[v17,003/116] KVM: x86/vmx: Refactor KVM VMX module init/exit functions

Commit Message

Isaku Yamahata Nov. 7, 2023, 2:55 p.m. UTC

From: Isaku Yamahata <[e-mail]>

Currently, KVM VMX module initialization/exit functions are a single
function each.  Refactor KVM VMX module initialization functions into KVM
common part and VMX part so that TDX specific part can be added cleanly.
Opportunistically refactor module exit function as well.

The current module initialization flow is,
0.) Check if VMX is supported,
1.) hyper-v specific initialization,
2.) system-wide x86 specific and vendor specific initialization,
3.) Final VMX specific system-wide initialization,
4.) calculate the sizes of VMX kvm structure and VMX vcpu structure,
5.) report those sizes to the KVM common layer and KVM common
    initialization

Refactor the KVM VMX module initialization function into functions with a
wrapper function to separate VMX logic in vmx.c from a file, main.c, common
among VMX and TDX.  Introduce a wrapper function for vmx_init().

The KVM architecture common layer allocates struct kvm with reported size
for architecture-specific code.  The KVM VMX module defines its structure
as struct vmx_kvm { struct kvm; VMX specific members;} and uses it as
struct vmx kvm.  Similar for vcpu structure. TDX KVM patches will define
TDX specific kvm and vcpu structures.

The current module exit function is also a single function, a combination
of VMX specific logic and common KVM logic.  Refactor it into VMX specific
logic and KVM common logic.  This is just refactoring to keep the VMX
specific logic in vmx.c from main.c.

Signed-off-by: Isaku Yamahata <[e-mail]>
---
 arch/x86/kvm/vmx/main.c    | 50 +++++++++++++++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c     | 54 +++++---------------------------------
 arch/x86/kvm/vmx/x86_ops.h | 13 ++++++++-
 3 files changed, 68 insertions(+), 49 deletions(-)

Comments

Binbin Wu Dec. 5, 2023, 7:42 a.m. UTC | #1

On 11/7/2023 10:55 PM, [e-mail] wrote:
> From: Isaku Yamahata <[e-mail]>
>
> Currently, KVM VMX module initialization/exit functions are a single
> function each.  Refactor KVM VMX module initialization functions into KVM
> common part and VMX part so that TDX specific part can be added cleanly.
> Opportunistically refactor module exit function as well.
>
> The current module initialization flow is,
> 0.) Check if VMX is supported,
> 1.) hyper-v specific initialization,
> 2.) system-wide x86 specific and vendor specific initialization,
> 3.) Final VMX specific system-wide initialization,
> 4.) calculate the sizes of VMX kvm structure and VMX vcpu structure,
> 5.) report those sizes to the KVM common layer and KVM common
>      initialization
>
> Refactor the KVM VMX module initialization function into functions with a
> wrapper function to separate VMX logic in vmx.c from a file, main.c, common
> among VMX and TDX.  Introduce a wrapper function for vmx_init().
>
> The KVM architecture common layer allocates struct kvm with reported size
> for architecture-specific code.  The KVM VMX module defines its structure
> as struct vmx_kvm { struct kvm; VMX specific members;} and uses it as
> struct vmx kvm.  Similar for vcpu structure. TDX KVM patches will define
> TDX specific kvm and vcpu structures.
>
> The current module exit function is also a single function, a combination
> of VMX specific logic and common KVM logic.  Refactor it into VMX specific
> logic and KVM common logic.  This is just refactoring to keep the VMX
> specific logic in vmx.c from main.c.
>
> Signed-off-by: Isaku Yamahata <[e-mail]>
> ---
>   arch/x86/kvm/vmx/main.c    | 50 +++++++++++++++++++++++++++++++++++
>   arch/x86/kvm/vmx/vmx.c     | 54 +++++---------------------------------
>   arch/x86/kvm/vmx/x86_ops.h | 13 ++++++++-
>   3 files changed, 68 insertions(+), 49 deletions(-)
>
[...]
> diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
> index 4af1b01aa9c0..c4e3ae971f94 100644
> --- a/arch/x86/kvm/vmx/x86_ops.h
> +++ b/arch/x86/kvm/vmx/x86_ops.h
> @@ -6,11 +6,22 @@
>   
>   #include "x86.h"
>   
> -__init int vmx_hardware_setup(void);
> +#if IS_ENABLED(CONFIG_HYPERV)
> +__init void hv_init_evmcs(void);
> +void hv_reset_evmcs(void);
> +#else /* IS_ENABLED(CONFIG_HYPERV) */
> +static inline void hv_init_evmcs(void) {}

Does this one need "__init"?
Though it's empty, I checked exist kernel code, other empty static 
inline ones
add "__init" for init code.

> +static inline void hv_reset_evmcs(void) {}
> +#endif /* IS_ENABLED(CONFIG_HYPERV) */
> +
> +bool kvm_is_vmx_supported(void);
> +int __init vmx_init(void);
> +void vmx_exit(void);
>   
>   extern struct kvm_x86_ops vt_x86_ops __initdata;
>   extern struct kvm_x86_init_ops vt_init_ops __initdata;
>   
> +__init int vmx_hardware_setup(void);
>   void vmx_hardware_unsetup(void);
>   int vmx_check_processor_compat(void);
>   int vmx_hardware_enable(void);

