On 16.09.24 15:20, Nina Schoetterl-Glausch wrote:
On Tue, 2024-09-10 at 19:58 +0200, David Hildenbrand wrote:
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 <da...@redhat.com>
Reviewed-by: Nina Schoetterl-Glausch <n...@linux.ibm.com>
Comment below.
---
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)
+{
Might be nice to guard/warn against s390_set_memory_limit not having been
called before.
What about the following on top:
diff --git a/target/s390x/cpu-sysemu.c b/target/s390x/cpu-sysemu.c
index 1915567b3a..07cb85103a 100644
--- a/target/s390x/cpu-sysemu.c
+++ b/target/s390x/cpu-sysemu.c
@@ -263,6 +263,8 @@ int s390_set_memory_limit(uint64_t new_limit, uint64_t
*hw_limit)
if (memory_limit) {
return -EBUSY;
+ } else if (!new_limit) {
+ return -EINVAL;
}
if (kvm_enabled()) {
ret = kvm_s390_set_mem_limit(new_limit, hw_limit);
@@ -275,6 +277,8 @@ int s390_set_memory_limit(uint64_t new_limit, uint64_t
*hw_limit)
uint64_t s390_get_memory_limit(void)
{
+ /* We expect to be called after s390_set_memory_limit(). */
+ assert(memory_limit);
return memory_limit;
}
--
Cheers,
David / dhildenb
