KVM: x86: fix overlap between SPTE_MMIO_MASK and generation

[linux-2.6-microblaze.git] / arch / x86 / kvm / mmu / mmu.c

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 57e4dbd..b9052c7 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -418,22 +418,24 @@ static inline bool is_access_track_spte(u64 spte)
  * requires a full MMU zap).  The flag is instead explicitly queried when
  * checking for MMIO spte cache hits.
  */
-#define MMIO_SPTE_GEN_MASK             GENMASK_ULL(18, 0)
+#define MMIO_SPTE_GEN_MASK             GENMASK_ULL(17, 0)
 
 #define MMIO_SPTE_GEN_LOW_START                3
 #define MMIO_SPTE_GEN_LOW_END          11
 #define MMIO_SPTE_GEN_LOW_MASK         GENMASK_ULL(MMIO_SPTE_GEN_LOW_END, \
                                                    MMIO_SPTE_GEN_LOW_START)
 
-#define MMIO_SPTE_GEN_HIGH_START       52
-#define MMIO_SPTE_GEN_HIGH_END         61
+#define MMIO_SPTE_GEN_HIGH_START       PT64_SECOND_AVAIL_BITS_SHIFT
+#define MMIO_SPTE_GEN_HIGH_END         62
 #define MMIO_SPTE_GEN_HIGH_MASK                GENMASK_ULL(MMIO_SPTE_GEN_HIGH_END, \
                                                    MMIO_SPTE_GEN_HIGH_START)
+
 static u64 generation_mmio_spte_mask(u64 gen)
 {
        u64 mask;
 
        WARN_ON(gen & ~MMIO_SPTE_GEN_MASK);
+       BUILD_BUG_ON((MMIO_SPTE_GEN_HIGH_MASK | MMIO_SPTE_GEN_LOW_MASK) & SPTE_SPECIAL_MASK);
 
        mask = (gen << MMIO_SPTE_GEN_LOW_START) & MMIO_SPTE_GEN_LOW_MASK;
        mask |= (gen << MMIO_SPTE_GEN_HIGH_START) & MMIO_SPTE_GEN_HIGH_MASK;
@@ -444,8 +446,6 @@ static u64 get_mmio_spte_generation(u64 spte)
 {
        u64 gen;
 
-       spte &= ~shadow_mmio_mask;
-
        gen = (spte & MMIO_SPTE_GEN_LOW_MASK) >> MMIO_SPTE_GEN_LOW_START;
        gen |= (spte & MMIO_SPTE_GEN_HIGH_MASK) >> MMIO_SPTE_GEN_HIGH_START;
        return gen;