| Message ID | 20220812062151.1980937-4-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Add panic test support | expand |
On Fri, 12 Aug 2022 08:21:50 +0200 Nico Boehr <nrb@linux.ibm.com> wrote: > The CPU timer interrupt stays pending as long as the CPU timer value is > negative. This can lead to interruption loops when the ext_new_psw mask > has external interrupts enabled. > > QEMU is able to detect this situation and panic the guest, so add a test > for it. > > Signed-off-by: Nico Boehr <nrb@linux.ibm.com> > Reviewed-by: Thomas Huth <thuth@redhat.com> > --- > s390x/Makefile | 1 + > s390x/panic-loop-extint.c | 59 +++++++++++++++++++++++++++++++++++++++ > s390x/unittests.cfg | 6 ++++ > 3 files changed, 66 insertions(+) > create mode 100644 s390x/panic-loop-extint.c > > diff --git a/s390x/Makefile b/s390x/Makefile > index efd5e0c13102..e4649da50d9d 100644 > --- a/s390x/Makefile > +++ b/s390x/Makefile > @@ -34,6 +34,7 @@ tests += $(TEST_DIR)/migration.elf > tests += $(TEST_DIR)/pv-attest.elf > tests += $(TEST_DIR)/migration-cmm.elf > tests += $(TEST_DIR)/migration-skey.elf > +tests += $(TEST_DIR)/panic-loop-extint.elf > > pv-tests += $(TEST_DIR)/pv-diags.elf > > diff --git a/s390x/panic-loop-extint.c b/s390x/panic-loop-extint.c > new file mode 100644 > index 000000000000..79d3f84a89ff > --- /dev/null > +++ b/s390x/panic-loop-extint.c > @@ -0,0 +1,59 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * External interrupt loop test > + * > + * Copyright IBM Corp. 2022 > + * > + * Authors: > + * Nico Boehr <nrb@linux.ibm.com> > + */ > +#include <libcflat.h> > +#include <asm/interrupt.h> > +#include <asm/barrier.h> > +#include <asm/time.h> > +#include <hardware.h> > +#include <bitops.h> > + > +static void ext_int_cleanup(struct stack_frame_int *stack) > +{ > + /* > + * Since we form a loop of ext interrupts, this code should never be > + * executed. In case it is executed, something went wrong and we want to > + * print a failure. > + * > + * Because the CPU timer subclass mask is still enabled, the CPU timer > + * interrupt will fire every time we enable external interrupts, > + * preventing us from printing the failure on the console. To avoid > + * this, clear the CPU timer subclass mask here. > + */ > + stack->crs[0] &= ~BIT(CTL0_CPU_TIMER); > +} > + > +int main(void) > +{ > + report_prefix_push("panic-loop-extint"); > + > + if (!host_is_qemu() || host_is_tcg()) { > + report_skip("QEMU-KVM-only test"); > + goto out; > + } > + > + expect_ext_int(); > + lowcore.ext_new_psw.mask |= PSW_MASK_EXT; > + > + load_psw_mask(extract_psw_mask() | PSW_MASK_EXT); you can use the recently introduced psw_mask_set_bits(PSW_MASK_EXT) > + > + register_ext_cleanup_func(ext_int_cleanup); > + > + cpu_timer_set_ms(10); > + ctl_set_bit(0, CTL0_CPU_TIMER); > + mdelay(2000); > + > + register_ext_cleanup_func(NULL); > + > + report_fail("survived extint loop"); > + > +out: > + report_prefix_pop(); > + return report_summary(); > +} > diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg > index f7b1fc3dbca1..b1b25f118ff6 100644 > --- a/s390x/unittests.cfg > +++ b/s390x/unittests.cfg > @@ -185,3 +185,9 @@ groups = migration > [migration-skey] > file = migration-skey.elf > groups = migration > + > +[panic-loop-extint] > +file = panic-loop-extint.elf > +groups = panic > +accel = kvm > +timeout = 5
Quoting Claudio Imbrenda (2022-08-12 11:29:12) > On Fri, 12 Aug 2022 08:21:50 +0200 > Nico Boehr <nrb@linux.ibm.com> wrote: [...] > > diff --git a/s390x/panic-loop-extint.c b/s390x/panic-loop-extint.c > > new file mode 100644 > > index 000000000000..79d3f84a89ff [...] > > +int main(void) > > +{ > > + report_prefix_push("panic-loop-extint"); > > + > > + if (!host_is_qemu() || host_is_tcg()) { > > + report_skip("QEMU-KVM-only test"); > > + goto out; > > + } > > + > > + expect_ext_int(); > > + lowcore.ext_new_psw.mask |= PSW_MASK_EXT; > > + > > + load_psw_mask(extract_psw_mask() | PSW_MASK_EXT); > > you can use the recently introduced psw_mask_set_bits(PSW_MASK_EXT) Done thanks.
diff --git a/s390x/Makefile b/s390x/Makefile index efd5e0c13102..e4649da50d9d 100644 --- a/s390x/Makefile +++ b/s390x/Makefile @@ -34,6 +34,7 @@ tests += $(TEST_DIR)/migration.elf tests += $(TEST_DIR)/pv-attest.elf tests += $(TEST_DIR)/migration-cmm.elf tests += $(TEST_DIR)/migration-skey.elf +tests += $(TEST_DIR)/panic-loop-extint.elf pv-tests += $(TEST_DIR)/pv-diags.elf diff --git a/s390x/panic-loop-extint.c b/s390x/panic-loop-extint.c new file mode 100644 index 000000000000..79d3f84a89ff --- /dev/null +++ b/s390x/panic-loop-extint.c @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * External interrupt loop test + * + * Copyright IBM Corp. 2022 + * + * Authors: + * Nico Boehr <nrb@linux.ibm.com> + */ +#include <libcflat.h> +#include <asm/interrupt.h> +#include <asm/barrier.h> +#include <asm/time.h> +#include <hardware.h> +#include <bitops.h> + +static void ext_int_cleanup(struct stack_frame_int *stack) +{ + /* + * Since we form a loop of ext interrupts, this code should never be + * executed. In case it is executed, something went wrong and we want to + * print a failure. + * + * Because the CPU timer subclass mask is still enabled, the CPU timer + * interrupt will fire every time we enable external interrupts, + * preventing us from printing the failure on the console. To avoid + * this, clear the CPU timer subclass mask here. + */ + stack->crs[0] &= ~BIT(CTL0_CPU_TIMER); +} + +int main(void) +{ + report_prefix_push("panic-loop-extint"); + + if (!host_is_qemu() || host_is_tcg()) { + report_skip("QEMU-KVM-only test"); + goto out; + } + + expect_ext_int(); + lowcore.ext_new_psw.mask |= PSW_MASK_EXT; + + load_psw_mask(extract_psw_mask() | PSW_MASK_EXT); + + register_ext_cleanup_func(ext_int_cleanup); + + cpu_timer_set_ms(10); + ctl_set_bit(0, CTL0_CPU_TIMER); + mdelay(2000); + + register_ext_cleanup_func(NULL); + + report_fail("survived extint loop"); + +out: + report_prefix_pop(); + return report_summary(); +} diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg index f7b1fc3dbca1..b1b25f118ff6 100644 --- a/s390x/unittests.cfg +++ b/s390x/unittests.cfg @@ -185,3 +185,9 @@ groups = migration [migration-skey] file = migration-skey.elf groups = migration + +[panic-loop-extint] +file = panic-loop-extint.elf +groups = panic +accel = kvm +timeout = 5