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 83f11c7474a1d74ef996ca7245078e1b6dda7051..2d4477c7147372c28ed84f5a513ca553dc46979c 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 6259d7467648e1209456abff3666ad9a4e4a3cb4..07491c9c6ed03c1306b4bf5f7dfe04db9e830441 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);