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Re: [Qemu-arm] [RFC v3 05/15] hw/arm/virt: handle max_vm_phys_shift conf
From: |
David Hildenbrand |
Subject: |
Re: [Qemu-arm] [RFC v3 05/15] hw/arm/virt: handle max_vm_phys_shift conflicts on migration |
Date: |
Tue, 3 Jul 2018 20:41:15 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 |
On 03.07.2018 09:19, Eric Auger wrote:
> When migrating a VM, we must make sure the destination host
> supports as many IPA bits as the source. Otherwise the migration
> must fail.
>
> We add a VMState infrastructure to machvirt. On pre_save(),
> the current source max_vm_phys_shift is saved.
>
> On destination, we cannot use this information when creating the
> VM. The VM is created using the max value reported by the
> destination host - or the kvm_type inherited value -. However on
> post_load() we can check that this value is compatible with the
> source saved value.
Just wondering, how exactly is the guest able to detect the 42b (e.g. vs
42b) configuration?
>
> Signed-off-by: Eric Auger <address@hidden>
> ---
> hw/arm/virt.c | 37 +++++++++++++++++++++++++++++++++++++
> include/hw/arm/virt.h | 2 ++
> 2 files changed, 39 insertions(+)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 04a32de..5a4d0bf 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -1316,6 +1316,40 @@ static uint64_t virt_cpu_mp_affinity(VirtMachineState
> *vms, int idx)
> return arm_cpu_mp_affinity(idx, clustersz);
> }
>
> +static int virt_post_load(void *opaque, int version_id)
> +{
> + VirtMachineState *vms = (VirtMachineState *)opaque;
> +
> + if (vms->max_vm_phys_shift < vms->source_max_vm_phys_shift) {
> + error_report("This host kernel only supports %d IPA bits whereas "
> + "the guest requires %d GPA bits",
> vms->max_vm_phys_shift,
> + vms->source_max_vm_phys_shift);
> + return -1;
> + }
> + return 0;
> +}
> +
> +static int virt_pre_save(void *opaque)
> +{
> + VirtMachineState *vms = (VirtMachineState *)opaque;
> +
> + vms->source_max_vm_phys_shift = vms->max_vm_phys_shift;
> + return 0;
> +}
> +
> +static const VMStateDescription vmstate_virt = {
> + .name = "virt",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .post_load = virt_post_load,
> + .pre_save = virt_pre_save,
> + .fields = (VMStateField[]) {
> + VMSTATE_INT32(source_max_vm_phys_shift, VirtMachineState),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> +
> static void machvirt_init(MachineState *machine)
> {
> VirtMachineState *vms = VIRT_MACHINE(machine);
> @@ -1537,6 +1571,7 @@ static void machvirt_init(MachineState *machine)
>
> vms->machine_done.notify = virt_machine_done;
> qemu_add_machine_init_done_notifier(&vms->machine_done);
> + vmstate_register(NULL, 0, &vmstate_virt, vms);
> }
>
> static bool virt_get_secure(Object *obj, Error **errp)
> @@ -1727,6 +1762,7 @@ static HotplugHandler
> *virt_machine_get_hotplug_handler(MachineState *machine,
>
> static int virt_kvm_type(MachineState *ms, const char *type_str)
> {
> + VirtMachineState *vms = VIRT_MACHINE(ms);
> int max_vm_phys_shift, ret = 0;
> uint64_t type;
>
> @@ -1747,6 +1783,7 @@ static int virt_kvm_type(MachineState *ms, const char
> *type_str)
> }
> ret = max_vm_phys_shift;
> out:
> + vms->max_vm_phys_shift = (max_vm_phys_shift > 0) ? ret : 40;
> return ret;
> }
>
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index 1a90ffc..91f6de2 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -125,6 +125,8 @@ typedef struct {
> uint32_t iommu_phandle;
> int psci_conduit;
> char *kvm_type;
> + int32_t max_vm_phys_shift;
> + int32_t source_max_vm_phys_shift;
> } VirtMachineState;
>
> #define VIRT_ECAM_ID(high) (high ? VIRT_PCIE_ECAM_HIGH : VIRT_PCIE_ECAM)
>
--
Thanks,
David / dhildenb
- [Qemu-arm] [RFC v3 02/15] hw/boards: Add a MachineState parameter to kvm_type callback, (continued)
- [Qemu-arm] [RFC v3 02/15] hw/boards: Add a MachineState parameter to kvm_type callback, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 03/15] kvm: add kvm_arm_get_max_vm_phys_shift, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 04/15] hw/arm/virt: support kvm_type property, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 09/15] hw/arm/boot: Expose the PC-DIMM nodes in the DT, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 15/15] hw/arm/virt: Add nvdimm and nvdimm-persistence options, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 01/15] linux-headers: header update for KVM/ARM KVM_ARM_GET_MAX_VM_PHYS_SHIFT, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 10/15] acpi: move build_srat_hotpluggable_memory to generic ACPI source, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 12/15] nvdimm: use configurable ACPI IO base and size, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 13/15] hw/arm/virt: Add nvdimm hot-plug infrastructure, Eric Auger, 2018/07/03
- [Qemu-arm] [RFC v3 05/15] hw/arm/virt: handle max_vm_phys_shift conflicts on migration, Eric Auger, 2018/07/03
- Re: [Qemu-arm] [RFC v3 05/15] hw/arm/virt: handle max_vm_phys_shift conflicts on migration,
David Hildenbrand <=
Re: [Qemu-arm] [RFC v3 00/15] ARM virt: PCDIMM/NVDIMM at 2TB, Igor Mammedov, 2018/07/18