Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 393 insertions, 0 deletions

diff --git a/plugins/api.c b/plugins/api.c
new file mode 100644
index 000000000..b143b09ce
--- /dev/null
+++ b/plugins/api.c
@@ -0,0 +1,393 @@
+/*
+ * QEMU Plugin API
+ *
+ * This provides the API that is available to the plugins to interact
+ * with QEMU. We have to be careful not to expose internal details of
+ * how QEMU works so we abstract out things like translation and
+ * instructions to anonymous data types:
+ *
+ *  qemu_plugin_tb
+ *  qemu_plugin_insn
+ *
+ * Which can then be passed back into the API to do additional things.
+ * As such all the public functions in here are exported in
+ * qemu-plugin.h.
+ *
+ * The general life-cycle of a plugin is:
+ *
+ *  - plugin is loaded, public qemu_plugin_install called
+ *    - the install func registers callbacks for events
+ *    - usually an atexit_cb is registered to dump info at the end
+ *  - when a registered event occurs the plugin is called
+ *     - some events pass additional info
+ *     - during translation the plugin can decide to instrument any
+ *       instruction
+ *  - when QEMU exits all the registered atexit callbacks are called
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019, Linaro
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/plugin.h"
+#include "tcg/tcg.h"
+#include "exec/exec-all.h"
+#include "exec/ram_addr.h"
+#include "disas/disas.h"
+#include "plugin.h"
+#ifndef CONFIG_USER_ONLY
+#include "qemu/plugin-memory.h"
+#include "hw/boards.h"
+#endif
+
+/* Uninstall and Reset handlers */
+
+void qemu_plugin_uninstall(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
+{
+    plugin_reset_uninstall(id, cb, false);
+}
+
+void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
+{
+    plugin_reset_uninstall(id, cb, true);
+}
+
+/*
+ * Plugin Register Functions
+ *
+ * This allows the plugin to register callbacks for various events
+ * during the translation.
+ */
+
+void qemu_plugin_register_vcpu_init_cb(qemu_plugin_id_t id,
+                                       qemu_plugin_vcpu_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_INIT, cb);
+}
+
+void qemu_plugin_register_vcpu_exit_cb(qemu_plugin_id_t id,
+                                       qemu_plugin_vcpu_simple_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_EXIT, cb);
+}
+
+void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
+                                          qemu_plugin_vcpu_udata_cb_t cb,
+                                          enum qemu_plugin_cb_flags flags,
+                                          void *udata)
+{
+    if (!tb->mem_only) {
+        plugin_register_dyn_cb__udata(&tb->cbs[PLUGIN_CB_REGULAR],
+                                      cb, flags, udata);
+    }
+}
+
+void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
+                                              enum qemu_plugin_op op,
+                                              void *ptr, uint64_t imm)
+{
+    if (!tb->mem_only) {
+        plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
+    }
+}
+
+void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
+                                            qemu_plugin_vcpu_udata_cb_t cb,
+                                            enum qemu_plugin_cb_flags flags,
+                                            void *udata)
+{
+    if (!insn->mem_only) {
+        plugin_register_dyn_cb__udata(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR],
+                                      cb, flags, udata);
+    }
+}
+
+void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
+                                                enum qemu_plugin_op op,
+                                                void *ptr, uint64_t imm)
+{
+    if (!insn->mem_only) {
+        plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
+                                  0, op, ptr, imm);
+    }
+}
+
+
+/*
+ * We always plant memory instrumentation because they don't finalise until
+ * after the operation has complete.
+ */
+void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
+                                      qemu_plugin_vcpu_mem_cb_t cb,
+                                      enum qemu_plugin_cb_flags flags,
+                                      enum qemu_plugin_mem_rw rw,
+                                      void *udata)
+{
+    plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
+                                    cb, flags, rw, udata);
+}
+
+void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
+                                          enum qemu_plugin_mem_rw rw,
+                                          enum qemu_plugin_op op, void *ptr,
+                                          uint64_t imm)
+{
+    plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
+                              rw, op, ptr, imm);
+}
+
+void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
+                                           qemu_plugin_vcpu_tb_trans_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb);
+}
+
+void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
+                                          qemu_plugin_vcpu_syscall_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
+}
+
+void
+qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
+                                         qemu_plugin_vcpu_syscall_ret_cb_t cb)
+{
+    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb);
+}
+
+/*
+ * Plugin Queries
+ *
+ * These are queries that the plugin can make to gauge information
+ * from our opaque data types. We do not want to leak internal details
+ * here just information useful to the plugin.
+ */
+
+/*
+ * Translation block information:
+ *
+ * A plugin can query the virtual address of the start of the block
+ * and the number of instructions in it. It can also get access to
+ * each translated instruction.
+ */
+
+size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb)
+{
+    return tb->n;
+}
+
+uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb)
+{
+    return tb->vaddr;
+}
+
+struct qemu_plugin_insn *
+qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
+{
+    struct qemu_plugin_insn *insn;
+    if (unlikely(idx >= tb->n)) {
+        return NULL;
+    }
+    insn = g_ptr_array_index(tb->insns, idx);
+    insn->mem_only = tb->mem_only;
+    return insn;
+}
+
+/*
+ * Instruction information
+ *
+ * These queries allow the plugin to retrieve information about each
+ * instruction being translated.
