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>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 83f11c7..2d4477c 100644 (file)
--- 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
index 6259d74..07491c9 100644 (file)
--- 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);