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* [kvm-unit-tests PATCH v2 0/2] powerpc: add little-endian support
@ 2016-02-26 17:08 ` Laurent Vivier
  0 siblings, 0 replies; 34+ messages in thread
From: Laurent Vivier @ 2016-02-26 17:08 UTC (permalink / raw)
  To: kvm, kvm-ppc; +Cc: drjones, thuth, dgibson, agraf, pbonzini, Laurent Vivier

This series must be applied on top of Drew's series (v7):

 ppc64: initial drop

It allows to build and use big-endian kvm-unit-tests on little-
endian host (Patch #1), and to build and use little-endian
kvm-unit-tests (Patch #2) on big and little endian hosts.

The series is also available from:

  https://github.com/vivier/kvm-unit-tests/commits/ppc64/endianness-v2

v2: replace FIXUP_ENDIAN from linux by a home made version
    (B_BE and RETURN_FROM_BE)

Laurent Vivier (2):
  powerpc: allow to build big-endian binaries on little-endian host
  powerpc: select endianness

 Makefile                  | 11 ++++++-----
 configure                 |  8 +++++++-
 lib/powerpc/asm/ppc_asm.h | 36 ++++++++++++++++++++++++++++++++++++
 lib/ppc64/asm/io.h        |  8 ++++++++
 lib/ppc64/asm/ppc_asm.h   |  1 +
 powerpc/Makefile          |  2 +-
 powerpc/Makefile.big      | 21 +++++++++++++++++++++
 powerpc/Makefile.common   | 29 +++++++++++++++--------------
 powerpc/Makefile.little   | 21 +++++++++++++++++++++
 powerpc/Makefile.ppc64    | 19 -------------------
 powerpc/cstart64.S        | 14 ++++++++++----
 11 files changed, 126 insertions(+), 44 deletions(-)
 create mode 100644 lib/powerpc/asm/ppc_asm.h
 create mode 100644 lib/ppc64/asm/ppc_asm.h
 create mode 100644 powerpc/Makefile.big
 create mode 100644 powerpc/Makefile.little
 delete mode 100644 powerpc/Makefile.ppc64

-- 
2.5.0


^ permalink raw reply	[flat|nested] 34+ messages in thread
* [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on decr excp
  2016-02-26 17:08   ` Laurent Vivier
@ 2019-05-15  0:28 ` Suraj Jitindar Singh
  -1 siblings, 0 replies; 34+ messages in thread
From: Suraj Jitindar Singh @ 2019-05-15  0:28 UTC (permalink / raw)
  To: kvm; +Cc: kvm-ppc, lvivier, thuth, dgibson, Suraj Jitindar Singh

Currently the handler for a decrementer exception will simply reload the
maximum value (0x7FFFFFFF), which will take ~4 seconds to expire again.
This means that if a vcpu cedes, it will be ~4 seconds between wakeups.

The h_cede_tm test is testing a known breakage when a guest cedes while
suspended. To be sure we cede 500 times to check for the bug. However
since it takes ~4 seconds to be woken up once we've ceded, we only get
through ~20 iterations before we reach the 90 seconds timeout and the
test appears to fail.

Add an option when registering the decrementer handler to specify the
value which should be reloaded by the handler, allowing the timeout to be
chosen.

Modify the spr test to use the max timeout to preserve existing
behaviour.
Modify the h_cede_tm test to use a 10ms timeout to ensure we can perform
500 iterations before hitting the 90 second time limit for a test.

This means the h_cede_tm test now succeeds rather than timing out.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>

---

V1 -> V2:
- Make decr variables static
- Load intial decr value in tm test to ensure known value present
---
 lib/powerpc/handlers.c | 7 ++++---
 powerpc/sprs.c         | 5 +++--
 powerpc/tm.c           | 4 +++-
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/lib/powerpc/handlers.c b/lib/powerpc/handlers.c
index be8226a..c8721e0 100644
--- a/lib/powerpc/handlers.c
+++ b/lib/powerpc/handlers.c
@@ -12,11 +12,12 @@
 
