feat(core/remote_io): add Remote I/O infrastructure

.vscode/settings.json

@@ -0,0 +1,7 @@
+{
+    "files.associations": {
+        "emul.h": "c",
+        "interrupts.h": "c",
+        "spinlock.h": "c"
+    }
+}

src/arch/armv8/armv8-a/cpu.c

@@ -29,7 +29,7 @@ void cpu_arch_profile_init(cpuid_t cpuid, paddr_t load_addr)
 
 void cpu_arch_profile_idle()
 {
-    int64_t err = psci_power_down(PSCI_WAKEUP_IDLE);
+    int64_t err = PSCI_E_NOT_SUPPORTED;
     if (err) {
         switch (err) {
             case PSCI_E_NOT_SUPPORTED:

src/core/hypercall.c

@@ -7,18 +7,22 @@
 #include <cpu.h>
 #include <vm.h>
 #include <ipc.h>
+#include <remote_io.h>
 
 long int hypercall(unsigned long id)
 {
     long int ret = -HC_E_INVAL_ID;
 
-    unsigned long ipc_id = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(0));
+    unsigned long hc_id = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(0));
     unsigned long arg1 = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(1));
     unsigned long arg2 = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(2));
 
     switch (id) {
         case HC_IPC:
-            ret = ipc_hypercall(ipc_id, arg1, arg2);
+            ret = ipc_hypercall(hc_id, arg1, arg2);
+            break;
+        case HC_REMOTE_IO:
+            ret = remote_io_hypercall(hc_id, arg1, arg2);
             break;
         default:
             WARNING("Unknown hypercall id %d", id);

src/core/inc/hypercall.h

@@ -9,7 +9,7 @@
 #include <bao.h>
 #include <arch/hypercall.h>
 
-enum { HC_INVAL = 0, HC_IPC = 1 };
+enum { HC_INVAL = 0, HC_IPC = 1, HC_REMOTE_IO = 2 };
 
 enum { HC_E_SUCCESS = 0, HC_E_FAILURE = 1, HC_E_INVAL_ID = 2, HC_E_INVAL_ARGS = 3 };
 

src/core/inc/ipc.h

@@ -20,7 +20,5 @@ struct ipc {
 struct vm_config;
 
 unsigned long ipc_hypercall(unsigned long arg0, unsigned long arg1, unsigned long arg2);
-void ipc_init();
-struct shmem* ipc_get_shmem(size_t shmem_id);
 
 #endif /* IPC_H */

src/core/inc/remote_io.h

@@ -0,0 +1,71 @@
+/**
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (c) Bao Project and Contributors. All rights reserved.
+ */
+
+#ifndef __REMOTE_IO_H__
+#define __REMOTE_IO_H__
+
+#include <bao.h>
+#include <emul.h>
+#include <list.h>
+#include <vm.h>
+
+/*!
+ * @enum    remote_io_shmem
+ * @brief   Contains all the information of a Remote I/O shared memory region
+ */
+struct remote_io_shmem {
+    paddr_t base;
+    size_t size;
+    size_t shmem_id;
+};
+
+/*!
+ * @struct  remote_io_dev
+ * @brief   Contains all the information of a Remote I/O device
+ */
+struct remote_io_dev {
+    vaddr_t va;        // Virtual address for device MMIO register access
+    size_t size;       // MMIO region size
+    irqid_t interrupt; // Interrupt
+    uint64_t id;       // Unique Remote I/O ID linking each frontend driver to the backend
+                       // device
+    bool is_backend;   // True if the device is a backend device
+    struct remote_io_shmem shmem; // Shared memory region
+};
+
+/*!
+ * @fn              remote_io_init
+ * @brief           Responsible for Remote I/O device initialization
+ * @return          void
+ */
+void remote_io_init();
+
+/*!
+ * @fn              remote_io_assign_cpus
+ * @brief           Assigns frontend and backend CPUs to VMs containing Remote I/O instances
+ * @return          void
+ */
+void remote_io_assign_cpus(struct vm* vm);
+
+/*!
+ * @fn              remote_io_hypercall
+ * @brief           Handle the Remote I/O hypercall
+ * @note            The Remote I/O hypercall is used by the backend to request or send information
+ * @param   arg0    First argument of the hypercall
+ * @param   arg1    Second argument of the hypercall
+ * @param   arg2    Third argument of the hypercall
+ * @return          unsigned long
+ */
+unsigned long remote_io_hypercall(unsigned long arg0, unsigned long arg1, unsigned long arg2);
+
+/*!
+ * @fn                      remote_io_mmio_emul_handler
+ * @brief                   Manages all MMIO register accesses for a Remote I/O driver
+ * @param   emul_access     Structure holding details for MMIO register access
+ * @return                  bool
+ */
+bool remote_io_mmio_emul_handler(struct emul_access* emul_access);
+
+#endif /* __REMOTE_IO_H__ */

