> -----Original Message----- > From: Eric Auger [mailto:eric.auger@xxxxxxxxxx] > Sent: Thursday, December 04, 2014 11:36 PM > To: Wu, Feng; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; > x86@xxxxxxxxxx; gleb@xxxxxxxxxx; pbonzini@xxxxxxxxxx; > dwmw2@xxxxxxxxxxxxx; joro@xxxxxxxxxx; alex.williamson@xxxxxxxxxx; > jiang.liu@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; > kvm@xxxxxxxxxxxxxxx > Subject: Re: [v2 18/25] KVM: kvm-vfio: implement the VFIO skeleton for VT-d > Posted-Interrupts > > Hi Feng, > > On 12/03/2014 08:39 AM, 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, > update > > QEMU will use KVM_DEV_VFIO_DEVICE_POSTING_IRQ attribute to setup > > IRTE for VT-d PI. This patch implement this IRQ attribute. > s/implement/implements > > > > Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx> > > --- > > include/linux/kvm_host.h | 19 ++++++++ > > virt/kvm/vfio.c | 103 > ++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 122 insertions(+), 0 deletions(-) > > > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > > index 5cd4420..8d06678 100644 > > --- a/include/linux/kvm_host.h > > +++ b/include/linux/kvm_host.h > > @@ -1134,6 +1134,25 @@ static inline int > kvm_arch_vfio_set_forward(struct kvm_fwd_irq *fwd_irq, > > } > > #endif > > > > +#ifdef __KVM_HAVE_ARCH_KVM_VFIO_POSTING > > +/* > > + * kvm_arch_vfio_update_pi_irte - set IRTE for Posted-Interrupts > > + * > > + * @kvm: kvm > > + * @host_irq: host irq of the interrupt > > + * @guest_irq: gsi of the interrupt > > + * returns 0 on success, < 0 on failure > > + */ > > +int kvm_arch_vfio_update_pi_irte(struct kvm *kvm, unsigned int host_irq, > > + uint32_t guest_irq); > > +#else > > +static int kvm_arch_vfio_update_pi_irte(struct kvm *kvm, unsigned int > host_irq, > > + uint32_t guest_irq) > > +{ > > + return 0; > > +} > > +#endif > > + > > #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT > > > > static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool > val) > > diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c > > index 6bc7001..5e5515f 100644 > > --- a/virt/kvm/vfio.c > > +++ b/virt/kvm/vfio.c > > @@ -446,6 +446,99 @@ out: > > return ret; > > } > > > > +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) > > + return pci_msi_vec_count(pdev); > > + else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) > > + return pci_msix_vec_count(pdev); > > + > > + return 0; > > +} > for platform case I was asked to move the retrieval of absolute irq > number to the architecture specific part. I don't know if it should > apply to PCI stuff as well? This explains why I need to pass the VFIO > device (or struct device handle) to the arch specific part. Actually we > do the same job, we provide a phys/virt IRQ mapping to KVM, right? So to > me our architecture specific API should look quite similar? In my patch, QEMU passes IRQ type(MSI/MSIx in my case), VFIO device index, and sub-index via "struct kvm_vfio_dev_irq" to KVM, then KVM will find the real host irq from the VFIO device index and the IRQ type. Is this something similar with your patch? > > > + > > +static int kvm_vfio_set_pi(struct kvm_device *kdev, int32_t __user *argp) > > +{ > > + struct kvm_vfio_dev_irq pi_info; > > + uint32_t *gsi; > > + 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_vfio_dev_irq, 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) > PCI specific check, same remark as above but I will let Alex further > comment on this and possibly invalidate this commeny ;-) > > + 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 || !dev_is_pci(dev)) { > > + ret = -EFAULT; > > + goto put_vfio_device; > > + } > > + > > + pdev = to_pci_dev(dev); > > + > > + max = kvm_vfio_pci_get_irq_count(pdev, pi_info.index); > > + if (max <= 0) { > > + ret = -EFAULT; > > + goto put_vfio_device; > > + } > > + > > + if (pi_info.argsz - minsz < pi_info.count * sizeof(int) || > shouldn' we use the actual datatype? I am afraid I don't get this, could you please be more specific? Thanks a lot! > > + pi_info.start >= max || pi_info.start + pi_info.count > max) { > > + ret = -EINVAL; > > + goto put_vfio_device; > > + } > > + > > + gsi = memdup_user((void __user *)((unsigned long)argp + minsz), > > + pi_info.count * sizeof(int)); > same question as above > > + if (IS_ERR(gsi)) { > > + ret = PTR_ERR(gsi); > > + goto put_vfio_device; > > + } > > + > > +#ifdef CONFIG_PCI_MSI > > + for (i = 0; i < pi_info.count; i++) { > > + list_for_each_entry(entry, &pdev->msi_list, list) { > > + if (entry->msi_attrib.entry_nr != pi_info.start+i) > > + continue; > > + > > + ret = kvm_arch_vfio_update_pi_irte(kdev->kvm, > > + entry->irq, > > + gsi[i]); > > + if (ret) { > > + ret = -EFAULT; > why -EFAULT? and not propagation of original error code? Yes, you are right. Thanks for the comments! > you may have posting set for part of the subindexes and unset for rest. > Isn't it an issue? QEMU will always set the posting for all the sub-indexes for MSI/MSIx, once the guest updates the configuration of some sub-indexes, KVM will update it accordingly. So in which case will what you mentioned above happen? Thanks, Feng > > Best Regards > > Eric > > + goto free_gsi; > > + } > > + } > > + } > > +#endif > > + > > + ret = 0; > > + > > +free_gsi: > > + kfree(gsi); > > + > > +put_vfio_device: > > + kvm_vfio_put_vfio_device(vdev); > > + return ret; > > +} > > + > > 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 +549,11 @@ 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; > > +#ifdef __KVM_HAVE_ARCH_KVM_VFIO_POSTING > > + case KVM_DEV_VFIO_DEVICE_POSTING_IRQ: > > + ret = kvm_vfio_set_pi(kdev, argp); > > + break; > > +#endif > > default: > > ret = -ENXIO; > > } > > @@ -511,6 +609,11 @@ static int kvm_vfio_has_attr(struct kvm_device > *dev, > > case KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ: > > return 0; > > #endif > > +#ifdef __KVM_HAVE_ARCH_KVM_VFIO_POSTING > > + case KVM_DEV_VFIO_DEVICE_POSTING_IRQ: > > + return 0; > > +#endif > > + > > } > > break; > > } > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
