Messages in this thread | | | From | Kuppuswamy Sathyanarayanan <> | Date | Tue, 30 Apr 2024 22:18:43 -0700 | Subject | Re: [PATCH v4 13/15] x86/sev: Take advantage of configfs visibility support in TSM |
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On Wed, Apr 24, 2024 at 9:00 AM Tom Lendacky <thomas.lendacky@amd.com> wrote: > > The TSM attestation report support provides multiple configfs attribute > types (both for standard and binary attributes) to allow for additional > attributes to be displayed for SNP as compared to TDX. With the ability > to hide attributes via configfs, consoldate the multiple attribute groups > into a single standard attribute group and a single binary attribute > group. Modify the TDX support to hide the attributes that were previously > "hidden" as a result of registering the selective attribute groups. > > Co-developed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> > --- > drivers/virt/coco/sev-guest/sev-guest.c | 3 +- > drivers/virt/coco/tdx-guest/tdx-guest.c | 29 ++++++++- > drivers/virt/coco/tsm.c | 82 ++++++++++++------------- > include/linux/tsm.h | 41 ++++++++++--- > 4 files changed, 102 insertions(+), 53 deletions(-) > > diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c > index 2abb51bd034f..ec3d894cfe31 100644 > --- a/drivers/virt/coco/sev-guest/sev-guest.c > +++ b/drivers/virt/coco/sev-guest/sev-guest.c > @@ -23,6 +23,7 @@ > #include <linux/sockptr.h> > #include <linux/cleanup.h> > #include <linux/uuid.h> > +#include <linux/configfs.h> > #include <uapi/linux/sev-guest.h> > #include <uapi/linux/psp-sev.h> > > @@ -975,7 +976,7 @@ static int __init sev_guest_probe(struct platform_device *pdev) > /* Set the privlevel_floor attribute based on the vmpck_id */ > sev_tsm_ops.privlevel_floor = vmpck_id; > > - ret = tsm_register(&sev_tsm_ops, snp_dev, &tsm_report_extra_type); > + ret = tsm_register(&sev_tsm_ops, snp_dev); > if (ret) > goto e_free_cert_data; > > diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c > index 1253bf76b570..964af57f345c 100644 > --- a/drivers/virt/coco/tdx-guest/tdx-guest.c > +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c > @@ -17,6 +17,7 @@ > #include <linux/delay.h> > #include <linux/tsm.h> > #include <linux/sizes.h> > +#include <linux/configfs.h> > > #include <uapi/linux/tdx-guest.h> > > @@ -249,6 +250,30 @@ static int tdx_report_new(struct tsm_report *report, void *data) > return ret; > } > > +static bool tdx_report_attr_visible(struct config_item *item, > + struct configfs_attribute *attr, int n) > +{ > + switch (n) { > + case TSM_REPORT_GENERATION: > + case TSM_REPORT_PROVIDER: > + return true; > + } > + > + return false; > +} > + > +static bool tdx_report_bin_attr_visible(struct config_item *item, > + struct configfs_bin_attribute *attr, int n) > +{ > + switch (n) { > + case TSM_REPORT_INBLOB: > + case TSM_REPORT_OUTBLOB: > + return true; > + } > + > + return false; > +} > + > static long tdx_guest_ioctl(struct file *file, unsigned int cmd, > unsigned long arg) > { > @@ -281,6 +306,8 @@ MODULE_DEVICE_TABLE(x86cpu, tdx_guest_ids); > static const struct tsm_ops tdx_tsm_ops = { > .name = KBUILD_MODNAME, > .report_new = tdx_report_new, > + .report_attr_visible = tdx_report_attr_visible, > + .report_bin_attr_visible = tdx_report_bin_attr_visible, > }; > > static int __init tdx_guest_init(void) > @@ -301,7 +328,7 @@ static int __init tdx_guest_init(void) > goto free_misc; > } > > - ret = tsm_register(&tdx_tsm_ops, NULL, NULL); > + ret = tsm_register(&tdx_tsm_ops, NULL); > if (ret) > goto free_quote; > > diff --git a/drivers/virt/coco/tsm.c b/drivers/virt/coco/tsm.c > index d1c2db83a8ca..dedb4f582630 100644 > --- a/drivers/virt/coco/tsm.c > +++ b/drivers/virt/coco/tsm.c > @@ -14,7 +14,6 @@ > > static struct tsm_provider { > const struct tsm_ops *ops; > - const