diff --git a/libraries/libmesosphere/include/mesosphere/kern_k_light_session.hpp b/libraries/libmesosphere/include/mesosphere/kern_k_light_session.hpp
index 2e3ad41c1..d37f69b48 100644
--- a/libraries/libmesosphere/include/mesosphere/kern_k_light_session.hpp
+++ b/libraries/libmesosphere/include/mesosphere/kern_k_light_session.hpp
@@ -34,6 +34,9 @@ namespace ams::kern {
                 ClientClosed = 2,
                 ServerClosed = 3,
             };
+        public:
+            static constexpr size_t DataSize = sizeof(u32) * 7;
+            static constexpr u32 ReplyFlag   = (1u << (BITSIZEOF(u32) - 1));
         private:
             KLightServerSession server;
             KLightClientSession client;
diff --git a/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp b/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp
index 43717e950..c125da29e 100644
--- a/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp
+++ b/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp
@@ -410,6 +410,9 @@ namespace ams::kern {
             void ClearCancellable() { this->cancellable = false; }
             void SetCancellable() { this->cancellable = true; }
 
+            constexpr u32 *GetLightSessionData() const { return this->light_ipc_data; }
+            constexpr void SetLightSessionData(u32 *data) { this->light_ipc_data = data; }
+
             bool HasWaiters() const { return !this->waiter_list.empty(); }
 
