commit 819bd3091e986c1b6b10203a7138a53b849a53e0
author Dominik Dingel <dingel@linux.vnet.ibm.com> Thu Sep 05 13:54:39 2013 +0200
committer Christian Borntraeger <borntraeger@de.ibm.com> Thu Feb 27 09:51:25 2014 +0100
tree e495be403908960a21e782ff6853e0b20e5e0106
parent 3a553fc65826e0e682ed0fff770ad0d421c6d407

s390x/async_pf: Check for apf extension and enable pfault

S390 can also use async page faults, to enhance guest scheduling.
In case of live migration we want to disable the feature and let
all pending request finish.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

target-s390x/cpu.c

diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
index ff57b80..f1319e5 100644
--- a/target-s390x/cpu.c
+++ b/target-s390x/cpu.c
@@ -83,6 +83,7 @@
     S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
     CPUS390XState *env = &cpu->env;
 
+    env->pfault_token = -1UL;
     s390_del_running_cpu(cpu);
     scc->parent_reset(s);
 #if !defined(CONFIG_USER_ONLY)
@@ -105,6 +106,8 @@
     /* architectured initial values for CR 0 and 14 */
     env->cregs[0] = CR0_RESET;
     env->cregs[14] = CR14_RESET;
+
+    env->pfault_token = -1UL;
 }
 
 /* CPUClass:reset() */
@@ -123,6 +126,9 @@
     /* architectured initial values for CR 0 and 14 */
     env->cregs[0] = CR0_RESET;
     env->cregs[14] = CR14_RESET;
+
+    env->pfault_token = -1UL;
+
     /* set halted to 1 to make sure we can add the cpu in
      * s390_ipl_cpu code, where CPUState::halted is set back to 0
      * after incrementing the cpu counter */

target-s390x/cpu.h

diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 96c2b4a..b09ff92 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -121,6 +121,10 @@
     uint64_t cputm;
     uint32_t todpr;
 
+    uint64_t pfault_token;
+    uint64_t pfault_compare;
+    uint64_t pfault_select;
+
     CPU_COMMON
 
     /* reset does memset(0) up to here */

target-s390x/kvm.c

diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index f60ccdc..9430a35 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -87,12 +87,14 @@
 };
 
 static int cap_sync_regs;
+static int cap_async_pf;
 
 static void *legacy_s390_alloc(size_t size);
 
 int kvm_arch_init(KVMState *s)
 {
     cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS);
+    cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
     if (!kvm_check_extension(s, KVM_CAP_S390_GMAP)
         || !kvm_check_extension(s, KVM_CAP_S390_COW)) {
         phys_mem_set_alloc(legacy_s390_alloc);
@@ -178,6 +180,29 @@
         return ret;
     }
 
+    if (cap_async_pf) {
+        reg.id = KVM_REG_S390_PFTOKEN;
+        reg.addr = (__u64)&(env->pfault_token);
+        ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
+        if (ret < 0) {
+            return ret;
+        }
+
+        reg.id = KVM_REG_S390_PFCOMPARE;
+        reg.addr = (__u64)&(env->pfault_compare);
+        ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
+        if (ret < 0) {
+            return ret;
+        }
+
+        reg.id = KVM_REG_S390_PFSELECT;
+        reg.addr = (__u64)&(env->pfault_select);
+        ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
     if (cap_sync_regs &&
         cs->kvm_run->kvm_valid_regs & KVM_SYNC_ACRS &&
         cs->kvm_run->kvm_valid_regs & KVM_SYNC_CRS) {
@@ -282,6 +307,29 @@
         return r;
     }
 
+    if (cap_async_pf) {
+        reg.id = KVM_REG_S390_PFTOKEN;
+        reg.addr = (__u64)&(env->pfault_token);
+        r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
+        if (r < 0) {
+            return r;
+        }
+
+        reg.id = KVM_REG_S390_PFCOMPARE;
+        reg.addr = (__u64)&(env->pfault_compare);
+        r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
+        if (r < 0) {
+            return r;
+        }
+
+        reg.id = KVM_REG_S390_PFSELECT;
+        reg.addr = (__u64)&(env->pfault_select);
+        r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
+        if (r < 0) {
+            return r;
+        }
+    }
+
     return 0;
 }