struct config_item_type *type; > void *data; > } provider; > static DECLARE_RWSEM(tsm_rwsem); > @@ -252,34 +251,18 @@ static ssize_t tsm_report_auxblob_read(struct config_item *cfg, void *buf, > } > CONFIGFS_BIN_ATTR_RO(tsm_report_, auxblob, NULL, TSM_OUTBLOB_MAX); > > -#define TSM_DEFAULT_ATTRS() \ > - &tsm_report_attr_generation, \ > - &tsm_report_attr_provider > - > static struct configfs_attribute *tsm_report_attrs[] = { > - TSM_DEFAULT_ATTRS(), > + [TSM_REPORT_GENERATION] = &tsm_report_attr_generation, > + [TSM_REPORT_PROVIDER] = &tsm_report_attr_provider, > + [TSM_REPORT_PRIVLEVEL] = &tsm_report_attr_privlevel, > + [TSM_REPORT_PRIVLEVEL_FLOOR] = &tsm_report_attr_privlevel_floor, > NULL, > }; > > -static struct configfs_attribute *tsm_report_extra_attrs[] = { > - TSM_DEFAULT_ATTRS(), > - &tsm_report_attr_privlevel, > - &tsm_report_attr_privlevel_floor, > - NULL, > -}; > - > -#define TSM_DEFAULT_BIN_ATTRS() \ > - &tsm_report_attr_inblob, \ > - &tsm_report_attr_outblob > - > static struct configfs_bin_attribute *tsm_report_bin_attrs[] = { > - TSM_DEFAULT_BIN_ATTRS(), > - NULL, > -}; > - > -static struct configfs_bin_attribute *tsm_report_bin_extra_attrs[] = { > - TSM_DEFAULT_BIN_ATTRS(), > - &tsm_report_attr_auxblob, > + [TSM_REPORT_INBLOB] = &tsm_report_attr_inblob, > + [TSM_REPORT_OUTBLOB] = &tsm_report_attr_outblob, > + [TSM_REPORT_AUXBLOB] = &tsm_report_attr_auxblob, > NULL, > }; > > @@ -297,21 +280,12 @@ static struct configfs_item_operations tsm_report_item_ops = { > .release = tsm_report_item_release, > }; > > -const struct config_item_type tsm_report_default_type = { > +static const struct config_item_type tsm_report_type = { > .ct_owner = THIS_MODULE, > .ct_bin_attrs = tsm_report_bin_attrs, > .ct_attrs = tsm_report_attrs, > .ct_item_ops = &tsm_report_item_ops, > }; > -EXPORT_SYMBOL_GPL(tsm_report_default_type); > - > -const struct config_item_type tsm_report_extra_type = { > - .ct_owner = THIS_MODULE, > - .ct_bin_attrs = tsm_report_bin_extra_attrs, > - .ct_attrs = tsm_report_extra_attrs, > - .ct_item_ops = &tsm_report_item_ops, > -}; > -EXPORT_SYMBOL_GPL(tsm_report_extra_type); > > static struct config_item *tsm_report_make_item(struct config_group *group, > const char *name) > @@ -326,12 +300,40 @@ static struct config_item *tsm_report_make_item(struct config_group *group, > if (!state) > return ERR_PTR(-ENOMEM); > > - config_item_init_type_name(&state->cfg, name, provider.type); > + config_item_init_type_name(&state->cfg, name, &tsm_report_type); > return &state->cfg; > } > > +static bool tsm_report_is_visible(struct config_item *item, > + struct configfs_attribute *attr, int n) > +{ > + guard(rwsem_read)(&tsm_rwsem); > + if (!provider.ops) > + return false; > + > + if (!provider.ops->report_attr_visible) > + return true; > + > + return provider.ops->report_attr_visible(item, attr, n); > +} > + > +static bool tsm_report_is_bin_visible(struct config_item *item, > + struct configfs_bin_attribute *attr, int n) > +{ > + guard(rwsem_read)(&tsm_rwsem); > + if (!provider.ops) > + return false; > + > + if (!provider.ops->report_bin_attr_visible) > + return true; > + > + return provider.ops->report_bin_attr_visible(item, attr, n); > +} > + > static struct configfs_group_operations tsm_report_group_ops = { > .make_item = tsm_report_make_item, > + .is_visible = tsm_report_is_visible, > + .is_bin_visible = tsm_report_is_bin_visible, > }; > > static const struct config_item_type tsm_reports_type = { > @@ -353,16 +355,10 @@ static struct configfs_subsystem tsm_configfs = { > .su_mutex = __MUTEX_INITIALIZER(tsm_configfs.su_mutex), > }; > > -int tsm_register(const struct tsm_ops *ops, void *priv, > - const struct config_item_type *type) > +int tsm_register(const struct tsm_ops *ops, void *priv) > { > const struct tsm_ops *conflict; > > - if (!type) > - type = &tsm_report_default_type; > - if (!