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authorDavid Hildenbrand <david@redhat.com>2020-09-18 10:51:22 +0200
committerCornelia Huck <cohuck@redhat.com>2020-10-02 13:52:49 +0200
commit20d143e2cab8b597bbdb7a15f123d9704fa8db18 (patch)
treea9b77da036804108c9914a126497db49def401ee /target/s390x/excp_helper.c
parentfabdada9357b9cfd980c7744ddce47e34600bbef (diff)
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s390x/tcg: Implement MONITOR CALL
Recent upstream Linux uses the MONITOR CALL instruction for things like BUG_ON() and WARN_ON(). We currently inject an operation exception when we hit a MONITOR CALL instruction - which is wrong, as the instruction is not glued to specific CPU features. Doing a simple WARN_ON_ONCE() currently results in a panic: [ 18.162801] illegal operation: 0001 ilc:2 [#1] SMP [ 18.162889] Modules linked in: [...] [ 18.165476] Kernel panic - not syncing: Fatal exception: panic_on_oops With a proper implementation, we now get: [ 18.242754] ------------[ cut here ]------------ [ 18.242855] WARNING: CPU: 7 PID: 1 at init/main.c:1534 [...] [ 18.242919] Modules linked in: [...] [ 18.246262] ---[ end trace a420477d71dc97b4 ]--- [ 18.259014] Freeing unused kernel memory: 4220K Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20200918085122.26132-1-david@redhat.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'target/s390x/excp_helper.c')
-rw-r--r--target/s390x/excp_helper.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/target/s390x/excp_helper.c b/target/s390x/excp_helper.c
index 3b58d10..0adfbbd 100644
--- a/target/s390x/excp_helper.c
+++ b/target/s390x/excp_helper.c
@@ -610,4 +610,27 @@ void s390x_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
tcg_s390_program_interrupt(env, PGM_SPECIFICATION, retaddr);
}
+static void QEMU_NORETURN monitor_event(CPUS390XState *env,
+ uint64_t monitor_code,
+ uint8_t monitor_class, uintptr_t ra)
+{
+ /* Store the Monitor Code and the Monitor Class Number into the lowcore */
+ stq_phys(env_cpu(env)->as,
+ env->psa + offsetof(LowCore, monitor_code), monitor_code);
+ stw_phys(env_cpu(env)->as,
+ env->psa + offsetof(LowCore, mon_class_num), monitor_class);
+
+ tcg_s390_program_interrupt(env, PGM_MONITOR, ra);
+}
+
+void HELPER(monitor_call)(CPUS390XState *env, uint64_t monitor_code,
+ uint32_t monitor_class)
+{
+ g_assert(monitor_class <= 0xff);
+
+ if (env->cregs[8] & (0x8000 >> monitor_class)) {
+ monitor_event(env, monitor_code, monitor_class, GETPC());
+ }
+}
+
#endif /* CONFIG_USER_ONLY */