[kvm-unit-tests PATCH v2 0/2] powerpc: Test SPR persistency during migration

[kvm-unit-tests PATCH v2 0/2] powerpc: Test SPR persistency during migration

[Thomas Huth]

Here's a KVM-unit-test to check the persistency of SPRs during migration.
First patch adds a helper script for doing migration tests in the
kvm-unit-test framework, and the second patch contains the SPR tester.

v2:
- Addressed review feedback from v1
- Now using cpu_relax() instead of asm volatile ("nop")

Thomas Huth (2):
  Add the possibility to do simple migration tests
  powerpc: Add Special Purpose Register persistency test

 powerpc/Makefile.common          |   3 +-
 powerpc/cstart64.S               |   2 +
 powerpc/run                      |   4 +
 powerpc/sprs.c                   | 304 +++++++++++++++++++++++++++++++++++++++
 powerpc/unittests.cfg            |   5 +
 scripts/qemu-migration-helper.sh |  68 +++++++++
 scripts/runtime.bash             |   3 +
 7 files changed, 388 insertions(+), 1 deletion(-)
 create mode 100644 powerpc/sprs.c
 create mode 100755 scripts/qemu-migration-helper.sh

-- 
1.8.3.1

[kvm-unit-tests PATCH v2 1/2] Add the possibility to do simple migration tests

[Thomas Huth]

To be able to do simple migration tests with kvm-unit-tests, too,
add a helper script that does all the necessary work: Start two
instances of QEMU (source and destination) with QMP sockets for
sending commands to them, then trigger the migration from one
instance to the other and finally signal the end of the migration
to the guest by injecting an NMI.
This helper script is now used automatically for powerpc tests
if the test is put into the "migration" group in the unittests.cfg
file.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 powerpc/run                      |  4 +++
 scripts/qemu-migration-helper.sh | 68 ++++++++++++++++++++++++++++++++++++++++
 scripts/runtime.bash             |  3 ++
 3 files changed, 75 insertions(+)
 create mode 100755 scripts/qemu-migration-helper.sh

diff --git a/powerpc/run b/powerpc/run
index 6269abb..f1528ed 100755
--- a/powerpc/run
+++ b/powerpc/run
@@ -41,6 +41,10 @@ if ! $qemu -machine '?' 2>&1 | grep 'pseries' > /dev/null; then
 	exit 2
 fi
 
+if [ "$MIGRATION" = "yes" ]; then
+	qemu="scripts/qemu-migration-helper.sh $qemu"
+fi
+
 M='-machine pseries'
 M+=",accel=$ACCEL"
 command="$qemu -nodefaults $M -bios $FIRMWARE"
diff --git a/scripts/qemu-migration-helper.sh b/scripts/qemu-migration-helper.sh
new file mode 100755
index 0000000..5842026
--- /dev/null
+++ b/scripts/qemu-migration-helper.sh
@@ -0,0 +1,68 @@
+#!/bin/bash
+# This script runs two instances of QEMU and then migrates the guest from one
+# instance to the other. The end of the migration is signalled to the guest by
+# injecting an NMI.
+
+if ! command -v nc >/dev/null 2>&1; then
+	echo "$0 needs nc (netcat)"
+	exit 1
+fi
+
+qemu=$1
+shift
+
+if ! command -v "$qemu" >/dev/null 2>&1; then
+	echo "The first parameter must be pointing to the QEMU executable"
+	exit 1
+fi
+
+migsock=`mktemp -u -t mig-helper-socket.XXXXXXXXXX`
+stdout1=`mktemp -t mig-helper-stdout1.XXXXXXXXXX`
+stdout2=`mktemp -t mig-helper-stdout2.XXXXXXXXXX`
+qmpout1=`mktemp -t mig-helper-qmpout1.XXXXXXXXXX`
+qmpout2=`mktemp -t mig-helper-qmpout2.XXXXXXXXXX`
+qmp1=`mktemp -u -t mig-helper-qmp1.XXXXXXXXXX`
+qmp2=`mktemp -u -t mig-helper-qmp2.XXXXXXXXXX`
+
+cleanup()
+{
+	rm -f ${stdout1} ${stdout2} ${migsock}
+	rm -f ${qmpout1} ${qmpout2} ${qmp1} ${qmp2}
+}
+trap cleanup EXIT
+
+qmp_cmd()
+{
+	echo '{ "execute": "qmp_capabilities" }{ "execute":' "$2" '}' | nc -U $1
+}
+
+$qemu $* -chardev socket,id=mon1,path=${qmp1},server,nowait \
+	 -mon chardev=mon1,mode=control > ${stdout1} &
+
+$qemu $* -chardev socket,id=mon2,path=${qmp2},server,nowait \
+	 -mon chardev=mon2,mode=control -incoming unix:${migsock} > ${stdout2} &
+
+# The test must prompt the user to migrate, so wait for the "migrate" keyword
+while ! grep -q -i "migrate" < ${stdout1} ; do
+	sleep 1
+done
+
+qmp_cmd ${qmp1} '"migrate", "arguments": { "uri": "unix:'${migsock}'" }' > ${qmpout1}
+
+# Wait for the migration to complete
+migstatus=`qmp_cmd ${qmp1} '"query-migrate"' | grep return`
+while ! grep -q '"completed"' <<<"$migstatus" ; do
+	sleep 1
+	migstatus=`qmp_cmd ${qmp1} '"query-migrate"' | grep return`
+	if grep -q '"failed"' <<<"$migstatus" ; then
+		echo "ERROR: Migration failed."
+		exit 1
+	fi
+done
+qmp_cmd ${qmp1} '"quit"'> ${qmpout1} 2>/dev/null
+
+qmp_cmd ${qmp2} '"inject-nmi"'> ${qmpout2}
+
+wait
+
+cat ${stdout1} ${stdout2}
diff --git a/scripts/runtime.bash b/scripts/runtime.bash
index 9c1bc3b..f58eb4e 100644
--- a/scripts/runtime.bash
+++ b/scripts/runtime.bash
@@ -98,6 +98,9 @@ function run()
     }
 
