Re: [Xen-devel] [RFC PATCH v2] xen/arm: Add support for GICv3 for domU

[Julien Grall <julien.grall@xxxxxxxxxx>]

On 10/29/2014 04:34 PM, Vijay Kilari wrote:
> Hi Stefano,
> 
> On Wed, Oct 29, 2014 at 9:43 PM, Stefano Stabellini
> <stefano.stabellini@xxxxxxxxxxxxx> wrote:
>> FYI we talked f2f about this and we reached the conclusion that we
>> should rework this patch to be non-intrusive and acceptable for 4.5.
>> After all without it we cannot boot guests on GICv3 systems.
> 
>    I am on travel for rest of the week. Is it ok if I look at it next week?
> Can we plan for 4.5 RC2?

That's ok. I can rework the patch for you.

Regards,

>>
>> On Tue, 28 Oct 2014, Julien Grall wrote:
>>> Hi Stefano,
>>>
>>> On 28/10/2014 18:12, Stefano Stabellini wrote:
>>>> I have just realized that this patch didn't make RC1 last Friday.
>>>
>>> I asked for few changes: documentation, way to implement the check... but
>>> Vijay never came back with a new version.
>>>
>>>> What should we do about it?
>>>>
>>>> Without it, I am not sure we should really claim that Xen 4.5 has GICv3
>>>> support, given that we wouldn't be able to start any guests on a GICv3
>>>> platform.
>>>>
>>>> I don't think is so risky it couldn't make RC2, but that's not entirely
>>>> up to me.
>>>
>>> This patch series requires to defer the VGIC initialization later.
>>>
>>> The patch [1] to implement this feature has been deferred to Xen 4.6 because
>>> it was only necessary to my non-pci passthrough series (which has not 
>>> reached
>>> Xen 4.5 for various reasons).
>>>
>>> I don't think this patch should go in Xen 4.5 at this stage of the release
>>> (RC1 went out last week), because it modify too much the way to initialize 
>>> the
>>> domain (VGIC has been deferred). Furthermore it has been reworked in a 
>>> private
>>> branch [2] to address the comments.
>>>
>>> By side effect, the toolstack part for the GICv3 would have to be defer.
>>>
>>> Regards,
>>>
>>> [1] https://patches.linaro.org/34664/
>>> [2]
>>> http://xenbits.xen.org/gitweb/?p=people/julieng/xen-unstable.git;a=commitdiff;h=002b216707ae90b669ffebf009042d5e42b26dc0;hp=30e15fa1f52aa790bf13b5f40dc62d832443846c
>>>
>>>> On Wed, 8 Oct 2014, Julien Grall wrote:
>>>>> Hello Vijay,
>>>>>
>>>>> On 10/06/2014 01:46 PM, vijay.kilari@xxxxxxxxx wrote:
>>>>>> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
>>>>>> index 7d9eec2..8f3f074 100644
>>>>>> --- a/tools/libxl/libxl_types.idl
>>>>>> +++ b/tools/libxl/libxl_types.idl
>>>>>> @@ -349,6 +349,7 @@ libxl_domain_build_info =
>>>>>> Struct("domain_build_info",[
>>>>>>       ("disable_migrate", libxl_defbool),
>>>>>>       ("cpuid",           libxl_cpuid_policy_list),
>>>>>>       ("blkdev_start",    string),
>>>>>> +    ("gic_version",     uint32),
>>>>>
>>>>> How would you differentiate GICv2 from GICv2m with an integer? I think
>>>>> an enum would be better to describe the GIC version.
>>>>>
>>>>>> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
>>>>>> index 2ec17ca..5fcb396 100644
>>>>>> --- a/tools/libxl/xl_cmdimpl.c
>>>>>> +++ b/tools/libxl/xl_cmdimpl.c
>>>>>> @@ -1523,6 +1523,9 @@ skip_vfb:
>>>>>>       if (!xlu_cfg_get_long (config, "pci_seize", &l, 0))
>>>>>>           pci_seize = l;
>>>>>>
