Re: [PATCH v14 13/15] selftests/powerpc: Add ptrace tests for TM SPR registers

[Simon Guo]

Hi Cyril,
On Wed, Sep 14, 2016 at 03:04:12PM +1000, Cyril Bur wrote:
> On Mon, 2016-09-12 at 15:33 +0800, wei.guo.si...@gmail.com wrote:
> > From: Anshuman Khandual 
> > 
> > This patch adds ptrace interface test for TM SPR registers. This
> > also adds ptrace interface based helper functions related to TM
> > SPR registers access.
> > 
> 
> I'm seeing this one fail a lot, it does occasionally succeed but fails
> a lot on my test setup.
> 
> I use qemu on a power8 for most of my testing:
> qemu-system-ppc64 --enable-kvm -machine pseries,accel=kvm,usb=off -m
> 4096 -realtime mlock=off -smp 4,sockets=1,cores=2,threads=2 -nographic
> -vga none
> 
> 
> > Signed-off-by: Anshuman Khandual 
> > Signed-off-by: Simon Guo 
> > ---
> >  tools/testing/selftests/powerpc/ptrace/Makefile|   3 +-
> >  .../selftests/powerpc/ptrace/ptrace-tm-spr.c   | 186
> > +
> >  tools/testing/selftests/powerpc/ptrace/ptrace.h|  35 
> >  3 files changed, 223 insertions(+), 1 deletion(-)
> >  create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-tm-
> > spr.c
> > 
> > diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile
> > b/tools/testing/selftests/powerpc/ptrace/Makefile
> > index 797840a..f34670e 100644
> > --- a/tools/testing/selftests/powerpc/ptrace/Makefile
> > +++ b/tools/testing/selftests/powerpc/ptrace/Makefile
> > @@ -1,7 +1,8 @@
> >  TEST_PROGS := ptrace-ebb ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr
> > \
> >  ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx
> > \
> > -ptrace-tm-spd-vsx
> > +ptrace-tm-spd-vsx ptrace-tm-spr
> >  
> > +include ../../lib.mk
> >  
> >  all: $(TEST_PROGS)
> >  CFLAGS += -m64
> > diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> > b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> > new file mode 100644
> > index 000..2863070
> > --- /dev/null
> > +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> > @@ -0,0 +1,186 @@
> > +/*
> > + * Ptrace test TM SPR registers
> > + *
> > + * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation; either version
> > + * 2 of the License, or (at your option) any later version.
> > + */
> > +#include "ptrace.h"
> > +
> > +/* Tracee and tracer shared data */
> > +struct shared {
> > +   int flag;
> > +   struct tm_spr_regs regs;
> > +};
> > +unsigned long tfhar;
> > +
> > +int shm_id;
> > +volatile struct shared *cptr, *pptr;
> > +
> > +int shm_id1;
> > +volatile int *cptr1, *pptr1;
> > +
> > +#define TM_SCHED   0xde018c01
> > +#define TM_KVM_SCHED   0xe001ac01
> > +
> > +int validate_tm_spr(struct tm_spr_regs *regs)
> > +{
> > +   if (regs->tm_tfhar != tfhar)
> > +   return TEST_FAIL;
> > +
> > +   if ((regs->tm_texasr != TM_SCHED) && (regs->tm_texasr !=
> > TM_KVM_SCHED))
> > +   return TEST_FAIL;
> 
> The above condition fails, should this test try again if this condition
> is true, rather than fail?
> 

I reproduced the failure with your configuration. Besides treclaim, there are 
many other reasons that may lead to the transaction failure according to ISA.  
At least I observed following Texasr values:
  11801
  18801
  1a801


I noticed some FIAR locates at IPI handling related code.  My previous 
configuration 
is 4 sockets/each with only 1 core/1 thread. That is probably the reason I 
always 
passed the test in the old configuration.(per my understanding, IPI is limited 
within 
threads).  So I removed the checking regarding specfied TEXASR value.

And I think I have reworked all your other comments.

I will send out v15 soon. Again thanks for your code inspection.

BR,
- Simon

Re: [PATCH v14 13/15] selftests/powerpc: Add ptrace tests for TM SPR registers

[Simon Guo]

On Wed, Sep 14, 2016 at 03:04:12PM +1000, Cyril Bur wrote:
> On Mon, 2016-09-12 at 15:33 +0800, wei.guo.si...@gmail.com wrote:
> > From: Anshuman Khandual 
> > 
> > This patch adds ptrace interface test for TM SPR registers. This
> > also adds ptrace interface based helper functions related to TM
> > SPR registers access.
> > 
> 
> I'm seeing this one fail a lot, it does occasionally succeed but fails
> a lot on my test setup.
> 
> I use qemu on a power8 for most of my testing:
> qemu-system-ppc64 --enable-kvm -machine pseries,accel=kvm,usb=off -m
> 4096 -realtime mlock=off -smp 4,sockets=1,cores=2,threads=2 -nographic
> -vga none
Hi Cyril,

Sorry for the late response. I am just back from a vacation.
Strangely the case always succeed in my machine. I will try to 
reproduce it with your configuration.

