| Message ID | 20231212094725.22184-8-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/spinlock: make recursive spinlocks a dedicated type | expand |
Hi Juergen, On 12/12/2023 09:47, Juergen Gross wrote: > -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, spinlock_t) > -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, rspinlock_t) > +#define spin_lock_init_prof(s, l) \ > + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) > +#define rspin_lock_init_prof(s, l) \ > + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) > > void _lock_profile_register_struct( > int32_t type, struct lock_profile_qhead *qhead, int32_t idx); > @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; > > #endif > > + Spurious change? > typedef union { > uint32_t head_tail; > struct { > @@ -261,4 +267,12 @@ void rspin_unlock_irqrestore(rspinlock_t *lock, unsigned long flags); > /* Ensure a lock is quiescent between two critical operations. */ > #define spin_barrier(l) _spin_barrier(l) > > +#define nrspin_trylock(l) spin_trylock(l) > +#define nrspin_lock(l) spin_lock(l) > +#define nrspin_unlock(l) spin_unlock(l) > +#define nrspin_lock_irq(l) spin_lock_irq(l) > +#define nrspin_unlock_irq(l) spin_unlock_irq(l) > +#define nrspin_lock_irqsave(l, f) spin_lock_irqsave(l, f) > +#define nrspin_unlock_irqrestore(l, f) spin_unlock_irqrestore(l, f) There is a comment describing [r]spinlock but not this new variant. Can you add one? That said, I know this is existing code, but I have to admit this is a bit unclear why we are allowing an recursive spinlock to be non-recursive. To me it sounds like we are making the typesafe not very safe because it doesn't guarantee that we are not mixing the call nrspin_* with rspin_*. Cheers,
On 12.12.23 19:49, Julien Grall wrote: > Hi Juergen, > > On 12/12/2023 09:47, Juergen Gross wrote: >> -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, spinlock_t) >> -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, rspinlock_t) >> +#define spin_lock_init_prof(s, l) \ >> + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) >> +#define rspin_lock_init_prof(s, l) \ >> + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) >> void _lock_profile_register_struct( >> int32_t type, struct lock_profile_qhead *qhead, int32_t idx); >> @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; >> #endif >> + > > Spurious change? Indeed, will remove it. > >> typedef union { >> uint32_t head_tail; >> struct { >> @@ -261,4 +267,12 @@ void rspin_unlock_irqrestore(rspinlock_t *lock, unsigned >> long flags); >> /* Ensure a lock is quiescent between two critical operations. */ >> #define spin_barrier(l) _spin_barrier(l) >> +#define nrspin_trylock(l) spin_trylock(l) >> +#define nrspin_lock(l) spin_lock(l) >> +#define nrspin_unlock(l) spin_unlock(l) >> +#define nrspin_lock_irq(l) spin_lock_irq(l) >> +#define nrspin_unlock_irq(l) spin_unlock_irq(l) >> +#define nrspin_lock_irqsave(l, f) spin_lock_irqsave(l, f) >> +#define nrspin_unlock_irqrestore(l, f) spin_unlock_irqrestore(l, f) > > There is a comment describing [r]spinlock but not this new variant. Can you add > one? Okay. > That said, I know this is existing code, but I have to admit this is a bit > unclear why we are allowing an recursive spinlock to be non-recursive. To me it > sounds like we are making the typesafe not very safe because it doesn't > guarantee that we are not mixing the call nrspin_* with rspin_*. This is the current API. If you have locked with nrspin_*, any rspin_* attempt on the same lock will spin until rspin_unlock (nrspin_* will not set recurse_cpu, but take the lock). If you have locked with rspin_*, any nrspin_* attempt on the same lock will spin, too. So I don't see any major problem regarding accidental misuse, which wouldn't be visible by deadlocks (there is no silent misbehavior). Juergen
On 13/12/2023 06:17, Juergen Gross wrote: > On 12.12.23 19:49, Julien Grall wrote: >> Hi Juergen, >> >> On 12/12/2023 09:47, Juergen Gross wrote: >>> -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, >>> spinlock_t) >>> -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, >>> rspinlock_t) >>> +#define spin_lock_init_prof(s, >>> l) \ >>> + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) >>> +#define rspin_lock_init_prof(s, >>> l) \ >>> + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) >>> void _lock_profile_register_struct( >>> int32_t type, struct lock_profile_qhead *qhead, int32_t idx); >>> @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; >>> #endif >>> + >> >> Spurious change? > > Indeed, will remove it. > >> >>> typedef union { >>> uint32_t head_tail; >>> struct { >>> @@ -261,4 +267,12 @@ void rspin_unlock_irqrestore(rspinlock_t *lock, >>> unsigned long flags); >>> /* Ensure a lock is quiescent between two critical operations. */ >>> #define spin_barrier(l) _spin_barrier(l) >>> +#define nrspin_trylock(l) spin_trylock(l) >>> +#define nrspin_lock(l) spin_lock(l) >>> +#define nrspin_unlock(l) spin_unlock(l) >>> +#define nrspin_lock_irq(l) spin_lock_irq(l) >>> +#define