From 44ec1d212499246be3cef40ce7c96a3f65286153 Mon Sep 17 00:00:00 2001 From: Steve Reinhardt Date: Wed, 22 Oct 2014 15:53:34 -0700 Subject: [PATCH] syscall_emul: add EmulatedDriver object Fake SE-mode device drivers can now be added by deriving from this abstract object. --- src/sim/Process.py | 8 ++++ src/sim/emul_driver.hh | 90 +++++++++++++++++++++++++++++++++++++++++ src/sim/process.cc | 19 ++++++++- src/sim/process.hh | 15 ++++++- src/sim/syscall_emul.hh | 36 +++++++++++++---- 5 files changed, 157 insertions(+), 11 deletions(-) create mode 100644 src/sim/emul_driver.hh diff --git a/src/sim/Process.py b/src/sim/Process.py index 6f2322805..7e5f75363 100644 --- a/src/sim/Process.py +++ b/src/sim/Process.py @@ -46,6 +46,12 @@ class Process(SimObject): def export_methods(cls, code): code('bool map(Addr vaddr, Addr paddr, int size);') +class EmulatedDriver(SimObject): + type = 'EmulatedDriver' + cxx_header = "sim/emul_driver.hh" + abstract = True + filename = Param.String("device file name (under /dev)") + class LiveProcess(Process): type = 'LiveProcess' cxx_header = "sim/process.hh" @@ -60,3 +66,5 @@ class LiveProcess(Process): pid = Param.Int(100, 'process id') ppid = Param.Int(99, 'parent process id') simpoint = Param.UInt64(0, 'simulation point at which to start simulation') + drivers = VectorParam.EmulatedDriver([], 'Available emulated drivers') + diff --git a/src/sim/emul_driver.hh b/src/sim/emul_driver.hh new file mode 100644 index 000000000..778fc6461 --- /dev/null +++ b/src/sim/emul_driver.hh @@ -0,0 +1,90 @@ +/* + * Copyright (c) 2014 Advanced Micro Devices, Inc. + * All rights reserved + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Author: Steve Reinhardt + */ + +#ifndef __SIM_EMUL_DRIVER_HH +#define __SIM_EMUL_DRIVER_HH + +#include + +#include "params/EmulatedDriver.hh" +#include "sim/sim_object.hh" + +class LiveProcess; +class ThreadContext; + +/** + * EmulatedDriver is an abstract base class for fake SE-mode device drivers. + * + * Specific drivers that allow applications to communicate with simulated + * hardware inside gem5 can be created by deriving from this class and + * overriding the abstract virtual methods. + * + * Currently only open() and ioctl() calls are supported, but other calls + * (e.g., read(), write(), mmap()) could be added as needed. + */ +class EmulatedDriver : public SimObject +{ + protected: + /** + * filename for opening this driver (under /dev) + */ + const std::string &filename; + + public: + EmulatedDriver(EmulatedDriverParams *p) + : SimObject(p), filename(p->filename) + { + } + + /** + * Check for a match with this driver's filename. + */ + bool match(const std::string &s) const { return (s == filename); } + + /** + * Abstract method, invoked when the user program calls open() on + * the device driver. The parameters are the same as those passed + * to openFunc() (q.v.). + * @return A newly allocated target fd, or -1 on error. + */ + virtual int open(LiveProcess *p, ThreadContext *tc, + int mode, int flags) = 0; + + /** + * Abstract method, invoked when the user program calls ioctl() on + * the file descriptor returned by a previous open(). The parameters + * are the same as those passed in to ioctlFunc() (q.v.). + * @return The return code for the ioctl, or the negation of the errno + * (see the SyscallReturn class). + */ + virtual int ioctl(LiveProcess *p, ThreadContext *tc, unsigned req) = 0; +}; + +#endif // __SIM_EMUL_DRIVER_HH diff --git a/src/sim/process.cc b/src/sim/process.cc index 913e9298d..15dc8c3e8 100644 --- a/src/sim/process.cc +++ b/src/sim/process.cc @@ -278,7 +278,7 @@ Process::alloc_fd(int sim_fd, string filename, int flags, int mode, bool pipe) // find first free target fd for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) { Process::FdMap *fdo = &fd_map[free_fd]; - if (fdo->fd == -1) { + if (fdo->fd == -1 && fdo->driver == NULL) { fdo->fd = sim_fd; fdo->filename = filename; fdo->mode = mode; @@ -309,6 +309,7 @@ Process::free_fd(int tgt_fd) fdo->flags = 0; fdo->isPipe = false; fdo->readPipeSource = 0; + fdo->driver = NULL; } @@ -567,7 +568,8 @@ Process::map(Addr vaddr, Addr