     cmdline=$(get_cmdline $kernel)
+    if grep -qw "migration" <<<$groups ; then
+        cmdline="MIGRATION=yes $cmdline"
+    fi
     if [ "$verbose" = "yes" ]; then
         echo $cmdline
     fi
-- 
1.8.3.1

[kvm-unit-tests PATCH v2 2/2] powerpc: Add Special Purpose Register persistency test

[Thomas Huth]

This test has two purposes: First, check whether the hypervisor can be
destabilized by writing random values into the SPRs of the PowerPC CPU
(this indeed revealed a bug last year, see CVE-2016-3044).
Second, this test can be used to check whether the SPRs are synchronized
properly between the KVM host CPU and QEMU, e.g. when migrating the VM
from one QEMU instance to another.
The test first fills the various SPRs with some non-zero value, then reads
the values back into a first array. It then either sleeps a short period
of time (for testing without migration, in the hope that we're rescheduled
on another host CPU), or it waits for a key or NMI (with the '-w' option)
so that it is possible to migrate the VM before continuing. The test then
finally reads the values from the SPRs back into another array and then
compares them with the initial values.
Currently the test only supports the SPRs from the PowerISA v2.01
(PowerPC 970) and PowerISA v2.07 specification (i.e. POWER8 CPUs),
but other versions should be pretty easy to add later.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 powerpc/Makefile.common |   3 +-
 powerpc/cstart64.S      |   2 +
 powerpc/sprs.c          | 304 ++++++++++++++++++++++++++++++++++++++++++++++++
 powerpc/unittests.cfg   |   5 +
 4 files changed, 313 insertions(+), 1 deletion(-)
 create mode 100644 powerpc/sprs.c

diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common
index 37f8caa..92809a5 100644
--- a/powerpc/Makefile.common
+++ b/powerpc/Makefile.common
@@ -9,7 +9,8 @@ tests-common = \
 	$(TEST_DIR)/spapr_hcall.elf \
 	$(TEST_DIR)/rtas.elf \
 	$(TEST_DIR)/emulator.elf \
-	$(TEST_DIR)/tm.elf
+	$(TEST_DIR)/tm.elf \
+	$(TEST_DIR)/sprs.elf
 
 tests-all = $(tests-common) $(tests)
 all: $(TEST_DIR)/boot_rom.bin $(tests-all)
diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S
index 2204e3b..ec673b3 100644
--- a/powerpc/cstart64.S
+++ b/powerpc/cstart64.S
@@ -247,6 +247,8 @@ call_handler:
 	.globl __start_interrupts
 __start_interrupts:
 
