct kvm_kernel_irq_routing_entry from guest irq
> + * - Get the destination vCPU of the interrupts
> + * - Update the IRTE according the VT-d PI Spec.
> + * 1) guest vector
> + * 2) Posted-Interrupts descritpor addresss
> + */
> +
> + return 0;
Why not make this an arch_ call like Eric did?
> +}
> +
> +static int kvm_vfio_pci_get_irq_count(struct pci_dev *pdev, int irq_type)
> +{
> + if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
> + u8 pin;
> + pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
> + if (pin)
> + return 1;
> + } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
> + u8 pos;
> + u16 flags;
> +
> + pos = pdev->msi_cap;
> + if (pos) {
> + pci_read_config_word(pdev,
> + pos + PCI_MSI_FLAGS, &flags);
> + return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
> + }
Looks like a copy of vfio code, but since that was written helpers have
been added to the kernel:
return pci_msi_vec_count(pdev);
> + } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
> + u8 pos;
> + u16 flags;
> +
> + pos = pdev->msix_cap;
> + if (pos) {
> + pci_read_config_word(pdev,
> + pos + PCI_MSIX_FLAGS, &flags);
> +
> + return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
> + }
return pci_msix_vec_count(pdev);
> + } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
> + if (pci_is_pcie(pdev))
> + return 1;
This is a virtual interrupt, this interface should never be used for it.
> +
> + return 0;
> +}
> +
> +static int kvm_vfio_set_pi(struct kvm_device *kdev, int32_t __user *argp)
> +{
> + struct kvm_posted_intr pi_info;
> + int *virq;
> + unsigned long minsz;
> + struct vfio_device *vdev;
> + struct msi_desc *entry;
> + struct device *dev;
> + struct pci_dev *pdev;
> + int i, max, ret;
> +
> + minsz = offsetofend(struct kvm_posted_intr, count);
> +
> + if (copy_from_user(&pi_info, (void __user *)argp, minsz))
> + return -EFAULT;
> +
> + if (pi_info.argsz < minsz || pi_info.index >= VFIO_PCI_NUM_IRQS)
> + return -EINVAL;
> +
> + vdev = kvm_vfio_get_vfio_device(pi_info.fd);
> + if (IS_ERR(vdev))
> + return PTR_ERR(vdev);
> +
> + dev = kvm_vfio_external_base_device(vdev);
> + if (!dev)
> + return -EFAULT;
Missing put
> +
> + pdev = to_pci_dev(dev);
We can't assume the user called with a PCI device, test it.
if (!dev_is_pci(dev)) {
put
return errno
}
pdev = to_pci_dev(dev);
...
> +
> + max = kvm_vfio_pci_get_irq_count(pdev, pi_info.index);
> +
> + if (pi_info.argsz - minsz < pi_info.count * sizeof(int) ||
> + pi_info.start >= max || pi_info.start + pi_info.count > max)
> + return -EINVAL;
Missing put
> +
> + virq = memdup_user((void __user *)((unsigned long)argp + minsz),
> + pi_info.count * sizeof(int));
> + if (IS_ERR(virq))
> + return PTR_ERR(virq);
put...
> +
> + for (i=0; i<pi_info.count; i++) {
> + list_for_each_entry(entry, &pdev->msi_list, list) {
This is unique to MSI/X but INTx and others can still make it here.
Also, this won't compile unless CONFIG_PCI_MSI. Does anything protect
this list?
> + if (entry->msi_attrib.entry_nr != pi_info.start+i)
> + continue;
> +
> + ret = kvm_update_pi_irte(kdev->kvm,
> + entry->irq, virq[i]);
> + if (ret) {
> + kfree(virq);
> + return -EFAULT;
put...
> + }
> + }
> + }
> +
> + kfree(virq);
put...
> +
> + return 0;
> +}
> +
> static int kvm_vfio_set_device(struct kvm_device *kdev, long attr, u64 arg)
> {
> int32_t __user *argp = (int32_t __user *)(unsigned long)arg;
> @@ -456,6 +565,9 @@ static int kvm_vfio_set_device(struct kvm_device *kdev, long attr, u64 arg)
> case KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ:
> ret = kvm_vfio_control_irq_forward(kdev, attr, argp);
> break;
> + case KVM_DEV_VFIO_DEVICE_POSTING_IRQ:
> + ret = kvm_vfio_set_pi(kdev, argp);
> + break;
ARCH #ifdefs?
> default:
> ret = -ENXIO;
> }
> @@ -511,6 +623,9 @@ static int kvm_vfio_has_attr(struct kvm_device *dev,
> case KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ:
> return 0;
> #endif
> + case KVM_DEV_VFIO_DEVICE_POSTING_IRQ:
> + return 0;
> +
Same here
> }
> break;
> }
I only see setup where, what if we want to stop posted interrupts? What
if we switch to a different mode, for example the guest reboots or
unloads the driver or switches to a different driver. Thanks,
Alex
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