[PATCH v12 12/77] KVM: x86: add kvm_x86_ops.desc_intercepted()

Adalbert Lazăr
2021-10-06T17:30:08Z

From: Nicu?or C??u <nicu.citu at icloud.com>

This function will be used to test if the descriptor-table registers
access is already tracked by userspace.

Signed-off-by: Nicu?or C??u <nicu.citu at icloud.com>
Signed-off-by: Adalbert Laz?r <alazar at bitdefender.com>
---
 arch/x86/include/asm/kvm-x86-ops.h |  1 +
 arch/x86/include/asm/kvm_host.h    |  1 +
 arch/x86/kvm/svm/svm.c             | 15 +++++++++++++++
 arch/x86/kvm/vmx/vmx.c             |  8 ++++++++
 4 files changed, 25 insertions(+)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h
b/arch/x86/include/asm/kvm-x86-ops.h
index dd08f3120f8f..30d01c9ed31b 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -126,6 +126,7 @@ KVM_X86_OP(control_cr3_intercept)
 KVM_X86_OP(cr3_write_intercepted)
 KVM_X86_OP(desc_ctrl_supported)
 KVM_X86_OP(control_desc_intercept)
+KVM_X86_OP(desc_intercepted)

 #undef KVM_X86_OP
 #undef KVM_X86_OP_NULL
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2e5ddb18804b..1182b0fbd245 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1351,6 +1351,7 @@ struct kvm_x86_ops {
 	void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	bool (*desc_ctrl_supported)(void);
 	void (*control_desc_intercept)(struct kvm_vcpu *vcpu, bool enable);
+	bool (*desc_intercepted)(struct kvm_vcpu *vcpu);
 	void (*sync_dirty_debug_regs)(struct kvm_vcpu *vcpu);
 	void (*set_dr7)(struct kvm_vcpu *vcpu, unsigned long value);
 	void (*cache_reg)(struct kvm_vcpu *vcpu, enum kvm_reg reg);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 0d46f5aa20c3..c1b1e5cdd508 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1805,6 +1805,20 @@ static void svm_control_desc_intercept(struct kvm_vcpu
*vcpu, bool enable)
 	}
 }

+static bool svm_desc_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	return (svm_is_intercept(svm, INTERCEPT_STORE_IDTR) ||
+		svm_is_intercept(svm, INTERCEPT_STORE_GDTR) ||
+		svm_is_intercept(svm, INTERCEPT_STORE_LDTR) ||
+		svm_is_intercept(svm, INTERCEPT_STORE_TR) ||
+		svm_is_intercept(svm, INTERCEPT_LOAD_IDTR) ||
+		svm_is_intercept(svm, INTERCEPT_LOAD_GDTR) ||
+		svm_is_intercept(svm, INTERCEPT_LOAD_LDTR) ||
+		svm_is_intercept(svm, INTERCEPT_LOAD_TR));
+}
+
 void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -4692,6 +4706,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.set_gdt = svm_set_gdt,
 	.desc_ctrl_supported = svm_desc_ctrl_supported,
 	.control_desc_intercept = svm_control_desc_intercept,
+	.desc_intercepted = svm_desc_intercepted,
 	.set_dr7 = svm_set_dr7,
 	.sync_dirty_debug_regs = svm_sync_dirty_debug_regs,
 	.cache_reg = svm_cache_reg,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d0f02d52b401..8f34b19827a3 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3405,6 +3405,13 @@ static void vmx_set_gdt(struct kvm_vcpu *vcpu, struct
desc_ptr *dt)
 	vmcs_writel(GUEST_GDTR_BASE, dt->address);
 }

+static bool vmx_desc_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	return !!(secondary_exec_controls_get(vmx) & SECONDARY_EXEC_DESC);
+}
+
 static bool rmode_segment_valid(struct kvm_vcpu *vcpu, int seg)
 {
 	struct kvm_segment var;
@@ -7647,6 +7654,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.set_gdt = vmx_set_gdt,
 	.desc_ctrl_supported = vmx_desc_ctrl_supported,
 	.control_desc_intercept = vmx_control_desc_intercept,
+	.desc_intercepted = vmx_desc_intercepted,
 	.set_dr7 = vmx_set_dr7,
 	.sync_dirty_debug_regs = vmx_sync_dirty_debug_regs,
 	.cache_reg = vmx_cache_reg,