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authorGleb Natapov <gleb@redhat.com>2010-10-19 18:13:41 +0200
committerAvi Kivity <avi@redhat.com>2011-01-12 11:23:23 +0200
commit8030089f9e93ee5cefe74d258e35edc7ce9e4b73 (patch)
treefc6f910bfa8867b8d8155e4ef1467f236341ade4 /virt
parentfc5f06fac6fb8ce469ea173370f2cd398f1d9f9a (diff)
downloadkernel-8030089f9e93ee5cefe74d258e35edc7ce9e4b73.tar.gz
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 <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c30
1 files changed, 17 insertions, 13 deletions
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(&current->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(&current->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(&current->mm->mmap_sem);
- BUG_ON(!kvm_is_mmio_pfn(pfn));
} else
pfn = page_to_pfn(page[0]);