+ */
+
+const void *qemu_plugin_insn_data(const struct qemu_plugin_insn *insn)
+{
+    return insn->data->data;
+}
+
+size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
+{
+    return insn->data->len;
+}
+
+uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
+{
+    return insn->vaddr;
+}
+
+void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
+{
+    return insn->haddr;
+}
+
+char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
+{
+    CPUState *cpu = current_cpu;
+    return plugin_disas(cpu, insn->vaddr, insn->data->len);
+}
+
+const char *qemu_plugin_insn_symbol(const struct qemu_plugin_insn *insn)
+{
+    const char *sym = lookup_symbol(insn->vaddr);
+    return sym[0] != 0 ? sym : NULL;
+}
+
+/*
+ * The memory queries allow the plugin to query information about a
+ * memory access.
+ */
+
+unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info)
+{
+    MemOp op = get_memop(info);
+    return op & MO_SIZE;
+}
+
+bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info)
+{
+    MemOp op = get_memop(info);
+    return op & MO_SIGN;
+}
+
+bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info)
+{
+    MemOp op = get_memop(info);
+    return (op & MO_BSWAP) == MO_BE;
+}
+
+bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info)
+{
+    return get_plugin_meminfo_rw(info) & QEMU_PLUGIN_MEM_W;
+}
+
+/*
+ * Virtual Memory queries
+ */
+
+#ifdef CONFIG_SOFTMMU
+static __thread struct qemu_plugin_hwaddr hwaddr_info;
+#endif
+
+struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
+                                                  uint64_t vaddr)
+{
+#ifdef CONFIG_SOFTMMU
+    CPUState *cpu = current_cpu;
+    unsigned int mmu_idx = get_mmuidx(info);
+    enum qemu_plugin_mem_rw rw = get_plugin_meminfo_rw(info);
+    hwaddr_info.is_store = (rw & QEMU_PLUGIN_MEM_W) != 0;
+
+    if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx,
+                           hwaddr_info.is_store, &hwaddr_info)) {
+        error_report("invalid use of qemu_plugin_get_hwaddr");
+        return NULL;
+    }
+
+    return &hwaddr_info;
+#else
+    return NULL;
+#endif
+}
+
+bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr)
+{
+#ifdef CONFIG_SOFTMMU
+    return haddr->is_io;
+#else
+    return false;
+#endif
+}
+
+uint64_t qemu_plugin_hwaddr_phys_addr(const struct qemu_plugin_hwaddr *haddr)
+{
+#ifdef CONFIG_SOFTMMU
+    if (haddr) {
+        if (!haddr->is_io) {
+            RAMBlock *block;
+            ram_addr_t offset;
+            void *hostaddr = haddr->v.ram.hostaddr;
+
+            block = qemu_ram_block_from_host(hostaddr, false, &offset);
+            if (!block) {
+                error_report("Bad host ram pointer %p", haddr->v.ram.hostaddr);
+                abort();
+            }
+
+            return block->offset + offset + block->mr->addr;
+        } else {
+            MemoryRegionSection *mrs = haddr->v.io.section;
+            return mrs->offset_within_address_space + haddr->v.io.offset;
+        }
+    }
+#endif
+    return 0;
+}
+
+const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
+{
+#ifdef CONFIG_SOFTMMU
+    if (h && h->is_io) {
+        MemoryRegionSection *mrs = h->v.io.section;
+        if (!mrs->mr->name) {
+            unsigned long maddr = 0xffffffff & (uintptr_t) mrs->mr;
+            g_autofree char *temp = g_strdup_printf("anon%08lx", maddr);
+            return g_intern_string(temp);
+        } else {
+            return g_intern_string(mrs->mr->name);
+        }
+    } else {
+        return g_intern_static_string("RAM");
+    }
+#else
+    return g_intern_static_string("Invalid");
+#endif
+}
+
+/*
+ * Queries to the number and potential maximum number of vCPUs there
+ * will be. This helps the plugin dimension per-vcpu arrays.
+ */
+
+#ifndef CONFIG_USER_ONLY
+static MachineState * get_ms(void)
+{
+    return MACHINE(qdev_get_machine());
+}
+#endif
+
+int qemu_plugin_n_vcpus(void)
+{
+#ifdef CONFIG_USER_ONLY
+    return -1;
+#else
+    return get_ms()->smp.cpus;
+#endif
+}
+
+int qemu_plugin_n_max_vcpus(void)
+{
+#ifdef CONFIG_USER_ONLY
+    return -1;
+#else
+    return get_ms()->smp.max_cpus;
+#endif
+}
+
+/*
+ * Plugin output
+ */
+void qemu_plugin_outs(const char *string)
+{
+    qemu_log_mask(CPU_LOG_PLUGIN, "%s", string);
+}
+
+bool qemu_plugin_bool_parse(const char *name, const char *value, bool *ret)
+{
+    return name && value && qapi_bool_parse(name, value, ret, NULL);
+}