nrspin_unlock_irq(l) spin_unlock_irq(l) >>> +#define nrspin_lock_irqsave(l, f) spin_lock_irqsave(l, f) >>> +#define nrspin_unlock_irqrestore(l, f) spin_unlock_irqrestore(l, f) >> >> There is a comment describing [r]spinlock but not this new variant. >> Can you add one? > > Okay. > >> That said, I know this is existing code, but I have to admit this is a >> bit unclear why we are allowing an recursive spinlock to be >> non-recursive. To me it sounds like we are making the typesafe not >> very safe because it doesn't guarantee that we are not mixing the call >> nrspin_* with rspin_*. > > This is the current API. I know. This is why I wrote "I know this is existing code". > > If you have locked with nrspin_*, any rspin_* attempt on the same lock will > spin until rspin_unlock (nrspin_* will not set recurse_cpu, but take the > lock). > > If you have locked with rspin_*, any nrspin_* attempt on the same lock will > spin, too. > > So I don't see any major problem regarding accidental misuse, which > wouldn't > be visible by deadlocks (there is no silent misbehavior). Right, so this will lead to a deadlock, which is my concern. If we were using rspinlock_* everywhere then the deadlock (at least in the case when you recurse) would in theory not be possible (unless you recurse too much). My point here is to simplify the interface rather than providing because I don't really see the benefits of providing a non-recursive version for recursive spinlock. Anyway as I said this is nothing new. Cheers,
On 13.12.23 09:36, Julien Grall wrote: > > > On 13/12/2023 06:17, Juergen Gross wrote: >> On 12.12.23 19:49, Julien Grall wrote: >>> Hi Juergen, >>> >>> On 12/12/2023 09:47, Juergen Gross wrote: >>>> -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, spinlock_t) >>>> -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, rspinlock_t) >>>> +#define spin_lock_init_prof(s, >>>> l) \ >>>> + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) >>>> +#define rspin_lock_init_prof(s, >>>> l) \ >>>> + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) >>>> void _lock_profile_register_struct( >>>> int32_t type, struct lock_profile_qhead *qhead, int32_t idx); >>>> @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; >>>> #endif >>>> + >>> >>> Spurious change? >> >> Indeed, will remove it. >> >>> >>>> typedef union { >>>> uint32_t head_tail; >>>> struct { >>>> @@ -261,4 +267,12 @@ void rspin_unlock_irqrestore(rspinlock_t *lock, >>>> unsigned long flags); >>>> /* Ensure a lock is quiescent between two critical operations. */ >>>> #define spin_barrier(l) _spin_barrier(l) >>>> +#define nrspin_trylock(l) spin_trylock(l) >>>> +#define nrspin_lock(l) spin_lock(l) >>>> +#define nrspin_unlock(l) spin_unlock(l) >>>> +#define nrspin_lock_irq(l) spin_lock_irq(l) >>>> +#define nrspin_unlock_irq(l) spin_unlock_irq(l) >>>> +#define nrspin_lock_irqsave(l, f) spin_lock_irqsave(l, f) >>>> +#define nrspin_unlock_irqrestore(l, f) spin_unlock_irqrestore(l, f) >>> >>> There is a comment describing [r]spinlock but not this new variant. Can you >>> add one? >> >> Okay. >> >>> That said, I know this is existing code, but I have to admit this is a bit >>> unclear why we are allowing an recursive spinlock to be non-recursive. To me >>> it sounds like we are making the typesafe not very safe because it doesn't >>> guarantee that we are not mixing the call nrspin_* with rspin_*. >> >> This is the current API. > > I know. This is why I wrote "I know this is existing code". > >> >> If you have locked with nrspin_*, any rspin_* attempt on the same lock will >> spin until rspin_unlock (nrspin_* will not set recurse_cpu, but take the >> lock). >> >> If you have locked with rspin_*, any nrspin_* attempt on the same lock will >> spin, too. >> >> So I don't see any major problem regarding accidental misuse, which wouldn't >> be visible by deadlocks (there is no silent misbehavior). > > Right, so this will lead to a deadlock, which is my concern. If we were using > rspinlock_* everywhere then the deadlock (at least in the case when you recurse) > would in theory not be possible (unless you recurse too much). A programming error can lead to a deadlock, yes. My understanding is that there are deliberate use cases of non-recursive locking as paths using recursive locking of the same lock are not allowed in those cases. Just using rspinlock_* instead of nrspinlock_* would silently ignore such cases, which is far worse than a deadlock, as those cases might introduce e.g. security holes. > My point here is to simplify the interface rather than providing because I don't > really see the benefits of providing a non-recursive version for recursive > spinlock. > > Anyway as I said this is nothing new. Correct. Nothing I'd like to address in this series. Juergen
