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authorHuang Ying <ying.huang@intel.com>2011-01-30 11:15:49 +0800
committerMarcelo Tosatti <mtosatti@redhat.com>2011-03-17 13:08:27 -0300
commitfafc3dbaac6447ab8f78d2f7f32a521b24fc6b36 (patch)
tree3934fab022773bc03c8af20021be79d112f584fa /virt
parent69ebb83e13e514222b0ae4f8bd813a17679ed876 (diff)
downloadlwn-fafc3dbaac6447ab8f78d2f7f32a521b24fc6b36.tar.gz
lwn-fafc3dbaac6447ab8f78d2f7f32a521b24fc6b36.zip
KVM: Replace is_hwpoison_address with __get_user_pages
is_hwpoison_address only checks whether the page table entry is hwpoisoned, regardless the memory page mapped. While __get_user_pages will check both. QEMU will clear the poisoned page table entry (via unmap/map) to make it possible to allocate a new memory page for the virtual address across guest rebooting. But it is also possible that the underlying memory page is kept poisoned even after the corresponding page table entry is cleared, that is, a new memory page can not be allocated. __get_user_pages can catch these situations. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4856a7dcbd7f..002fe0b12c9f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1028,6 +1028,15 @@ static pfn_t get_fault_pfn(void)
return fault_pfn;
}
+static inline int check_user_page_hwpoison(unsigned long addr)
+{
+ int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
+
+ rc = __get_user_pages(current, current->mm, addr, 1,
+ flags, NULL, NULL, NULL);
+ return rc == -EHWPOISON;
+}
+
static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
bool *async, bool write_fault, bool *writable)
{
@@ -1075,7 +1084,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
return get_fault_pfn();
down_read(&current->mm->mmap_sem);
- if (is_hwpoison_address(addr)) {
+ if (check_user_page_hwpoison(addr)) {
up_read(&current->mm->mmap_sem);
get_page(hwpoison_page);
return page_to_pfn(hwpoison_page);