[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-arm] [RFC 5/6] hw/arm/virt: support kvm_type property
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-arm] [RFC 5/6] hw/arm/virt: support kvm_type property |
Date: |
Wed, 20 Jun 2018 18:15:05 +0100 |
User-agent: |
Mutt/1.10.0 (2018-05-17) |
* Eric Auger (address@hidden) wrote:
> The kvm-type property currently is used to pass
> a user parameter to KVM_CREATE_VM. This matches
> the way KVM/ARM expects to pass the max_vm_phys_shift
> parameter.
>
> This patch adds the support or the kvm-type property in
> machvirt and also implements the machine class kvm_type()
> callback so that it either returns the kvm-type value
> provided by the user or returns the max_vm_phys_shift
> exposed by KVM.
>
> for instance, the usespace can use the following option to
> instantiate a 42b IPA guest: -machine kvm-type=42
Without saying if this is better or worse, it is different from x86,
where we have the number of physical address bits as a -cpu parameter
rather than a machine parameter, e.g.
qemu-system-x86_64 -M pc,accel=kvm -cpu SandyBridge,phys-bits=36
or
qemu-system-x86_64 -M pc,accel=kvm -cpu SandyBridge,host-phys-bits=true
our machine types can override the default value though.
One other complication (that I don't know if it applies to ARM) is that
TCG only supports phys-bits=40, so we refuse a TCG run with an
explicitly set phys-bits!=40.
Dave
> Signed-off-by: Eric Auger <address@hidden>
> ---
> hw/arm/virt.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> include/hw/arm/virt.h | 1 +
> 2 files changed, 45 insertions(+)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index dd92ab9..1700556 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -1585,6 +1585,21 @@ static void virt_set_iommu(Object *obj, const char
> *value, Error **errp)
> }
> }
>
> +static char *virt_get_kvm_type(Object *obj, Error **errp)
> +{
> + VirtMachineState *vms = VIRT_MACHINE(obj);
> +
> + return g_strdup(vms->kvm_type);
> +}
> +
> +static void virt_set_kvm_type(Object *obj, const char *value, Error **errp)
> +{
> + VirtMachineState *vms = VIRT_MACHINE(obj);
> +
> + g_free(vms->kvm_type);
> + vms->kvm_type = g_strdup(value);
> +}
> +
> static CpuInstanceProperties
> virt_cpu_index_to_props(MachineState *ms, unsigned cpu_index)
> {
> @@ -1646,6 +1661,31 @@ static HotplugHandler
> *virt_machine_get_hotplug_handler(MachineState *machine,
> return NULL;
> }
>
> +static int virt_kvm_type(MachineState *ms, const char *type_str)
> +{
> + int max_vm_phys_shift, ret = 0;
> + uint64_t type;
> +
> + if (!type_str) {
> + max_vm_phys_shift = kvm_get_max_vm_phys_shift(ms);
> + if (max_vm_phys_shift < 0) {
> + goto out;
> + }
> + } else {
> + type = g_ascii_strtoll(type_str, NULL, 0);
> + type &= 0xFF;
> + max_vm_phys_shift = (int)type;
> + if (max_vm_phys_shift < 40 || max_vm_phys_shift > 52) {
> + warn_report("valid kvm-type type values are within [40, 52]:"
> + " option is ignored and VM is created with 40b IPA");
> + goto out;
> + }
> + }
> + ret = max_vm_phys_shift;
> +out:
> + return ret;
> +}
> +
> static void virt_machine_class_init(ObjectClass *oc, void *data)
> {
> MachineClass *mc = MACHINE_CLASS(oc);
> @@ -1668,6 +1708,7 @@ static void virt_machine_class_init(ObjectClass *oc,
> void *data)
> mc->cpu_index_to_instance_props = virt_cpu_index_to_props;
> mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15");
> mc->get_default_cpu_node_id = virt_get_default_cpu_node_id;
> + mc->kvm_type = virt_kvm_type;
> assert(!mc->get_hotplug_handler);
> mc->get_hotplug_handler = virt_machine_get_hotplug_handler;
> hc->plug = virt_machine_device_plug_cb;
> @@ -1756,6 +1797,9 @@ static void virt_3_0_instance_init(Object *obj)
> "Valid values are none and smmuv3",
> NULL);
>
> + object_property_add_str(obj, "kvm-type",
> + virt_get_kvm_type, virt_set_kvm_type, NULL);
> +
> vms->memmap = a15memmap;
> vms->irqmap = a15irqmap;
> }
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index 4ac7ef6..2674ce7 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -118,6 +118,7 @@ typedef struct {
> uint32_t msi_phandle;
> uint32_t iommu_phandle;
> int psci_conduit;
> + char *kvm_type;
> } VirtMachineState;
>
> #define TYPE_VIRT_MACHINE MACHINE_TYPE_NAME("virt")
> --
> 2.5.5
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- [Qemu-arm] [RFC 0/6] KVM/ARM: Dynamic and larger GPA size, Eric Auger, 2018/06/20
- [Qemu-arm] [RFC 1/6] linux-headers: Partial update for KVM/ARM KVM_ARM_GET_MAX_VM_PHYS_SHIFT, Eric Auger, 2018/06/20
- [Qemu-arm] [RFC 3/6] kvm: add kvm_get_max_vm_phys_shift, Eric Auger, 2018/06/20
- [Qemu-arm] [RFC 4/6] hw/arm/virt: Add virt-3.0 machine type, Eric Auger, 2018/06/20
- [Qemu-arm] [RFC 2/6] hw/boards: Add a MachineState parameter to kvm_type callback, Eric Auger, 2018/06/20
- [Qemu-arm] [RFC 5/6] hw/arm/virt: support kvm_type property, Eric Auger, 2018/06/20
- Re: [Qemu-arm] [RFC 5/6] hw/arm/virt: support kvm_type property,
Dr. David Alan Gilbert <=
- [Qemu-arm] [RFC 6/6] hw/arm/virt: handle max_vm_phys_shift conflicts on migration, Eric Auger, 2018/06/20