[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 6 of 9] x86/mm: New domctl: add a shared page to the physmap
>>> On 09.12.11 at 21:22, Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx> wrote: > This domctl is useful to, for example, populate parts of a domain's > physmap with shared frames, directly. As said before - there's no consumer of this new code within the series, and hence you're asking to add dead code. That's no appropriate imo. Jan > Signed-off-by: Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx> > > diff -r bfebf49b3eb6 -r bba44de8394a xen/arch/x86/mm/mem_sharing.c > --- a/xen/arch/x86/mm/mem_sharing.c > +++ b/xen/arch/x86/mm/mem_sharing.c > @@ -851,6 +851,74 @@ err_out: > return ret; > } > > +int mem_sharing_add_to_physmap(struct domain *sd, unsigned long sgfn, > shr_handle_t sh, > + struct domain *cd, unsigned long cgfn) > +{ > + struct page_info *spage; > + int ret = -EINVAL; > + mfn_t smfn, cmfn; > + p2m_type_t smfn_type, cmfn_type; > + struct gfn_info *gfn_info; > + struct p2m_domain *p2m = p2m_get_hostp2m(cd); > + p2m_access_t a; > + DECLARE_PG_LOCK_DATA(pld); > + > + /* XXX if sd == cd handle potential deadlock by ordering > + * the get_ and put_gfn's */ > + smfn = get_gfn_query(sd, sgfn, &smfn_type); > + cmfn = get_gfn_type_access(p2m, cgfn, &cmfn_type, &a, p2m_query, NULL); > + > + /* Get the source shared page, check and lock */ > + ret = XEN_DOMCTL_MEM_SHARING_S_HANDLE_INVALID; > + spage = __grab_shared_page(smfn, &pld); > + if ( spage == NULL ) > + goto err_out; > + ASSERT(smfn_type == p2m_ram_shared); > + > + /* Check that the handles match */ > + if ( spage->shared_info->handle != sh ) > + goto err_unlock; > + > + /* Make sure the target page is a hole in the physmap */ > + if ( mfn_valid(cmfn) || > + (!(p2m_is_ram(cmfn_type))) ) > + { > + ret = XEN_DOMCTL_MEM_SHARING_C_HANDLE_INVALID; > + goto err_unlock; > + } > + > + /* This is simpler than regular sharing */ > + BUG_ON(!get_page_and_type(spage, dom_cow, PGT_shared_page)); > + if ( (gfn_info = mem_sharing_gfn_alloc(spage, cd, cgfn)) == NULL ) > + { > + put_page_and_type(spage); > + ret = -ENOMEM; > + goto err_unlock; > + } > + > + p2m_lock(p2m); > + ret = set_p2m_entry(p2m, cgfn, smfn, PAGE_ORDER_4K, p2m_ram_shared, a); > + p2m_unlock(p2m); > + > + /* Tempted to turn this into an assert */ > + if ( !ret ) { > + ret = -ENOENT; > + mem_sharing_gfn_destroy(gfn_info, 0); > + put_page_and_type(spage); > + } else { > + atomic_inc(&cd->shr_pages); > + atomic_inc(&nr_shared_mfns); > + ret = 0; > + } > + > +err_unlock: > + mem_sharing_page_unlock(spage, &pld); > +err_out: > + put_gfn(cd, cgfn); > + put_gfn(sd, sgfn); > + return ret; > +} > + > int mem_sharing_unshare_page(struct domain *d, > unsigned long gfn, > uint16_t flags) > @@ -1085,6 +1153,42 @@ int mem_sharing_domctl(struct domain *d, > } > break; > > + case XEN_DOMCTL_MEM_EVENT_OP_SHARING_ADD_PHYSMAP: > + { > + unsigned long sgfn, cgfn; > + struct domain *cd; > + shr_handle_t sh; > + > + 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) ) > + { > + put_domain(cd); > + return -EINVAL; > + } > + > + if ( > XEN_DOMCTL_MEM_SHARING_FIELD_IS_GREF(mec->u.share.source_gfn) ) > + { > + /* Cannot add a gref to the physmap */ > + put_domain(cd); > + return -EINVAL; > + } > + > + sgfn = mec->u.share.source_gfn; > + sh = mec->u.share.source_handle; > + cgfn = mec->u.share.client_gfn; > + > + rc = mem_sharing_add_to_physmap(d, sgfn, sh, cd, cgfn); > + > + put_domain(cd); > + } > + break; > + > case XEN_DOMCTL_MEM_EVENT_OP_SHARING_RESUME: > { > if ( !mem_sharing_enabled(d) ) > diff -r bfebf49b3eb6 -r bba44de8394a xen/include/public/domctl.h > --- a/xen/include/public/domctl.h > +++ b/xen/include/public/domctl.h > @@ -771,6 +771,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_mem_e > #define XEN_DOMCTL_MEM_EVENT_OP_SHARING_DEBUG_GFN 5 > #define XEN_DOMCTL_MEM_EVENT_OP_SHARING_DEBUG_MFN 6 > #define XEN_DOMCTL_MEM_EVENT_OP_SHARING_DEBUG_GREF 7 > +#define XEN_DOMCTL_MEM_EVENT_OP_SHARING_ADD_PHYSMAP 8 > > #define XEN_DOMCTL_MEM_SHARING_S_HANDLE_INVALID (-10) > #define XEN_DOMCTL_MEM_SHARING_C_HANDLE_INVALID (-9) > @@ -797,7 +798,7 @@ struct xen_domctl_mem_sharing_op { > } u; > uint64_aligned_t handle; /* OUT: the handle */ > } nominate; > - struct mem_sharing_op_share { /* OP_SHARE */ > + struct mem_sharing_op_share { /* OP_SHARE/ADD_PHYSMAP */ > uint64_aligned_t source_gfn; /* IN: the gfn of the source > page */ > uint64_aligned_t source_handle; /* IN: handle to the source > page */ > uint64_aligned_t client_domain; /* IN: the client domain id */ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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