KVM: TDX: Convert INIT_MEM_REGION and INIT_VCPU to "unlocked" vCPU ioctl

Handle the KVM_TDX_INIT_MEM_REGION and KVM_TDX_INIT_VCPU vCPU sub-ioctls
in the unlocked variant, i.e. outside of vcpu->mutex, in anticipation of
taking kvm->lock along with all other vCPU mutexes, at which point the
sub-ioctls _must_ start without vcpu->mutex held.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Link: https://patch.msgid.link/20251030200951.3402865-24-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index fdf178443f850a45735daf810135ea1aa5b60820..de709fb5bd76a103f174f95c3ca8c39474efea0e 100644 (file)
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -128,6 +128,7 @@ KVM_X86_OP(enable_smi_window)
 KVM_X86_OP_OPTIONAL(dev_get_attr)
 KVM_X86_OP_OPTIONAL(mem_enc_ioctl)
 KVM_X86_OP_OPTIONAL(vcpu_mem_enc_ioctl)
+KVM_X86_OP_OPTIONAL(vcpu_mem_enc_unlocked_ioctl)
 KVM_X86_OP_OPTIONAL(mem_enc_register_region)
 KVM_X86_OP_OPTIONAL(mem_enc_unregister_region)
 KVM_X86_OP_OPTIONAL(vm_copy_enc_context_from)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 87a5f5100b1d7ec1ae33e4b8c34a3180d21f9ecd..2bfae1cfa514cd04b1d1859f020d404df56fa091 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1914,6 +1914,7 @@ struct kvm_x86_ops {
        int (*dev_get_attr)(u32 group, u64 attr, u64 *val);
        int (*mem_enc_ioctl)(struct kvm *kvm, void __user *argp);
        int (*vcpu_mem_enc_ioctl)(struct kvm_vcpu *vcpu, void __user *argp);
+       int (*vcpu_mem_enc_unlocked_ioctl)(struct kvm_vcpu *vcpu, void __user *argp);
        int (*mem_enc_register_region)(struct kvm *kvm, struct kvm_enc_region *argp);
        int (*mem_enc_unregister_region)(struct kvm *kvm, struct kvm_enc_region *argp);
        int (*vm_copy_enc_context_from)(struct kvm *kvm, unsigned int source_fd);

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 0eb2773b2ae235ffdce889d815a6919eaacd2c64..a46ccd6707859f69db4166e72d636939fdb0a5f7 100644 (file)
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -831,6 +831,14 @@ static int vt_vcpu_mem_enc_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
        return tdx_vcpu_ioctl(vcpu, argp);
 }
 
+static int vt_vcpu_mem_enc_unlocked_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
+{
+       if (!is_td_vcpu(vcpu))
+               return -EINVAL;
+
+       return tdx_vcpu_unlocked_ioctl(vcpu, argp);
+}
+
 static int vt_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn,
                                     bool is_private)
 {
@@ -1005,6 +1013,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 
        .mem_enc_ioctl = vt_op_tdx_only(mem_enc_ioctl),
        .vcpu_mem_enc_ioctl = vt_op_tdx_only(vcpu_mem_enc_ioctl),
+       .vcpu_mem_enc_unlocked_ioctl = vt_op_tdx_only(vcpu_mem_enc_unlocked_ioctl),
 
        .gmem_max_mapping_level = vt_op_tdx_only(gmem_max_mapping_level)
 };

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index f42cc955d49c926f154939f2040fe2ce72c94551..3b4d62a3bf314e9d39d1e425d289b02db2c45c02 100644 (file)
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -3181,6 +3181,42 @@ static int tdx_vcpu_init_mem_region(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *c
        return ret;
 }
 
+int tdx_vcpu_unlocked_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
+{
+       struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm);
+       struct kvm_tdx_cmd cmd;
+       int r;
+
+       r = tdx_get_cmd(argp, &cmd);
+       if (r)
+               return r;
+
+       if (!is_hkid_assigned(kvm_tdx) || kvm_tdx->state == TD_STATE_RUNNABLE)
+               return -EINVAL;
+
+       if (mutex_lock_killable(&vcpu->mutex))
+               return -EINTR;
+
+       vcpu_load(vcpu);
+
+       switch (cmd.id) {
+       case KVM_TDX_INIT_MEM_REGION:
+               r = tdx_vcpu_init_mem_region(vcpu, &cmd);
+               break;
+       case KVM_TDX_INIT_VCPU:
+               r = tdx_vcpu_init(vcpu, &cmd);
+               break;
+       default:
+               r = -ENOIOCTLCMD;
+               break;
+       }
+
+       vcpu_put(vcpu);
+
+       mutex_unlock(&vcpu->mutex);
+       return r;
+}
+
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
 {
        struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm);
@@ -3195,12 +3231,6 @@ int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
                return ret;
 
        switch (cmd.id) {
-       case KVM_TDX_INIT_VCPU:
-               ret = tdx_vcpu_init(vcpu, &cmd);
-               break;
-       case KVM_TDX_INIT_MEM_REGION:
-               ret = tdx_vcpu_init_mem_region(vcpu, &cmd);
-               break;
        case KVM_TDX_GET_CPUID:
                ret = tdx_vcpu_get_cpuid(vcpu, &cmd);
                break;

diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 9697368d65b3a133017e553bbd900f55deadd753..a7a8709195801085897cbf03242f797ce92be128 100644 (file)
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -149,6 +149,7 @@ int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
 int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
 
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
+int tdx_vcpu_unlocked_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
 
 void tdx_flush_tlb_current(struct kvm_vcpu *vcpu);
 void tdx_flush_tlb_all(struct kvm_vcpu *vcpu);

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b85cb213a3369eb0eb77b3f223bde823eb6b21ba..593fccc9cf1c4dcb2c2b9030f40a187c7c80a3b0 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7243,6 +7243,13 @@ static int kvm_vm_ioctl_set_clock(struct kvm *kvm, void __user *argp)
 long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
                                  unsigned long arg)
 {
+       struct kvm_vcpu *vcpu = filp->private_data;
+       void __user *argp = (void __user *)arg;
+
+       if (ioctl == KVM_MEMORY_ENCRYPT_OP &&
+           kvm_x86_ops.vcpu_mem_enc_unlocked_ioctl)
+               return kvm_x86_call(vcpu_mem_enc_unlocked_ioctl)(vcpu, argp);
+
        return -ENOIOCTLCMD;
 }