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

[David Kiarie <davidkiarie4@gmail.com>]

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.

>
> 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");
>>
>