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[Qemu-devel] [PULL 12/15] s390x/tcg: fix CPU hotplug with single-threade
From: |
Cornelia Huck |
Subject: |
[Qemu-devel] [PULL 12/15] s390x/tcg: fix CPU hotplug with single-threaded TCG |
Date: |
Mon, 2 Jul 2018 13:17:34 +0200 |
From: David Hildenbrand <address@hidden>
run_on_cpu() doesn't seem to work reliably until the CPU has been fully
created if the single-threaded TCG main loop is already running.
Therefore, hotplugging a CPU under single-threaded TCG does currently
not work. We should use the direct call instead of going via
run_on_cpu().
So let's use run_on_cpu() for KVM only - KVM requires it due to the initial
CPU reset ioctl. As a nice side effect, we get rid of the ifdef.
Reviewed-by: Thomas Huth <address@hidden>
Signed-off-by: David Hildenbrand <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Cornelia Huck <address@hidden>
---
target/s390x/cpu.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 40d6980229..271c5ce652 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -218,11 +218,18 @@ static void s390_cpu_realizefn(DeviceState *dev, Error
**errp)
#endif
s390_cpu_gdb_init(cs);
qemu_init_vcpu(cs);
-#if !defined(CONFIG_USER_ONLY)
- run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
-#else
- cpu_reset(cs);
-#endif
+
+ /*
+ * KVM requires the initial CPU reset ioctl to be executed on the target
+ * CPU thread. CPU hotplug under single-threaded TCG will not work with
+ * run_on_cpu(), as run_on_cpu() will not work properly if called while
+ * the main thread is already running but the CPU hasn't been realized.
+ */
+ if (kvm_enabled()) {
+ run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
+ } else {
+ cpu_reset(cs);
+ }
scc->parent_realize(dev, &err);
out:
--
2.14.4
- [Qemu-devel] [PULL 02/15] loader: Check access size when calling rom_ptr() to avoid crashes, (continued)
- [Qemu-devel] [PULL 02/15] loader: Check access size when calling rom_ptr() to avoid crashes, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 03/15] s390x/cpumodel: default enable bpb and ppa15 for z196 and later, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 04/15] s390x/tcg: avoid overflows in time2tod/tod2time, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 05/15] s390x/kvm: pass values instead of pointers to kvm_s390_set_clock_*(), Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 07/15] s390x/tcg: drop tod_basetime, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 08/15] s390x/tcg: properly implement the TOD, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 09/15] s390x/tcg: SET CLOCK COMPARATOR can clear CKC interrupts, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 06/15] s390x/tod: factor out TOD into separate device, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 11/15] s390x/tcg: rearm the CKC timer during migration, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 10/15] s390x/tcg: implement SET CLOCK, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 12/15] s390x/tcg: fix CPU hotplug with single-threaded TCG,
Cornelia Huck <=
- [Qemu-devel] [PULL 13/15] s390x/kvm: legacy_s390_alloc() only supports one allocation, Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 14/15] s390x/kvm: indicate alignment in legacy_s390_alloc(), Cornelia Huck, 2018/07/02
- [Qemu-devel] [PULL 15/15] s390x/tcg: fix locking problem with tcg_s390_tod_updated, Cornelia Huck, 2018/07/02
- Re: [Qemu-devel] [PULL 00/15] s390x patches for 3.0, Peter Maydell, 2018/07/02