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