+VECTOR(0x100)
+VECTOR(0x200)
 VECTOR(0x300)
 VECTOR(0x400)
 VECTOR(0x500)
diff --git a/powerpc/sprs.c b/powerpc/sprs.c
new file mode 100644
index 0000000..528901b
--- /dev/null
+++ b/powerpc/sprs.c
@@ -0,0 +1,304 @@
+/*
+ * Test Special Purpose Registers
+ *
+ * Copyright 2017  Thomas Huth, Red Hat Inc.
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ *
+ * The basic idea of this test is to check whether the contents of the Special
+ * Purpose Registers (SPRs) are preserved correctly during migration. So we
+ * fill in the SPRs with a well-known value, read the values back (since not
+ * all bits might be retained in the SPRs), then wait for a key or NMI (if the
+ * '-w' option has been specified) so that the user has a chance to migrate the
+ * VM. Alternatively, the test can also simply sleep a little bit with the
+ * H_CEDE hypercall, in the hope that we'll get scheduled to another host CPU
+ * and thus register contents might have changed, too (in case of bugs).
+ * Finally, we read back the values from the SPRs and compare them with the
+ * values before the migration. Mismatches are reported as test failures.
+ * Note that we do not test all SPRs since some of the registers change their
+ * content automatically, and some are only accessible with hypervisor privi-
+ * leges or have bad side effects, so we have to omit those registers.
+ */
+#include <libcflat.h>
+#include <util.h>
+#include <alloc.h>
+#include <asm/handlers.h>
+#include <asm/hcall.h>
+#include <asm/processor.h>
+#include <asm/barrier.h>
+
+#define mfspr(nr) ({ \
+	uint64_t ret; \
+	asm volatile("mfspr %0,%1" : "=r"(ret) : "i"(nr)); \
+	ret; \
+})
+
+#define mtspr(nr, val) \
+	asm volatile("mtspr %0,%1" : : "i"(nr), "r"(val))
+
+uint64_t before[1024], after[1024];
+
+volatile int nmi_occurred;
+
+static void nmi_handler(struct pt_regs *regs __unused, void *opaque __unused)
+{
+	nmi_occurred = 1;
+}
+
+static int h_get_term_char(uint64_t termno)
+{
+	register uint64_t r3 asm("r3") = 0x54; /* H_GET_TERM_CHAR */
+	register uint64_t r4 asm("r4") = termno;
+	register uint64_t r5 asm("r5");
+
+	asm volatile (" sc 1 "	: "+r"(r3), "+r"(r4), "=r"(r5)
+				: "r"(r3),  "r"(r4));
+
+	return r3 == H_SUCCESS && r4 > 0 ? r5 >> 48 : 0;
+}
+
+/* Common SPRs for all PowerPC CPUs */
+static void set_sprs_common(uint64_t val)
+{
+	mtspr(9, val);		/* CTR */
+	// mtspr(273, val);	/* SPRG1 */  /* Used by our exception handler */
+	mtspr(274, val);	/* SPRG2 */
+	mtspr(275, val);	/* SPRG3 */
+}
+
+/* SPRs from PowerPC Operating Environment Architecture, Book III, Vers. 2.01 */
+static void set_sprs_book3s_201(uint64_t val)
+{
+	mtspr(18, val);		/* DSISR */
+	mtspr(19, val);		/* DAR */
+	mtspr(152, val);	/* CTRL */
+	mtspr(256, val);	/* VRSAVE */
+	mtspr(786, val);	/* MMCRA */
+	mtspr(795, val);	/* MMCR0 */
+	mtspr(798, val);	/* MMCR1 */
+}
+
+/* SPRs from PowerISA 2.07 Book III-S */
+static void set_sprs_book3s_207(uint64_t val)
+{
+	mtspr(3, val);		/* DSCR */
+	mtspr(13, val);		/* AMR */
+	mtspr(17, val);		/* DSCR */
+	mtspr(18, val);		/* DSISR */
+	mtspr(19, val);		/* DAR */
+	mtspr(29, val);		/* AMR */
+	mtspr(61, val);		/* IAMR */
+	// mtspr(152, val);	/* CTRL */  /* TODO: Needs a fix in KVM */
+	mtspr(153, val);	/* FSCR */
