From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752871Ab1LILdd (ORCPT ); Fri, 9 Dec 2011 06:33:33 -0500 Received: from acsinet15.oracle.com ([141.146.126.227]:52944 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751065Ab1LILdc (ORCPT ); Fri, 9 Dec 2011 06:33:32 -0500 From: annie.li@oracle.com To: xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, konrad.wilk@oracle.com, jeremy@goop.org, paul.durrant@citrix.com, Ian.Campbell@citrix.com, annie.li@oracle.com Cc: kurt.hackel@oracle.com Subject: [PATCH V3 2/2] xen/granttable: Support transitive grants Date: Fri, 9 Dec 2011 19:33:24 +0800 Message-Id: <1323430404-5540-1-git-send-email-annie.li@oracle.com> X-Mailer: git-send-email 1.7.6.4 In-Reply-To: <1323430321-5465-1-git-send-email-annie.li@oracle.com> References: <1323430321-5465-1-git-send-email-annie.li@oracle.com> X-Source-IP: ucsinet21.oracle.com [156.151.31.93] X-CT-RefId: str=0001.0A090207.4EE1F208.0090,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These allow a domain A which has been granted access on a page of domain B's memory to issue domain C with a copy-grant on the same page. This is useful e.g. for forwarding packets between domains. Signed-off-by: Annie Li --- drivers/xen/grant-table.c | 70 +++++++++++++++++++++++++++++++++++++++++++++ include/xen/grant_table.h | 12 ++++++++ 2 files changed, 82 insertions(+), 0 deletions(-) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 0ac16fa..7835ffc 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -130,6 +130,18 @@ struct gnttab_ops { */ void (*update_subpage_entry)(grant_ref_t, domid_t, unsigned long, int, unsigned, unsigned); + /* + * Redirect an available grant entry on domain A to another grant + * reference of domain B, then allow domain C to use grant reference + * of domain B transitively. First parameter is an available grant entry + * reference on domain A, second one is id of domain C which accesses + * grant entry transitively, third one is grant type and flag + * information, forth one is id of domain B whose grant entry is finally + * accessed transitively, last one is grant entry transitive reference + * of domain B. + */ + void (*update_trans_entry)(grant_ref_t, domid_t, int, domid_t, + grant_ref_t); }; static struct gnttab_ops *gnttab_interface; @@ -331,6 +343,63 @@ bool gnttab_subpage_grants_available(void) } EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available); +void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid, + int flags, domid_t trans_domid, + grant_ref_t trans_gref) +{ + gnttab_shared.v2[ref].transitive.trans_domid = trans_domid; + gnttab_shared.v2[ref].transitive.gref = trans_gref; + gnttab_shared.v2[ref].hdr.domid = domid; + wmb(); + gnttab_shared.v2[ref].hdr.flags = + GTF_permit_access | GTF_transitive | flags; +} + +int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, + int flags, domid_t trans_domid, + grant_ref_t trans_gref) +{ + if (flags & (GTF_accept_transfer | GTF_reading | + GTF_writing | GTF_sub_page)) + return -EPERM; + + if (gnttab_interface->update_trans_entry == NULL) + return -ENOSYS; + + gnttab_interface->update_trans_entry(ref, domid, flags, trans_domid, + trans_gref); + + return 0; +} +EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans_ref); + +int gnttab_grant_foreign_access_trans(domid_t domid, int flags, + domid_t trans_domid, + grant_ref_t trans_gref) +{ + int ref, rc; + + ref = get_free_entries(1); + if (unlikely(ref < 0)) + return -ENOSPC; + + rc = gnttab_grant_foreign_access_trans_ref(ref, domid, flags, + trans_domid, trans_gref); + if (rc < 0) { + put_free_entry(ref); + return rc; + } + + return ref; +} +EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans); + +bool gnttab_trans_grants_available(void) +{ + return gnttab_interface->update_trans_entry != NULL; +} +EXPORT_SYMBOL_GPL(gnttab_trans_grants_available); + static int gnttab_query_foreign_access_v1(grant_ref_t ref) { return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); @@ -884,6 +953,7 @@ static struct gnttab_ops gnttab_v2_ops = { .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, .query_foreign_access = gnttab_query_foreign_access_v2, .update_subpage_entry = gnttab_update_subpage_entry_v2, + .update_trans_entry = gnttab_update_trans_entry_v2, }; static void gnttab_request_version(void) diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 2b492b9..f1e17b7 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -65,6 +65,9 @@ int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, int flags, unsigned page_off, unsigned length); +int gnttab_grant_foreign_access_trans(domid_t domid, int flags, + domid_t trans_domid, + grant_ref_t trans_gref); /* * Are sub-page grants available on this version of Xen? Returns true if they @@ -73,6 +76,12 @@ int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, bool gnttab_subpage_grants_available(void); /* + * Are transitive grants available on this version of Xen? Returns true if they + * are, and false if they're not. + */ +bool gnttab_trans_grants_available(void); + +/* * End access through the given grant reference, iff the grant entry is no * longer in use. Return 1 if the grant entry was freed, 0 if it is still in * use. @@ -121,6 +130,9 @@ int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, unsigned long frame, int flags, unsigned page_off, unsigned length); +int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, + int flags, domid_t trans_domid, + grant_ref_t trans_gref); void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, unsigned long pfn); -- 1.7.6.4