diff options
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/assigned-dev.c | 93 | ||||
| -rw-r--r-- | virt/kvm/iommu.c | 8 |
2 files changed, 88 insertions, 13 deletions
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c index 3ad0925d23a..758e3b36d4c 100644 --- a/virt/kvm/assigned-dev.c +++ b/virt/kvm/assigned-dev.c @@ -17,6 +17,8 @@ #include <linux/pci.h> #include <linux/interrupt.h> #include <linux/slab.h> +#include <linux/namei.h> +#include <linux/fs.h> #include "irq.h" static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head, @@ -480,12 +482,76 @@ out: return r; } +/* + * We want to test whether the caller has been granted permissions to + * use this device. To be able to configure and control the device, + * the user needs access to PCI configuration space and BAR resources. + * These are accessed through PCI sysfs. PCI config space is often + * passed to the process calling this ioctl via file descriptor, so we + * can't rely on access to that file. We can check for permissions + * on each of the BAR resource files, which is a pretty clear + * indicator that the user has been granted access to the device. + */ +static int probe_sysfs_permissions(struct pci_dev *dev) +{ +#ifdef CONFIG_SYSFS + int i; + bool bar_found = false; + + for (i = PCI_STD_RESOURCES; i <= PCI_STD_RESOURCE_END; i++) { + char *kpath, *syspath; + struct path path; + struct inode *inode; + int r; + + if (!pci_resource_len(dev, i)) + continue; + + kpath = kobject_get_path(&dev->dev.kobj, GFP_KERNEL); + if (!kpath) + return -ENOMEM; + + /* Per sysfs-rules, sysfs is always at /sys */ + syspath = kasprintf(GFP_KERNEL, "/sys%s/resource%d", kpath, i); + kfree(kpath); + if (!syspath) + return -ENOMEM; + + r = kern_path(syspath, LOOKUP_FOLLOW, &path); + kfree(syspath); + if (r) + return r; + + inode = path.dentry->d_inode; + + r = inode_permission(inode, MAY_READ | MAY_WRITE | MAY_ACCESS); + path_put(&path); + if (r) + return r; + + bar_found = true; + } + + /* If no resources, probably something special */ + if (!bar_found) + return -EPERM; + + return 0; +#else + return -EINVAL; /* No way to control the device without sysfs */ +#endif +} + static int kvm_vm_ioctl_assign_device(struct kvm *kvm, struct kvm_assigned_pci_dev *assigned_dev) { int r = 0, idx; struct kvm_assigned_dev_kernel *match; struct pci_dev *dev; + u8 header_type; + + if (!(assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU)) + return -EINVAL; mutex_lock(&kvm->lock); idx = srcu_read_lock(&kvm->srcu); @@ -513,6 +579,18 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, r = -EINVAL; goto out_free; } + + /* Don't allow bridges to be assigned */ + pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type); + if ((header_type & PCI_HEADER_TYPE) != PCI_HEADER_TYPE_NORMAL) { + r = -EPERM; + goto out_put; + } + + r = probe_sysfs_permissions(dev); + if (r) + goto out_put; + if (pci_enable_device(dev)) { printk(KERN_INFO "%s: Could not enable PCI device\n", __func__); r = -EBUSY; @@ -544,16 +622,14 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, list_add(&match->list, &kvm->arch.assigned_dev_head); - if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) { - if (!kvm->arch.iommu_domain) { - r = kvm_iommu_map_guest(kvm); - if (r) - goto out_list_del; - } - r = kvm_assign_device(kvm, match); + if (!kvm->arch.iommu_domain) { + r = kvm_iommu_map_guest(kvm); if (r) goto out_list_del; } + r = kvm_assign_device(kvm, match); + if (r) + goto out_list_del; out: srcu_read_unlock(&kvm->srcu, idx); @@ -593,8 +669,7 @@ static int kvm_vm_ioctl_deassign_device(struct kvm *kvm, goto out; } - if (match->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) - kvm_deassign_device(kvm, match); + kvm_deassign_device(kvm, match); kvm_free_assigned_device(kvm, match); diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index a195c07fa82..304d7e5717e 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -113,7 +113,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot) /* Map into IO address space */ r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn), - get_order(page_size), flags); + page_size, flags); if (r) { printk(KERN_ERR "kvm_iommu_map_address:" "iommu failed to map pfn=%llx\n", pfn); @@ -292,15 +292,15 @@ static void kvm_iommu_put_pages(struct kvm *kvm, while (gfn < end_gfn) { unsigned long unmap_pages; - int order; + size_t size; /* Get physical address */ phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn)); pfn = phys >> PAGE_SHIFT; /* Unmap address from IO address space */ - order = iommu_unmap(domain, gfn_to_gpa(gfn), 0); - unmap_pages = 1ULL << order; + size = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE); + unmap_pages = 1ULL << get_order(size); /* Unpin all pages we just unmapped to not leak any memory */ kvm_unpin_pages(kvm, pfn, unmap_pages); |