Re: [Qemu-devel] [PATCH V5 5/5] machine: remove iommu property

[Marcel Apfelbaum <marcel@redhat.com>]

On 06/28/2016 05:57 AM, David Gibson wrote:
> On Mon, Jun 27, 2016 at 06:38:35PM +0300, Marcel Apfelbaum wrote:
>> Since iommu devices can be created with '-device' there is
>> no need to keep iommu as machine and mch property.
>
> Doesn't this break backwards compatibility?
>


Hi David,

Intel IOMMU was a kind of POC until recent development.
The new IOMMU features will require more command line options,
so even if we keep the machine property around, it can't be really used.

More on this was discussed in a prev thread.
https://www.mail-archive.com/qemu-devel@nongnu.org/msg377385.html

Thanks,
Marcel

>>
>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>> ---
>>   hw/core/machine.c         | 20 --------------------
>>   hw/pci-host/q35.c         | 12 ------------
>>   include/hw/pci-host/q35.h |  1 -
>>   qemu-options.hx           |  3 ---
>>   4 files changed, 36 deletions(-)
>>
>> diff --git a/hw/core/machine.c b/hw/core/machine.c
>> index ccdd5fa..8f94301 100644
>> --- a/hw/core/machine.c
>> +++ b/hw/core/machine.c
>> @@ -300,20 +300,6 @@ static void machine_set_firmware(Object *obj, const char *value, Error **errp)
>>       ms->firmware = g_strdup(value);
>>   }
>>
>> -static bool machine_get_iommu(Object *obj, Error **errp)
>> -{
>> -    MachineState *ms = MACHINE(obj);
>> -
>> -    return ms->iommu;
>> -}
>> -
>> -static void machine_set_iommu(Object *obj, bool value, Error **errp)
>> -{
>> -    MachineState *ms = MACHINE(obj);
>> -
>> -    ms->iommu = value;
>> -}
>> -
>>   static void machine_set_suppress_vmdesc(Object *obj, bool value, Error **errp)
>>   {
>>       MachineState *ms = MACHINE(obj);
>> @@ -493,12 +479,6 @@ static void machine_initfn(Object *obj)
>>       object_property_set_description(obj, "firmware",
>>                                       "Firmware image",
>>                                       NULL);
>> -    object_property_add_bool(obj, "iommu",
>> -                             machine_get_iommu,
>> -                             machine_set_iommu, NULL);
>> -    object_property_set_description(obj, "iommu",
>> -                                    "Set on/off to enable/disable Intel IOMMU (VT-d)",
>> -                                    NULL);
>>       object_property_add_bool(obj, "suppress-vmdesc",
>>                                machine_get_suppress_vmdesc,
>>                                machine_set_suppress_vmdesc, NULL);
>> diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
>> index 4bd5fb5..181bc3b 100644
>> --- a/hw/pci-host/q35.c
>> +++ b/hw/pci-host/q35.c
>> @@ -427,14 +427,6 @@ static void mch_reset(DeviceState *qdev)
>>       mch_update(mch);
>>   }
>>
>> -static void mch_init_dmar(MCHPCIState *mch)
>> -{
>> -    mch->iommu = INTEL_IOMMU_DEVICE(qdev_create(NULL, TYPE_INTEL_IOMMU_DEVICE));
>> -    object_property_add_child(OBJECT(mch), "intel-iommu",
>> -                              OBJECT(mch->iommu), NULL);
>> -    qdev_init_nofail(DEVICE(mch->iommu));
>> -}
>> -
>>   static void mch_realize(PCIDevice *d, Error **errp)
>>   {
>>       int i;
>> @@ -493,10 +485,6 @@ static void mch_realize(PCIDevice *d, Error **errp)
>>                    mch->pci_address_space, &mch->pam_regions[i+1],
>>                    PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
>>       }
>> -    /* Intel IOMMU (VT-d) */
>> -    if (object_property_get_bool(qdev_get_machine(), "iommu", NULL)) {
>> -        mch_init_dmar(mch);
>> -    }
>>   }
>>
>>   uint64_t mch_mcfg_base(void)
>> diff --git a/include/hw/pci-host/q35.h b/include/hw/pci-host/q35.h
>> index c5c073d..3dee058 100644
>> --- a/include/hw/pci-host/q35.h
>> +++ b/include/hw/pci-host/q35.h
>> @@ -60,7 +60,6 @@ typedef struct MCHPCIState {
>>       ram_addr_t above_4g_mem_size;
>>       uint64_t pci_hole64_size;
>>       uint32_t short_root_bus;
>> -    IntelIOMMUState *iommu;
>>   } MCHPCIState;
>>
>>   typedef struct Q35PCIHost {
>> diff --git a/qemu-options.hx b/qemu-options.hx
>> index 44c658f..1d3c02e 100644
>> --- a/qemu-options.hx
>> +++ b/qemu-options.hx
>> @@ -38,7 +38,6 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
>>       "                kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
>>       "                dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
>>       "                mem-merge=on|off controls memory merge support (default: on)\n"
>> -    "                iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n"
>>       "                igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
>>       "                aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
>>       "                dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
>> @@ -73,8 +72,6 @@ Include guest memory in a core dump. The default is on.
>>   Enables or disables memory merge support. This feature, when supported by
>>   the host, de-duplicates identical memory pages among VMs instances
>>   (enabled by default).
>> -@item iommu=on|off
>> -Enables or disables emulated Intel IOMMU (VT-d) support. The default is off.
>>   @item aes-key-wrap=on|off
>>   Enables or disables AES key wrapping support on s390-ccw hosts. This feature
>>   controls whether AES wrapping keys will be created to allow
>