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authorBen-Ami Yassour <benami@il.ibm.com>2008-07-28 19:26:24 +0300
committerAvi Kivity <avi@qumranet.com>2008-10-15 10:15:17 +0200
commitcbff90a7caa49507d399c9a55ba4a411e840bfb4 (patch)
treebadd7eb07475ace6098f0bff66ce296c5ac0f7b7 /virt
parent0293615f3fb9886b6b23800c121be293bb7483e9 (diff)
downloadlinux-2.6.38-lt-ux500-cbff90a7caa49507d399c9a55ba4a411e840bfb4.tar.gz
KVM: direct mmio pfn check
Userspace may specify memory slots that are backed by mmio pages rather than normal RAM. In some cases it is not enough to identify these mmio pages by pfn_valid(). This patch adds checking the PageReserved as well. Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com> Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7dd9b0b85e4..5eb96c7c8d7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -76,6 +76,14 @@ static inline int valid_vcpu(int n)
return likely(n >= 0 && n < KVM_MAX_VCPUS);
}
+static inline int is_mmio_pfn(pfn_t pfn)
+{
+ if (pfn_valid(pfn))
+ return PageReserved(pfn_to_page(pfn));
+
+ return true;
+}
+
/*
* Switches to specified vcpu, until a matching vcpu_put()
*/
@@ -740,7 +748,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
}
pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
- BUG_ON(pfn_valid(pfn));
+ BUG_ON(!is_mmio_pfn(pfn));
} else
pfn = page_to_pfn(page[0]);
@@ -754,10 +762,10 @@ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
pfn_t pfn;
pfn = gfn_to_pfn(kvm, gfn);
- if (pfn_valid(pfn))
+ if (!is_mmio_pfn(pfn))
return pfn_to_page(pfn);
- WARN_ON(!pfn_valid(pfn));
+ WARN_ON(is_mmio_pfn(pfn));
get_page(bad_page);
return bad_page;
@@ -773,7 +781,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean);
void kvm_release_pfn_clean(pfn_t pfn)
{
- if (pfn_valid(pfn))
+ if (!is_mmio_pfn(pfn))
put_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
@@ -799,7 +807,7 @@ EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
void kvm_set_pfn_dirty(pfn_t pfn)
{
- if (pfn_valid(pfn)) {
+ if (!is_mmio_pfn(pfn)) {
struct page *page = pfn_to_page(pfn);
if (!PageReserved(page))
SetPageDirty(page);
@@ -809,14 +817,14 @@ EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
void kvm_set_pfn_accessed(pfn_t pfn)
{
- if (pfn_valid(pfn))
+ if (!is_mmio_pfn(pfn))
mark_page_accessed(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
void kvm_get_pfn(pfn_t pfn)
{
- if (pfn_valid(pfn))
+ if (!is_mmio_pfn(pfn))
get_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_get_pfn);