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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>,
        Jim Mattson <jmattson@google.com>, erdemaktas@google.com,
        Connor Kuehl <ckuehl@redhat.com>,
        Sean Christopherson <seanjc@google.com>
Subject: [RFC PATCH v5 020/104] KVM: TDX: allocate per-package mutex
Date:   Fri,  4 Mar 2022 11:48:36 -0800
Message-Id: <f7b44d1d5a61f788294c399b63b505b3ff4d301b.1646422845.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

Several TDX SEAMCALLs are per-package scope (concretely per memory
controller) and they need to be serialized per-package.  Allocate mutex for
it.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/vmx/main.c    |  8 +++++++-
 arch/x86/kvm/vmx/tdx.c     | 18 ++++++++++++++++++
 arch/x86/kvm/vmx/x86_ops.h |  2 ++
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 8103d1c32cc9..6111c6485d8e 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -25,6 +25,12 @@ static __init int vt_hardware_setup(void)
 	return 0;
 }
 
+static void vt_hardware_unsetup(void)
+{
+	tdx_hardware_unsetup();
+	vmx_hardware_unsetup();
+}
+
 static int vt_vm_init(struct kvm *kvm)
 {
 	int ret;
@@ -42,7 +48,7 @@ static int vt_vm_init(struct kvm *kvm)
 struct kvm_x86_ops vt_x86_ops __initdata = {
 	.name = "kvm_intel",
 
-	.hardware_unsetup = vmx_hardware_unsetup,
+	.hardware_unsetup = vt_hardware_unsetup,
 
 	.hardware_enable = vmx_hardware_enable,
 	.hardware_disable = vmx_hardware_disable,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index e8d293a3c11c..1c8222f54764 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -34,6 +34,8 @@ struct tdx_capabilities {
 /* Capabilities of KVM + the TDX module. */
 struct tdx_capabilities tdx_caps;
 
+static struct mutex *tdx_mng_key_config_lock;
+
 static u64 hkid_mask __ro_after_init;
 static u8 hkid_start_pos __ro_after_init;
 
@@ -112,7 +114,9 @@ bool tdx_is_vm_type_supported(unsigned long type)
 
 static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
 {
+	int max_pkgs;
 	u32 max_pa;
+	int i;
 
 	if (!enable_ept) {
 		pr_warn("Cannot enable TDX with EPT disabled\n");
@@ -127,6 +131,14 @@ static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
 	if (WARN_ON_ONCE(x86_ops->tlb_remote_flush))
 		return -EIO;
 
+	max_pkgs = topology_max_packages();
+	tdx_mng_key_config_lock = kcalloc(max_pkgs, sizeof(*tdx_mng_key_config_lock),
+				   GFP_KERNEL);
+	if (!tdx_mng_key_config_lock)
+		return -ENOMEM;
+	for (i = 0; i < max_pkgs; i++)
+		mutex_init(&tdx_mng_key_config_lock[i]);
+
 	max_pa = cpuid_eax(0x80000008) & 0xff;
 	hkid_start_pos = boot_cpu_data.x86_phys_bits;
 	hkid_mask = GENMASK_ULL(max_pa - 1, hkid_start_pos);
@@ -147,6 +159,12 @@ void __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
 		enable_tdx = false;
 }
 
+void tdx_hardware_unsetup(void)
+{
+	/* kfree accepts NULL. */
+	kfree(tdx_mng_key_config_lock);
+}
+
 void __init tdx_pre_kvm_init(unsigned int *vcpu_size,
 			unsigned int *vcpu_align, unsigned int *vm_size)
 {
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 78331dbc29f7..da32b4b86b19 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -131,11 +131,13 @@ void __init tdx_pre_kvm_init(unsigned int *vcpu_size,
 			unsigned int *vcpu_align, unsigned int *vm_size);
 bool tdx_is_vm_type_supported(unsigned long type);
 void __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
+void tdx_hardware_unsetup(void);
 #else
 static inline void tdx_pre_kvm_init(
 	unsigned int *vcpu_size, unsigned int *vcpu_align, unsigned int *vm_size) {}
 static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
 static inline void tdx_hardware_setup(struct kvm_x86_ops *x86_ops) {}
+static inline void tdx_hardware_unsetup(void) {}
 #endif
 
 #endif /* __KVM_X86_VMX_X86_OPS_H */
-- 
2.25.1