diff options
Diffstat (limited to 'include/xen/interface/grant_table.h')
| -rw-r--r-- | include/xen/interface/grant_table.h | 167 |
1 files changed, 162 insertions, 5 deletions
diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h index 39e571796e32..a17d84433e6a 100644 --- a/include/xen/interface/grant_table.h +++ b/include/xen/interface/grant_table.h @@ -85,12 +85,22 @@ */ /* + * Reference to a grant entry in a specified domain's grant table. + */ +typedef uint32_t grant_ref_t; + +/* * A grant table comprises a packed array of grant entries in one or more * page frames shared between Xen and a guest. * [XEN]: This field is written by Xen and read by the sharing guest. * [GST]: This field is written by the guest and read by Xen. */ -struct grant_entry { + +/* + * Version 1 of the grant table entry structure is maintained purely + * for backwards compatibility. New guests should use version 2. + */ +struct grant_entry_v1 { /* GTF_xxx: various type and flag information. [XEN,GST] */ uint16_t flags; /* The domain being granted foreign privileges. [GST] */ @@ -108,10 +118,13 @@ struct grant_entry { * GTF_permit_access: Allow @domid to map/access @frame. * GTF_accept_transfer: Allow @domid to transfer ownership of one page frame * to this guest. Xen writes the page number to @frame. + * GTF_transitive: Allow @domid to transitively access a subrange of + * @trans_grant in @trans_domid. No mappings are allowed. */ #define GTF_invalid (0U<<0) #define GTF_permit_access (1U<<0) #define GTF_accept_transfer (2U<<0) +#define GTF_transitive (3U<<0) #define GTF_type_mask (3U<<0) /* @@ -119,6 +132,9 @@ struct grant_entry { * GTF_readonly: Restrict @domid to read-only mappings and accesses. [GST] * GTF_reading: Grant entry is currently mapped for reading by @domid. [XEN] * GTF_writing: Grant entry is currently mapped for writing by @domid. [XEN] + * GTF_sub_page: Grant access to only a subrange of the page. @domid + * will only be allowed to copy from the grant, and not + * map it. [GST] */ #define _GTF_readonly (2) #define GTF_readonly (1U<<_GTF_readonly) @@ -126,6 +142,8 @@ struct grant_entry { #define GTF_reading (1U<<_GTF_reading) #define _GTF_writing (4) #define GTF_writing (1U<<_GTF_writing) +#define _GTF_sub_page (8) +#define GTF_sub_page (1U<<_GTF_sub_page) /* * Subflags for GTF_accept_transfer: @@ -142,15 +160,81 @@ struct grant_entry { #define _GTF_transfer_completed (3) #define GTF_transfer_completed (1U<<_GTF_transfer_completed) +/* + * Version 2 grant table entries. These fulfil the same role as + * version 1 entries, but can represent more complicated operations. + * Any given domain will have either a version 1 or a version 2 table, + * and every entry in the table will be the same version. + * + * The interface by which domains use grant references does not depend + * on the grant table version in use by the other domain. + */ -/*********************************** - * GRANT TABLE QUERIES AND USES +/* + * Version 1 and version 2 grant entries share a common prefix. The + * fields of the prefix are documented as part of struct + * grant_entry_v1. */ +struct grant_entry_header { + uint16_t flags; + domid_t domid; +}; /* - * Reference to a grant entry in a specified domain's grant table. + * Version 2 of the grant entry structure, here is an union because three + * different types are suppotted: full_page, sub_page and transitive. + */ +union grant_entry_v2 { + struct grant_entry_header hdr; + + /* + * This member is used for V1-style full page grants, where either: + * + * -- hdr.type is GTF_accept_transfer, or + * -- hdr.type is GTF_permit_access and GTF_sub_page is not set. + * + * In that case, the frame field has the same semantics as the + * field of the same name in the V1 entry structure. + */ + struct { + struct grant_entry_header hdr; + uint32_t pad0; + uint64_t frame; + } full_page; + + /* + * If the grant type is GTF_grant_access and GTF_sub_page is set, + * @domid is allowed to access bytes [@page_off,@page_off+@length) + * in frame @frame. + */ + struct { + struct grant_entry_header hdr; + uint16_t page_off; + uint16_t length; + uint64_t frame; + } sub_page; + + /* + * If the grant is GTF_transitive, @domid is allowed to use the + * grant @gref in domain @trans_domid, as if it was the local + * domain. Obviously, the transitive access must be compatible + * with the original grant. + */ + struct { + struct grant_entry_header hdr; + domid_t trans_domid; + uint16_t pad0; + grant_ref_t gref; + } transitive; + + uint32_t __spacer[4]; /* Pad to a power of two */ +}; + +typedef uint16_t grant_status_t; + +/*********************************** + * GRANT TABLE QUERIES AND USES */ -typedef uint32_t grant_ref_t; /* * Handle to track a mapping created via a grant reference. @@ -322,6 +406,79 @@ struct gnttab_query_size { DEFINE_GUEST_HANDLE_STRUCT(gnttab_query_size); /* + * GNTTABOP_unmap_and_replace: Destroy one or more grant-reference mappings + * tracked by <handle> but atomically replace the page table entry with one + * pointing to the machine address under <new_addr>. <new_addr> will be + * redirected to the null entry. + * NOTES: + * 1. The call may fail in an undefined manner if either mapping is not + * tracked by <handle>. + * 2. After executing a batch of unmaps, it is guaranteed that no stale + * mappings will remain in the device or host TLBs. + */ +#define GNTTABOP_unmap_and_replace 7 +struct gnttab_unmap_and_replace { + /* IN parameters. */ + uint64_t host_addr; + uint64_t new_addr; + grant_handle_t handle; + /* OUT parameters. */ + int16_t status; /* GNTST_* */ +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_unmap_and_replace); + +/* + * GNTTABOP_set_version: Request a particular version of the grant + * table shared table structure. This operation can only be performed + * once in any given domain. It must be performed before any grants + * are activated; otherwise, the domain will be stuck with version 1. + * The only defined versions are 1 and 2. + */ +#define GNTTABOP_set_version 8 +struct gnttab_set_version { + /* IN parameters */ + uint32_t version; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_set_version); + +/* + * GNTTABOP_get_status_frames: Get the list of frames used to store grant + * status for <dom>. In grant format version 2, the status is separated + * from the other shared grant fields to allow more efficient synchronization + * using barriers instead of atomic cmpexch operations. + * <nr_frames> specify the size of vector <frame_list>. + * The frame addresses are returned in the <frame_list>. + * Only <nr_frames> addresses are returned, even if the table is larger. + * NOTES: + * 1. <dom> may be specified as DOMID_SELF. + * 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF. + */ +#define GNTTABOP_get_status_frames 9 +struct gnttab_get_status_frames { + /* IN parameters. */ + uint32_t nr_frames; + domid_t dom; + /* OUT parameters. */ + int16_t status; /* GNTST_* */ + GUEST_HANDLE(uint64_t) frame_list; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_status_frames); + +/* + * GNTTABOP_get_version: Get the grant table version which is in + * effect for domain <dom>. + */ +#define GNTTABOP_get_version 10 +struct gnttab_get_version { + /* IN parameters */ + domid_t dom; + uint16_t pad; + /* OUT parameters */ + uint32_t version; +}; +DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_version); + +/* * Bitfield values for update_pin_status.flags. */ /* Map the grant entry for access by I/O devices. */ |