[PATCH v1 06/14] s390x: introduce s390_get_memory_limit()

[David Hildenbrand <david@redhat.com>]

Let's add s390_get_memory_limit(), to query what has been successfully
set via s390_set_memory_limit(). Allow setting the limit only once.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/cpu-sysemu.c | 19 +++++++++++++++++--
 target/s390x/cpu.h        |  1 +
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/target/s390x/cpu-sysemu.c b/target/s390x/cpu-sysemu.c
index 1cd30c1d84..1915567b3a 100644
--- a/target/s390x/cpu-sysemu.c
+++ b/target/s390x/cpu-sysemu.c
@@ -255,12 +255,27 @@ unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
     return s390_count_running_cpus();
 }
 
+static uint64_t memory_limit;
+
 int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit)
 {
+    int ret = 0;
+
+    if (memory_limit) {
+        return -EBUSY;
+    }
     if (kvm_enabled()) {
-        return kvm_s390_set_mem_limit(new_limit, hw_limit);
+        ret = kvm_s390_set_mem_limit(new_limit, hw_limit);
+    }
+    if (!ret) {
+        memory_limit = new_limit;
     }
-    return 0;
+    return ret;
+}
+
+uint64_t s390_get_memory_limit(void)
+{
+    return memory_limit;
 }
 
 void s390_set_max_pagesize(uint64_t pagesize, Error **errp)
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index d6b75ad0e0..7a51b606ed 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -895,6 +895,7 @@ static inline void s390_do_cpu_load_normal(CPUState *cs, run_on_cpu_data arg)
 /* cpu.c */
 void s390_crypto_reset(void);
 int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit);
+uint64_t s390_get_memory_limit(void);
 void s390_set_max_pagesize(uint64_t pagesize, Error **errp);
 void s390_cmma_reset(void);
 void s390_enable_css_support(S390CPU *cpu);
-- 
2.46.0