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authorJim Mattson <jmattson@google.com>2018-05-09 17:02:05 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2018-05-14 18:24:26 +0200
commit3a2936dedd207b99c64bf1507a62a9ae44114220 (patch)
tree137cbab7344cb910caa650f51cf3fea92ebb85c8 /arch
parent1313cc2bd8f6568dd8801feef446afbe43e6d313 (diff)
kvm: mmu: Don't expose private memslots to L2
These private pages have special purposes in the virtualization of L1, but not in the virtualization of L2. In particular, L1's APIC access page should never be entered into L2's page tables, because this causes a great deal of confusion when the APIC virtualization hardware is being used to accelerate L2's accesses to its own APIC. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/mmu.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ca04766edbd4..8af8c8f88bd7 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3807,6 +3807,14 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
struct kvm_memory_slot *slot;
bool async;
+ /*
+ * Don't expose private memslots to L2.
+ */
+ if (is_guest_mode(vcpu) && !kvm_is_visible_gfn(vcpu->kvm, gfn)) {
+ *pfn = KVM_PFN_NOSLOT;
+ return false;
+ }
+
slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
async = false;
*pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async, write, writable);