[oe-commits] [openembedded-core] 103/122: qemu: Add patch to avoid qemuppc boot hangs
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Mon Dec 4 17:26:21 UTC 2017
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rpurdie pushed a commit to branch rocko
in repository openembedded-core.
commit 8834117a1cbde26d0a36691a2e4635afaa3b6ea7
Author: Richard Purdie <richard.purdie at linuxfoundation.org>
AuthorDate: Tue Nov 21 11:32:55 2017 +0000
qemu: Add patch to avoid qemuppc boot hangs
qemuppc boots are occasionally hanging on the autobuilder. This adds a
patch which fixes the issue in local testing. Its being discussed with
upstream qemu.
Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>
(cherry picked from commit 87719e35db08b21cd43ab3ebd72f4567ca0fdc65)
Signed-off-by: Armin Kuster <akuster808 at gmail.com>
---
meta/recipes-devtools/qemu/qemu/ppc_locking.patch | 105 ++++++++++++++++++++++
meta/recipes-devtools/qemu/qemu_2.10.0.bb | 1 +
2 files changed, 106 insertions(+)
diff --git a/meta/recipes-devtools/qemu/qemu/ppc_locking.patch b/meta/recipes-devtools/qemu/qemu/ppc_locking.patch
new file mode 100644
index 0000000..6f72243
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/ppc_locking.patch
@@ -0,0 +1,105 @@
+I've tracked down what I think is a problem causing qemu-system-ppc
+to hang whilst booting images.
+
+I believe the decrementer timer stops receiving interrupts so
+tasks in our images hang indefinitely as the timer stopped.
+
+It can be summed up with this line of debug:
+
+ppc_set_irq: 0x55b4e0d562f0 n_IRQ 8 level 1 => pending 00000100req 00000004
+
+It should normally read:
+
+ppc_set_irq: 0x55b4e0d562f0 n_IRQ 8 level 1 => pending 00000100req 00000002
+
+The question is why CPU_INTERRUPT_EXITTB ends up being set when the
+lines above this log message clearly sets CPU_INTERRUPT_HARD (via
+cpu_interrupt() ).
+
+I note in cpu.h:
+
+ /* updates protected by BQL */
+ uint32_t interrupt_request;
+
+(for struct CPUState)
+
+The ppc code does "cs->interrupt_request |= CPU_INTERRUPT_EXITTB" in 5
+places, 3 in excp_helper.c and 2 in helper_regs.h. In all cases,
+g_assert(qemu_mutex_iothread_locked()); fails. If I do something like:
+
+if (!qemu_mutex_iothread_locked()) {
+ qemu_mutex_lock_iothread();
+ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
+ qemu_mutex_unlock_iothread();
+} else {
+ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
+}
+
+in these call sites then I can no longer lock qemu up with my test
+case.
+
+I suspect the _HARD setting gets overwritten which stops the
+decrementer interrupts being delivered.
+
+Upstream-Status: Submitted [Issue discussed on qemu mailing list 2017/11/20]
+RP 2017/11/20
+
+Index: qemu-2.10.1/target/ppc/excp_helper.c
+===================================================================
+--- qemu-2.10.1.orig/target/ppc/excp_helper.c
++++ qemu-2.10.1/target/ppc/excp_helper.c
+@@ -207,7 +207,9 @@ static inline void powerpc_excp(PowerPCC
+ "Entering checkstop state\n");
+ }
+ cs->halted = 1;
+- cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
++ qemu_mutex_lock_iothread();
++ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
++ qemu_mutex_unlock_iothread();
+ }
+ if (env->msr_mask & MSR_HVB) {
+ /* ISA specifies HV, but can be delivered to guest with HV clear
+@@ -940,7 +942,9 @@ void helper_store_msr(CPUPPCState *env,
+
+ if (excp != 0) {
+ CPUState *cs = CPU(ppc_env_get_cpu(env));
+- cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
++ qemu_mutex_lock_iothread();
++ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
++ qemu_mutex_unlock_iothread();
+ raise_exception(env, excp);
+ }
+ }
+@@ -995,7 +999,9 @@ static inline void do_rfi(CPUPPCState *e
+ /* No need to raise an exception here,
+ * as rfi is always the last insn of a TB
+ */
+- cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
++ qemu_mutex_lock_iothread();
++ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
++ qemu_mutex_unlock_iothread();
+
+ /* Reset the reservation */
+ env->reserve_addr = -1;
+Index: qemu-2.10.1/target/ppc/helper_regs.h
+===================================================================
+--- qemu-2.10.1.orig/target/ppc/helper_regs.h
++++ qemu-2.10.1/target/ppc/helper_regs.h
+@@ -114,11 +114,15 @@ static inline int hreg_store_msr(CPUPPCS
+ }
+ if (((value >> MSR_IR) & 1) != msr_ir ||
+ ((value >> MSR_DR) & 1) != msr_dr) {
+- cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
++ qemu_mutex_lock_iothread();
++ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
++ qemu_mutex_unlock_iothread();
+ }
+ if ((env->mmu_model & POWERPC_MMU_BOOKE) &&
+ ((value >> MSR_GS) & 1) != msr_gs) {
+- cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
++ qemu_mutex_lock_iothread();
++ cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
++ qemu_mutex_unlock_iothread();
+ }
+ if (unlikely((env->flags & POWERPC_FLAG_TGPR) &&
+ ((value ^ env->msr) & (1 << MSR_TGPR)))) {
diff --git a/meta/recipes-devtools/qemu/qemu_2.10.0.bb b/meta/recipes-devtools/qemu/qemu_2.10.0.bb
index 75e2a25..a9b4939 100644
--- a/meta/recipes-devtools/qemu/qemu_2.10.0.bb
+++ b/meta/recipes-devtools/qemu/qemu_2.10.0.bb
@@ -28,6 +28,7 @@ SRC_URI = "http://wiki.qemu-project.org/download/${BP}.tar.bz2 \
file://CVE-2017-13673.patch \
file://CVE-2017-13672.patch \
file://CVE-2017-14167.patch \
+ file://ppc_locking.patch \
"
UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+\..*)\.tar"
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