KVM: MTRR: sort variable MTRRs

Sort all valid variable MTRRs based on its base address, it will help us to
check a range to see if it's fully contained in variable MTRRs

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
[Fix list insertion sort, simplify var_mtrr_range_is_valid to just
 test the V bit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

4 files changed, 45 insertions, 11 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f73554874845..f2d60cce7595 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -345,12 +345,15 @@ enum {
 struct kvm_mtrr_range {
         u64 base;
         u64 mask;
+        struct list_head node;
 };
 
 struct kvm_mtrr {
         struct kvm_mtrr_range var_ranges[KVM_NR_VAR_MTRR];
         mtrr_type fixed_ranges[KVM_NR_FIXED_MTRR_REGION];
         u64 deftype;
+
+        struct list_head head;
 };
 
 struct kvm_vcpu_arch {
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index b081e3ba186f..faa582488bb8 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -285,6 +285,39 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
         kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
 }
 
+static bool var_mtrr_range_is_valid(struct kvm_mtrr_range *range)
+{
+        return (range->mask & (1 << 11)) != 0;
+}
+
+static void set_var_mtrr_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+        struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
+        struct kvm_mtrr_range *tmp, *cur;
+        int index, is_mtrr_mask;
+
+        index = (msr - 0x200) / 2;
+        is_mtrr_mask = msr - 0x200 - 2 * index;
+        cur = &mtrr_state->var_ranges[index];
+
+        /* remove the entry if it's in the list. */
+        if (var_mtrr_range_is_valid(cur))
+                list_del(&mtrr_state->var_ranges[index].node);
+
+        if (!is_mtrr_mask)
+                cur->base = data;
+        else
+                cur->mask = data;
+
+        /* add it to the list if it's enabled. */
+        if (var_mtrr_range_is_valid(cur)) {
+                list_for_each_entry(tmp, &mtrr_state->head, node)
+                        if (cur->base >= tmp->base)
+                                break;
+                list_add_tail(&cur->node, &tmp->node);
+        }
+}
+
 int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 {
         int index;
@@ -299,16 +332,8 @@ int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
                 vcpu->arch.mtrr_state.deftype = data;
         else if (msr == MSR_IA32_CR_PAT)
                 vcpu->arch.pat = data;
-        else {  /* Variable MTRRs */
-                int is_mtrr_mask;
-
-                index = (msr - 0x200) / 2;
-                is_mtrr_mask = msr - 0x200 - 2 * index;
-                if (!is_mtrr_mask)
-                        vcpu->arch.mtrr_state.var_ranges[index].base = data;
-                else
-                        vcpu->arch.mtrr_state.var_ranges[index].mask = data;
-        }
+        else
+                set_var_mtrr_msr(vcpu, msr, data);
 
         update_mtrr(vcpu, msr);
         return 0;
@@ -354,6 +379,11 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
         return 0;
 }
 
+void kvm_vcpu_mtrr_init(struct kvm_vcpu *vcpu)
+{
+        INIT_LIST_HEAD(&vcpu->arch.mtrr_state.head);
+}
+
 u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
 {
         struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2ffad7f2a28e..6574fa36cb65 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7379,13 +7379,13 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 {
         int r;
 
+        kvm_vcpu_mtrr_init(vcpu);
         r = vcpu_load(vcpu);
         if (r)
                 return r;
         kvm_vcpu_reset(vcpu, false);
         kvm_mmu_setup(vcpu);
         vcpu_put(vcpu);
-
         return r;
 }
 
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index aeb0bb2f1df4..0e4727c49279 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -162,6 +162,7 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt,
         gva_t addr, void *val, unsigned int bytes,
         struct x86_exception *exception);
 
+void kvm_vcpu_mtrr_init(struct kvm_vcpu *vcpu);
 u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn);
 bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data);
 int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data);