diff options
| author | Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> | 2023-09-05 10:12:46 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2023-09-08 16:41:36 +0100 |
| commit | c8f2eb5d414b788420b938f2ffdde891aa6c3ae8 (patch) | |
| tree | 31e339b0f3f4c21d6961ade03485aa1ad9ad1d1e /target/arm | |
| parent | d03396a8bb19b77d4d0fa2ad2143999510f0d44e (diff) | |
arm/kvm: Enable support for KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
Now that we have Eager Page Split support added for ARM in the kernel,
enable it in Qemu. This adds,
-eager-split-size to -accel sub-options to set the eager page split chunk size.
-enable KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE.
The chunk size specifies how many pages to break at a time, using a
single allocation. Bigger the chunk size, more pages need to be
allocated ahead of time.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Message-id: 20230905091246.1931-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm')
| -rw-r--r-- | target/arm/kvm.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/target/arm/kvm.c b/target/arm/kvm.c index 23aeb09949..b66b936a95 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -30,6 +30,7 @@ #include "exec/address-spaces.h" #include "hw/boards.h" #include "hw/irq.h" +#include "qapi/visitor.h" #include "qemu/log.h" const KVMCapabilityInfo kvm_arch_required_capabilities[] = { @@ -287,6 +288,26 @@ int kvm_arch_init(MachineState *ms, KVMState *s) } } + if (s->kvm_eager_split_size) { + uint32_t sizes; + + sizes = kvm_vm_check_extension(s, KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES); + if (!sizes) { + s->kvm_eager_split_size = 0; + warn_report("Eager Page Split support not available"); + } else if (!(s->kvm_eager_split_size & sizes)) { + error_report("Eager Page Split requested chunk size not valid"); + ret = -EINVAL; + } else { + ret = kvm_vm_enable_cap(s, KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE, 0, + s->kvm_eager_split_size); + if (ret < 0) { + error_report("Enabling of Eager Page Split failed: %s", + strerror(-ret)); + } + } + } + kvm_arm_init_debug(s); return ret; @@ -1069,6 +1090,46 @@ bool kvm_arch_cpu_check_are_resettable(void) return true; } +static void kvm_arch_get_eager_split_size(Object *obj, Visitor *v, + const char *name, void *opaque, + Error **errp) +{ + KVMState *s = KVM_STATE(obj); + uint64_t value = s->kvm_eager_split_size; + + visit_type_size(v, name, &value, errp); +} + +static void kvm_arch_set_eager_split_size(Object *obj, Visitor *v, + const char *name, void *opaque, + Error **errp) +{ + KVMState *s = KVM_STATE(obj); + uint64_t value; + + if (s->fd != -1) { + error_setg(errp, "Unable to set early-split-size after KVM has been initialized"); + return; + } + + if (!visit_type_size(v, name, &value, errp)) { + return; + } + + if (value && !is_power_of_2(value)) { + error_setg(errp, "early-split-size must be a power of two"); + return; + } + + s->kvm_eager_split_size = value; +} + void kvm_arch_accel_class_init(ObjectClass *oc) { + object_class_property_add(oc, "eager-split-size", "size", + kvm_arch_get_eager_split_size, + kvm_arch_set_eager_split_size, NULL, NULL); + + object_class_property_set_description(oc, "eager-split-size", + "Eager Page Split chunk size for hugepages. (default: 0, disabled)"); } |