Patch

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index ea6c368db8cb..266760865ed8 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -165,3 +165,53 @@  struct kvm_x86_init_ops vt_init_ops __initdata = {
 	.runtime_ops = &vt_x86_ops,
 	.pmu_ops = &intel_pmu_ops,
 };
+
+static int __init vt_init(void)
+{
+	unsigned int vcpu_size, vcpu_align;
+	int r;
+
+	if (!kvm_is_vmx_supported())
+		return -EOPNOTSUPP;
+
+	/*
+	 * Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing
+	 * to unwind if a later step fails.
+	 */
+	hv_init_evmcs();
+
+	r = kvm_x86_vendor_init(&vt_init_ops);
+	if (r)
+		return r;
+
+	r = vmx_init();
+	if (r)
+		goto err_vmx_init;
+
+	/*
+	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
+	 * exposed to userspace!
+	 */
+	vcpu_size = sizeof(struct vcpu_vmx);
+	vcpu_align = __alignof__(struct vcpu_vmx);
+	r = kvm_init(vcpu_size, vcpu_align, THIS_MODULE);
+	if (r)
+		goto err_kvm_init;
+
+	return 0;
+
+err_kvm_init:
+	vmx_exit();
+err_vmx_init:
+	kvm_x86_vendor_exit();
+	return r;
+}
+module_init(vt_init);
+
+static void vt_exit(void)
+{
+	kvm_exit();
+	kvm_x86_vendor_exit();
+	vmx_exit();
+}
+module_exit(vt_exit);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0f3769cc3741..34165a3c99fa 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -544,7 +544,7 @@  static int hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-static __init void hv_init_evmcs(void)
+__init void hv_init_evmcs(void)
 {
 	int cpu;
 
@@ -580,7 +580,7 @@  static __init void hv_init_evmcs(void)
 	}
 }
 
-static void hv_reset_evmcs(void)
+void hv_reset_evmcs(void)
 {
 	struct hv_vp_assist_page *vp_ap;
 
@@ -604,10 +604,6 @@  static void hv_reset_evmcs(void)
 	vp_ap->current_nested_vmcs = 0;
 	vp_ap->enlighten_vmentry = 0;
 }
-
-#else /* IS_ENABLED(CONFIG_HYPERV) */
-static void hv_init_evmcs(void) {}
-static void hv_reset_evmcs(void) {}
 #endif /* IS_ENABLED(CONFIG_HYPERV) */
 
 /*
@@ -2748,7 +2744,7 @@  static bool __kvm_is_vmx_supported(void)
 	return true;
 }
 
-static bool kvm_is_vmx_supported(void)
+bool kvm_is_vmx_supported(void)
 {
 	bool supported;
 
@@ -8465,7 +8461,7 @@  static void vmx_cleanup_l1d_flush(void)
 	l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO;
 }
 
-static void __vmx_exit(void)
+void vmx_exit(void)
 {
 	allow_smaller_maxphyaddr = false;
 
@@ -8474,32 +8470,10 @@  static void __vmx_exit(void)
 	vmx_cleanup_l1d_flush();
 }
 
-static void vmx_exit(void)
-{
-	kvm_exit();
-	kvm_x86_vendor_exit();
-
-	__vmx_exit();
-}
-module_exit(vmx_exit);
-
-static int __init vmx_init(void)
+int __init vmx_init(void)
 {
 	int r, cpu;
 
-	if (!kvm_is_vmx_supported())
-		return -EOPNOTSUPP;
-
-	/*
-	 * Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing
-	 * to unwind if a later step fails.
-	 */
-	hv_init_evmcs();
-
-	r = kvm_x86_vendor_init(&vt_init_ops);
-	if (r)
-		return r;
-
 	/*
 	 * Must be called after common x86 init so enable_ept is properly set
 	 * up. Hand the parameter mitigation value in which was stored in
@@ -8509,7 +8483,7 @@  static int __init vmx_init(void)
 	 */
 	r = vmx_setup_l1d_flush(vmentry_l1d_flush_param);
 	if (r)
-		goto err_l1d_flush;
+		return r;
 
 	for_each_possible_cpu(cpu)
 		pi_init_cpu(cpu);
@@ -8526,21 +8500,5 @@  static int __init vmx_init(void)
 	if (!enable_ept)
 		allow_smaller_maxphyaddr = true;
 
-	/*
-	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
-	 * exposed to userspace!
-	 */
-	r = kvm_init(sizeof(struct vcpu_vmx), __alignof__(struct vcpu_vmx),
-		     THIS_MODULE);
-	if (r)
-		goto err_kvm_init;
-
 	return 0;
-
-err_kvm_init:
-	__vmx_exit();
-err_l1d_flush:
-	kvm_x86_vendor_exit();
-	return r;
 }
-module_init(vmx_init);
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 4af1b01aa9c0..c4e3ae971f94 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -6,11 +6,22 @@ 
 
 #include "x86.h"
 
-__init int vmx_hardware_setup(void);
+#if IS_ENABLED(CONFIG_HYPERV)
+__init void hv_init_evmcs(void);
+void hv_reset_evmcs(void);
+#else /* IS_ENABLED(CONFIG_HYPERV) */
+static inline void hv_init_evmcs(void) {}
+static inline void hv_reset_evmcs(void) {}
+#endif /* IS_ENABLED(CONFIG_HYPERV) */
+
+bool kvm_is_vmx_supported(void);
+int __init vmx_init(void);
+void vmx_exit(void);
 
 extern struct kvm_x86_ops vt_x86_ops __initdata;
 extern struct kvm_x86_init_ops vt_init_ops __initdata;
 
+__init int vmx_hardware_setup(void);
 void vmx_hardware_unsetup(void);
 int vmx_check_processor_compat(void);
 int vmx_hardware_enable(void);