diff options
| -rw-r--r-- | arch/x86/kvm/vmx.c | 2 | ||||
| -rw-r--r-- | mm/gup.c | 1 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 59 |
3 files changed, 56 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 85e2f0a882ca..e564fa2c7ac8 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1112,7 +1112,7 @@ static inline bool cpu_has_broken_vmx_preemption_timer(void) /* Clear the reserved bits */ eax &= ~(0x3U << 14 | 0xfU << 28); - for (i = 0; i < sizeof(vmx_preemption_cpu_tfms)/sizeof(u32); i++) + for (i = 0; i < ARRAY_SIZE(vmx_preemption_cpu_tfms); i++) if (eax == vmx_preemption_cpu_tfms[i]) return true; @@ -720,6 +720,7 @@ retry: } return 0; } +EXPORT_SYMBOL_GPL(fixup_user_fault); static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ef54b4c31792..154b9ab459b0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1442,6 +1442,52 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) return true; } +static int hva_to_pfn_remapped(struct vm_area_struct *vma, + unsigned long addr, bool *async, + bool write_fault, kvm_pfn_t *p_pfn) +{ + unsigned long pfn; + int r; + + r = follow_pfn(vma, addr, &pfn); + if (r) { + /* + * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does + * not call the fault handler, so do it here. + */ + bool unlocked = false; + r = fixup_user_fault(current, current->mm, addr, + (write_fault ? FAULT_FLAG_WRITE : 0), + &unlocked); + if (unlocked) + return -EAGAIN; + if (r) + return r; + + r = follow_pfn(vma, addr, &pfn); + if (r) + return r; + + } + + + /* + * Get a reference here because callers of *hva_to_pfn* and + * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the + * returned pfn. This is only needed if the VMA has VM_MIXEDMAP + * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will + * simply do nothing for reserved pfns. + * + * Whoever called remap_pfn_range is also going to call e.g. + * unmap_mapping_range before the underlying pages are freed, + * causing a call to our MMU notifier. + */ + kvm_get_pfn(pfn); + + *p_pfn = pfn; + return 0; +} + /* * Pin guest page in memory and return its pfn. * @addr: host virtual address which maps memory to the guest @@ -1461,7 +1507,7 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, { struct vm_area_struct *vma; kvm_pfn_t pfn = 0; - int npages; + int npages, r; /* we can do it either atomically or asynchronously, not both */ BUG_ON(atomic && async); @@ -1483,14 +1529,17 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, goto exit; } +retry: vma = find_vma_intersection(current->mm, addr, addr + 1); if (vma == NULL) pfn = KVM_PFN_ERR_FAULT; - else if ((vma->vm_flags & VM_PFNMAP)) { - pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + - vma->vm_pgoff; - BUG_ON(!kvm_is_reserved_pfn(pfn)); + else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) { + r = hva_to_pfn_remapped(vma, addr, async, write_fault, &pfn); + if (r == -EAGAIN) + goto retry; + if (r < 0) + pfn = KVM_PFN_ERR_FAULT; } else { if (async && vma_is_valid(vma, write_fault)) *async = true; |