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Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 64c42d90112b..2c9661f230a9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5062,6 +5062,30 @@ void kvm_after_handle_nmi(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_after_handle_nmi);
+static void kvm_set_mmio_spte_mask(void)
+{
+ u64 mask;
+ int maxphyaddr = boot_cpu_data.x86_phys_bits;
+
+ /*
+ * Set the reserved bits and the present bit of an paging-structure
+ * entry to generate page fault with PFER.RSV = 1.
+ */
+ mask = ((1ull << (62 - maxphyaddr + 1)) - 1) << maxphyaddr;
+ mask |= 1ull;
+
+#ifdef CONFIG_X86_64
+ /*
+ * If reserved bit is not supported, clear the present bit to disable
+ * mmio page fault.
+ */
+ if (maxphyaddr == 52)
+ mask &= ~1ull;
+#endif
+
+ kvm_mmu_set_mmio_spte_mask(mask);
+}
+
int kvm_arch_init(void *opaque)
{
int r;
@@ -5088,6 +5112,7 @@ int kvm_arch_init(void *opaque)
if (r)
goto out;
+ kvm_set_mmio_spte_mask();
kvm_init_msr_list();
kvm_x86_ops = ops;