KVM: MMU: Map device MMIO as UC in EPT

Software are not allow to access device MMIO using cacheable memory type, the patch limit MMIO region with UC and WC(guest can select WC using PAT and PCD/PWT). Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
git-mirror · Feb 15, 2009 · 2aaf69d · 2aaf69d
1 parent abe6655
commit 2aaf69d
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
@@ -1698,8 +1698,13 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
 	if (largepage)
 		spte |= PT_PAGE_SIZE_MASK;
 	if (mt_mask) {
-		mt_mask = get_memory_type(vcpu, gfn) <<
-			  kvm_x86_ops->get_mt_mask_shift();
+		if (!kvm_is_mmio_pfn(pfn)) {
+			mt_mask = get_memory_type(vcpu, gfn) <<
+				kvm_x86_ops->get_mt_mask_shift();
+			mt_mask |= VMX_EPT_IGMT_BIT;
+		} else
+			mt_mask = MTRR_TYPE_UNCACHABLE <<
+				kvm_x86_ops->get_mt_mask_shift();
 		spte |= mt_mask;
 	}
 

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
@@ -3687,8 +3687,7 @@ static int __init vmx_init(void)
 	if (vm_need_ept()) {
 		bypass_guest_pf = 0;
 		kvm_mmu_set_base_ptes(VMX_EPT_READABLE_MASK |
-			VMX_EPT_WRITABLE_MASK |
-			VMX_EPT_IGMT_BIT);
+			VMX_EPT_WRITABLE_MASK);
 		kvm_mmu_set_mask_ptes(0ull, 0ull, 0ull, 0ull,
 				VMX_EPT_EXECUTABLE_MASK,
 				VMX_EPT_DEFAULT_MT << VMX_EPT_MT_EPTE_SHIFT);