Re: [Qemu-devel] [V4 2/4] hw/core: Add AMD IO MMU to machine properties

[Marcel Apfelbaum <marcel@redhat.com>]

On 01/18/2016 06:48 PM, David Kiarie wrote:
>
>
> On 1/18/2016 7:21 PM, Marcel Apfelbaum wrote:
>> On 01/18/2016 05:25 PM, David Kiarie wrote:
>>> Add IO MMU as a string to machine properties which
>>> is used to control whether and the type of IO MMU
>>> to emulate
>>>
>>> Signed-off-by: David Kiarie <davidkiarie4@gmail.com>
>>> ---
>>>   hw/core/machine.c             | 17 +++++++++--------
>>>   include/hw/boards.h           |  3 ++-
>>>   include/hw/i386/intel_iommu.h |  1 +
>>>   qemu-options.hx               |  6 +++---
>>>   util/qemu-config.c            |  4 ++--
>>>   vl.c                          |  8 ++++++++
>>>   6 files changed, 25 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/hw/core/machine.c b/hw/core/machine.c
>>> index c46ddc7..cb309aa 100644
>>> --- a/hw/core/machine.c
>>> +++ b/hw/core/machine.c
>>> @@ -283,18 +283,19 @@ 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)
>>> +static char *machine_get_iommu(Object *obj, Error **errp)
>>>   {
>>>       MachineState *ms = MACHINE(obj);
>>>
>>> -    return ms->iommu;
>>> +    return g_strdup(ms->iommu);
>>>   }
>>>
>>> -static void machine_set_iommu(Object *obj, bool value, Error **errp)
>>> +static void machine_set_iommu(Object *obj, const char *value, Error **errp)
>>>   {
>>>       MachineState *ms = MACHINE(obj);
>>>
>>> -    ms->iommu = value;
>>> +    g_free(ms->iommu);
>>> +    ms->iommu = g_strdup(value);
>>>   }
>>>
>>>   static void machine_set_suppress_vmdesc(Object *obj, bool value, Error **errp)
>>> @@ -454,11 +455,10 @@ 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_add_str(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)",
>>> +                                    "IOMMU list",
>>>                                       NULL);
>>>       object_property_add_bool(obj, "suppress-vmdesc",
>>>                                machine_get_suppress_vmdesc,
>>> @@ -484,6 +484,7 @@ static void machine_finalize(Object *obj)
>>>       g_free(ms->dumpdtb);
>>>       g_free(ms->dt_compatible);
>>>       g_free(ms->firmware);
>>> +    g_free(ms->iommu);
>>>   }
>>>
>>>   bool machine_usb(MachineState *machine)
>>> diff --git a/include/hw/boards.h b/include/hw/boards.h
>>> index 0f30959..b119245 100644
>>> --- a/include/hw/boards.h
>>> +++ b/include/hw/boards.h
>>> @@ -36,6 +36,7 @@ bool machine_usb(MachineState *machine);
>>>   bool machine_kernel_irqchip_allowed(MachineState *machine);
>>>   bool machine_kernel_irqchip_required(MachineState *machine);
>>>   bool machine_kernel_irqchip_split(MachineState *machine);
>>> +bool machine_amd_iommu(MachineState *machine);
>>>   int machine_kvm_shadow_mem(MachineState *machine);
>>>   int machine_phandle_start(MachineState *machine);
>>>   bool machine_dump_guest_core(MachineState *machine);
>>> @@ -126,7 +127,7 @@ struct MachineState {
>>>       bool usb_disabled;
>>>       bool igd_gfx_passthru;
>>>       char *firmware;
>>> -    bool iommu;
>>> +    char *iommu;
>>>       bool suppress_vmdesc;
>>>
>>>       ram_addr_t ram_size;
>>> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
>>> index 5dbadb7..0b32bd6 100644
>>> --- a/include/hw/i386/intel_iommu.h
>>> +++ b/include/hw/i386/intel_iommu.h
>>> @@ -27,6 +27,7 @@
>>>   #define TYPE_INTEL_IOMMU_DEVICE "intel-iommu"
