x86/shadow: account for ioreq server pages before complaining about not found mapping prepare_ring_for_helper(), just like share_xen_page_with_guest(), takes a write reference on the page, and hence should similarly be accounted for when determining whether to log a complaint. This requires using recursive locking for the ioreq server lock, as the offending invocation of sh_remove_all_mappings() is down the call stack from hvm_set_ioreq_server_state(). (While not strictly needed to be done in all other instances too, convert all of them for consistency.) At once improve the usefulness of the shadow error message: Log all values involved in triggering it as well as the GFN (to aid understanding which guest page it is that there is a problem with - in cases like the one here the GFN is invariant across invocations, while the MFN obviously can [and will] vary). Signed-off-by: Jan Beulich --- a/xen/arch/x86/hvm/ioreq.c +++ b/xen/arch/x86/hvm/ioreq.c @@ -240,6 +240,30 @@ static int hvm_map_ioreq_page( return 0; } +bool_t is_ioreq_server_page(struct domain *d, const struct page_info *page) +{ + const struct hvm_ioreq_server *s; + bool_t found = 0; + + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); + + list_for_each_entry ( s, + &d->arch.hvm_domain.ioreq_server.list, + list_entry ) + { + if ( (s->ioreq.va && s->ioreq.page == page) || + (s->bufioreq.va && s->bufioreq.page == page) ) + { + found = 1; + break; + } + } + + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); + + return found; +} + static void hvm_remove_ioreq_gmfn( struct domain *d, struct hvm_ioreq_page *iorp) { @@ -671,7 +695,7 @@ int hvm_create_ioreq_server(struct domai goto fail1; domain_pause(d); - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); rc = -EEXIST; if ( is_default && d->arch.hvm_domain.default_ioreq_server != NULL ) @@ -694,14 +718,14 @@ int hvm_create_ioreq_server(struct domai if ( id ) *id = s->id; - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); domain_unpause(d); return 0; fail3: fail2: - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); domain_unpause(d); xfree(s); @@ -714,7 +738,7 @@ int hvm_destroy_ioreq_server(struct doma struct hvm_ioreq_server *s; int rc; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); rc = -ENOENT; list_for_each_entry ( s, @@ -743,7 +767,7 @@ int hvm_destroy_ioreq_server(struct doma break; } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } @@ -756,7 +780,7 @@ int hvm_get_ioreq_server_info(struct dom struct hvm_ioreq_server *s; int rc; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); rc = -ENOENT; list_for_each_entry ( s, @@ -781,7 +805,7 @@ int hvm_get_ioreq_server_info(struct dom break; } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } @@ -793,7 +817,7 @@ int hvm_map_io_range_to_ioreq_server(str struct hvm_ioreq_server *s; int rc; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); rc = -ENOENT; list_for_each_entry ( s, @@ -833,7 +857,7 @@ int hvm_map_io_range_to_ioreq_server(str } } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } @@ -845,7 +869,7 @@ int hvm_unmap_io_range_from_ioreq_server struct hvm_ioreq_server *s; int rc; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); rc = -ENOENT; list_for_each_entry ( s, @@ -885,7 +909,7 @@ int hvm_unmap_io_range_from_ioreq_server } } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } @@ -896,7 +920,7 @@ int hvm_set_ioreq_server_state(struct do struct list_head *entry; int rc; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); rc = -ENOENT; list_for_each ( entry, @@ -925,7 +949,7 @@ int hvm_set_ioreq_server_state(struct do break; } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } @@ -934,7 +958,7 @@ int hvm_all_ioreq_servers_add_vcpu(struc struct hvm_ioreq_server *s; int rc; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); list_for_each_entry ( s, &d->arch.hvm_domain.ioreq_server.list, @@ -947,7 +971,7 @@ int hvm_all_ioreq_servers_add_vcpu(struc goto fail; } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return 0; @@ -957,7 +981,7 @@ int hvm_all_ioreq_servers_add_vcpu(struc list_entry ) hvm_ioreq_server_remove_vcpu(s, v); - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } @@ -966,21 +990,21 @@ void hvm_all_ioreq_servers_remove_vcpu(s { struct hvm_ioreq_server *s; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); list_for_each_entry ( s, &d->arch.hvm_domain.ioreq_server.list, list_entry ) hvm_ioreq_server_remove_vcpu(s, v); - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); } void hvm_destroy_all_ioreq_servers(struct domain *d) { struct hvm_ioreq_server *s, *next; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); /* No need to domain_pause() as the domain is being torn down */ @@ -1003,7 +1027,7 @@ void hvm_destroy_all_ioreq_servers(struc xfree(s); } - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); } static int hvm_replace_event_channel(struct vcpu *v, domid_t remote_domid, @@ -1027,7 +1051,7 @@ int hvm_set_dm_domain(struct domain *d, struct hvm_ioreq_server *s; int rc = 0; - spin_lock(&d->arch.hvm_domain.ioreq_server.lock); + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); /* * Lack of ioreq server is not a failure. HVM_PARAM_DM_DOMAIN will @@ -1076,7 +1100,7 @@ int hvm_set_dm_domain(struct domain *d, domain_unpause(d); done: - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); return rc; } --- a/xen/arch/x86/mm/shadow/common.c +++ b/xen/arch/x86/mm/shadow/common.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include "private.h" @@ -2591,7 +2592,8 @@ int sh_remove_write_access_from_sl1p(str /* Remove all mappings of a guest frame from the shadow tables. * Returns non-zero if we need to flush TLBs. */ -static int sh_remove_all_mappings(struct domain *d, mfn_t gmfn) +static int sh_remove_all_mappings(struct domain *d, mfn_t gmfn, + unsigned long gfn) { struct page_info *page = mfn_to_page(gmfn); @@ -2643,19 +2645,24 @@ static int sh_remove_all_mappings(struct /* If that didn't catch the mapping, something is very wrong */ if ( !sh_check_page_has_no_refs(page) ) { - /* Don't complain if we're in HVM and there are some extra mappings: + /* + * Don't complain if we're in HVM and there are some extra mappings: * The qemu helper process has an untyped mapping of this dom's RAM * and the HVM restore program takes another. - * Also allow one typed refcount for xenheap pages, to match - * share_xen_page_with_guest(). */ + * Also allow one typed refcount for + * - Xen heap pages, to match share_xen_page_with_guest(), + * - ioreq server pages, to match prepare_ring_for_helper(). + */ if ( !(shadow_mode_external(d) && (page->count_info & PGC_count_mask) <= 3 && ((page->u.inuse.type_info & PGT_count_mask) - == !!is_xen_heap_page(page))) ) + == (is_xen_heap_page(page) || + is_ioreq_server_page(d, page)))) ) { - SHADOW_ERROR("can't find all mappings of mfn %lx: " - "c=%08lx t=%08lx\n", mfn_x(gmfn), - page->count_info, page->u.inuse.type_info); + SHADOW_ERROR("can't find all mappings of mfn %lx (gfn %lx): " + "c=%lx t=%lx x=%d i=%d\n", mfn_x(gmfn), gfn, + page->count_info, page->u.inuse.type_info, + !!is_xen_heap_page(page), is_ioreq_server_page(d, page)); } } @@ -3515,7 +3522,7 @@ static void sh_unshadow_for_p2m_change(s if ( (p2m_is_valid(p2mt) || p2m_is_grant(p2mt)) && mfn_valid(mfn) ) { sh_remove_all_shadows_and_parents(d, mfn); - if ( sh_remove_all_mappings(d, mfn) ) + if ( sh_remove_all_mappings(d, mfn, gfn) ) flush_tlb_mask(d->domain_dirty_cpumask); } } @@ -3550,7 +3557,8 @@ static void sh_unshadow_for_p2m_change(s { /* This GFN->MFN mapping has gone away */ sh_remove_all_shadows_and_parents(d, omfn); - if ( sh_remove_all_mappings(d, omfn) ) + if ( sh_remove_all_mappings(d, omfn, + gfn + (i << PAGE_SHIFT)) ) cpumask_or(&flushmask, &flushmask, d->domain_dirty_cpumask); } @@ -3766,7 +3774,8 @@ int shadow_track_dirty_vram(struct domai dirty = 1; /* TODO: Heuristics for finding the single mapping of * this gmfn */ - flush_tlb |= sh_remove_all_mappings(d, mfn); + flush_tlb |= sh_remove_all_mappings(d, mfn, + begin_pfn + i); } else { --- a/xen/include/asm-x86/hvm/ioreq.h +++ b/xen/include/asm-x86/hvm/ioreq.h @@ -21,6 +21,7 @@ bool_t hvm_io_pending(struct vcpu *v); bool_t handle_hvm_io_completion(struct vcpu *v); +bool_t is_ioreq_server_page(struct domain *d, const struct page_info *page); int hvm_create_ioreq_server(struct domain *d, domid_t domid, bool_t is_default, int bufioreq_handling,