             constexpr s64 GetLastScheduledTick() const { return this->last_scheduled_tick; }
diff --git a/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_light_ipc_asm.s b/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_light_ipc_asm.s
new file mode 100644
index 000000000..acc64aa19
--- /dev/null
+++ b/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_light_ipc_asm.s
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* ams::kern::svc::CallSendSyncRequestLight64() */
+.section    .text._ZN3ams4kern3svc26CallSendSyncRequestLight64Ev, "ax", %progbits
+.global     _ZN3ams4kern3svc26CallSendSyncRequestLight64Ev
+.type       _ZN3ams4kern3svc26CallSendSyncRequestLight64Ev, %function
+_ZN3ams4kern3svc26CallSendSyncRequestLight64Ev:
+    /* Allocate space for the light ipc data. */
+    sub     sp, sp, #(4 * 8)
+
+    /* Store the light ipc data. */
+    stp     w1, w2, [sp, #(4 * 0)]
+    stp     w3, w4, [sp, #(4 * 2)]
+    stp     w5, w6, [sp, #(4 * 4)]
+    str     w7,     [sp, #(4 * 6)]
+
+    /* Invoke the svc handler. */
+    mov     x1, sp
+    stp     x29, x30, [sp, #-16]!
+    bl      _ZN3ams4kern3svc22SendSyncRequestLight64EjPj
+    ldp     x29, x30, [sp], #16
+
+    /* Load the light ipc data. */
+    ldp     w1, w2, [sp, #(4 * 0)]
+    ldp     w3, w4, [sp, #(4 * 2)]
+    ldp     w5, w6, [sp, #(4 * 4)]
+    ldr     w7,     [sp, #(4 * 6)]
+
+    /* Free the stack space for the light ipc data. */
+    add     sp, sp, #(4 * 8)
+
+    ret
+
+/* ams::kern::svc::CallSendSyncRequestLight64From32() */
+.section    .text._ZN3ams4kern3svc32CallSendSyncRequestLight64From32Ev, "ax", %progbits
+.global     _ZN3ams4kern3svc32CallSendSyncRequestLight64From32Ev
+.type       _ZN3ams4kern3svc32CallSendSyncRequestLight64From32Ev, %function
+_ZN3ams4kern3svc32CallSendSyncRequestLight64From32Ev:
+    /* Load x4-x7 from where the svc handler stores them. */
+    ldp     x4, x5, [sp, #(8 * 0)]
+    ldp     x6, x7, [sp, #(8 * 2)]
+
+    /* Allocate space for the light ipc data. */
+    sub     sp, sp, #(4 * 8)
+
+    /* Store the light ipc data. */
+    stp     w1, w2, [sp, #(4 * 0)]
+    stp     w3, w4, [sp, #(4 * 2)]
+    stp     w5, w6, [sp, #(4 * 4)]
+    str     w7,     [sp, #(4 * 6)]
+
+    /* Invoke the svc handler. */
+    mov     x1, sp
+    stp     x29, x30, [sp, #-16]!
+    bl      _ZN3ams4kern3svc28SendSyncRequestLight64From32EjPj
+    ldp     x29, x30, [sp], #16
+
+    /* Load the light ipc data. */
+    ldp     w1, w2, [sp, #(4 * 0)]
+    ldp     w3, w4, [sp, #(4 * 2)]
+    ldp     w5, w6, [sp, #(4 * 4)]
+    ldr     w7,     [sp, #(4 * 6)]
+
+    /* Free the stack space for the light ipc data. */
+    add     sp, sp, #(4 * 8)
+
+    /* Save x4-x7 to where the svc handler stores them. */
+    stp     x4, x5, [sp, #(8 * 0)]
+    stp     x6, x7, [sp, #(8 * 2)]
+
+    ret
+
+
+/* ams::kern::svc::CallReplyAndReceiveLight64() */
+.section    .text._ZN3ams4kern3svc26CallReplyAndReceiveLight64Ev, "ax", %progbits
+.global     _ZN3ams4kern3svc26CallReplyAndReceiveLight64Ev
+.type       _ZN3ams4kern3svc26CallReplyAndReceiveLight64Ev, %function
+_ZN3ams4kern3svc26CallReplyAndReceiveLight64Ev:
+    /* Allocate space for the light ipc data. */
+    sub     sp, sp, #(4 * 8)
+
+    /* Store the light ipc data. */
+    stp     w1, w2, [sp, #(4 * 0)]
+    stp     w3, w4, [sp, #(4 * 2)]
+    stp     w5, w6, [sp, #(4 * 4)]
+    str     w7,     [sp, #(4 * 6)]
+
+    /* Invoke the svc handler. */
+    mov     x1, sp
+    stp     x29, x30, [sp, #-16]!
+    bl      _ZN3ams4kern3svc22ReplyAndReceiveLight64EjPj
+    ldp     x29, x30, [sp], #16
+
+    /* Load the light ipc data. */
+    ldp     w1, w2, [sp, #(4 * 0)]
+    ldp     w3, w4, [sp, #(4 * 2)]
+    ldp     w5, w6, [sp, #(4 * 4)]
+    ldr     w7,     [sp, #(4 * 6)]
+
+    /* Free the stack space for the light ipc data. */
+    add     sp, sp, #(4 * 8)
+
+    ret
+
+/* ams::kern::svc::CallReplyAndReceiveLight64From32() */
+.section    .text._ZN3ams4kern3svc32CallReplyAndReceiveLight64From32Ev, "ax", %progbits
+.global     _ZN3ams4kern3svc32CallReplyAndReceiveLight64From32Ev
+.type       _ZN3ams4kern3svc32CallReplyAndReceiveLight64From32Ev, %function
+_ZN3ams4kern3svc32CallReplyAndReceiveLight64From32Ev:
+    /* Load x4-x7 from where the svc handler stores them. */
+    ldp     x4, x5, [sp, #(8 * 0)]
+    ldp     x6, x7, [sp, #(8 * 2)]
+
+    /* Allocate space for the light ipc data. */
+    sub     sp, sp, #(4 * 8)
+
+    /* Store the light ipc data. */
+    stp     w1, w2, [sp, #(4 * 0)]
+    stp     w3, w4, [sp, #(4 * 2)]
+    stp     w5, w6, [sp, #(4 * 4)]
+    str     w7,     [sp, #(4 * 6)]
+
+    /* Invoke the svc handler. */
+    mov     x1, sp
+    stp     x29, x30, [sp, #-16]!
+    bl      _ZN3ams4kern3svc28ReplyAndReceiveLight64From32EjPj
+    ldp     x29, x30, [sp], #16
+
+    /* Load the light ipc data. */
+    ldp     w1, w2, [sp, #(4 * 0)]
+    ldp     w3, w4, [sp, #(4 * 2)]
+    ldp     w5, w6, [sp, #(4 * 4)]
+    ldr     w7,     [sp, #(4 * 6)]
+
+    /* Free the stack space for the light ipc data. */
+    add     sp, sp, #(4 * 8)
+
+    /* Save x4-x7 to where the svc handler stores them. */
+    stp     x4, x5, [sp, #(8 * 0)]
+    stp     x6, x7, [sp, #(8 * 2)]
+
+    ret
diff --git a/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_tables.cpp b/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_tables.cpp
index 9e7510f1f..3bb4b84b4 100644
--- a/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_tables.cpp
+++ b/libraries/libmesosphere/source/arch/arm64/svc/kern_svc_tables.cpp
@@ -22,6 +22,13 @@
 
 namespace ams::kern::svc {
 
+    /* Declare special prototypes for the light ipc handlers. */
+    void CallSendSyncRequestLight64();
+    void CallSendSyncRequestLight64From32();
+
+    void CallReplyAndReceiveLight64();
+    void CallReplyAndReceiveLight64From32();
+
     namespace {
 
