[v10,11/81] KVM: x86: add kvm_x86_ops.desc_ctrl_supported()

Commit Message

Adalbert Lazăr Nov. 25, 2020, 9:34 a.m. UTC

When the introspection tool tries to enable the KVMI_VCPU_EVENT_DESCRIPTOR
event, this function is used to check if the control of VM-exits caused
by descriptor-table registers access is supported.

Signed-off-by: Adalbert Lazăr <[e-mail]>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm/svm.c          | 6 ++++++
 arch/x86/kvm/vmx/capabilities.h | 7 ++++++-
 arch/x86/kvm/vmx/vmx.c          | 1 +
 4 files changed, 14 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a402384a9326..1e9cb521324e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1130,6 +1130,7 @@  struct kvm_x86_ops {
 	void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*get_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
+	bool (*desc_ctrl_supported)(void);
 	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 5000ee25545b..f3ee6bad0db5 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1630,6 +1630,11 @@  static void svm_set_gdt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
 	vmcb_mark_dirty(svm->vmcb, VMCB_DT);
 }
 
+static bool svm_desc_ctrl_supported(void)
+{
+	return true;
+}
+
 static void update_cr0_intercept(struct vcpu_svm *svm)
 {
 	ulong gcr0 = svm->vcpu.arch.cr0;
@@ -4260,6 +4265,7 @@  static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.set_idt = svm_set_idt,
 	.get_gdt = svm_get_gdt,
 	.set_gdt = svm_set_gdt,
+	.desc_ctrl_supported = svm_desc_ctrl_supported,
 	.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/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 3a1861403d73..6695b061bae4 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -142,12 +142,17 @@  static inline bool cpu_has_vmx_ept(void)
 		SECONDARY_EXEC_ENABLE_EPT;
 }
 
-static inline bool vmx_umip_emulated(void)
+static inline bool vmx_desc_ctrl_supported(void)
 {
 	return vmcs_config.cpu_based_2nd_exec_ctrl &
 		SECONDARY_EXEC_DESC;
 }
 
+static inline bool vmx_umip_emulated(void)
+{
+	return vmx_desc_ctrl_supported();
+}
+
 static inline bool cpu_has_vmx_rdtscp(void)
 {
 	return vmcs_config.cpu_based_2nd_exec_ctrl &
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 7b2a60cd7a76..a5e1f61d2622 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7656,6 +7656,7 @@  static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.set_idt = vmx_set_idt,
 	.get_gdt = vmx_get_gdt,
 	.set_gdt = vmx_set_gdt,
+	.desc_ctrl_supported = vmx_desc_ctrl_supported,
 	.set_dr7 = vmx_set_dr7,
 	.sync_dirty_debug_regs = vmx_sync_dirty_debug_regs,
 	.cache_reg = vmx_cache_reg,