>>>   #define INTEL_IOMMU_DEVICE(obj) \
>>>        OBJECT_CHECK(IntelIOMMUState, (obj), TYPE_INTEL_IOMMU_DEVICE)
>>> +#define INTEL_IOMMU_STR "intel"
>>>
>>>   /* DMAR Hardware Unit Definition address (IOMMU unit) */
>>>   #define Q35_HOST_BRIDGE_IOMMU_ADDR  0xfed90000ULL
>>> diff --git a/qemu-options.hx b/qemu-options.hx
>>> index 215d00d..ac327c8 100644
>>> --- a/qemu-options.hx
>>> +++ b/qemu-options.hx
>>> @@ -38,7 +38,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
>>>       "                kvm_shadow_mem=size of KVM shadow MMU\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"
>>> +    "                iommu=amd|intel enables and selects the emulated IO MMU (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"
>>> @@ -72,8 +72,8 @@ 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 iommu=intel|amd
>>> +Enables and selects the emulated IO MMU. 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
>>> diff --git a/util/qemu-config.c b/util/qemu-config.c
>>> index 687fd34..f79b98c 100644
>>> --- a/util/qemu-config.c
>>> +++ b/util/qemu-config.c
>>> @@ -213,8 +213,8 @@ static QemuOptsList machine_opts = {
>>>               .help = "firmware image",
>>>           },{
>>>               .name = "iommu",
>>> -            .type = QEMU_OPT_BOOL,
>>> -            .help = "Set on/off to enable/disable Intel IOMMU (VT-d)",
>>> +            .type =  QEMU_OPT_STRING,
>>> +            .help = "Enables IO MMU and sets the emulated type",
>>>           },{
>>>               .name = "suppress-vmdesc",
>>>               .type = QEMU_OPT_BOOL,
>>> diff --git a/vl.c b/vl.c
>>> index b7a083e..4e39caa 100644
>>> --- a/vl.c
>>> +++ b/vl.c
>>> @@ -65,6 +65,8 @@ int main(int argc, char **argv)
>>>   #include "sysemu/accel.h"
>>>   #include "hw/usb.h"
>>>   #include "hw/i386/pc.h"
>>> +#include "hw/i386/amd_iommu.h"
>>> +#include "hw/i386/intel_iommu.h"
>>>   #include "hw/isa/isa.h"
>>>   #include "hw/bt.h"
>>>   #include "sysemu/watchdog.h"
>>> @@ -3677,6 +3679,12 @@ int main(int argc, char **argv, char **envp)
>>>                   if (!opts) {
>>>                       exit(1);
>>>                   }
>>> +                const char *iommu = qemu_opt_get(opts, "iommu");
>>> +                if (iommu && !(g_strcmp0(iommu, AMD_IOMMU_STR) ||
>>> +                    g_strcmp0(iommu, INTEL_IOMMU_STR))) {
>>
>> Hi,
>>
>> I am sorry for bugging you, please don't re-post before
>> you get more meaningful reviews, that being said:
>>
>> I don't know if the above will work as
>>    (g_strcmp0(iommu, AMD_IOMMU_STR) || g_strcmp0(iommu, INTEL_IOMMU_STR))
>> will always return 1. Right :) ?
>
> Yep, always true.
>
> Above fails though if the string doesn't match any 'iommu' type string.

If you agree that the above is always true, !() is always false =>
if statement always false, meaning you never get the error message.

Thanks,
Marcel

>
>>
>> However, you should put this check in machine_set_iommu. You fill in the errp
>> and you will get a nice error message when the machine properties are parsed.
>>
>> Thanks,
>> Marcel
>>
>>
>>
>>> +                    fprintf(stderr, "Invalid IO MMU type %s\n", iommu);
>>> +                    exit(1);
>>> +                }
>>>                   break;
>>>                case QEMU_OPTION_no_kvm:
>>>                   olist = qemu_find_opts("machine");
>>>
>>
>