6 files changed, 37 insertions, 7 deletions
diff --git a/src/sim/faults.cc b/src/sim/faults.cc
index 93e766526..b0fa6fedb 100644
--- a/src/sim/faults.cc
+++ b/src/sim/faults.cc
@@ -59,6 +59,11 @@ void ReExec::invoke(ThreadContext *tc, const StaticInstPtr &inst)
     tc->pcState(tc->pcState());
 }
 
+void SyscallRetryFault::invoke(ThreadContext *tc, const StaticInstPtr &inst)
+{
+    tc->pcState(tc->pcState());
+}
+
 void GenericPageTableFault::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     bool handled = false;
diff --git a/src/sim/faults.hh b/src/sim/faults.hh
index da0ea22fa..be7aab582 100644
--- a/src/sim/faults.hh
+++ b/src/sim/faults.hh
@@ -72,6 +72,22 @@ class ReExec : public FaultBase
                 StaticInst::nullStaticInstPtr);
 };
 
+/*
+ * This class is needed to allow system call retries to occur for blocking
+ * system calls in SE mode. A retry fault will be generated by the system call
+ * emulation code if blocking conditions arise; the fault is passed up the
+ * function call chain into the CPU model where it is handled by retrying the
+ * syscall instruction on a later tick.
+ */
+class SyscallRetryFault : public FaultBase
+{
+  public:
+    virtual FaultName name() const { return "System call retry fault"; }
+    SyscallRetryFault() {}
+    void invoke(ThreadContext *tc, const StaticInstPtr &inst =
+                StaticInst::nullStaticInstPtr);
+};
+
 class GenericPageTableFault : public FaultBase
 {
   private:
diff --git a/src/sim/process.cc b/src/sim/process.cc
index 4c44f4086..5acfa88b3 100644
--- a/src/sim/process.cc
+++ b/src/sim/process.cc
@@ -269,7 +269,7 @@ Process::map(Addr vaddr, Addr paddr, int size, bool cacheable)
 }
 
 void
-Process::syscall(int64_t callnum, ThreadContext *tc)
+Process::syscall(int64_t callnum, ThreadContext *tc, Fault *fault)
 {
     num_syscalls++;
 
@@ -277,7 +277,7 @@ Process::syscall(int64_t callnum, ThreadContext *tc)
     if (desc == NULL)
         fatal("Syscall %d out of range", callnum);
 
-    desc->doSyscall(callnum, this, tc);
+    desc->doSyscall(callnum, this, tc, fault);
 }
 
 IntReg
diff --git a/src/sim/process.hh b/src/sim/process.hh
index 2191c3cd0..101e4a31c 100644
--- a/src/sim/process.hh
+++ b/src/sim/process.hh
@@ -80,7 +80,7 @@ class Process : public SimObject
     void initState() override;
     DrainState drain() override;
 
-    void syscall(int64_t callnum, ThreadContext *tc);
+    void syscall(int64_t callnum, ThreadContext *tc, Fault *fault);
     virtual TheISA::IntReg getSyscallArg(ThreadContext *tc, int &i) = 0;
     virtual TheISA::IntReg getSyscallArg(ThreadContext *tc, int &i, int width);
     virtual void setSyscallArg(ThreadContext *tc, int i,
diff --git a/src/sim/syscall_desc.cc b/src/sim/syscall_desc.cc
index bb0e80f5f..13b519081 100644
--- a/src/sim/syscall_desc.cc
+++ b/src/sim/syscall_desc.cc
@@ -33,16 +33,21 @@
 
 #include "sim/syscall_desc.hh"
 
+#include <memory>
+
 #include "base/trace.hh"
+#include "base/types.hh"
 #include "config/the_isa.hh"
 #include "cpu/base.hh"
 #include "cpu/thread_context.hh"
+#include "sim/faults.hh"
 #include "sim/process.hh"
 #include "sim/syscall_debug_macros.hh"
 #include "sim/syscall_return.hh"
 
 void
-SyscallDesc::doSyscall(int callnum, Process *process, ThreadContext *tc)
+SyscallDesc::doSyscall(int callnum, Process *process, ThreadContext *tc,
+                       Fault *fault)
 {
     TheISA::IntReg arg[6] M5_VAR_USED;
 
@@ -71,9 +76,10 @@ SyscallDesc::doSyscall(int callnum, Process *process, ThreadContext *tc)
      * blocking behavior, warn that the system call will retry;
      * alternatively, print the return value.
      */
-    if (retval.needsRetry())
+    if (retval.needsRetry()) {
+        *fault = std::make_shared<SyscallRetryFault>();
         DPRINTF_SYSCALL(Base, "%s needs retry\n", _name);
-    else
+    } else
         DPRINTF_SYSCALL(Base, "%s returns %d\n", _name, retval.encodedValue());
 
     if (!(_flags & SyscallDesc::SuppressReturnValue) && !retval.needsRetry())
diff --git a/src/sim/syscall_desc.hh b/src/sim/syscall_desc.hh
index 37aaad14d..b4d24e672 100644
--- a/src/sim/syscall_desc.hh
+++ b/src/sim/syscall_desc.hh
@@ -48,6 +48,8 @@
 
 #include <string>
 
+#include "base/types.hh"
+
 class Process;
 class SyscallReturn;
 class ThreadContext;
@@ -91,7 +93,8 @@ class SyscallDesc {
      * @param proc Handle for the owning Process to pass information
      * @param tc Handle for owning ThreadContext to pass information
      */
-    void doSyscall(int callnum, Process *proc, ThreadContext *tc);
+    void doSyscall(int callnum, Process *proc, ThreadContext *tc,
+                   Fault *fault);
 
     /**
      * Return false if WarnOnce is set and a warning has already been issued.