Merge tag 'xfs-for-linus-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-drm-fsl-dcu.git] / arch / x86 / kvm / vmx.c

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e856dd566f4c2a6c10a4a6dc9c6ea018fe72cdda..83b7b5cd75d52dd67976274da3c11807f1c35490 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8632,22 +8632,17 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
        u64 ipat = 0;
 
        /* For VT-d and EPT combination
-        * 1. MMIO: always map as UC
+        * 1. MMIO: guest may want to apply WC, trust it.
         * 2. EPT with VT-d:
         *   a. VT-d without snooping control feature: can't guarantee the
-        *      result, try to trust guest.
+        *      result, try to trust guest.  So the same as item 1.
         *   b. VT-d with snooping control feature: snooping control feature of
         *      VT-d engine can guarantee the cache correctness. Just set it
         *      to WB to keep consistent with host. So the same as item 3.
         * 3. EPT without VT-d: always map as WB and set IPAT=1 to keep
         *    consistent with host MTRR
         */
-       if (is_mmio) {
-               cache = MTRR_TYPE_UNCACHABLE;
-               goto exit;
-       }
-
-       if (!kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
+       if (!is_mmio && !kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
                ipat = VMX_EPT_IPAT_BIT;
                cache = MTRR_TYPE_WRBACK;
                goto exit;
@@ -8655,7 +8650,10 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 
        if (kvm_read_cr0(vcpu) & X86_CR0_CD) {
                ipat = VMX_EPT_IPAT_BIT;
-               cache = MTRR_TYPE_UNCACHABLE;
+               if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
+                       cache = MTRR_TYPE_WRBACK;
+               else
+                       cache = MTRR_TYPE_UNCACHABLE;
                goto exit;
        }