[PATCH 10/15] KVM: MTRR: sort variable MTRRs

[Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |  3 +++
 arch/x86/kvm/mtrr.c             | 39 +++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/x86.c              |  2 +-
 arch/x86/kvm/x86.h              |  1 +
 4 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f3fc152..5be8f2e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -347,6 +347,7 @@ enum {
 struct kvm_mtrr_range {
 	u64 base;
 	u64 mask;
+	struct list_head node;
 };
 
 struct kvm_mtrr {
@@ -362,6 +363,8 @@ struct kvm_mtrr {
 			unsigned mtrr_enabled:1;
 		};
 	};
+
+	struct list_head head;
 };
 
 struct kvm_vcpu_arch {
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index aeb9767..8e3b81a 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -262,6 +262,38 @@ do_zap:
 	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)
+{
+	u64 start, end;
+
+	if (!(range->mask & (1 << 11)))
+		return false;
+
+	var_mtrr_range(range, &start, &end);
+	return end > start;
+}
+
+static void set_var_mtrr_start(struct kvm_mtrr *mtrr_state, int index)
+{
+	/* remove the entry if it's in the list. */
+	if (var_mtrr_range_is_valid(&mtrr_state->var_ranges[index]))
+		list_del(&mtrr_state->var_ranges[index].node);
+}
+
+static void set_var_mtrr_end(struct kvm_mtrr *mtrr_state, int index)
+{
+	struct kvm_mtrr_range *tmp, *cur = &mtrr_state->var_ranges[index];
+
+	/* add it to the list if it's valid. */
+	if (var_mtrr_range_is_valid(&mtrr_state->var_ranges[index])) {
+		list_for_each_entry(tmp, &mtrr_state->head, node)
+			if (cur->base < tmp->base)
+				list_add_tail(&cur->node, &tmp->node);
+
+		list_add_tail(&cur->node, &mtrr_state->head);
+	}
+}
+
 int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 {
 	int index;
@@ -281,10 +313,12 @@ int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 
 		index = (msr - 0x200) / 2;
 		is_mtrr_mask = msr - 0x200 - 2 * index;
+		set_var_mtrr_start(&vcpu->arch.mtrr_state, index);
 		if (!is_mtrr_mask)
 			vcpu->arch.mtrr_state.var_ranges[index].base = data;
 		else
 			vcpu->arch.mtrr_state.var_ranges[index].mask = data;
+		set_var_mtrr_end(&vcpu->arch.mtrr_state, index);
 	}
 
 	update_mtrr(vcpu, msr);
@@ -331,6 +365,11 @@ 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 64c2891..8084ac3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6991,7 +6991,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 	kvm_vcpu_reset(vcpu, false);
 	kvm_mmu_setup(vcpu);
 	vcpu_put(vcpu);
-
+	kvm_vcpu_mtrr_init(vcpu);
 	return r;
 }
 
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 956558d..a3dae49 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);
 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);
 int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata);
-- 
2.1.0

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