On Fri, 2018-09-07 at 15:36 -0700, Alison Schofield wrote:
> Define a global mapping structure to track the mapping of userspace
> keys to hardware keyids in MKTME (Multi-Key Total Memory Encryption).
> This data will be used for the memory encryption system call and the
> kernel key service API.
This is also for earlier patches. I kind of feel uncomfortable because
I can neither TME nor MKTME how they reside in the chipset/board. Are
they inside the CPU package? Or is it perhaps a separate chip outside
the CPU? I would guess not but the problem is that I have to guess in
the first place.
> Implement helper functions to access this mapping structure and make
> them visible to the MKTME Kernel Key Service: security/keys/mktme_keys
>
> Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
> ---
> arch/x86/include/asm/mktme.h | 11 ++++++
> arch/x86/mm/mktme.c | 85
> ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 96 insertions(+)
>
> diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
> index dbfbd955da98..f6acd551457f 100644
> --- a/arch/x86/include/asm/mktme.h
> +++ b/arch/x86/include/asm/mktme.h
> @@ -13,6 +13,17 @@ extern phys_addr_t mktme_keyid_mask;
> extern int mktme_nr_keyids;
> extern int mktme_keyid_shift;
>
> +/* Manage mappings between hardware keyids and userspace keys */
> +extern int mktme_map_alloc(void);
> +extern void mktme_map_free(void);
> +extern void mktme_map_lock(void);
> +extern void mktme_map_unlock(void);
> +extern int mktme_map_get_free_keyid(void);
> +extern void mktme_map_clear_keyid(int keyid);
> +extern void mktme_map_set_keyid(int keyid, unsigned int serial);
> +extern int mktme_map_keyid_from_serial(unsigned int serial);
> +extern unsigned int mktme_map_serial_from_keyid(int keyid);
> +
> extern struct page_ext_operations page_mktme_ops;
>
> #define page_keyid page_keyid
> diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
> index 660caf6a5ce1..5246d8323359 100644
> --- a/arch/x86/mm/mktme.c
> +++ b/arch/x86/mm/mktme.c
> @@ -63,6 +63,91 @@ int vma_keyid(struct vm_area_struct *vma)
> return (prot & mktme_keyid_mask) >> mktme_keyid_shift;
> }
>
> +/*
> + * struct mktme_mapping and the mktme_map_* functions manage the mapping
> + * of userspace keys to hardware keyids in MKTME. They are used by the
> + * the encrypt_mprotect system call and the MKTME Key Service API.
> + */
> +struct mktme_mapping {
> + struct mutex lock; /* protect this map & HW
> state */
> + unsigned int mapped_keyids;
> + unsigned int serial[];
> +};
> +
> +struct mktme_mapping *mktme_map;
> +
> +static inline long mktme_map_size(void)
> +{
> + long size = 0;
> +
> + size += sizeof(mktme_map);
> + size += sizeof(mktme_map->serial[0]) * mktme_nr_keyids;
> + return size;
> +}
> +
> +int mktme_map_alloc(void)
> +{
> + mktme_map = kzalloc(mktme_map_size(), GFP_KERNEL);
> + if (!mktme_map)
> + return 0;
> + mutex_init(&mktme_map->lock);
> + return 1;
> +}
> +
> +void mktme_map_free(void)
> +{
> + kfree(mktme_map);
> +}
> +
> +void mktme_map_lock(void)
> +{
> + mutex_lock(&mktme_map->lock);
> +}
> +
> +void mktme_map_unlock(void)
> +{
> + mutex_unlock(&mktme_map->lock);
> +}
> +
> +void mktme_map_set_keyid(int keyid, unsigned int serial)
> +{
> + mktme_map->serial[keyid] = serial;
> + mktme_map->mapped_keyids++;
> +}
> +
> +void mktme_map_clear_keyid(int keyid)
> +{
> + mktme_map->serial[keyid] = 0;
> + mktme_map->mapped_keyids--;
> +}
> +
> +unsigned int mktme_map_serial_from_keyid(int keyid)
> +{
> + return mktme_map->serial[keyid];
> +}
> +
> +int mktme_map_keyid_from_serial(unsigned int serial)
> +{
> + int i;
> +
> + for (i = 1; i < mktme_nr_keyids; i++)
> + if (mktme_map->serial[i] == serial)
> + return i;
> + return 0;
> +}
> +
> +int mktme_map_get_free_keyid(void)
> +{
> + int i;
> +
> + if (mktme_map->mapped_keyids < mktme_nr_keyids) {
> + for (i = 1; i < mktme_nr_keyids; i++)
> + if (mktme_map->serial[i] == 0)
> + return i;
> + }
> + return 0;
> +}
The kdoc header is missing from all above.
/Jarkko
