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

[Vijay Kilari <vijay.kilari@xxxxxxxxx>]

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?

>
> 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
>>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel