kvm: x86: Move kvm_set_mmio_spte_mask() from x86.c to mmu.c

As a prerequisite to fix several SPTE reserved bits related calculation
errors caused by MKTME, which requires kvm_set_mmio_spte_mask() to use
local static variable defined in mmu.c.

Also move call site of kvm_set_mmio_spte_mask() from kvm_arch_init() to
kvm_mmu_module_init() so that kvm_set_mmio_spte_mask() can be static.

Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1e9ba81accba..b1d4f55395cd 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5998,6 +5998,35 @@ static void mmu_destroy_caches(void)
 	kmem_cache_destroy(mmu_page_header_cache);
 }
 
+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 the uppermost physical address bit, which would be reserved as
+	 * long as the supported physical address width is less than 52.
+	 */
+	mask = 1ull << 51;
+
+	/* Set the present bit. */
+	mask |= 1ull;
+
+	/*
+	 * If reserved bit is not supported, clear the present bit to disable
+	 * mmio page fault.
+	 */
+	if (IS_ENABLED(CONFIG_X86_64) && maxphyaddr == 52)
+		mask &= ~1ull;
+
+	kvm_mmu_set_mmio_spte_mask(mask, mask);
+}
+
 int kvm_mmu_module_init(void)
 {
 	int ret = -ENOMEM;
@@ -6014,6 +6043,8 @@ int kvm_mmu_module_init(void)
 
 	kvm_mmu_reset_all_pte_masks();
 
+	kvm_set_mmio_spte_mask();
+
 	pte_list_desc_cache = kmem_cache_create("pte_list_desc",
 					    sizeof(struct pte_list_desc),
 					    0, SLAB_ACCOUNT, NULL);