+	mtspr(157, val);	/* UAMOR */
+	mtspr(159, val);	/* PSPB */
+	mtspr(256, val);	/* VRSAVE */
+	// mtspr(272, val);	/* SPRG0 */ /* Used by our exception handler */
+	mtspr(769, val);	/* MMCR2 */
+	mtspr(770, val);	/* MMCRA */
+	mtspr(771, val);	/* PMC1 */
+	mtspr(772, val);	/* PMC2 */
+	mtspr(773, val);	/* PMC3 */
+	mtspr(774, val);	/* PMC4 */
+	mtspr(775, val);	/* PMC5 */
+	mtspr(776, val);	/* PMC6 */
+	mtspr(779, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070);	/* MMCR0 */
+	mtspr(784, val);	/* SIER */
+	mtspr(785, val);	/* MMCR2 */
+	mtspr(786, val);	/* MMCRA */
+	mtspr(787, val);	/* PMC1 */
+	mtspr(788, val);	/* PMC2 */
+	mtspr(789, val);	/* PMC3 */
+	mtspr(790, val);	/* PMC4 */
+	mtspr(791, val);	/* PMC5 */
+	mtspr(792, val);	/* PMC6 */
+	mtspr(795, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070);	/* MMCR0 */
+	mtspr(796, val);	/* SIAR */
+	mtspr(797, val);	/* SDAR */
+	mtspr(798, val);	/* MMCR1 */
+	mtspr(800, val);	/* BESCRS */
+	mtspr(801, val);	/* BESCCRSU */
+	mtspr(802, val);	/* BESCRR */
+	mtspr(803, val);	/* BESCRRU */
+	mtspr(804, val);	/* EBBHR */
+	mtspr(805, val);	/* EBBRR */
+	mtspr(806, val);	/* BESCR */
+	mtspr(815, val);	/* TAR */
+}
+
+static void set_sprs(uint64_t val)
+{
+	uint32_t pvr = mfspr(287);	/* Processor Version Register */
+
+	set_sprs_common(val);
+
+	switch (pvr >> 16) {
+	case 0x39:			/* PPC970 */
+	case 0x3C:			/* PPC970FX */
+	case 0x44:			/* PPC970MP */
+		set_sprs_book3s_201(val);
+		break;
+	case 0x4b:			/* POWER8E */
+	case 0x4c:			/* POWER8NVL */
+	case 0x4d:			/* POWER8 */
+		set_sprs_book3s_207(val);
+		break;
+	default:
+		puts("Warning: Unknown processor version!\n");
+	}
+}
+
+static void get_sprs_common(uint64_t *v)
+{
+	v[9] = mfspr(9);	/* CTR */
+	// v[273] = mfspr(273);	/* SPRG1 */ /* Used by our exception handler */
+	v[274] = mfspr(274);	/* SPRG2 */
+	v[275] = mfspr(275);	/* SPRG3 */
+}
+
+static void get_sprs_book3s_201(uint64_t *v)
+{
+	v[18] = mfspr(18);	/* DSISR */
+	v[19] = mfspr(19);	/* DAR */
+	v[136] = mfspr(136);	/* CTRL */
+	v[256] = mfspr(256);	/* VRSAVE */
+	v[786] = mfspr(786);	/* MMCRA */
+	v[795] = mfspr(795);	/* MMCR0 */
+	v[798] = mfspr(798);	/* MMCR1 */
+}
+
+static void get_sprs_book3s_207(uint64_t *v)
+{
+	v[3] = mfspr(3);	/* DSCR */
+	v[13] = mfspr(13);	/* AMR */
+	v[17] = mfspr(17);	/* DSCR */
+	v[18] = mfspr(18);	/* DSISR */
+	v[19] = mfspr(19);	/* DAR */
+	v[29] = mfspr(29);	/* AMR */
+	v[61] = mfspr(61);	/* IAMR */
+	// v[136] = mfspr(136);	/* CTRL */  /* TODO: Needs a fix in KVM */
+	v[153] = mfspr(153);	/* FSCR */
+	v[157] = mfspr(157);	/* UAMOR */
+	v[159] = mfspr(159);	/* PSPB */
+	v[256] = mfspr(256);	/* VRSAVE */
+	v[259] = mfspr(259);	/* SPRG3 (read only) */
+	// v[272] = mfspr(272);	/* SPRG0 */  /* Used by our exception handler */
+	v[769] = mfspr(769);	/* MMCR2 */
+	v[770] = mfspr(770);	/* MMCRA */
+	v[771] = mfspr(771);	/* PMC1 */
+	v[772] = mfspr(772);	/* PMC2 */
+	v[773] = mfspr(773);	/* PMC3 */
+	v[774] = mfspr(774);	/* PMC4 */
+	v[775] = mfspr(775);	/* PMC5 */
+	v[776] = mfspr(776);	/* PMC6 */
+	v[779] = mfspr(779);	/* MMCR0 */
+	v[780] = mfspr(780);	/* SIAR (read only) */
+	v[781] = mfspr(781);	/* SDAR (read only) */
+	v[782] = mfspr(782);	/* MMCR1 (read only) */
