[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[qemu-s390x] [PULL 04/15] s390x: Fence huge pages prior to 3.1
From: |
Cornelia Huck |
Subject: |
[qemu-s390x] [PULL 04/15] s390x: Fence huge pages prior to 3.1 |
Date: |
Thu, 4 Oct 2018 17:28:46 +0200 |
From: Janosch Frank <address@hidden>
As the kernel has no way of disallowing the start of a huge page
backed VM, we can migrate a running huge backed VM to a host that has
no huge page KVM support.
Let's glue huge page support support to the 3.1 machine, so we do not
migrate to a destination host that doesn't have QEMU huge page support
and can stop migration if KVM doesn't indicate support.
Signed-off-by: Janosch Frank <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: David Hildenbrand <address@hidden>
Signed-off-by: Cornelia Huck <address@hidden>
---
hw/s390x/s390-virtio-ccw.c | 10 ++++++++++
include/hw/s390x/s390-virtio-ccw.h | 3 +++
target/s390x/kvm.c | 6 ++++++
3 files changed, 19 insertions(+)
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index f0f7fdcadd..53fd7c975f 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -456,6 +456,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void
*data)
s390mc->ri_allowed = true;
s390mc->cpu_model_allowed = true;
s390mc->css_migration_enabled = true;
+ s390mc->hpage_1m_allowed = true;
mc->init = ccw_init;
mc->reset = s390_machine_reset;
mc->hot_add_cpu = s390_hot_add_cpu;
@@ -535,6 +536,12 @@ bool cpu_model_allowed(void)
return get_machine_class()->cpu_model_allowed;
}
+bool hpage_1m_allowed(void)
+{
+ /* for "none" machine this results in true */
+ return get_machine_class()->hpage_1m_allowed;
+}
+
static char *machine_get_loadparm(Object *obj, Error **errp)
{
S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
@@ -747,6 +754,9 @@ static void ccw_machine_3_0_instance_options(MachineState
*machine)
static void ccw_machine_3_0_class_options(MachineClass *mc)
{
+ S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
+
+ s390mc->hpage_1m_allowed = false;
ccw_machine_3_1_class_options(mc);
SET_MACHINE_COMPAT(mc, CCW_COMPAT_3_0);
}
diff --git a/include/hw/s390x/s390-virtio-ccw.h
b/include/hw/s390x/s390-virtio-ccw.h
index e9c4f4182b..8aa27199c9 100644
--- a/include/hw/s390x/s390-virtio-ccw.h
+++ b/include/hw/s390x/s390-virtio-ccw.h
@@ -39,12 +39,15 @@ typedef struct S390CcwMachineClass {
bool ri_allowed;
bool cpu_model_allowed;
bool css_migration_enabled;
+ bool hpage_1m_allowed;
} S390CcwMachineClass;
/* runtime-instrumentation allowed by the machine */
bool ri_allowed(void);
/* cpu model allowed by the machine */
bool cpu_model_allowed(void);
+/* 1M huge page mappings allowed by the machine */
+bool hpage_1m_allowed(void);
/**
* Returns true if (vmstate based) migration of the channel subsystem
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 348e8cc546..323cb00e6a 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -292,6 +292,12 @@ static int kvm_s390_configure_mempath_backing(KVMState *s)
return 0;
}
+ if (!hpage_1m_allowed()) {
+ error_report("This QEMU machine does not support huge page "
+ "mappings");
+ return -EINVAL;
+ }
+
if (path_psize != 1 * MiB) {
error_report("Memory backing with 2G pages was specified, "
"but KVM does not support this memory backing");
--
2.14.4
- [qemu-s390x] [PULL 00/15] s390x updates, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 01/15] hw/s390x/ipl: Fix alignment problems of S390IPLState members, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 04/15] s390x: Fence huge pages prior to 3.1,
Cornelia Huck <=
- [qemu-s390x] [PULL 05/15] target/s390x: exception on non-aligned LPSW(E), Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 02/15] hw/s390x/css: Remove QEMU_PACKED from struct SenseId, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 06/15] s390x: move tcg_s390_program_interrupt() into TCG code and mark it noreturn, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 07/15] s390x/tcg: factor out and fix DATA exception injection, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 08/15] s390x/tcg: store in the TB flags if AFP is enabled, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 09/15] s390x/tcg: support flags for instructions, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 10/15] s390x/tcg: add instruction flags for floating point instructions, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 11/15] s390x/tcg: check for AFP-register, BFP and DFP data exceptions, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 14/15] s390x/tcg: refactor specification checking, Cornelia Huck, 2018/10/04
- [qemu-s390x] [PULL 12/15] s390x/tcg: handle privileged instructions via flags, Cornelia Huck, 2018/10/04