From 0abcd4ae8344b523f2b462a182fddf181d2b2fa5 Mon Sep 17 00:00:00 2001

From: Andrew Jones <drjones@redhat.com>

Date: Tue, 21 Jan 2014 10:46:52 +0100

Subject: use recommended max vcpu count

RH-Author: Andrew Jones <drjones@redhat.com>

Message-id: <1390301212-15344-1-git-send-email-drjones@redhat.com>

Patchwork-id: 56862

O-Subject: [RHEL7.0 qemu-kvm PATCH v6] use recommended max vcpu count

Bugzilla: 998708

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Marcelo Tosatti <mtosatti@redhat.com>

The recommended vcpu max limit (KVM_CAP_NR_VCPUS) should be used instead

of the actual max vcpu limit (KVM_CAP_MAX_VCPUS) to give an error.

This commit matches the limit to current KVM_CAP_NR_VCPUS value.

Rebase notes (2.11.0):

- Update commit log

Merged patches 2.12.0:

- 6553300 redhat: globally limit the maximum number of CPUs

- 8453db7 redhat: remove manual max_cpus limitations for ppc

Merged patches (2.11.0):

- fdeef3c1c7 RHEL: Set vcpus hard limit to 240 for Power

- 0584216921 Match POWER max cpus to x86

Signed-off-by: Andrew Jones <drjones@redhat.com>

(cherry picked from commit a4ceb63bdc5cbac19f5f633ec761b9de0dedb55e)

(cherry picked from commit a1f26d85171b4d554225150053700e93ba6eba10)

(cherry picked from commit 00b09fb8ae2fa23abfaba4e89f7daa1ba0ef9ec5)

(cherry picked from commit bd420a814a24c56d1ff1564d92f36219106ef81b)

(cherry picked from commit 79b73eacc15f2c06587734c6259b49d911327369)

---

 accel/kvm/kvm-all.c | 12 ++++++++++++

 vl.c                | 23 +++++++++++++++++++++++

 2 files changed, 35 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c

index ffee68e..3f1c06e 100644

--- a/accel/kvm/kvm-all.c

+++ b/accel/kvm/kvm-all.c

@@ -1587,6 +1587,18 @@ static int kvm_init(MachineState *ms)

     soft_vcpus_limit = kvm_recommended_vcpus(s);

     hard_vcpus_limit = kvm_max_vcpus(s);

+#ifdef HOST_PPC64

+    /*

+     * On POWER, the kernel advertises a soft limit based on the

+     * number of CPU threads on the host.  We want to allow exceeding

+     * this for testing purposes, so we don't want to set hard limit

+     * to soft limit as on x86.

+     */

+#else

+    /* RHEL doesn't support nr_vcpus > soft_vcpus_limit */

+    hard_vcpus_limit = soft_vcpus_limit;

+#endif

+

     while (nc->name) {

         if (nc->num > soft_vcpus_limit) {

             warn_report("Number of %s cpus requested (%d) exceeds "

diff --git a/vl.c b/vl.c

index cbd6bcc..f3acab3 100644

--- a/vl.c

+++ b/vl.c

@@ -135,6 +135,12 @@ int main(int argc, char **argv)

 #define MAX_VIRTIO_CONSOLES 1

 #define MAX_SCLP_CONSOLES 1

+#if defined(CONFIG_RHV)

+#define RHEL_MAX_CPUS 384

+#else

+#define RHEL_MAX_CPUS 240

+#endif

+

 static const char *data_dir[16];

 static int data_dir_idx;

 const char *bios_name = NULL;

@@ -1520,6 +1526,20 @@ MachineClass *find_default_machine(void)

     return mc;

 }

+/* Maximum number of CPUs limited for Red Hat Enterprise Linux */

+static void limit_max_cpus_in_machines(void)

+{

+    GSList *el, *machines = object_class_get_list(TYPE_MACHINE, false);

+

+    for (el = machines; el; el = el->next) {

+        MachineClass *mc = el->data;

+

+        if (mc->max_cpus > RHEL_MAX_CPUS) {

+            mc->max_cpus = RHEL_MAX_CPUS;

+        }

+    }

+}

+

 MachineInfoList *qmp_query_machines(Error **errp)

 {

     GSList *el, *machines = object_class_get_list(TYPE_MACHINE, false);

@@ -4084,6 +4104,9 @@ int main(int argc, char **argv, char **envp)

     replay_configure(icount_opts);

+    /* Maximum number of CPUs limited for Red Hat Enterprise Linux */

+    limit_max_cpus_in_machines();

+

     machine_class = select_machine();

     set_memory_options(&ram_slots, &maxram_size, machine_class);

-- 

1.8.3.1