 /*
  * Generic handler for decrementer exceptions (0x900)
- * Just reset the decrementer back to its maximum value (0x7FFFFFFF)
+ * Just reset the decrementer back to the value specified when registering the
+ * handler
  */
-void dec_except_handler(struct pt_regs *regs __unused, void *data __unused)
+void dec_except_handler(struct pt_regs *regs __unused, void *data)
 {
-	uint32_t dec = 0x7FFFFFFF;
+	uint64_t dec = *((uint64_t *) data);
 
 	asm volatile ("mtdec %0" : : "r" (dec));
 }
diff --git a/powerpc/sprs.c b/powerpc/sprs.c
index 6744bd8..0e2e1c9 100644
--- a/powerpc/sprs.c
+++ b/powerpc/sprs.c
@@ -253,6 +253,7 @@ int main(int argc, char **argv)
 		0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL,
 		-1ULL,
 	};
+	static uint64_t decr = 0x7FFFFFFF; /* Max value */
 
 	for (i = 1; i < argc; i++) {
 		if (!strcmp(argv[i], "-w")) {
@@ -288,8 +289,8 @@ int main(int argc, char **argv)
 		(void) getchar();
 	} else {
 		puts("Sleeping...\n");
-		handle_exception(0x900, &dec_except_handler, NULL);
-		asm volatile ("mtdec %0" : : "r" (0x3FFFFFFF));
+		handle_exception(0x900, &dec_except_handler, &decr);
+		asm volatile ("mtdec %0" : : "r" (decr));
 		hcall(H_CEDE);
 	}
 
diff --git a/powerpc/tm.c b/powerpc/tm.c
index bd56baa..c588985 100644
--- a/powerpc/tm.c
+++ b/powerpc/tm.c
@@ -95,11 +95,13 @@ static bool enable_tm(void)
 static void test_h_cede_tm(int argc, char **argv)
 {
 	int i;
+	static uint64_t decr = 0x3FFFFF; /* ~10ms */
 
 	if (argc > 2)
 		report_abort("Unsupported argument: '%s'", argv[2]);
 
-	handle_exception(0x900, &dec_except_handler, NULL);
+	handle_exception(0x900, &dec_except_handler, &decr);
+	asm volatile ("mtdec %0" : : "r" (decr));
 
 	if (!start_all_cpus(halt, 0))
 		report_abort("Failed to start secondary cpus");
-- 
2.13.6


^ permalink raw reply related	[flat|nested] 34+ messages in thread
end of thread, other threads:[~2019-05-17 10:20 UTC | newest]

Thread overview: 34+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-02-26 17:08 [kvm-unit-tests PATCH v2 0/2] powerpc: add little-endian support Laurent Vivier
2016-02-26 17:08 ` Laurent Vivier
2016-02-26 17:08 ` [kvm-unit-tests PATCH v2 1/2] powerpc: allow to build big-endian binaries on little-endian host Laurent Vivier
2016-02-26 17:08   ` Laurent Vivier
2016-02-26 17:41   ` Andrew Jones
2016-02-26 17:41     ` Andrew Jones
2016-02-26 17:42   ` Andrew Jones
2016-02-26 17:42     ` Andrew Jones
2016-02-26 17:08 ` [kvm-unit-tests PATCH v2 2/2] powerpc: select endianness Laurent Vivier
2016-02-26 17:08   ` Laurent Vivier
2016-02-26 18:45   ` Andrew Jones
2016-02-26 18:45     ` Andrew Jones
2016-02-29 13:24     ` Laurent Vivier
2016-02-29 13:24       ` Laurent Vivier
2016-02-29 16:06     ` Paolo Bonzini
2016-02-29 16:06       ` Paolo Bonzini
2016-02-29 16:44       ` Laurent Vivier
2016-02-29 16:44         ` Laurent Vivier
2016-02-29 17:53     ` Laurent Vivier
2016-02-29 17:53       ` Laurent Vivier
2019-05-15  0:28 [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on decr excp Suraj Jitindar Singh
2019-05-15  0:28 ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on decr Suraj Jitindar Singh
2019-05-15  0:28 ` [kvm-unit-tests PATCH v2 2/2] powerpc: Make h_cede_tm test run by default Suraj Jitindar Singh
2019-05-15  0:28   ` Suraj Jitindar Singh
2019-05-15 16:25   ` Laurent Vivier
2019-05-15 16:25     ` Laurent Vivier
2019-05-17 10:13   ` Thomas Huth
2019-05-17 10:13     ` Thomas Huth
2019-05-15 16:22 ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on decr excp Laurent Vivier
2019-05-15 16:22   ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on Laurent Vivier
2019-05-15 23:27   ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on decr excp Suraj Jitindar Singh
2019-05-15 23:27     ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on Suraj Jitindar Singh
2019-05-17 10:20     ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on decr excp Thomas Huth
2019-05-17 10:20       ` [kvm-unit-tests PATCH v2 1/2] powerpc: Allow for a custom decr value to be specified to load on Thomas Huth

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