From 8030089f9e93ee5cefe74d258e35edc7ce9e4b73 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Tue, 19 Oct 2010 18:13:41 +0200 Subject: KVM: improve hva_to_pfn() readability Improve vma handling code readability in hva_to_pfn() and fix async pf handling code to properly check vma returned by find_vma(). Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- virt/kvm/kvm_main.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 228f00f87966..475a100f3a22 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -952,6 +952,12 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_hva); +static pfn_t get_fault_pfn(void) +{ + get_page(fault_page); + return fault_pfn; +} + static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, bool *async) { @@ -974,7 +980,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, struct vm_area_struct *vma; if (atomic) - goto return_fault_page; + return get_fault_pfn(); down_read(¤t->mm->mmap_sem); if (is_hwpoison_address(addr)) { @@ -983,22 +989,20 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, return page_to_pfn(hwpoison_page); } - vma = find_vma(current->mm, addr); + vma = find_vma_intersection(current->mm, addr, addr+1); - if (vma == NULL || addr < vma->vm_start || - !(vma->vm_flags & VM_PFNMAP)) { - if (async && !(vma->vm_flags & VM_PFNMAP) && - (vma->vm_flags & VM_WRITE)) + if (vma == NULL) + pfn = get_fault_pfn(); + else if ((vma->vm_flags & VM_PFNMAP)) { + pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + + vma->vm_pgoff; + BUG_ON(!kvm_is_mmio_pfn(pfn)); + } else { + if (async && (vma->vm_flags & VM_WRITE)) *async = true; - up_read(¤t->mm->mmap_sem); -return_fault_page: - get_page(fault_page); - return page_to_pfn(fault_page); + pfn = get_fault_pfn(); } - - pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; up_read(¤t->mm->mmap_sem); - BUG_ON(!kvm_is_mmio_pfn(pfn)); } else pfn = page_to_pfn(page[0]); -- cgit v1.2.3-59-g8ed1b