> > +   if ((regs->tm_texasr != TM_SCHED) && (regs->tm_texasr !=
> > TM_KVM_SCHED))
> > +   return TEST_FAIL;
> 
> The above condition fails, should this test try again if this condition
> is true, rather than fail?
If you have the value of "regs->tm_texasr" in hand, please let
me know.

Thanks for the elaborated comment in other mails and I will 
work on that.

BR,
- Simon

Re: [PATCH v14 13/15] selftests/powerpc: Add ptrace tests for TM SPR registers

[Cyril Bur]

On Mon, 2016-09-12 at 15:33 +0800, wei.guo.si...@gmail.com wrote:
> From: Anshuman Khandual 
> 
> This patch adds ptrace interface test for TM SPR registers. This
> also adds ptrace interface based helper functions related to TM
> SPR registers access.
> 

I'm seeing this one fail a lot, it does occasionally succeed but fails
a lot on my test setup.

I use qemu on a power8 for most of my testing:
qemu-system-ppc64 --enable-kvm -machine pseries,accel=kvm,usb=off -m
4096 -realtime mlock=off -smp 4,sockets=1,cores=2,threads=2 -nographic
-vga none


> Signed-off-by: Anshuman Khandual 
> Signed-off-by: Simon Guo 
> ---
>  tools/testing/selftests/powerpc/ptrace/Makefile|   3 +-
>  .../selftests/powerpc/ptrace/ptrace-tm-spr.c   | 186
> +
>  tools/testing/selftests/powerpc/ptrace/ptrace.h|  35 
>  3 files changed, 223 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-tm-
> spr.c
> 
> diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile
> b/tools/testing/selftests/powerpc/ptrace/Makefile
> index 797840a..f34670e 100644
> --- a/tools/testing/selftests/powerpc/ptrace/Makefile
> +++ b/tools/testing/selftests/powerpc/ptrace/Makefile
> @@ -1,7 +1,8 @@
>  TEST_PROGS := ptrace-ebb ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr
> \
>  ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx
> \
> -ptrace-tm-spd-vsx
> +ptrace-tm-spd-vsx ptrace-tm-spr
>  
> +include ../../lib.mk
>  
>  all: $(TEST_PROGS)
>  CFLAGS += -m64
> diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> new file mode 100644
> index 000..2863070
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> @@ -0,0 +1,186 @@
> +/*
> + * Ptrace test TM SPR registers
> + *
> + * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +#include "ptrace.h"
> +
> +/* Tracee and tracer shared data */
> +struct shared {
> + int flag;
> + struct tm_spr_regs regs;
> +};
> +unsigned long tfhar;
> +
> +int shm_id;
> +volatile struct shared *cptr, *pptr;
> +
> +int shm_id1;
> +volatile int *cptr1, *pptr1;
> +
> +#define TM_SCHED 0xde018c01
> +#define TM_KVM_SCHED 0xe001ac01
> +
> +int validate_tm_spr(struct tm_spr_regs *regs)
> +{
> + if (regs->tm_tfhar != tfhar)
> + return TEST_FAIL;
> +
> + if ((regs->tm_texasr != TM_SCHED) && (regs->tm_texasr !=
> TM_KVM_SCHED))
> + return TEST_FAIL;

The above condition fails, should this test try again if this condition
is true, rather than fail?

> +
> + if ((regs->tm_texasr == TM_KVM_SCHED) && (regs->tm_tfiar !=
> 0))
> + return TEST_FAIL;
> +
> + return TEST_PASS;
> +}
> +

[snip]

[PATCH v14 13/15] selftests/powerpc: Add ptrace tests for TM SPR registers

[wei . guo . simon]

From: Anshuman Khandual 

This patch adds ptrace interface test for TM SPR registers. This
also adds ptrace interface based helper functions related to TM
SPR registers access.

