KVM: x86: fix CR0.CD virtualization

Currently, CR0.CD is not checked when we virtualize memory cache type for
noncoherent_dma guests, this patch fixes it by :

- setting UC for all memory if CR0.CD = 1
- zapping all the last sptes in MMU if CR0.CD is changed

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 06a186b..2764381 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8628,7 +8628,8 @@ static int get_ept_level(void)
 
 static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 {
-       u64 ret;
+       u8 cache;
+       u64 ipat = 0;
 
        /* For VT-d and EPT combination
         * 1. MMIO: always map as UC
@@ -8641,16 +8642,27 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
         * 3. EPT without VT-d: always map as WB and set IPAT=1 to keep
         *    consistent with host MTRR
         */
-       if (is_mmio)
-               ret = MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT;
-       else if (kvm_arch_has_noncoherent_dma(vcpu->kvm))
-               ret = kvm_get_guest_memory_type(vcpu, gfn) <<
-                     VMX_EPT_MT_EPTE_SHIFT;
-       else
-               ret = (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT)
-                       | VMX_EPT_IPAT_BIT;
+       if (is_mmio) {
+               cache = MTRR_TYPE_UNCACHABLE;
+               goto exit;
+       }
 
-       return ret;
+       if (!kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
+               ipat = VMX_EPT_IPAT_BIT;
+               cache = MTRR_TYPE_WRBACK;
+               goto exit;
+       }
+
+       if (kvm_read_cr0(vcpu) & X86_CR0_CD) {
+               ipat = VMX_EPT_IPAT_BIT;
+               cache = MTRR_TYPE_UNCACHABLE;
+               goto exit;
+       }
+
+       cache = kvm_get_guest_memory_type(vcpu, gfn);
+
+exit:
+       return (cache << VMX_EPT_MT_EPTE_SHIFT) | ipat;
 }
 
 static int vmx_get_lpage_level(void)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 43f0df7..43fdb10 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -621,6 +621,10 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 
        if ((cr0 ^ old_cr0) & update_bits)
                kvm_mmu_reset_context(vcpu);
+
+       if ((cr0 ^ old_cr0) & X86_CR0_CD)
+               kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
+
        return 0;
 }
 EXPORT_SYMBOL_GPL(kvm_set_cr0);