From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andres Lagar-Cavilla Subject: [PATCH 02 of 12] x86/mm: Update mem sharing interface to (re)allow sharing of grants Date: Sun, 15 Jan 2012 21:56:22 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: ian.campbell@citrix.com, andres@gridcentric.ca, tim@xen.org, keir.xen@gmail.com, JBeulich@suse.com, ian.jackson@citrix.com, adin@gridcentric.ca List-Id: xen-devel@lists.xenproject.org xen/arch/x86/mm/mem_sharing.c | 57 ++++++++++++++++++++++++++++++++++++------ xen/include/public/domctl.h | 9 ++++++ 2 files changed, 57 insertions(+), 9 deletions(-) Previosuly, the mem sharing code would return an opaque handle to index shared pages (and nominees) in its global hash table. By removing the hash table, the new interfaces requires a gfn and a version. However, when sharing grants, the caller provides a grant ref and a version. Update interface to handle this case. Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Adin Scannell diff -r 2a4112172e44 -r e0d8333e4725 xen/arch/x86/mm/mem_sharing.c --- a/xen/arch/x86/mm/mem_sharing.c +++ b/xen/arch/x86/mm/mem_sharing.c @@ -733,18 +733,57 @@ int mem_sharing_domctl(struct domain *d, case XEN_DOMCTL_MEM_EVENT_OP_SHARING_SHARE: { - unsigned long sgfn = mec->u.share.source_gfn; - shr_handle_t sh = mec->u.share.source_handle; - struct domain *cd = get_domain_by_id(mec->u.share.client_domain); - if ( cd ) + unsigned long sgfn, cgfn; + struct domain *cd; + shr_handle_t sh, ch; + + if ( !mem_sharing_enabled(d) ) + return -EINVAL; + + cd = get_domain_by_id(mec->u.share.client_domain); + if ( !cd ) + return -ESRCH; + + if ( !mem_sharing_enabled(cd) ) { - unsigned long cgfn = mec->u.share.client_gfn; - shr_handle_t ch = mec->u.share.client_handle; - rc = mem_sharing_share_pages(d, sgfn, sh, cd, cgfn, ch); put_domain(cd); + return -EINVAL; } - else - return -EEXIST; + + if ( XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF(mec->u.share.source_gfn) ) + { + grant_ref_t gref = (grant_ref_t) + (XEN_DOMCTL_MEM_SHARING_FIELD_GET_GREF( + mec->u.share.source_gfn)); + if ( mem_sharing_gref_to_gfn(d, gref, &sgfn) < 0 ) + { + put_domain(cd); + return -EINVAL; + } + } else { + sgfn = mec->u.share.source_gfn; + } + + if ( XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF(mec->u.share.client_gfn) ) + { + grant_ref_t gref = (grant_ref_t) + (XEN_DOMCTL_MEM_SHARING_FIELD_GET_GREF( + mec->u.share.client_gfn)); + if ( mem_sharing_gref_to_gfn(cd, gref, &cgfn) < 0 ) + { + put_domain(cd); + return -EINVAL; + } + } else { + cgfn = mec->u.share.client_gfn; + } + + sh = mec->u.share.source_handle; + ch = mec->u.share.client_handle; + + rc = mem_sharing_share_pages(d, sgfn, sh, cd, cgfn, ch); + + put_domain(cd); } break; diff -r 2a4112172e44 -r e0d8333e4725 xen/include/public/domctl.h --- a/xen/include/public/domctl.h +++ b/xen/include/public/domctl.h @@ -775,6 +775,15 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_mem_e #define XEN_DOMCTL_MEM_SHARING_S_HANDLE_INVALID (-10) #define XEN_DOMCTL_MEM_SHARING_C_HANDLE_INVALID (-9) +#define XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF_FLAG (1ULL << 62) + +#define XEN_DOMCTL_MEM_SHARING_FIELD_MAKE_GREF(field, val) \ + (field) = (XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF_FLAG | val) +#define XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF(field) \ + ((field) & XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF_FLAG) +#define XEN_DOMCTL_MEM_SHARING_FIELD_GET_GREF(field) \ + ((field) & (~XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF_FLAG)) + struct xen_domctl_mem_sharing_op { uint8_t op; /* XEN_DOMCTL_MEM_EVENT_OP_* */