paddr, int size) LiveProcess::LiveProcess(LiveProcessParams * params, ObjectFile *_objFile) : Process(params), objFile(_objFile), - argv(params->cmd), envp(params->env), cwd(params->cwd) + argv(params->cmd), envp(params->env), cwd(params->cwd), + drivers(params->drivers) { __uid = params->uid; __euid = params->euid; @@ -608,6 +610,19 @@ LiveProcess::getSyscallArg(ThreadContext *tc, int &i, int width) return getSyscallArg(tc, i); } + +EmulatedDriver * +LiveProcess::findDriver(std::string filename) +{ + for (EmulatedDriver *d : drivers) { + if (d->match(filename)) + return d; + } + + return NULL; +} + + LiveProcess * LiveProcess::create(LiveProcessParams * params) { diff --git a/src/sim/process.hh b/src/sim/process.hh index 03380acf7..6e26bb8bd 100644 --- a/src/sim/process.hh +++ b/src/sim/process.hh @@ -50,6 +50,7 @@ struct LiveProcessParams; class SyscallDesc; class System; class ThreadContext; +class EmulatedDriver; template struct AuxVector @@ -139,10 +140,11 @@ class Process : public SimObject bool isPipe; int readPipeSource; uint64_t fileOffset; + EmulatedDriver *driver; FdMap() : fd(-1), filename("NULL"), mode(0), flags(0), - isPipe(false), readPipeSource(0), fileOffset(0) + isPipe(false), readPipeSource(0), fileOffset(0), driver(NULL) { } void serialize(std::ostream &os); @@ -256,6 +258,9 @@ class LiveProcess : public Process uint64_t __pid; uint64_t __ppid; + // Emulated drivers available to this process + std::vector drivers; + public: enum AuxiliaryVectorType { @@ -325,6 +330,14 @@ class LiveProcess : public Process virtual SyscallDesc *getDesc(int callnum) = 0; + /** + * Find an emulated device driver. + * + * @param filename Name of the device (under /dev) + * @return Pointer to driver object if found, else NULL + */ + EmulatedDriver *findDriver(std::string filename); + // this function is used to create the LiveProcess object, since // we can't tell which subclass of LiveProcess to use until we // open and look at the object file. diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh index dff34982d..1c84e9f48 100644 --- a/src/sim/syscall_emul.hh +++ b/src/sim/syscall_emul.hh @@ -77,6 +77,7 @@ #include "mem/page_table.hh" #include "mem/se_translating_port_proxy.hh" #include "sim/byteswap.hh" +#include "sim/emul_driver.hh" #include "sim/process.hh" #include "sim/syscallreturn.hh" #include "sim/system.hh" @@ -604,11 +605,17 @@ ioctlFunc(SyscallDesc *desc, int callnum, LiveProcess *process, DPRINTF(SyscallVerbose, "ioctl(%d, 0x%x, ...)\n", fd, req); - if (fd < 0 || process->sim_fd(fd) < 0) { + Process::FdMap *fdObj = process->sim_fd_obj(fd); + + if (fdObj == NULL) { // doesn't map to any simulator fd: not a valid target fd return -EBADF; } + if (fdObj->driver != NULL) { + return fdObj->driver->ioctl(process, tc, req); + } + if (OS::isTtyReq(req)) { return -ENOTTY; } @@ -629,13 +636,6 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process, process->getSyscallArg(tc, index))) return -EFAULT; - if (path == "/dev/sysdev0") { - // This is a memory-mapped high-resolution timer device on Alpha. - // We don't support it, so just punt. - warn("Ignoring open(%s, ...)\n", path); - return -ENOENT; - } - int tgtFlags = process->getSyscallArg(tc, index); int mode = process->getSyscallArg(tc, index); int hostFlags = 0; @@ -661,6 +661,26 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process, DPRINTF(SyscallVerbose, "opening file %s\n", path.c_str()); + if (startswith(path, "/dev/")) { + std::string filename = path.substr(strlen("/dev/")); + if (filename == "sysdev0") { + // This is a memory-mapped high-resolution timer device on Alpha. + // We don't support it, so just punt. + warn("Ignoring open(%s, ...)\n", path); + return -ENOENT; + } + + EmulatedDriver *drv = process->findDriver(filename); + if (drv != NULL) { + // the driver's open method will allocate a fd from the + // process if necessary. + return drv->open(process, tc, mode, hostFlags); + } + + // fall through here for pass through to host devices, such as + // /dev/zero + } + int fd; int local_errno; if (startswith(path, "/proc/") || startswith(path, "/system/") || -- 2.30.2