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authorPaolo Bonzini <pbonzini@redhat.com>2020-05-29 05:42:55 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2020-06-01 04:26:05 -0400
commita8387d0b471f7c8d4d936af0d6dc44dff5c41c6c (patch)
tree32c5927976e9b8a29ea2337d81a27cfbf3cf2a17 /virt
parentcc440cdad5b7a4c1de12dace725209eb3e0cf663 (diff)
Revert "KVM: No need to retry for hva_to_pfn_remapped()"
This reverts commit 5b494aea13fe9ec67365510c0d75835428cbb303. If unlocked==true then the vma pointer could be invalidated, so the 2nd follow_pfn() is potentially racy: we do need to get out and redo find_vma_intersection(). Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index da6da386b591..c9c6db5f77c2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1831,6 +1831,8 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
r = fixup_user_fault(current, current->mm, addr,
(write_fault ? FAULT_FLAG_WRITE : 0),
&unlocked);
+ if (unlocked)
+ return -EAGAIN;
if (r)
return r;
@@ -1901,12 +1903,15 @@ 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_IO | VM_PFNMAP)) {
r = hva_to_pfn_remapped(vma, addr, async, write_fault, writable, &pfn);
+ if (r == -EAGAIN)
+ goto retry;
if (r < 0)
pfn = KVM_PFN_ERR_FAULT;
} else {

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