         #ifndef MESOSPHERE_USE_STUBBED_SVC_TABLES
@@ -59,6 +66,9 @@ namespace ams::kern::svc {
             AMS_SVC_FOREACH_KERN_DEFINITION(AMS_KERN_SVC_SET_TABLE_ENTRY, _)
             #undef AMS_KERN_SVC_SET_TABLE_ENTRY
 
+            table[svc::SvcId_SendSyncRequestLight] = CallSendSyncRequestLight64From32;
+            table[svc::SvcId_ReplyAndReceiveLight] = CallReplyAndReceiveLight64From32;
+
             return table;
         }();
 
@@ -70,6 +80,9 @@ namespace ams::kern::svc {
             AMS_SVC_FOREACH_KERN_DEFINITION(AMS_KERN_SVC_SET_TABLE_ENTRY, _)
             #undef AMS_KERN_SVC_SET_TABLE_ENTRY
 
+            table[svc::SvcId_SendSyncRequestLight] = CallSendSyncRequestLight64;
+            table[svc::SvcId_ReplyAndReceiveLight] = CallReplyAndReceiveLight64;
+
             return table;
         }();
 
diff --git a/libraries/libmesosphere/source/kern_k_light_client_session.cpp b/libraries/libmesosphere/source/kern_k_light_client_session.cpp
index b2c5686ef..deacc8ee0 100644
--- a/libraries/libmesosphere/source/kern_k_light_client_session.cpp
+++ b/libraries/libmesosphere/source/kern_k_light_client_session.cpp
@@ -30,7 +30,24 @@ namespace ams::kern {
     Result KLightClientSession::SendSyncRequest(u32 *data) {
         MESOSPHERE_ASSERT_THIS();
 
-        MESOSPHERE_UNIMPLEMENTED();
+        /* Get the request thread. */
+        KThread *cur_thread = GetCurrentThreadPointer();
+
+        /* Set the light data. */
+        cur_thread->SetLightSessionData(data);
+
+        /* Send the request. */
+        {
+            KScopedSchedulerLock sl;
+
+            cur_thread->SetSyncedObject(nullptr, ResultSuccess());
+
+            R_TRY(this->parent->OnRequest(cur_thread));
+        }
+
+        /* Get the result. */
+        KSynchronizationObject *dummy;
+        return cur_thread->GetWaitResult(std::addressof(dummy));
     }
 
 }
diff --git a/libraries/libmesosphere/source/kern_k_light_server_session.cpp b/libraries/libmesosphere/source/kern_k_light_server_session.cpp
index c3995191c..7c3cc1ce9 100644
--- a/libraries/libmesosphere/source/kern_k_light_server_session.cpp
+++ b/libraries/libmesosphere/source/kern_k_light_server_session.cpp
@@ -27,18 +27,152 @@ namespace ams::kern {
 
     void KLightServerSession::OnClientClosed() {
         MESOSPHERE_ASSERT_THIS();
+
+        this->CleanupRequests();
     }
 
     Result KLightServerSession::OnRequest(KThread *request_thread) {
-        MESOSPHERE_UNIMPLEMENTED();
+        MESOSPHERE_ASSERT_THIS();
+        MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
+
+        /* Check that the server isn't closed. */
+        R_UNLESS(!this->parent->IsServerClosed(), svc::ResultSessionClosed());
+
+        /* Try to sleep the thread. */
+        R_UNLESS(this->request_queue.SleepThread(request_thread), svc::ResultTerminationRequested());
+
+        /* If we don't have a current request, wake up a server thread to handle it. */
+        if (this->current_request == nullptr) {
+            this->server_queue.WakeupFrontThread();
+        }
+
+        return ResultSuccess();
     }
 
