[v9,15/84] KVM: x86: add .desc_intercepted()

Commit Message

Adalbert Lazăr July 21, 2020, 9:08 p.m. UTC

From: Nicușor Cîțu <[e-mail]>

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

Signed-off-by: Nicușor Cîțu <[e-mail]>
Signed-off-by: Adalbert Lazăr <[e-mail]>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/svm/svm.c          | 15 +++++++++++++++
 arch/x86/kvm/svm/svm.h          |  7 +++++++
 arch/x86/kvm/vmx/vmx.c          |  8 ++++++++
 4 files changed, 31 insertions(+)

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 83dfa0247130..2ed1e5621ccf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1125,6 +1125,7 @@  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 c70c14461483..cc55c571fe86 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1553,6 +1553,20 @@  static void svm_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
 	}
 }
 
+static inline bool svm_desc_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	return (get_intercept(svm, INTERCEPT_STORE_IDTR) ||
+		get_intercept(svm, INTERCEPT_STORE_GDTR) ||
+		get_intercept(svm, INTERCEPT_STORE_LDTR) ||
+		get_intercept(svm, INTERCEPT_STORE_TR) ||
+		get_intercept(svm, INTERCEPT_LOAD_IDTR) ||
+		get_intercept(svm, INTERCEPT_LOAD_GDTR) ||
+		get_intercept(svm, INTERCEPT_LOAD_LDTR) ||
+		get_intercept(svm, INTERCEPT_LOAD_TR));
+}
+
 static void update_cr0_intercept(struct vcpu_svm *svm)
 {
 	ulong gcr0 = svm->vcpu.arch.cr0;
@@ -4082,6 +4096,7 @@  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/svm/svm.h b/arch/x86/kvm/svm/svm.h
index d5c956e07c12..f86fababe413 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -318,6 +318,13 @@  static inline void clr_intercept(struct vcpu_svm *svm, int bit)
 	recalc_intercepts(svm);
 }
 
+static inline bool get_intercept(struct vcpu_svm *svm, int bit)
+{
+	struct vmcb *vmcb = get_host_vmcb(svm);
+
+	return (vmcb->control.intercept & (1ULL << bit));
+}
+
 static inline bool is_intercept(struct vcpu_svm *svm, int bit)
 {
 	return (svm->vmcb->control.intercept & (1ULL << bit)) != 0;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 199ffd318145..3b5778003b58 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3388,6 +3388,13 @@  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;
@@ -7915,6 +7922,7 @@  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,