src/core/inc/shmem.h

@@ -0,0 +1,14 @@
+/**
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (c) Bao Project and Contributors. All rights reserved.
+ */
+
+#ifndef SHMEM_H
+#define SHMEM_H
+
+#include <mem.h>
+
+void shmem_init();
+struct shmem* shmem_get(size_t shmem_id);
+
+#endif /* SHMEM_H */

src/core/inc/vm.h

@@ -17,6 +17,7 @@
 #include <bitmap.h>
 #include <io.h>
 #include <ipc.h>
+#include <remote_io.h>
 
 struct vm_mem_region {
     paddr_t base;
@@ -47,6 +48,11 @@ struct vm_platform {
     size_t dev_num;
     struct vm_dev_region* devs;
 
+    /* Remote I/O devices */
+    size_t remote_io_dev_num;
+    bool remote_io_pooling;
+    struct remote_io_dev* remote_io_devs;
+
     // /**
     //  * In MPU-based platforms which might also support virtual memory
     //  * (i.e. aarch64 cortex-r) the hypervisor sets up the VM using an MPU by
@@ -84,6 +90,11 @@ struct vm {
 
     size_t ipc_num;
     struct ipc* ipcs;
+
+    /* Remote I/O devices */
+    size_t remote_io_dev_num;
+    bool remote_io_pooling;
+    struct remote_io_dev* remote_io_devs;
 };
 
 struct vcpu {

src/core/ipc.c

@@ -9,6 +9,7 @@
 #include <vmm.h>
 #include <hypercall.h>
 #include <config.h>
+#include <shmem.h>
 
 enum { IPC_NOTIFY };
 
@@ -20,18 +21,6 @@ union ipc_msg_data {
     uint64_t raw;
 };
 
-static size_t shmem_table_size;
-static struct shmem* shmem_table;
-
-struct shmem* ipc_get_shmem(size_t shmem_id)
-{
-    if (shmem_id < shmem_table_size) {
-        return &shmem_table[shmem_id];
-    } else {
-        return NULL;
-    }
-}
-
 static struct ipc* ipc_find_by_shmemid(struct vm* vm, size_t shmem_id)
 {
     struct ipc* ipc_obj = NULL;
@@ -73,7 +62,7 @@ unsigned long ipc_hypercall(unsigned long ipc_id, unsigned long ipc_event, unsig
     struct shmem* shmem = NULL;
     bool valid_ipc_obj = ipc_id < cpu()->vcpu->vm->ipc_num;
     if (valid_ipc_obj) {
-        shmem = ipc_get_shmem(cpu()->vcpu->vm->ipcs[ipc_id].shmem_id);
+        shmem = shmem_get(cpu()->vcpu->vm->ipcs[ipc_id].shmem_id);
     }
     bool valid_shmem = shmem != NULL;
 
@@ -98,31 +87,3 @@ unsigned long ipc_hypercall(unsigned long ipc_id, unsigned long ipc_event, unsig
 
     return ret;
 }
-
-static void ipc_alloc_shmem()
-{
-    for (size_t i = 0; i < shmem_table_size; i++) {
-        struct shmem* shmem = &shmem_table[i];
-        if (!shmem->place_phys) {
-            size_t n_pg = NUM_PAGES(shmem->size);
-            struct ppages ppages = mem_alloc_ppages(shmem->colors, n_pg, false);
-            if (ppages.num_pages < n_pg) {
-                ERROR("failed to allocate shared memory");
-            }
-            shmem->phys = ppages.base;
-        }
-    }
-}
-
-void ipc_init()
-{
-    if (cpu_is_master()) {
-        shmem_table_size = config.shmemlist_size;
-        shmem_table = config.shmemlist;
-        ipc_alloc_shmem();
-
-        for (size_t i = 0; i < config.shmemlist_size; i++) {
-            config.shmemlist[i].cpu_masters = 0;
-        }
-    }
-}

src/core/objects.mk

@@ -13,3 +13,5 @@ core-objs-y+=console.o
 core-objs-y+=ipc.o
 core-objs-y+=objpool.o
 core-objs-y+=hypercall.o
+core-objs-y+=shmem.o
+core-objs-y+=remote_io.o