     Result KLightServerSession::ReplyAndReceive(u32 *data) {
-        MESOSPHERE_UNIMPLEMENTED();
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Set the server context. */
+        KThread *server_thread = GetCurrentThreadPointer();
+        server_thread->SetLightSessionData(data);
+
+        /* Reply, if we need to. */
+        KThread *cur_request = nullptr;
+        if (data[0] & KLightSession::ReplyFlag) {
+            KScopedSchedulerLock sl;
+
+            /* Check that we're open. */
+            R_UNLESS(!this->parent->IsClientClosed(), svc::ResultSessionClosed());
+            R_UNLESS(!this->parent->IsServerClosed(), svc::ResultSessionClosed());
+
+            /* Check that we have a request to reply to. */
+            R_UNLESS(this->current_request != nullptr, svc::ResultInvalidState());
+
+            /* Check that the server thread is correct. */
+            R_UNLESS(this->server_thread == server_thread, svc::ResultInvalidState());
+
+            /* If we can reply, do so. */
+            if (!this->current_request->IsTerminationRequested()) {
+                MESOSPHERE_ASSERT(this->current_request->GetState() == KThread::ThreadState_Waiting);
+                MESOSPHERE_ASSERT(this->current_request == this->request_queue.GetFront());
+                std::memcpy(this->current_request->GetLightSessionData(), server_thread->GetLightSessionData(), KLightSession::DataSize);
+                this->request_queue.WakeupThread(this->current_request);
+            }
+
+            /* Clear our current request. */
+            cur_request = this->current_request;
+            this->current_request = nullptr;
+            this->server_thread   = nullptr;
+        }
+
+        /* Close the current request, if we had one. */
+        if (cur_request != nullptr) {
+            cur_request->Close();
+        }
+
+        /* Receive. */
+        bool set_cancellable = false;
+        while (true) {
+            KScopedSchedulerLock sl;
+
+            /* Check that we aren't already receiving. */
+            R_UNLESS(this->server_queue.IsEmpty(),   svc::ResultInvalidState());
+            R_UNLESS(this->server_thread == nullptr, svc::ResultInvalidState());
+
+            /* If we cancelled in a previous loop, clear cancel state. */
+            if (set_cancellable) {
+                server_thread->ClearCancellable();
+                set_cancellable = false;
+            }
+
+            /* Check that we're open. */
+            R_UNLESS(!this->parent->IsClientClosed(), svc::ResultSessionClosed());
+            R_UNLESS(!this->parent->IsServerClosed(), svc::ResultSessionClosed());
+
+            /* If we have a request available, use it. */
+            if (this->current_request == nullptr && this->request_queue.IsEmpty()) {
+                this->current_request = this->request_queue.GetFront();
+                this->current_request->Open();
+                this->server_thread   = server_thread;
+            } else {
+                /* Otherwise, wait for a request to come in. */
+                R_UNLESS(this->server_queue.SleepThread(server_thread), svc::ResultTerminationRequested());
+
+                /* Check if we were cancelled. */
+                if (server_thread->IsWaitCancelled()) {
+                    this->server_queue.WakeupThread(server_thread);
+                    server_thread->ClearWaitCancelled();
+                    return svc::ResultCancelled();
+                }
+
+                /* Otherwise, mark as cancellable. */
+                server_thread->SetCancellable();
+                set_cancellable = true;
+            }
+        }
+
+        /* Copy the client data. */
+        std::memcpy(server_thread->GetLightSessionData(), this->current_request->GetLightSessionData(), KLightSession::DataSize);
     }
 
     void KLightServerSession::CleanupRequests() {
-        MESOSPHERE_UNIMPLEMENTED();
+        /* Cleanup all pending requests. */
+        KThread *cur_request = nullptr;
+        {
+            KScopedSchedulerLock sl;
+
+            /* Handle the current request. */
+            if (this->current_request != nullptr) {
+                /* Reply to the current request. */
+                if (!this->current_request->IsTerminationRequested()) {
+                    MESOSPHERE_ASSERT(this->current_request->GetState() == KThread::ThreadState_Waiting);
+                    MESOSPHERE_ASSERT(this->current_request == this->request_queue.GetFront());
+                    this->request_queue.WakeupThread(this->current_request);
+                    this->current_request->SetSyncedObject(nullptr, svc::ResultSessionClosed());
+                }
+
+                /* Clear our current request. */
+                cur_request = this->current_request;
+                this->current_request = nullptr;
+                this->server_thread   = nullptr;
+            }
+
+            /* Reply to all other requests. */
+            while (!this->request_queue.IsEmpty()) {
+                KThread *client_thread = this->request_queue.WakeupFrontThread();
+                client_thread->SetSyncedObject(nullptr, svc::ResultSessionClosed());
+            }
+
+            /* Wake up all server threads. */
+            while (!this->server_queue.IsEmpty()) {
+                this->server_queue.WakeupFrontThread();
+            }
+        }
+
+        /* Close the current request, if we had one. */
+        if (cur_request != nullptr) {
+            cur_request->Close();
+        }
     }
 
