Currently these is no way to know the TDX module version from the
userspace. such information is helpful for bug reporting or
debugging.
With the tdx-host device in place, expose the TDX module version as
a device attribute via sysfs.
Signed-off-by: Chao Gao <chao.gao@intel.com>
---
.../ABI/testing/sysfs-devices-faux-tdx-host | 6 +++++
MAINTAINERS | 1 +
drivers/virt/coco/tdx-host/tdx-host.c | 25 ++++++++++++++++++-
3 files changed, 31 insertions(+), 1 deletion(-)
create mode 100644 Documentation/ABI/testing/sysfs-devices-faux-tdx-host
diff --git a/Documentation/ABI/testing/sysfs-devices-faux-tdx-host b/Documentation/ABI/testing/sysfs-devices-faux-tdx-host
new file mode 100644
index 000000000000..18d4a4a71b80
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-faux-tdx-host
@@ -0,0 +1,6 @@
+What: /sys/devices/faux/tdx_host/version
+Contact: linux-coco@lists.linux.dev
+Description: (RO) Report the version of the loaded TDX module. The TDX module
+ version is formatted as x.y.z, where "x" is the major version,
+ "y" is the minor version and "z" is the update version. Versions
+ are used for bug reporting, TD-Preserving updates and etc.
diff --git a/MAINTAINERS b/MAINTAINERS
index c1ad1294560c..7560dcf8a53d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27333,6 +27333,7 @@ L: x86@kernel.org
L: linux-coco@lists.linux.dev
S: Supported
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/tdx
+F: Documentation/ABI/testing/sysfs-devices-faux-tdx-host
F: Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest
F: arch/x86/boot/compressed/tdx*
F: arch/x86/coco/tdx/
diff --git a/drivers/virt/coco/tdx-host/tdx-host.c b/drivers/virt/coco/tdx-host/tdx-host.c
index 49c205913ef6..968a19f4e01a 100644
--- a/drivers/virt/coco/tdx-host/tdx-host.c
+++ b/drivers/virt/coco/tdx-host/tdx-host.c
@@ -22,6 +22,29 @@ MODULE_DEVICE_TABLE(x86cpu, tdx_host_ids);
static struct faux_device *fdev;
+static ssize_t version_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ const struct tdx_sys_info *tdx_sysinfo = tdx_get_sysinfo();
+ const struct tdx_sys_info_version *ver;
+
+ if (!tdx_sysinfo)
+ return -ENXIO;
+
+ ver = &tdx_sysinfo->version;
+
+ return sysfs_emit(buf, "%u.%u.%02u\n", ver->major_version,
+ ver->minor_version,
+ ver->update_version);
+}
+static DEVICE_ATTR_RO(version);
+
+static struct attribute *tdx_host_attrs[] = {
+ &dev_attr_version.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(tdx_host);
+
static int __init tdx_host_init(void)
{
int r;
@@ -34,7 +57,7 @@ static int __init tdx_host_init(void)
if (r)
return r;
- fdev = faux_device_create(KBUILD_MODNAME, NULL, NULL);
+ fdev = faux_device_create_with_groups(KBUILD_MODNAME, NULL, NULL, tdx_host_groups);
if (!fdev)
return -ENODEV;
--
2.47.3On Tue, Sep 30, 2025 at 07:22:45PM -0700, Chao Gao wrote: > diff --git a/MAINTAINERS b/MAINTAINERS > index c1ad1294560c..7560dcf8a53d 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -27333,6 +27333,7 @@ L: x86@kernel.org > L: linux-coco@lists.linux.dev > S: Supported > T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/tdx > +F: Documentation/ABI/testing/sysfs-devices-faux-tdx-host > F: Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest > F: arch/x86/boot/compressed/tdx* > F: arch/x86/coco/tdx/ The entry was updated recently: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/tree/MAINTAINERS?h=x86/tdx#n27325 I think you need to rebase onto current tip tree. -- Kiryl Shutsemau / Kirill A. Shutemov
On Tue, 2025-09-30 at 19:22 -0700, Chao Gao wrote:
> Currently these is no way to know the TDX module version from the
^
there is
> userspace. such information is helpful for bug reporting or
^
Such
> debugging.
>
>
[...]
> +static ssize_t version_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + const struct tdx_sys_info *tdx_sysinfo = tdx_get_sysinfo();
> + const struct tdx_sys_info_version *ver;
> +
> + if (!tdx_sysinfo)
> + return -ENXIO;
> +
> + ver = &tdx_sysinfo->version;
> +
> + return sysfs_emit(buf, "%u.%u.%02u\n", ver->major_version,
> + ver->minor_version,
> + ver->update_version);
Nit: not sure whether the "%u.%u.%02u" needs a comment, e.g., why the %02u
is used for the update_version?
On Wed, Oct 01, 2025 at 04:12:10AM +0000, Huang, Kai wrote:
> On Tue, 2025-09-30 at 19:22 -0700, Chao Gao wrote:
> > Currently these is no way to know the TDX module version from the
> ^
> there is
>
> > userspace. such information is helpful for bug reporting or
> ^
> Such
>
> > debugging.
> >
> >
>
> [...]
>
> > +static ssize_t version_show(struct device *dev, struct device_attribute *attr,
> > + char *buf)
> > +{
> > + const struct tdx_sys_info *tdx_sysinfo = tdx_get_sysinfo();
> > + const struct tdx_sys_info_version *ver;
> > +
> > + if (!tdx_sysinfo)
> > + return -ENXIO;
> > +
> > + ver = &tdx_sysinfo->version;
> > +
> > + return sysfs_emit(buf, "%u.%u.%02u\n", ver->major_version,
> > + ver->minor_version,
> > + ver->update_version);
>
> Nit: not sure whether the "%u.%u.%02u" needs a comment, e.g., why the %02u
> is used for the update_version?
That's how TDX module version formatted:
https://github.com/intel/tdx-module/tags
I think it is good idea to match it.
--
Kiryl Shutsemau / Kirill A. Shutemov
On Wed, 2025-10-01 at 12:27 +0100, Kiryl Shutsemau wrote:
> On Wed, Oct 01, 2025 at 04:12:10AM +0000, Huang, Kai wrote:
> > On Tue, 2025-09-30 at 19:22 -0700, Chao Gao wrote:
> > > Currently these is no way to know the TDX module version from the
> > ^
> > there is
> >
> > > userspace. such information is helpful for bug reporting or
> > ^
> > Such
> >
> > > debugging.
> > >
> > >
> >
> > [...]
> >
> > > +static ssize_t version_show(struct device *dev, struct device_attribute *attr,
> > > + char *buf)
> > > +{
> > > + const struct tdx_sys_info *tdx_sysinfo = tdx_get_sysinfo();
> > > + const struct tdx_sys_info_version *ver;
> > > +
> > > + if (!tdx_sysinfo)
> > > + return -ENXIO;
> > > +
> > > + ver = &tdx_sysinfo->version;
> > > +
> > > + return sysfs_emit(buf, "%u.%u.%02u\n", ver->major_version,
> > > + ver->minor_version,
> > > + ver->update_version);
> >
> > Nit: not sure whether the "%u.%u.%02u" needs a comment, e.g., why the %02u
> > is used for the update_version?
>
> That's how TDX module version formatted:
>
> https://github.com/intel/tdx-module/tags
>
> I think it is good idea to match it.
Yeah agreed!
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