(type == &tsm_report_default_type || type == &tsm_report_extra_type)) > - return -EINVAL; > - > guard(rwsem_write)(&tsm_rwsem); > conflict = provider.ops; > if (conflict) { > @@ -372,7 +368,6 @@ int tsm_register(const struct tsm_ops *ops, void *priv, > > provider.ops = ops; > provider.data = priv; > - provider.type = type; > return 0; > } > EXPORT_SYMBOL_GPL(tsm_register); > @@ -384,7 +379,6 @@ int tsm_unregister(const struct tsm_ops *ops) > return -EBUSY; > provider.ops = NULL; > provider.data = NULL; > - provider.type = NULL; > return 0; > } > EXPORT_SYMBOL_GPL(tsm_unregister); > diff --git a/include/linux/tsm.h b/include/linux/tsm.h > index 50c5769657d8..fa19291a9854 100644 > --- a/include/linux/tsm.h > +++ b/include/linux/tsm.h > @@ -4,6 +4,7 @@ > > #include <linux/sizes.h> > #include <linux/types.h> > +#include <linux/configfs.h> > > #define TSM_INBLOB_MAX 64 > #define TSM_OUTBLOB_MAX SZ_32K > @@ -42,12 +43,40 @@ struct tsm_report { > u8 *auxblob; > }; > > +/** > + * enum tsm_attr_index - index used to reference report attributes > + * @TSM_REPORT_GENERATION: index of the report generation number attribute > + * @TSM_REPORT_PROVIDER: index of the provider name attribute > + * @TSM_REPORT_PRIVLEVEL: index of the desired privilege level attribute > + * @TSM_REPORT_PRIVLEVEL_FLOOR: index of the minimum allowed privileg level attribute
/s/privleg/privlege
> + */ > +enum tsm_attr_index { > + TSM_REPORT_GENERATION,
Do we need an index for the generation attribute ? Since it is a core function, we can allow it by default.
> + TSM_REPORT_PROVIDER,
Same as above.
> + TSM_REPORT_PRIVLEVEL, > + TSM_REPORT_PRIVLEVEL_FLOOR, > +}; > + > +/** > + * enum tsm_bin_attr_index - index used to reference binary report attributes > + * @TSM_REPORT_INBLOB: index of the binary report input attribute > + * @TSM_REPORT_OUTBLOB: index of the binary report output attribute > + * @TSM_REPORT_AUXBLOB: index of the binary auxiliary data attribute > + */ > +enum tsm_bin_attr_index { > + TSM_REPORT_INBLOB, > + TSM_REPORT_OUTBLOB, > + TSM_REPORT_AUXBLOB, > +};
Why differentiate between bin attr and regular attr? Why not use the same enum?
> + > /** > * struct tsm_ops - attributes and operations for tsm instances > * @name: tsm id reflected in /sys/kernel/config/tsm/report/$report/provider > * @privlevel_floor: convey base privlevel for nested scenarios > * @report_new: Populate @report with the report blob and auxblob > * (optional), return 0 on successful population, or -errno otherwise > + * @report_attr_visible: show or hide a report attribute entry > + * @report_bin_attr_visible: show or hide a report binary attribute entry > * > * Implementation specific ops, only one is expected to be registered at > * a time i.e. only one of "sev-guest", "tdx-guest", etc. > @@ -56,14 +85,12 @@ struct tsm_ops { > const char *name; > unsigned int privlevel_floor; > int (*report_new)(struct tsm_report *report, void *data); > + bool (*report_attr_visible)(struct config_item *item, > + struct configfs_attribute *attr, int n); > + bool (*report_bin_attr_visible)(struct config_item *item, > + struct configfs_bin_attribute *attr, int n);
I think we can use a single callback . We don't really gain anything with bin attr differentiation.
> }; > > -extern const struct config_item_type tsm_report_default_type; > - > -/* publish @privlevel, @privlevel_floor, and @auxblob attributes */ > -extern const struct config_item_type tsm_report_extra_type; > - > -int tsm_register(const struct tsm_ops *ops, void *priv, > - const struct config_item_type *type); > +int tsm_register(const struct tsm_ops *ops, void *priv); > int tsm_unregister(const struct tsm_ops *ops); > #endif /* __TSM_H */ > -- > 2.43.2 >
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