 }
diff --git a/libraries/libmesosphere/source/kern_k_thread.cpp b/libraries/libmesosphere/source/kern_k_thread.cpp
index 45c6b11ce..d12637b64 100644
--- a/libraries/libmesosphere/source/kern_k_thread.cpp
+++ b/libraries/libmesosphere/source/kern_k_thread.cpp
@@ -720,8 +720,8 @@ namespace ams::kern {
         /* Check if we're waiting and cancellable. */
         if (this->GetState() == ThreadState_Waiting && this->cancellable) {
             if (this->sleeping_queue != nullptr) {
-                /* TODO: Cancel light IPC. */
-                MESOSPHERE_UNIMPLEMENTED();
+                this->sleeping_queue->WakeupThread(this);
+                this->wait_cancelled = true;
             } else {
                 this->SetSyncedObject(nullptr, svc::ResultCancelled());
                 this->SetState(ThreadState_Runnable);
diff --git a/libraries/libmesosphere/source/svc/kern_svc_light_ipc.cpp b/libraries/libmesosphere/source/svc/kern_svc_light_ipc.cpp
index 8e80e3932..6796e674e 100644
--- a/libraries/libmesosphere/source/svc/kern_svc_light_ipc.cpp
+++ b/libraries/libmesosphere/source/svc/kern_svc_light_ipc.cpp
@@ -21,28 +21,48 @@ namespace ams::kern::svc {
 
     namespace {
 
+        ALWAYS_INLINE Result SendSyncRequestLight(ams::svc::Handle session_handle, u32 *args) {
+            /* Get the light client session from its handle. */
+            KScopedAutoObject session = GetCurrentProcess().GetHandleTable().GetObject<KLightClientSession>(session_handle);
+            R_UNLESS(session.IsNotNull(), svc::ResultInvalidHandle());
 
+            /* Send the request. */
+            R_TRY(session->SendSyncRequest(args));
+
+            return ResultSuccess();
+        }
+
+        ALWAYS_INLINE Result ReplyAndReceiveLight(ams::svc::Handle session_handle, u32 *args) {
+            /* Get the light server session from its handle. */
+            KScopedAutoObject session = GetCurrentProcess().GetHandleTable().GetObject<KLightServerSession>(session_handle);
+            R_UNLESS(session.IsNotNull(), svc::ResultInvalidHandle());
+
+            /* Handle the request. */
+            R_TRY(session->ReplyAndReceive(args));
+
+            return ResultSuccess();
+        }
 
     }
 
     /* =============================    64 ABI    ============================= */
 
-    Result SendSyncRequestLight64(ams::svc::Handle session_handle) {
-        MESOSPHERE_PANIC("Stubbed SvcSendSyncRequestLight64 was called.");
+    Result SendSyncRequestLight64(ams::svc::Handle session_handle, u32 *args) {
+        return SendSyncRequestLight(session_handle, args);
     }
 
-    Result ReplyAndReceiveLight64(ams::svc::Handle handle) {
-        MESOSPHERE_PANIC("Stubbed SvcReplyAndReceiveLight64 was called.");
+    Result ReplyAndReceiveLight64(ams::svc::Handle session_handle, u32 *args) {
+        return ReplyAndReceiveLight(session_handle, args);
     }
 
     /* ============================= 64From32 ABI ============================= */
 
-    Result SendSyncRequestLight64From32(ams::svc::Handle session_handle) {
-        MESOSPHERE_PANIC("Stubbed SvcSendSyncRequestLight64From32 was called.");
+    Result SendSyncRequestLight64From32(ams::svc::Handle session_handle, u32 *args) {
+        return SendSyncRequestLight(session_handle, args);
     }
 
-    Result ReplyAndReceiveLight64From32(ams::svc::Handle handle) {
-        MESOSPHERE_PANIC("Stubbed SvcReplyAndReceiveLight64From32 was called.");
+    Result ReplyAndReceiveLight64From32(ams::svc::Handle session_handle, u32 *args) {
+        return ReplyAndReceiveLight(session_handle, args);
     }
 
 }