feat: add backing storage runtime option for running machines from disk

Author: edubart

src/Makefile

@@ -337,6 +337,7 @@ LIBCARTESI_OBJS:= \
 	virtio-net-carrier-slirp.o \
 	dtb.o \
 	os.o \
+	os-mmap.o \
 	htif.o \
 	htif-factory.o \
 	shadow-state.o \

src/compiler-defines.h

@@ -27,6 +27,12 @@
 
 #define NO_INLINE __attribute__((noinline))
 
+#if defined(__GNUC__)
+#define FORCE_OPTIMIZE_O3 __attribute__((optimize("-O3")))
+#else
+#define FORCE_OPTIMIZE_O3
+#endif
+
 #define NO_RETURN [[noreturn]]
 
 // These macros are used only in very hot code paths (such as TLB hit checks).

src/is-pristine.h

@@ -0,0 +1,37 @@
+// Copyright Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: LGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option) any
+// later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+// PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License along
+// with this program (see COPYING). If not, see <https://www.gnu.org/licenses/>.
+//
+
+#ifndef IS_PRISTINE_H
+#define IS_PRISTINE_H
+
+#include "compiler-defines.h"
+#include <stddef.h>
+#include <stdint.h>
+
+namespace cartesi {
+
+// NOLINTNEXTLINE(clang-diagnostic-unknown-attributes)
+static inline bool FORCE_OPTIMIZE_O3 is_pristine(const unsigned char *data, size_t length) {
+    unsigned char bits = 0;
+    for (size_t i = 0; i < length; ++i) {
+        bits |= data[i];
+    }
+    return bits == 0;
+}
+
+} // namespace cartesi
+
+#endif

src/json-util.cpp

@@ -789,6 +789,8 @@ void ju_get_opt_field(const nlohmann::json &j, const K &key, machine_runtime_con
     ju_get_opt_field(j[key], "skip_root_hash_store"s, value.skip_root_hash_store, path + to_string(key) + "/");
     ju_get_opt_field(j[key], "skip_version_check"s, value.skip_version_check, path + to_string(key) + "/");
     ju_get_opt_field(j[key], "soft_yield"s, value.soft_yield, path + to_string(key) + "/");
+    ju_get_opt_field(j[key], "copy_reflink"s, value.copy_reflink, path + to_string(key) + "/");
+    ju_get_opt_field(j[key], "backing_storage"s, value.backing_storage, path + to_string(key) + "/");
 }
 
 template void ju_get_opt_field<uint64_t>(const nlohmann::json &j, const uint64_t &key, machine_runtime_config &value,
@@ -1971,6 +1973,8 @@ void to_json(nlohmann::json &j, const machine_runtime_config &runtime) {
         {"skip_root_hash_store", runtime.skip_root_hash_store},
         {"skip_version_check", runtime.skip_version_check},
         {"soft_yield", runtime.soft_yield},
+        {"copy_reflink", runtime.copy_reflink},
+        {"backing_storage", runtime.backing_storage},
     };
 }
 

src/machine-config.cpp

@@ -77,6 +77,7 @@ machine_config machine_config::load(const std::string &dir) {
         }
         ju_get_field(j, std::string("config"), c, "");
         adjust_image_filenames(c, dir);
+        c.load_dir = dir;
     } catch (std::exception &e) {
         throw std::runtime_error{e.what()};
     }

src/machine-config.h

@@ -211,6 +211,8 @@ struct machine_config final {
     /// \brief Stores the machine config to a directory
     /// \param dir Directory where "config" will be stored
     void store(const std::string &dir) const;
+
+    std::string load_dir{}; ///< Directory this machine config was loaded from
 };
 
 } // namespace cartesi

src/machine-runtime-config.h

@@ -18,6 +18,7 @@
 #define MACHINE_RUNTIME_CONFIG_H
 
 #include <cstdint>
+#include <string>
 
 /// \file
 /// \brief Runtime configuration for machines.
@@ -42,6 +43,8 @@ struct machine_runtime_config {
     bool skip_root_hash_store{};
     bool skip_version_check{};
     bool soft_yield{};
+    bool copy_reflink{};
+    std::string backing_storage{};
 };
 
 /// \brief CONCURRENCY constants