Signed-off-by: Anshuman Khandual 
Signed-off-by: Simon Guo 
---
 tools/testing/selftests/powerpc/ptrace/Makefile|   3 +-
 .../selftests/powerpc/ptrace/ptrace-tm-spr.c   | 186 +
 tools/testing/selftests/powerpc/ptrace/ptrace.h|  35 
 3 files changed, 223 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c

diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile 
b/tools/testing/selftests/powerpc/ptrace/Makefile
index 797840a..f34670e 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile
@@ -1,7 +1,8 @@
 TEST_PROGS := ptrace-ebb ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
 ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \
-ptrace-tm-spd-vsx
+ptrace-tm-spd-vsx ptrace-tm-spr
 
+include ../../lib.mk
 
 all: $(TEST_PROGS)
 CFLAGS += -m64
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c 
b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
new file mode 100644
index 000..2863070
--- /dev/null
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
@@ -0,0 +1,186 @@
+/*
+ * Ptrace test TM SPR registers
+ *
+ * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include "ptrace.h"
+
+/* Tracee and tracer shared data */
+struct shared {
+   int flag;
+   struct tm_spr_regs regs;
+};
+unsigned long tfhar;
+
+int shm_id;
+volatile struct shared *cptr, *pptr;
+
+int shm_id1;
+volatile int *cptr1, *pptr1;
+
+#define TM_SCHED   0xde018c01
+#define TM_KVM_SCHED   0xe001ac01
+
+int validate_tm_spr(struct tm_spr_regs *regs)
+{
+   if (regs->tm_tfhar != tfhar)
+   return TEST_FAIL;
+
+   if ((regs->tm_texasr != TM_SCHED) && (regs->tm_texasr != TM_KVM_SCHED))
+   return TEST_FAIL;
+
+   if ((regs->tm_texasr == TM_KVM_SCHED) && (regs->tm_tfiar != 0))
+   return TEST_FAIL;
+
+   return TEST_PASS;
+}
+
+void tm_spr(void)
+{
+   unsigned long result, texasr;
+   int ret;
+
+   cptr = (struct shared *)shmat(shm_id, NULL, 0);
+   cptr1 = (int *)shmat(shm_id1, NULL, 0);
+
+trans:
+   cptr1[0] = 0;
+   asm __volatile__(
+   "1: ;"
+   /* TM failover handler should follow TBEGIN */
+   "mflr 31;"
+   "bl 4f;"/* $ = TFHAR - 12 */
+   "4: ;"
+   "mflr %[tfhar];"
+   "mtlr 31;"
+
+   TBEGIN
+   "beq 2f;"
+
+   TSUSPEND
+   "li 8, 1;"
+   "sth 8, 0(%[cptr1]);"
+   TRESUME
+   "b .;"
+
+   TEND
+   "li 0, 0;"
+   "ori %[res], 0, 0;"
+   "b 3f;"
+
+   "2: ;"
+
+   "li 0, 1;"
+   "ori %[res], 0, 0;"
+   "mfspr %[texasr], %[sprn_texasr];"
+
+   "3: ;"
+   : [tfhar] "=r" (tfhar), [res] "=r" (result),
+   [texasr] "=r" (texasr), [cptr1] "=r" (cptr1)
+   : [sprn_texasr] "i"  (SPRN_TEXASR)
+   : "memory", "r0", "r1", "r2", "r3", "r4",
+   "r8", "r9", "r10", "r11", "r31"
+   );
+
+   /* There are 2 32bit instructions before tbegin. */
+   tfhar += 12;
+
+   if (result) {
+   if (!cptr->flag)
+   goto trans;
+
+   ret = validate_tm_spr((struct tm_spr_regs *)>regs);
+   shmdt((void *)cptr);
+   shmdt((void *)cptr1);
+   if (ret)
+   exit(1);
+   exit(0);
+   }
+   shmdt((void *)cptr);
+   shmdt((void *)cptr1);
+   exit(1);
+}
+
+int trace_tm_spr(pid_t child)
+{
+   int ret;
+
+   ret = start_trace(child);
+   if (ret)
+   return TEST_FAIL;
+
+   ret = show_tm_spr(child, (struct tm_spr_regs *)>regs);
+   if (ret)
+   return TEST_FAIL;
+
+   printf("TFHAR: %lx TEXASR: %lx TFIAR: %lx\n", pptr->regs.tm_tfhar,
+   pptr->regs.tm_texasr, pptr->regs.tm_tfiar);
+
+   pptr->flag = 1;
+   ret = stop_trace(child);
+   if (ret)
+   return TEST_FAIL;
+
+   return TEST_PASS;
+}
+
+int ptrace_tm_spr(void)
+{
+   pid_t pid;
+   int ret, status;
+
+   SKIP_IF(!((long)get_auxv_entry(AT_HWCAP2) & PPC_FEATURE2_HTM));
+   shm_id =