[PATCH v10 08/81] KVM: x86: add kvm_x86_ops.bp_intercepted()

["Adalbert Lazăr" <alazar@bitdefender.com>]

From: Nicușor Cîțu <nicu.citu@icloud.com>

Both, the introspection tool and the device manager can request #BP
interception. This function will be used to check if this interception
is already enabled by either side.

Signed-off-by: Nicușor Cîțu <nicu.citu@icloud.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm/svm.c          | 8 ++++++++
 arch/x86/kvm/svm/svm.h          | 7 +++++++
 arch/x86/kvm/vmx/vmx.c          | 6 ++++++
 4 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f002cdb13a0b..e46fee59d4ed 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1104,6 +1104,7 @@ struct kvm_x86_ops {
 	void (*vcpu_load)(struct kvm_vcpu *vcpu, int cpu);
 	void (*vcpu_put)(struct kvm_vcpu *vcpu);
 
+	bool (*bp_intercepted)(struct kvm_vcpu *vcpu);
 	void (*update_exception_bitmap)(struct kvm_vcpu *vcpu);
 	int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
 	int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 6dc337b9c231..95c7072cde8e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1738,6 +1738,13 @@ static void svm_set_segment(struct kvm_vcpu *vcpu,
 	vmcb_mark_dirty(svm->vmcb, VMCB_SEG);
 }
 
+static bool svm_bp_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	return get_exception_intercept(svm, BP_VECTOR);
+}
+
 static void update_exception_bitmap(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -4213,6 +4220,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.vcpu_blocking = svm_vcpu_blocking,
 	.vcpu_unblocking = svm_vcpu_unblocking,
 
+	.bp_intercepted = svm_bp_intercepted,
 	.update_exception_bitmap = update_exception_bitmap,
 	.get_msr_feature = svm_get_msr_feature,
 	.get_msr = svm_get_msr,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index fdff76eb6ceb..dca2dfe2e30d 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -294,6 +294,13 @@ static inline void clr_exception_intercept(struct vcpu_svm *svm, u32 bit)
 	recalc_intercepts(svm);
 }
 
+static inline bool get_exception_intercept(struct vcpu_svm *svm, int bit)
+{
+	struct vmcb *vmcb = get_host_vmcb(svm);
+
+	return vmcb_is_intercept(&vmcb->control, INTERCEPT_EXCEPTION_OFFSET + bit);
+}
+
 static inline void svm_set_intercept(struct vcpu_svm *svm, int bit)
 {
 	struct vmcb *vmcb = get_host_vmcb(svm);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c3441e7e5a87..93a97aa3d847 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -807,6 +807,11 @@ static u32 vmx_read_guest_seg_ar(struct vcpu_vmx *vmx, unsigned seg)
 	return *p;
 }
 
+static bool vmx_bp_intercepted(struct kvm_vcpu *vcpu)
+{
+	return (vmcs_read32(EXCEPTION_BITMAP) & (1u << BP_VECTOR));
+}
+
 void update_exception_bitmap(struct kvm_vcpu *vcpu)
 {
 	u32 eb;
@@ -7611,6 +7616,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.vcpu_load = vmx_vcpu_load,
 	.vcpu_put = vmx_vcpu_put,
 
+	.bp_intercepted = vmx_bp_intercepted,
 	.update_exception_bitmap = update_exception_bitmap,
 	.get_msr_feature = vmx_get_msr_feature,
 	.get_msr = vmx_get_msr,