On Thu, Jan 24, 2019 at 02:00:20PM +0100, Andrew Jones wrote:
> On Thu, Jan 24, 2019 at 11:16:32AM +0000, Alexandru Elisei wrote:
> > On arm and arm64, kvm-unit-tests uses the QEMU chr-testdev device to shut
> > down the virtual machine at the end of a test. The function
> > psci_system_off() provides another mechanism for terminating the virtual
> > machine. If the chr-testdev device hasn't been initialized successfully,
> > then use psci_system_off() to terminate the test instead of
> > chr_testdev_exit().
> >
> > chr-testdev is implemented on top of virtio console. This patch makes it
> > possible for a virtual machine manager which doesn't have support for
> > chr-testdev, but has been configured not to emulate a virtio console, to
> > gracefully terminate a virtual machine after a test has been completed.
> >
> > There is one limitation to using psci_system_off() to terminate a test:
> > chr-testdev allows kvm-unit-tests to specify an exit code;
> > psci_system_off() has no such mechanism.
> >
> > Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> > ---
> > lib/arm/io.c | 14 ++++++++++++--
> > 1 file changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/arm/io.c b/lib/arm/io.c
> > index 87435150f73e..9fe9bd0bf659 100644
> > --- a/lib/arm/io.c
> > +++ b/lib/arm/io.c
> > @@ -11,6 +11,7 @@
> > #include <libcflat.h>
> > #include <devicetree.h>
> > #include <chr-testdev.h>
> > +#include "arm/asm/psci.h"
> > #include <asm/spinlock.h>
> > #include <asm/io.h>
> >
> > @@ -18,6 +19,8 @@
> >
> > extern void halt(int code);
> >
> > +static bool testdev_enabled;
> > +
> > /*
> > * Use this guess for the pl011 base in order to make an attempt at
> > * having earlier printf support. We'll overwrite it with the real
> > @@ -65,8 +68,12 @@ static void uart0_init(void)
> >
> > void io_init(void)
> > {
> > + int err;
> > +
> > uart0_init();
> > - chr_testdev_init();
> > + err = chr_testdev_init();
> > + if (!err)
> > + testdev_enabled = true;
> > }
> >
> > void puts(const char *s)
> > @@ -79,7 +86,10 @@ void puts(const char *s)
> >
> > void exit(int code)
> > {
> > - chr_testdev_exit(code);
> > + if (testdev_enabled)
> > + chr_testdev_exit(code);
> > + else
> > + psci_system_off();
> > halt(code);
> > __builtin_unreachable();
> > }
> > --
> > 2.17.0
> >
>
> chr_testdev_init() ensures vcon is NULL if it fails to initialize.
> chr_testdev_exit() immediately returns if vcon is NULL. This was
> done by design to allow fallback exits to be placed below the
> chr_testdev_exit call, e.g. halt().
>
> We should be able to drop patch 3/7 and change exit() to this
>
> void exit(int code)
> {
> chr_testdev_exit(code);
> psci_system_off();
> halt(code);
> __builtin_unreachable();
> }
>
There's also a framework for exits that can't return status codes. powerpc
uses it. Before exiting with psci_system_off we need to make this print
statement
printf("\nEXIT: STATUS=%d\n", ((code) << 1) | 1);
And run_qemu in arm/run needs to be changed to run_qemu_status. It's
hacky, but maybe we can live with it until kvmtool offers some sort of
debug exit.
Thanks,
drew
