[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [Xen-devel] [PATCH 6/6] Change MMU_PT_UPDATE_RESERVE_AD to support update page table for foreign domain
Keir, this is the updated version, please have a look on it. Thanks Yunhong Jiang Currently MMU_PT_UPDATE_RESERVE_AD support only update page table for current domain. This patch add support for foreign domain also. Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx> diff -r 9a74617c4a28 xen/arch/x86/mm.c --- a/xen/arch/x86/mm.c Tue Jun 30 01:44:30 2009 +0800 +++ b/xen/arch/x86/mm.c Tue Jun 30 01:51:15 2009 +0800 @@ -110,6 +110,7 @@ #include <asm/hypercall.h> #include <asm/shared.h> #include <public/memory.h> +#include <public/sched.h> #include <xsm/xsm.h> #include <xen/trace.h> @@ -2999,8 +3000,9 @@ int do_mmu_update( unsigned long gpfn, gmfn, mfn; struct page_info *page; int rc = 0, okay = 1, i = 0; - unsigned int cmd, done = 0; - struct domain *d = current->domain; + unsigned int cmd, done = 0, pt_dom; + struct domain *d = current->domain, *pt_owner = NULL; + struct vcpu *v = current; struct domain_mmap_cache mapcache; if ( unlikely(count & MMU_UPDATE_PREEMPTED) ) @@ -3018,7 +3020,28 @@ int do_mmu_update( goto out; } - if ( !set_foreigndom(foreigndom) ) + pt_dom = foreigndom >> 16; + if (pt_dom) + { + /* the page table belongs to foreign domain */ + pt_owner = rcu_lock_domain_by_id(pt_dom - 1); + if (!pt_owner ) + { + rc = -EINVAL; + goto out; + } + if( !IS_PRIV_FOR(d, pt_owner) ) + { + rc = -ESRCH; + goto out; + } + if (pt_dom == d) + rcu_unlock_domain(pt_owner); + v = pt_owner->vcpu[0]; + } else + pt_owner = d; + + if ( !set_foreigndom(foreigndom & 0xFFFFU) ) { rc = -ESRCH; goto out; @@ -3059,9 +3082,9 @@ int do_mmu_update( req.ptr -= cmd; gmfn = req.ptr >> PAGE_SHIFT; - mfn = gmfn_to_mfn(d, gmfn); - - if ( unlikely(!get_page_from_pagenr(mfn, d)) ) + mfn = gmfn_to_mfn(pt_owner, gmfn); + + if ( unlikely(!get_page_from_pagenr(mfn, pt_owner)) ) { MEM_LOG("Could not get page for normal update"); break; @@ -3080,24 +3103,21 @@ int do_mmu_update( { l1_pgentry_t l1e = l1e_from_intpte(req.val); okay = mod_l1_entry(va, l1e, mfn, - cmd == MMU_PT_UPDATE_PRESERVE_AD, - current); + cmd == MMU_PT_UPDATE_PRESERVE_AD, v); } break; case PGT_l2_page_table: { l2_pgentry_t l2e = l2e_from_intpte(req.val); okay = mod_l2_entry(va, l2e, mfn, - cmd == MMU_PT_UPDATE_PRESERVE_AD, - current); + cmd == MMU_PT_UPDATE_PRESERVE_AD, v); } break; case PGT_l3_page_table: { l3_pgentry_t l3e = l3e_from_intpte(req.val); rc = mod_l3_entry(va, l3e, mfn, - cmd == MMU_PT_UPDATE_PRESERVE_AD, 1, - current); + cmd == MMU_PT_UPDATE_PRESERVE_AD, 1, v); okay = !rc; } break; @@ -3106,8 +3126,7 @@ int do_mmu_update( { l4_pgentry_t l4e = l4e_from_intpte(req.val); rc = mod_l4_entry(va, l4e, mfn, - cmd == MMU_PT_UPDATE_PRESERVE_AD, 1, - current); + cmd == MMU_PT_UPDATE_PRESERVE_AD, 1, v); okay = !rc; } break; @@ -3115,7 +3134,7 @@ int do_mmu_update( case PGT_writable_page: perfc_incr(writable_mmu_updates); okay = paging_write_guest_entry( - current, va, req.val, _mfn(mfn)); + v, va, req.val, _mfn(mfn)); break; } page_unlock(page); @@ -3126,7 +3145,7 @@ int do_mmu_update( { perfc_incr(writable_mmu_updates); okay = paging_write_guest_entry( - current, va, req.val, _mfn(mfn)); + v, va, req.val, _mfn(mfn)); put_page_type(page); } @@ -3191,6 +3210,9 @@ int do_mmu_update( perfc_add(num_page_updates, i); out: + if (pt_owner && (pt_owner != d)) + rcu_unlock_domain(pt_owner); + /* Add incremental work we have done to the @done output parameter. */ if ( unlikely(!guest_handle_is_null(pdone)) ) { diff -r 9a74617c4a28 xen/include/public/xen.h --- a/xen/include/public/xen.h Tue Jun 30 01:44:30 2009 +0800 +++ b/xen/include/public/xen.h Tue Jun 30 01:44:33 2009 +0800 @@ -166,10 +166,14 @@ DEFINE_XEN_GUEST_HANDLE(xen_pfn_t); * ptr[1:0] specifies the appropriate MMU_* command. * * ptr[1:0] == MMU_NORMAL_PT_UPDATE: - * Updates an entry in a page table. If updating an L1 table, and the new + * Updates an entry in a page table. + * The page table can be owned by current domain, or a foreign domain. If + * the page table belongs to a foreign domain, it should be specified in + * upper 16 bits in FD + * If updating an L1 table, and the new * table entry is valid/present, the mapped frame must belong to the FD, if - * an FD has been specified. If attempting to map an I/O page then the - * caller assumes the privilege of the FD. + * an foreign domain specified in lower 16 btis in FD. If attempting to map + * an I/O page then the caller assumes the privilege of the FD. * FD == DOMID_IO: Permit /only/ I/O mappings, at the priv level of the caller. * FD == DOMID_XEN: Map restricted areas of Xen's heap space. * ptr[:2] -- Machine address of the page-table entry to modify. Keir Fraser wrote: > On 01/06/2009 10:35, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx> wrote: > >> I think I missed this logic, I just make sure the domain is >> suspended, but seems be wrong because a suspended domain can still >> be killed and relinquish resources. So I will add this logic and >> resend the patch. >> >> But I'm not sure if we need make sure the guest is suspended/paused >> during these functions, as exchange a page or pte in flight may >> cause trouble. Or we can leave it to user space tools, since this >> situation will not damage xen HV itself. > > The HV should not bother to do the suspend check. It is a higher-level > problem which should be checked by the tools. > > -- Keir Attachment:
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