+	v[784] = mfspr(784);	/* SIER */
+	v[785] = mfspr(785);	/* MMCR2 */
+	v[786] = mfspr(786);	/* MMCRA */
+	v[787] = mfspr(787);	/* PMC1 */
+	v[788] = mfspr(788);	/* PMC2 */
+	v[789] = mfspr(789);	/* PMC3 */
+	v[790] = mfspr(790);	/* PMC4 */
+	v[791] = mfspr(791);	/* PMC5 */
+	v[792] = mfspr(792);	/* PMC6 */
+	v[795] = mfspr(795);	/* MMCR0 */
+	v[796] = mfspr(796);	/* SIAR */
+	v[797] = mfspr(797);	/* SDAR */
+	v[798] = mfspr(798);	/* MMCR1 */
+	v[800] = mfspr(800);	/* BESCRS */
+	v[801] = mfspr(801);	/* BESCCRSU */
+	v[802] = mfspr(802);	/* BESCRR */
+	v[803] = mfspr(803);	/* BESCRRU */
+	v[804] = mfspr(804);	/* EBBHR */
+	v[805] = mfspr(805);	/* EBBRR */
+	v[806] = mfspr(806);	/* BESCR */
+	v[815] = mfspr(815);	/* TAR */
+}
+
+static void get_sprs(uint64_t *v)
+{
+	uint32_t pvr = mfspr(287);	/* Processor Version Register */
+
+	get_sprs_common(v);
+
+	switch (pvr >> 16) {
+	case 0x39:			/* PPC970 */
+	case 0x3C:			/* PPC970FX */
+	case 0x44:			/* PPC970MP */
+		get_sprs_book3s_201(v);
+		break;
+	case 0x4b:			/* POWER8E */
+	case 0x4c:			/* POWER8NVL */
+	case 0x4d:			/* POWER8 */
+		get_sprs_book3s_207(v);
+		break;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int i;
+	bool waitkey = false;
+	uint64_t pat = 0xcafefacec0debabeULL;
+	const uint64_t patterns[] = {
+		0xcafefacec0debabeULL, ~0xcafefacec0debabeULL,
+		0xAAAA5555AAAA5555ULL, 0x5555AAAA5555AAAAULL,
+		0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL,
+		-1ULL,
+	};
+
+	for (i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "-w")) {
+			waitkey = true;
+		} else if (!strcmp(argv[i], "-p")) {
+			i += 1;
+			if (i >= argc || *argv[i] < '0'
+			    || *argv[i] >= '0' + ARRAY_SIZE(patterns))
+				report_abort("Error: bad value for -p");
+			pat ^= patterns[*argv[i] - '0'];
+		} else if (!strcmp(argv[i], "-t")) {
+			/* Randomize with timebase register */
+			asm volatile("mftb %0" : "=r"(i));
+			pat ^= i;
+			asm volatile("mftb %0" : "=r"(i));
+			pat ^= ~(uint64_t)i << 32;
+		} else {
+			report_abort("Warning: Unsupported argument: %s",
+			             argv[i]);
+		}
+	}
+
+	printf("Settings SPRs to 0x%lx...\n", pat);
+	set_sprs(pat);
+
+	memset(before, 0, sizeof(before));
+	memset(after, 0, sizeof(after));
+
+	get_sprs(before);
+
+	if (waitkey) {
+		handle_exception(0x100, &nmi_handler, NULL);
+		puts("Now migrate the VM, then press a key or send NMI...\n");
+		while (!nmi_occurred && h_get_term_char(0) == 0)
+			cpu_relax();
+	} else {
+		puts("Sleeping...\n");
+		handle_exception(0x900, &dec_except_handler, NULL);
+		asm volatile ("mtdec %0" : : "r" (0x3FFFFFFF));
+		hcall(H_CEDE);
+	}
+
+	get_sprs(after);
+
+	puts("Checking SPRs...\n");
+	for (i = 0; i < 1024; i++) {
+		if (before[i] != 0 || after[i] != 0)
+			report("SPR %d:\t0x%016lx <==> 0x%016lx",
+				before[i] == after[i], i, before[i], after[i]);
+	}
+
+	return report_summary();
+}
diff --git a/powerpc/unittests.cfg b/powerpc/unittests.cfg
index 20dbde6..fb6b70e 100644
--- a/powerpc/unittests.cfg
+++ b/powerpc/unittests.cfg
@@ -59,3 +59,8 @@ file = tm.elf
 smp = 2,threads=2
 extra_params = -append "h_cede_tm"
 groups = nodefault,h_cede_tm
+
+[sprs]
+file = sprs.elf
+extra_params = -append '-w'
+groups = migration
-- 
1.8.3.1

Re: [kvm-unit-tests PATCH v2 1/2] Add the possibility to do simple migration tests

[Radim Krčmář]

2017-03-14 11:23+0100, Thomas Huth:
> To be able to do simple migration tests with kvm-unit-tests, too,
> add a helper script that does all the necessary work: Start two
> instances of QEMU (source and destination) with QMP sockets for
> sending commands to them, then trigger the migration from one
> instance to the other and finally signal the end of the migration
> to the guest by injecting an NMI.
> This helper script is now used automatically for powerpc tests
> if the test is put into the "migration" group in the unittests.cfg
> file.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  powerpc/run                      |  4 +++
>  scripts/qemu-migration-helper.sh | 68 ++++++++++++++++++++++++++++++++++++++++
>  scripts/runtime.bash             |  3 ++
>  3 files changed, 75 insertions(+)
>  create mode 100755 scripts/qemu-migration-helper.sh
> 
> diff --git a/powerpc/run b/powerpc/run
> index 6269abb..f1528ed 100755
> --- a/powerpc/run
> +++ b/powerpc/run
> @@ -41,6 +41,10 @@ if ! $qemu -machine '?' 2>&1 | grep 'pseries' > /dev/null; then
>  	exit 2
>  fi
>  
> +if [ "$MIGRATION" = "yes" ]; then
> +	qemu="scripts/qemu-migration-helper.sh $qemu"
> +fi

I think this script could be useful for other architectures as well ...
what about adding migration_cmd to scripts/arch-run.bash

  migration_cmd ()
  {
  	if [ "$MIGRATION" = "yes" ]; then
  		echo "scripts/qemu-migration-helper.sh"
  	fi
  }

and using only

  command="$(timeout_cmd) $(migration_cmd) $command"

in arch scripts?

> +
>  M='-machine pseries'
>  M+=",accel=$ACCEL"
>  command="$qemu -nodefaults $M -bios $FIRMWARE"
> diff --git a/scripts/qemu-migration-helper.sh b/scripts/qemu-migration-helper.sh
> new file mode 100755
> index 0000000..5842026
> --- /dev/null
> +++ b/scripts/qemu-migration-helper.sh

This doesn't seem to work with standalone tests, because they don't
bundle scripts/qemu-migration-helper.sh ...

Any reason why we couldn't turn it into a

  qemu-migration-helper () {
    ...
  }

wrapper (likely inside scripts/arch-run.bash), so it would get sourced
into the standalone test?

> @@ -0,0 +1,68 @@
> +#!/bin/bash
> +# This script runs two instances of QEMU and then migrates the guest from one
> +# instance to the other. The end of the migration is signalled to the guest by
> +# injecting an NMI.
> +
> +if ! command -v nc >/dev/null 2>&1; then
> +	echo "$0 needs nc (netcat)"
> +	exit 1
> +fi
> +
> +qemu=$1
> +shift
> +
> +if ! command -v "$qemu" >/dev/null 2>&1; then
> +	echo "The first parameter must be pointing to the QEMU executable"
> +	exit 1
> +fi
> +
> +migsock=`mktemp -u -t mig-helper-socket.XXXXXXXXXX`
> +stdout1=`mktemp -t mig-helper-stdout1.XXXXXXXXXX`
> +stdout2=`mktemp -t mig-helper-stdout2.XXXXXXXXXX`
> +qmpout1=`mktemp -t mig-helper-qmpout1.XXXXXXXXXX`
> +qmpout2=`mktemp -t mig-helper-qmpout2.XXXXXXXXXX`
> +qmp1=`mktemp -u -t mig-helper-qmp1.XXXXXXXXXX`
> +qmp2=`mktemp -u -t mig-helper-qmp2.XXXXXXXXXX`
> +
> +cleanup()
> +{
> +	rm -f ${stdout1} ${stdout2} ${migsock}
> +	rm -f ${qmpout1} ${qmpout2} ${qmp1} ${qmp2}
> +}
> +trap cleanup EXIT
> +
> +qmp_cmd()
> +{
> +	echo '{ "execute": "qmp_capabilities" }{ "execute":' "$2" '}' | nc -U $1
> +}
> +
> +$qemu $* -chardev socket,id=mon1,path=${qmp1},server,nowait \

I have a bad feeling about $*, please use "$@" instead.

