From: Cornelia Huck <cohuck@redhat.com>
To: peter.maydell@linaro.org
Cc: qemu-devel@nongnu.org, rth@twiddle.net, agraf@suse.de,
thuth@redhat.com, borntraeger@de.ibm.com, david@redhat.com,
Cornelia Huck <cohuck@redhat.com>
Subject: [Qemu-devel] [PULL v2 32/38] s390x: allow CPU hotplug in random core-id order
Date: Tue, 19 Sep 2017 18:43:31 +0200 [thread overview]
Message-ID: <20170919164337.18555-33-cohuck@redhat.com> (raw)
In-Reply-To: <20170919164337.18555-1-cohuck@redhat.com>
From: David Hildenbrand <david@redhat.com>
SCLP correctly indicates the core-id aka. CPU address for each available
CPU.
As the core-id corresponds to cpu_index, also a newly created kvm vcpu
gets assigned this core-id as vcpu id. So SIGP in the kernel works
correctly (it uses the vcpu id to lookup the correct CPU).
So there should be nothing hindering us from hotplugging CPUs in random
core-id order.
This now makes sure that the output from "query-hotpluggable-cpus"
is completely true. Until now, a specific order is implicit. Performance
vice, hotplugging CPUs in non-sequential order might not be the best thing
to do, as VCPU lookup inside KVM might be a little slower. But that
doesn't hinder us from supporting it.
next_core_id is now used by linux user only.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-23-david@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
target/s390x/cpu.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 5724dffb88..34538c3ab9 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -199,6 +199,7 @@ static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
#else
/* implicitly set for linux-user only */
cpu->env.core_id = scc->next_core_id;
+ scc->next_core_id++;
#endif
if (cpu_exists(cpu->env.core_id)) {
@@ -206,12 +207,6 @@ static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
", it already exists", cpu->env.core_id);
goto out;
}
- if (cpu->env.core_id != scc->next_core_id) {
- error_setg(&err, "Unable to add CPU with core-id: %" PRIu32
- ", the next available core-id is %" PRIu32, cpu->env.core_id,
- scc->next_core_id);
- goto out;
- }
/* sync cs->cpu_index and env->core_id. The latter is needed for TCG. */
cs->cpu_index = env->core_id;
@@ -219,7 +214,6 @@ static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
if (err != NULL) {
goto out;
}
- scc->next_core_id++;
#if !defined(CONFIG_USER_ONLY)
qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
--
2.13.5
next prev parent reply other threads:[~2017-09-19 16:46 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-19 16:42 [Qemu-devel] [PULL v2 00/38] various s390x patches (+some fixes) Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 01/38] s390x/css: fix cc handling for XSCH Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 02/38] tests: Enable the drive_del test also on s390x Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 03/38] s390x/pci: remove idx from msix msg data Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 04/38] s390x/pci: fixup ind_offset of msix routing entry Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 05/38] s390x/pci: add iommu replay callback Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 06/38] hw/misc/ivshmem: Fix ivshmem_recv_msg() to also work on big endian systems Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 07/38] s390x/css: drop data-check in interpretation Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 08/38] s390x/css: fix NULL handling for CCW addresses Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 09/38] s390x/css: remove unused error handling branch Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 10/38] s390: set DHCP client architecure id for netboot Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 11/38] exec, dump, i386, ppc, s390x: don't include exec/cpu-all.h explicitly Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 12/38] cpu: drop old comments describing members Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 13/38] s390x: get rid of s390-virtio.c Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 14/38] s390x: rename s390-virtio.h to s390-virtio-hcall.h Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 15/38] s390x: move s390_virtio_hypercall() " Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 16/38] s390x: move subsystem_reset() to s390-virtio-ccw.h Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 17/38] target/s390x: move some s390x typedefs to cpu-qom.h Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 18/38] s390x: move sclp_service_call() to sclp.h Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 19/38] target/s390x: use trigger_pgm_exception() in s390_cpu_handle_mmu_fault() Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 20/38] target/s390x: use program_interrupt() in per_check_exception() Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 21/38] s390x: allow only 1 CPU with TCG Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 22/38] target/s390x: set cpu->id for linux user when realizing Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 23/38] target/s390x: use "core-id" for cpu number/address/id handling Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 24/38] target/s390x: rename next_cpu_id to next_core_id Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 25/38] s390x: print CPU definitions in sorted order Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 26/38] s390x: allow cpu hotplug via device_add Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 27/38] s390x: CPU hot unplug via device_del cannot work for now Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 28/38] s390x: implement query-hotpluggable-cpus Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 29/38] s390x: get rid of cpu_states and use possible_cpus instead Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 30/38] s390x: get rid of cpu_s390x_create() Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 31/38] s390x: generate sclp cpu information from possible_cpus Cornelia Huck
2017-09-19 16:43 ` Cornelia Huck [this message]
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 33/38] virtio-ccw: remove stale comments on endianness Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 34/38] configure: Allow --enable-seccomp on s390x, too Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 35/38] s390x/ccw: create s390 phb for compat reasons as well Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 36/38] virtio-gpu: Handle endian conversion Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 37/38] virtio-ccw: Create a virtio gpu device for the ccw bus Cornelia Huck
2017-09-19 16:43 ` [Qemu-devel] [PULL v2 38/38] MAINTAINERS/s390x: add terminal3270.c Cornelia Huck
2017-09-19 17:03 ` [Qemu-devel] [PULL v2 00/38] various s390x patches (+some fixes) Christian Borntraeger
2017-09-20 7:20 ` Cornelia Huck
2017-09-19 18:23 ` Peter Maydell
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