Re: [kvm-unit-tests PATCH v4 4/8] migration: Support multiple migrations

2024-02-09 Thread Thomas Huth

On 09/02/2024 10.11, Nicholas Piggin wrote:

Support multiple migrations by flipping dest file/socket variables to
source after the migration is complete, ready to start again. A new
destination is created if the test outputs the migrate line again.
Test cases may now switch to calling migrate() one or more times.

Signed-off-by: Nicholas Piggin 
---
  lib/migrate.c |  8 ++--
  lib/migrate.h |  1 +
  scripts/arch-run.bash | 86 ---
  3 files changed, 77 insertions(+), 18 deletions(-)


Reviewed-by: Thomas Huth 




[kvm-unit-tests PATCH v4 4/8] migration: Support multiple migrations

2024-02-09 Thread Nicholas Piggin
Support multiple migrations by flipping dest file/socket variables to
source after the migration is complete, ready to start again. A new
destination is created if the test outputs the migrate line again.
Test cases may now switch to calling migrate() one or more times.

Signed-off-by: Nicholas Piggin 
---
 lib/migrate.c |  8 ++--
 lib/migrate.h |  1 +
 scripts/arch-run.bash | 86 ---
 3 files changed, 77 insertions(+), 18 deletions(-)

diff --git a/lib/migrate.c b/lib/migrate.c
index 527e63ae..b7721659 100644
--- a/lib/migrate.c
+++ b/lib/migrate.c
@@ -8,8 +8,10 @@
 #include 
 #include "migrate.h"
 
-/* static for now since we only support migrating exactly once per test. */
-static void migrate(void)
+/*
+ * Initiate migration and wait for it to complete.
+ */
+void migrate(void)
 {
puts("Now migrate the VM, then press a key to continue...\n");
(void)getchar();
@@ -19,8 +21,6 @@ static void migrate(void)
 /*
  * Initiate migration and wait for it to complete.
  * If this function is called more than once, it is a no-op.
- * Since migrate_cmd can only migrate exactly once this function can
- * simplify the control flow, especially when skipping tests.
  */
 void migrate_once(void)
 {
diff --git a/lib/migrate.h b/lib/migrate.h
index 3c94e6af..2af06a72 100644
--- a/lib/migrate.h
+++ b/lib/migrate.h
@@ -6,4 +6,5 @@
  * Author: Nico Boehr 
  */
 
+void migrate(void);
 void migrate_once(void);
diff --git a/scripts/arch-run.bash b/scripts/arch-run.bash
index 9a5aaddc..c2002d7a 100644
--- a/scripts/arch-run.bash
+++ b/scripts/arch-run.bash
@@ -129,12 +129,16 @@ run_migration ()
return 77
fi
 
+   migcmdline=$@
+
trap 'trap - TERM ; kill 0 ; exit 2' INT TERM
-   trap 'rm -f ${migout1} ${migout_fifo1} ${migsock} ${qmp1} ${qmp2} 
${fifo}' RETURN EXIT
+   trap 'rm -f ${migout1} ${migout2} ${migout_fifo1} ${migout_fifo2} 
${migsock} ${qmp1} ${qmp2} ${fifo}' RETURN EXIT
 
migsock=$(mktemp -u -t mig-helper-socket.XX)
migout1=$(mktemp -t mig-helper-stdout1.XX)
migout_fifo1=$(mktemp -u -t mig-helper-fifo-stdout1.XX)
+   migout2=$(mktemp -t mig-helper-stdout2.XX)
+   migout_fifo2=$(mktemp -u -t mig-helper-fifo-stdout2.XX)
qmp1=$(mktemp -u -t mig-helper-qmp1.XX)
qmp2=$(mktemp -u -t mig-helper-qmp2.XX)
fifo=$(mktemp -u -t mig-helper-fifo.XX)
@@ -142,20 +146,54 @@ run_migration ()
qmpout2=/dev/null
 
mkfifo ${migout_fifo1}
-   eval "$@" -chardev socket,id=mon1,path=${qmp1},server=on,wait=off \
+   mkfifo ${migout_fifo2}
+
+   eval "$migcmdline" \
+   -chardev socket,id=mon1,path=${qmp1},server=on,wait=off \
-mon chardev=mon1,mode=control > ${migout_fifo1} &
live_pid=$!
cat ${migout_fifo1} | tee ${migout1} &
 
-   # We have to use cat to open the named FIFO, because named FIFO's, 
unlike
-   # pipes, will block on open() until the other end is also opened, and 
that
-   # totally breaks QEMU...
+   # Start the first destination QEMU machine in advance of the test
+   # reaching the migration point, since we expect at least one migration.
+   # Then destination machines are started after the test outputs
+   # subsequent "Now migrate the VM" messages.
+   do_migration || return $?
+
+   while ps -p ${live_pid} > /dev/null ; do
+   # Wait for test exit or further migration messages.
+   if ! grep -q -i "Now migrate the VM" < ${migout1} ; then
+   sleep 0.1
+   else
+   do_migration || return $?
+   fi
+   done
+
+   wait ${live_pid}
+   ret=$?
+
+   while (( $(jobs -r | wc -l) > 0 )); do
+   sleep 0.1
+   done
+
+   return $ret
+}
+
+do_migration ()
+{
+   # We have to use cat to open the named FIFO, because named FIFO's,
+   # unlike pipes, will block on open() until the other end is also
+   # opened, and that totally breaks QEMU...
mkfifo ${fifo}
-   eval "$@" -chardev socket,id=mon2,path=${qmp2},server=on,wait=off \
-   -mon chardev=mon2,mode=control -incoming unix:${migsock} < 
<(cat ${fifo}) &
+   eval "$migcmdline" \
+   -chardev socket,id=mon2,path=${qmp2},server=on,wait=off \
+   -mon chardev=mon2,mode=control -incoming unix:${migsock} \
+   < <(cat ${fifo}) > ${migout_fifo2} &
incoming_pid=$!
+   cat ${migout_fifo2} | tee ${migout2} &
 
-   # The test must prompt the user to migrate, so wait for the "migrate" 
keyword
+   # The test must prompt the user to migrate, so wait for the
+   # "Now migrate VM" console message.
while ! grep -q -i "Now migrate the VM" < ${migout1} ; do
if ! ps -p ${live_pid} > /dev/null ; then