-----Original Message-----
From: Brost, Matthew <matthew.br...@intel.com>
Sent: Tuesday, August 26, 2025 11:04 AM
To: Cavitt, Jonathan <jonathan.cav...@intel.com>
Cc: intel-gfx@lists.freedesktop.org; Gupta, saurabhg
<saurabhg.gu...@intel.com>; Zuo, Alex <alex....@intel.com>; Harrison, John C
<john.c.harri...@intel.com>
Subject: Re: [PATCH 2/2] drm/xe/xe_vm: Add error injection support to lock and
prep
>
> On Tue, Aug 26, 2025 at 03:43:55PM +0000, Jonathan Cavitt wrote:
> > Add error injection support to the function
> > vm_bind_ioctl_ops_lock_and_prep. This necessitates marking the function
> > as noinline.
> >
> > Signed-off-by: Jonathan Cavitt <jonathan.cav...@intel.com>
> > Cc: Matthew Brost <matthew.br...@intel.com>
> > Cc: John Harrison <john.c.harri...@intel.com>
> > ---
> > drivers/gpu/drm/xe/xe_vm.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> > index 1a8841116e40..e527c90b8c33 100644
> > --- a/drivers/gpu/drm/xe/xe_vm.c
> > +++ b/drivers/gpu/drm/xe/xe_vm.c
> > @@ -3201,9 +3201,10 @@ static int vm_bind_ioctl_ops_prefetch_ranges(struct
> > xe_vm *vm, struct xe_vma_ops
> > return 0;
> > }
> >
> > -static int vm_bind_ioctl_ops_lock_and_prep(struct drm_exec *exec,
> > - struct xe_vm *vm,
> > - struct xe_vma_ops *vops)
> > +static noinline int
>
> Ideally in [1] we'd have something like this:
>
> #ifdef CONFIG_FUNCTION_ERROR_INJECTION
> #define error_injectable noinline
> #else
> #define error_injectable
> #endif
>
> That might take sometime to get through, but in the meantine can we
> define something on the Xe side for this?
>
> [1]
> https://elixir.bootlin.com/linux/v6.16.3/source/include/asm-generic/error-injection.h
In the short term, I think something like what's done with the
xe_is_injection_active function
in xe_guc_ct.c would work. Let me try applying that.
>
> > +vm_bind_ioctl_ops_lock_and_prep(struct drm_exec *exec,
> > + struct xe_vm *vm,
> > + struct xe_vma_ops *vops)
> > {
> > struct xe_vma_op *op;
> > int err;
> > @@ -3220,6 +3221,7 @@ static int vm_bind_ioctl_ops_lock_and_prep(struct
> > drm_exec *exec,
> >
> > return 0;
> > }
> > +ALLOW_ERROR_INJECTION(vm_bind_ioctl_ops_lock_and_prep, ERRNO);
> >
>
> We absolutely need the same injection points which are removed in patch
> #1 + an IGT with the same coverage. Please add similar points. VM binds
They're already present.
> are a deep software pipeline that can be unwound at any point of
> failure. Different injection points trigger various unwind flows that
> need to be tested. It took me a long time to get this right, is easy to
> break, so we need good testing in place.
AFAICT, the test xe_vm@bind-array-conflict-error-inject test only exercises
the vm_bind_ioctl_ops_lock_and_prep function. I can add additional points
to test in the test file if that's what is desired.
-Jonathan Cavitt
>
> Matt
>
> > static void op_trace(struct xe_vma_op *op)
> > {
> > --
> > 2.43.0
> >
>
