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[PATCH v7 7/7] hw/arm/virt: Add properties to disable high memory region
From: |
Gavin Shan |
Subject: |
[PATCH v7 7/7] hw/arm/virt: Add properties to disable high memory regions |
Date: |
Sun, 30 Oct 2022 06:43:07 +0800 |
The 3 high memory regions are usually enabled by default, but they may
be not used. For example, VIRT_HIGH_GIC_REDIST2 isn't needed by GICv2.
This leads to waste in the PA space.
Add properties ("highmem-redists", "highmem-ecam", "highmem-mmio") to
allow users selectively disable them if needed. After that, the high
memory region for GICv3 or GICv4 redistributor can be disabled by user,
the number of maximal supported CPUs needs to be calculated based on
'vms->highmem_redists'. The follow-up error message is also improved
to indicate if the high memory region for GICv3 and GICv4 has been
enabled or not.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
---
docs/system/arm/virt.rst | 13 +++++++
hw/arm/virt.c | 75 ++++++++++++++++++++++++++++++++++++++--
2 files changed, 86 insertions(+), 2 deletions(-)
diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
index 4454706392..188a4f211f 100644
--- a/docs/system/arm/virt.rst
+++ b/docs/system/arm/virt.rst
@@ -98,6 +98,19 @@ compact-highmem
Set ``on``/``off`` to enable/disable the compact layout for high memory
regions.
The default is ``on`` for machine types later than ``virt-7.2``.
+highmem-redists
+ Set ``on``/``off`` to enable/disable the high memory region for GICv3 or
+ GICv4 redistributor. The default is ``on``. Setting this to ``off`` will
+ limit the maximum number of CPUs when GICv3 or GICv4 is used.
+
+highmem-ecam
+ Set ``on``/``off`` to enable/disable the high memory region for PCI ECAM.
+ The default is ``on`` for machine types later than ``virt-3.0``.
+
+highmem-mmio
+ Set ``on``/``off`` to enable/disable the high memory region for PCI MMIO.
+ The default is ``on``.
+
gic-version
Specify the version of the Generic Interrupt Controller (GIC) to provide.
Valid values are:
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 020a95cfa2..65cff7add1 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2095,14 +2095,20 @@ static void machvirt_init(MachineState *machine)
if (vms->gic_version == VIRT_GIC_VERSION_2) {
virt_max_cpus = GIC_NCPU;
} else {
- virt_max_cpus = virt_redist_capacity(vms, VIRT_GIC_REDIST) +
- virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2);
+ virt_max_cpus = virt_redist_capacity(vms, VIRT_GIC_REDIST);
+ if (vms->highmem_redists) {
+ virt_max_cpus += virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2);
+ }
}
if (max_cpus > virt_max_cpus) {
error_report("Number of SMP CPUs requested (%d) exceeds max CPUs "
"supported by machine 'mach-virt' (%d)",
max_cpus, virt_max_cpus);
+ if (vms->gic_version != VIRT_GIC_VERSION_2 && !vms->highmem_redists) {
+ error_printf("Try 'highmem-redists=on' for more CPUs\n");
+ }
+
exit(1);
}
@@ -2371,6 +2377,49 @@ static void virt_set_compact_highmem(Object *obj, bool
value, Error **errp)
vms->highmem_compact = value;
}
+static bool virt_get_highmem_redists(Object *obj, Error **errp)
+{
+ VirtMachineState *vms = VIRT_MACHINE(obj);
+
+ return vms->highmem_redists;
+}
+
+static void virt_set_highmem_redists(Object *obj, bool value, Error **errp)
+{
+ VirtMachineState *vms = VIRT_MACHINE(obj);
+
+ vms->highmem_redists = value;
+}
+
+static bool virt_get_highmem_ecam(Object *obj, Error **errp)
+{
+ VirtMachineState *vms = VIRT_MACHINE(obj);
+
+ return vms->highmem_ecam;
+}
+
+static void virt_set_highmem_ecam(Object *obj, bool value, Error **errp)
+{
+ VirtMachineState *vms = VIRT_MACHINE(obj);
+
+ vms->highmem_ecam = value;
+}
+
+static bool virt_get_highmem_mmio(Object *obj, Error **errp)
+{
+ VirtMachineState *vms = VIRT_MACHINE(obj);
+
+ return vms->highmem_mmio;
+}
+
+static void virt_set_highmem_mmio(Object *obj, bool value, Error **errp)
+{
+ VirtMachineState *vms = VIRT_MACHINE(obj);
+
+ vms->highmem_mmio = value;
+}
+
+
static bool virt_get_its(Object *obj, Error **errp)
{
VirtMachineState *vms = VIRT_MACHINE(obj);
@@ -2996,6 +3045,28 @@ static void virt_machine_class_init(ObjectClass *oc,
void *data)
"Set on/off to enable/disable
compact "
"layout for high memory regions");
+ object_class_property_add_bool(oc, "highmem-redists",
+ virt_get_highmem_redists,
+ virt_set_highmem_redists);
+ object_class_property_set_description(oc, "highmem-redists",
+ "Set on/off to enable/disable high "
+ "memory region for GICv3 or GICv4 "
+ "redistributor");
+
+ object_class_property_add_bool(oc, "highmem-ecam",
+ virt_get_highmem_ecam,
+ virt_set_highmem_ecam);
+ object_class_property_set_description(oc, "highmem-ecam",
+ "Set on/off to enable/disable high "
+ "memory region for PCI ECAM");
+
+ object_class_property_add_bool(oc, "highmem-mmio",
+ virt_get_highmem_mmio,
+ virt_set_highmem_mmio);
+ object_class_property_set_description(oc, "highmem-mmio",
+ "Set on/off to enable/disable high "
+ "memory region for PCI MMIO");
+
object_class_property_add_str(oc, "gic-version", virt_get_gic_version,
virt_set_gic_version);
object_class_property_set_description(oc, "gic-version",
--
2.23.0
- [PATCH v7 0/7] hw/arm/virt: Improve address assignment for high memory regions, Gavin Shan, 2022/10/29
- [PATCH v7 2/7] hw/arm/virt: Rename variable size to region_size in virt_set_high_memmap(), Gavin Shan, 2022/10/29
- [PATCH v7 1/7] hw/arm/virt: Introduce virt_set_high_memmap() helper, Gavin Shan, 2022/10/29
- [PATCH v7 3/7] hw/arm/virt: Introduce variable region_base in virt_set_high_memmap(), Gavin Shan, 2022/10/29
- [PATCH v7 4/7] hw/arm/virt: Introduce virt_get_high_memmap_enabled() helper, Gavin Shan, 2022/10/29
- [PATCH v7 5/7] hw/arm/virt: Improve high memory region address assignment, Gavin Shan, 2022/10/29
- [PATCH v7 6/7] hw/arm/virt: Add 'compact-highmem' property, Gavin Shan, 2022/10/29
- [PATCH v7 7/7] hw/arm/virt: Add properties to disable high memory regions,
Gavin Shan <=