>>>>>> +    if (!xlu_cfg_get_long (config, "gic_version", &l, 0))
>>>>>> +        b_info->gic_version = l;
>>>>>> +
>>>>>
>>>>> You have to document this new option in docs/man/xl.cfg.pod.5
>>>>>
>>>>> [..]
>>>>>
>>>>>> diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
>>>>>> index 370dd99..1bea026 100644
>>>>>> --- a/xen/arch/arm/domctl.c
>>>>>> +++ b/xen/arch/arm/domctl.c
>>>>>> @@ -10,6 +10,8 @@
>>>>>>   #include <xen/errno.h>
>>>>>>   #include <xen/sched.h>
>>>>>>   #include <xen/hypercall.h>
>>>>>> +#include <asm/gic.h>
>>>>>> +#include <xen/guest_access.h>
>>>>>>   #include <public/domctl.h>
>>>>>>
>>>>>>   long arch_do_domctl(struct xen_domctl *domctl, struct domain *d,
>>>>>> @@ -39,9 +41,36 @@ long arch_do_domctl(struct xen_domctl *domctl, struct
>>>>>> domain *d,
>>>>>>           if ( domctl->u.configuredomain.nr_spis > (gic_number_lines() -
>>>>>> 32) )
>>>>>>               return -EINVAL;
>>>>>>
>>>>>> -        return domain_configure_vgic(d,
>>>>>> domctl->u.configuredomain.nr_spis);
>>>>>> -    }
>>>>>> +        if ( domain_configure_vgic(d,
>>>>>> domctl->u.configuredomain.nr_spis) )
>>>>>> +            return -EINVAL;
>>>>>
>>>>> domain_configure_vgic should be called after we check that current
>>>>> version of GIC match. The user may want to chose to emulate a GICv2 on
>>>>> GICv3 hardware.
>>>>>
>>>>>> diff --git a/xen/include/public/arch-arm.h
>>>>>> b/xen/include/public/arch-arm.h
>>>>>> index cebb349..6f80c99 100644
>>>>>> --- a/xen/include/public/arch-arm.h
>>>>>> +++ b/xen/include/public/arch-arm.h
>>>>>> @@ -363,6 +363,14 @@ typedef uint64_t xen_callback_t;
>>>>>>    * should instead use the FDT.
>>>>>>    */
>>>>>>
>>>>>> +/* GICv3 address space */
>>>>>> +#define GUEST_GICV3_GICD_BASE      0x03001000ULL
>>>>>> +#define GUEST_GICV3_GICD_SIZE      0x10000ULL
>>>>>> +#define GUEST_GICV3_GICR_BASE      0x03020000ULL
>>>>>> +#define GUEST_GICV3_GICR_SIZE      0x200000ULL
>>>>>> +#define GUEST_GICV3_RDIST_STRIDE   0x20000ULL
>>>>>> +#define GUEST_GICV3_RDIST_REGIONS  0x1ULL
>>>>>> +
>>>>>
>>>>> This should go after "/* Physical Address Space */
>>>>>
>>>>>>   /* Physical Address Space */
>>>>>>   #define GUEST_GICD_BASE   0x03001000ULL
>>>>>>   #define GUEST_GICD_SIZE   0x00001000ULL
>>>>>
>>>>> Please modify those defines, along *GICC* to add GICV2 in the name.
>>>>>
>>>>>> diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
>>>>>> index 8adb8e2..502cfb6 100644
>>>>>> --- a/xen/include/public/domctl.h
>>>>>> +++ b/xen/include/public/domctl.h
>>>>>> @@ -73,6 +73,8 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_createdomain_t);
>>>>>>   struct xen_domctl_configuredomain {
>>>>>>       /* IN parameters */
>>>>>>       uint32_t nr_spis;
>>>>>> +    /* IN/OUT parameter */
>>>>>> +    uint32_t gic_version;
>>>>>
>>>>> uint32_t sounds a bit too much for the gic_version. Maybe a uint8_t?
>>>>> Also a better name would be vgic_version.
>>>>>
>>>>> Futhermore, people reading the structure don't know what value should be
>>>>> expected in this field. I would introduce define to specify the
>>>>> different value.
>>>>>
>>>>> Regards,
>>>>>
>>>>> --
>>>>> Julien Grall
>>>>>
>>>
>>> --
>>> Julien Grall
>>>


-- 
Julien Grall

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