The difference can be seen in:
  # f () { g $*; }
  # g () {echo $#; }
  # f 1 2; f "1 2"
  2
  2
  # f () { g "$@"; }
  # f 1 2; f "1 2"
  2
  1

> +	 -mon chardev=mon1,mode=control > ${stdout1} &
> +
> +$qemu $* -chardev socket,id=mon2,path=${qmp2},server,nowait \
> +	 -mon chardev=mon2,mode=control -incoming unix:${migsock} > ${stdout2} &
> +
> +# The test must prompt the user to migrate, so wait for the "migrate" keyword
> +while ! grep -q -i "migrate" < ${stdout1} ; do
> +	sleep 1
> +done
> +
> +qmp_cmd ${qmp1} '"migrate", "arguments": { "uri": "unix:'${migsock}'" }' > ${qmpout1}
> +
> +# Wait for the migration to complete
> +migstatus=`qmp_cmd ${qmp1} '"query-migrate"' | grep return`
> +while ! grep -q '"completed"' <<<"$migstatus" ; do
> +	sleep 1
> +	migstatus=`qmp_cmd ${qmp1} '"query-migrate"' | grep return`
> +	if grep -q '"failed"' <<<"$migstatus" ; then
> +		echo "ERROR: Migration failed."
> +		exit 1
> +	fi
> +done
> +qmp_cmd ${qmp1} '"quit"'> ${qmpout1} 2>/dev/null
> +
> +qmp_cmd ${qmp2} '"inject-nmi"'> ${qmpout2}

qmpout* seems unused ... couldn't we just redirect to /dev/null?

> +
> +wait
> +
> +cat ${stdout1} ${stdout2}

The test might hang and we would never see its output ...
I think that stdout1 could be duplicated using a crazy technique similar
to what run_qemu() uses.  And do we need to capture stdout2 at all?

Thanks.

Re: [kvm-unit-tests PATCH v2 1/2] Add the possibility to do simple migration tests

[Thomas Huth]

On 15.03.2017 17:36, Radim Krčmář wrote:
> 2017-03-14 11:23+0100, Thomas Huth:
>> To be able to do simple migration tests with kvm-unit-tests, too,
>> add a helper script that does all the necessary work: Start two
>> instances of QEMU (source and destination) with QMP sockets for
>> sending commands to them, then trigger the migration from one
>> instance to the other and finally signal the end of the migration
>> to the guest by injecting an NMI.
>> This helper script is now used automatically for powerpc tests
>> if the test is put into the "migration" group in the unittests.cfg
>> file.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>  powerpc/run                      |  4 +++
>>  scripts/qemu-migration-helper.sh | 68 ++++++++++++++++++++++++++++++++++++++++
>>  scripts/runtime.bash             |  3 ++
>>  3 files changed, 75 insertions(+)
>>  create mode 100755 scripts/qemu-migration-helper.sh
>>
>> diff --git a/powerpc/run b/powerpc/run
>> index 6269abb..f1528ed 100755
>> --- a/powerpc/run
>> +++ b/powerpc/run
>> @@ -41,6 +41,10 @@ if ! $qemu -machine '?' 2>&1 | grep 'pseries' > /dev/null; then
>>  	exit 2
>>  fi
>>  
>> +if [ "$MIGRATION" = "yes" ]; then
>> +	qemu="scripts/qemu-migration-helper.sh $qemu"
>> +fi
> 
> I think this script could be useful for other architectures as well ...
> what about adding migration_cmd to scripts/arch-run.bash
> 
>   migration_cmd ()
>   {
>   	if [ "$MIGRATION" = "yes" ]; then
>   		echo "scripts/qemu-migration-helper.sh"
>   	fi
>   }
> 
> and using only
> 
>   command="$(timeout_cmd) $(migration_cmd) $command"
> 
> in arch scripts?

Yes, sounds like a good idea, I'll change my patch accordingly.

>> +
>>  M='-machine pseries'
>>  M+=",accel=$ACCEL"
>>  command="$qemu -nodefaults $M -bios $FIRMWARE"
>> diff --git a/scripts/qemu-migration-helper.sh b/scripts/qemu-migration-helper.sh
>> new file mode 100755
>> index 0000000..5842026
>> --- /dev/null
>> +++ b/scripts/qemu-migration-helper.sh
> 
> This doesn't seem to work with standalone tests, because they don't
> bundle scripts/qemu-migration-helper.sh ...
> 
> Any reason why we couldn't turn it into a
> 
>   qemu-migration-helper () {
>     ...
>   }
> 
> wrapper (likely inside scripts/arch-run.bash), so it would get sourced
> into the standalone test?

Oh, well, I've completely forgot about that standalone test feature ...
I'll have a look...

>> @@ -0,0 +1,68 @@
>> +#!/bin/bash
>> +# This script runs two instances of QEMU and then migrates the guest from one
>> +# instance to the other. The end of the migration is signalled to the guest by
>> +# injecting an NMI.
>> +
>> +if ! command -v nc >/dev/null 2>&1; then
>> +	echo "$0 needs nc (netcat)"
>> +	exit 1
>> +fi
>> +
>> +qemu=$1
>> +shift
>> +
>> +if ! command -v "$qemu" >/dev/null 2>&1; then
>> +	echo "The first parameter must be pointing to the QEMU executable"
>> +	exit 1
>> +fi
>> +
>> +migsock=`mktemp -u -t mig-helper-socket.XXXXXXXXXX`
>> +stdout1=`mktemp -t mig-helper-stdout1.XXXXXXXXXX`
>> +stdout2=`mktemp -t mig-helper-stdout2.XXXXXXXXXX`
>> +qmpout1=`mktemp -t mig-helper-qmpout1.XXXXXXXXXX`
>> +qmpout2=`mktemp -t mig-helper-qmpout2.XXXXXXXXXX`
>> +qmp1=`mktemp -u -t mig-helper-qmp1.XXXXXXXXXX`
>> +qmp2=`mktemp -u -t mig-helper-qmp2.XXXXXXXXXX`
>> +
>> +cleanup()
>> +{
>> +	rm -f ${stdout1} ${stdout2} ${migsock}
>> +	rm -f ${qmpout1} ${qmpout2} ${qmp1} ${qmp2}
>> +}
>> +trap cleanup EXIT
>> +
>> +qmp_cmd()
>> +{
>> +	echo '{ "execute": "qmp_capabilities" }{ "execute":' "$2" '}' | nc -U $1
>> +}
>> +
>> +$qemu $* -chardev socket,id=mon1,path=${qmp1},server,nowait \
> 
> I have a bad feeling about $*, please use "$@" instead.

Sure, will do.

>> +	 -mon chardev=mon1,mode=control > ${stdout1} &
>> +
>> +$qemu $* -chardev socket,id=mon2,path=${qmp2},server,nowait \
>> +	 -mon chardev=mon2,mode=control -incoming unix:${migsock} > ${stdout2} &
>> +
>> +# The test must prompt the user to migrate, so wait for the "migrate" keyword
>> +while ! grep -q -i "migrate" < ${stdout1} ; do
>> +	sleep 1
>> +done
>> +
>> +qmp_cmd ${qmp1} '"migrate", "arguments": { "uri": "unix:'${migsock}'" }' > ${qmpout1}
>> +
>> +# Wait for the migration to complete
>> +migstatus=`qmp_cmd ${qmp1} '"query-migrate"' | grep return`
>> +while ! grep -q '"completed"' <<<"$migstatus" ; do
>> +	sleep 1
>> +	migstatus=`qmp_cmd ${qmp1} '"query-migrate"' | grep return`
>> +	if grep -q '"failed"' <<<"$migstatus" ; then
>> +		echo "ERROR: Migration failed."
>> +		exit 1
>> +	fi
>> +done
>> +qmp_cmd ${qmp1} '"quit"'> ${qmpout1} 2>/dev/null
>> +
>> +qmp_cmd ${qmp2} '"inject-nmi"'> ${qmpout2}
> 
> qmpout* seems unused ... couldn't we just redirect to /dev/null?

It's useful for debugging (you just got to make sure that it does not
get deleted at the end)... but I could also set the variables to
/dev/null instead, so the output gets written there by default.

>> +
>> +wait
>> +
>> +cat ${stdout1} ${stdout2}
> 
> The test might hang and we would never see its output ...
> I think that stdout1 could be duplicated using a crazy technique similar
> to what run_qemu() uses.  And do we need to capture stdout2 at all?

At least on ppc, we need both outputs, since the return code of the test
is finally passed via the console output there. But I'll see whether I
can come up with something better here instead...

Thanks for the review!

 Thomas