Re: [PATCH v2 07/21] coco/tdx-host: Expose P-SEAMLDR information via sysfs
From: Sagi Shahar
Date: Fri Oct 31 2025 - 10:32:01 EST
On Thu, Oct 30, 2025 at 6:05 PM <dan.j.williams@xxxxxxxxx> wrote:
>
> Sagi Shahar wrote:
> > On Tue, Sep 30, 2025 at 9:55 PM Chao Gao <chao.gao@xxxxxxxxx> wrote:
> > >
> > > TDX Module updates require userspace to select the appropriate module
> > > to load. Expose necessary information to facilitate this decision. Two
> > > values are needed:
> > >
> > > - P-SEAMLDR version: for compatibility checks between TDX Module and
> > > P-SEAMLDR
> > > - num_remaining_updates: indicates how many updates can be performed
> > >
> > > Expose them as tdx-host device attributes.
> > >
> > > Note that P-SEAMLDR sysfs nodes are hidden when INTEL_TDX_MODULE_UPDATE
> > > isn't enabled or when P-SEAMLDR isn't loaded by BIOS, both of which
> > > cause seamldr_get_info() to return NULL.
> > >
> > > Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
> > > Tested-by: Farrah Chen <farrah.chen@xxxxxxxxx>
> > > ---
> > > .../ABI/testing/sysfs-devices-faux-tdx-host | 25 ++++++++
> > > drivers/virt/coco/tdx-host/tdx-host.c | 63 ++++++++++++++++++-
> > > 2 files changed, 87 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/Documentation/ABI/testing/sysfs-devices-faux-tdx-host b/Documentation/ABI/testing/sysfs-devices-faux-tdx-host
> >
> > Trying to apply this patch locally fails because
> > sysfs-devices-faux-tdx-host does not exist. There are also conflicts
> > around drivers/virt/coco/tdx-host/tdx-host.c.
> >
> > I'm looking at the base commit specified in the cover letter [1] but
> > even the current head of the tsm/tdx tree [2] doesn't have the
> > sysfs-devices-faux-tdx-host file. Are there any other dependencies for
> > this series?
>
> I hit the same head scratcher, but then realized that Chao did say that
> you also need to apply:
>
> https://lore.kernel.org/linux-coco/20251001022309.277238-1-chao.gao@xxxxxxxxx
>
> ...so:
>
> git checkout -b $branch 9332e088937f
> b4 shazam 20251001022309.277238-1-chao.gao@xxxxxxxxx
> b4 shazam 20251001025442.427697-1-chao.gao@xxxxxxxxx
>
> ...works for me.
Thanks, I missed that one. It's working now