On 12.12.2023 10:47, Juergen Gross wrote: > In order to prepare a type-safe recursive spinlock structure, add > explicitly non-recursive locking functions to be used for non-recursive > locking of spinlocks, which are used recursively, too. > > Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Jan Beulich <jbeulich@suse.com> preferably with ... > --- a/xen/include/xen/spinlock.h > +++ b/xen/include/xen/spinlock.h > @@ -101,6 +101,8 @@ struct lock_profile_qhead { > }; > > #define _LOCK_PROFILE(lockname) { .name = #lockname, .lock = &lockname, } > +#define _RLOCK_PROFILE(lockname) { .name = #lockname, .rlock = &lockname, \ > + .is_rlock = 1, } ... "true" used here, ... > @@ -133,13 +135,16 @@ struct lock_profile_qhead { > break; \ > } \ > prof->name = #l; \ > - prof->lock = &(s)->l; \ > + prof->lockptr = &(s)->l; \ > + prof->is_rlock = isr; \ > prof->next = (s)->profile_head.elem_q; \ > (s)->profile_head.elem_q = prof; \ > } while( 0 ) > > -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, spinlock_t) > -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, rspinlock_t) > +#define spin_lock_init_prof(s, l) \ > + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) ... "false" here, ... > +#define rspin_lock_init_prof(s, l) \ > + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) ... "true" again here, and ... > @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; > > #endif > > + > typedef union { > uint32_t head_tail; > struct { ... definitely with this hunk dropped. Jan
On 29.02.24 14:49, Jan Beulich wrote: > On 12.12.2023 10:47, Juergen Gross wrote: >> In order to prepare a type-safe recursive spinlock structure, add >> explicitly non-recursive locking functions to be used for non-recursive >> locking of spinlocks, which are used recursively, too. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> > > Acked-by: Jan Beulich <jbeulich@suse.com> > preferably with ... > >> --- a/xen/include/xen/spinlock.h >> +++ b/xen/include/xen/spinlock.h >> @@ -101,6 +101,8 @@ struct lock_profile_qhead { >> }; >> >> #define _LOCK_PROFILE(lockname) { .name = #lockname, .lock = &lockname, } >> +#define _RLOCK_PROFILE(lockname) { .name = #lockname, .rlock = &lockname, \ >> + .is_rlock = 1, } > > ... "true" used here, ... > >> @@ -133,13 +135,16 @@ struct lock_profile_qhead { >> break; \ >> } \ >> prof->name = #l; \ >> - prof->lock = &(s)->l; \ >> + prof->lockptr = &(s)->l; \ >> + prof->is_rlock = isr; \ >> prof->next = (s)->profile_head.elem_q; \ >> (s)->profile_head.elem_q = prof; \ >> } while( 0 ) >> >> -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, spinlock_t) >> -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, rspinlock_t) >> +#define spin_lock_init_prof(s, l) \ >> + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) > > ... "false" here, ... > >> +#define rspin_lock_init_prof(s, l) \ >> + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) > > ... "true" again here, and ... > >> @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; >> >> #endif >> >> + >> typedef union { >> uint32_t head_tail; >> struct { > > ... definitely with this hunk dropped. I'm fine with all of above. Juergen
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index eeb65ca6bb..7466d12b0c 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -105,7 +105,7 @@ void share_xen_page_with_guest(struct page_info *page, struct domain *d, if ( page_get_owner(page) == d ) return; - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); /* * The incremented type count pins as writable or read-only. @@ -136,7 +136,7 @@ void share_xen_page_with_guest(struct page_info *page, struct domain *d, page_list_add_tail(page, &d->xenpage_list); } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); } int xenmem_add_to_physmap_one( diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c index 69ce1fd5cf..998cb53a58 100644 --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -212,7 +212,7 @@ void dump_pageframe_info(struct domain *d) { unsigned long total[MASK_EXTR(PGT_type_mask, PGT_type_mask) + 1] = {}; - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_for_each ( page, &d->page_list ) { unsigned int index = MASK_EXTR(page->u.inuse.type_info, @@ -231,13 +231,13 @@ void dump_pageframe_info(struct domain *d) _p(mfn_x(page_to_mfn(page))), page->count_info, page->u.inuse.type_info); } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); } if ( is_hvm_domain(d) ) p2m_pod_dump_data(d); - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_for_each ( page, &d->xenpage_list ) { @@ -253,7 +253,7 @@ void dump_pageframe_info(struct domain *d) page->count_info, page->u.inuse.type_info); } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); } void update_guest_memory_policy(struct vcpu *v, @@ -2446,10 +2446,10 @@ int domain_relinquish_resources(struct domain *d) d->arch.auto_unmask = 0; } - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_splice(&d->arch.relmem_list, &d->page_list); INIT_PAGE_LIST_HEAD(&d->arch.relmem_list); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); PROGRESS(xen): diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 0a66db10b9..c35a68fbd5 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -482,7 +482,7 @@ void share_xen_page_with_guest(struct page_info *page, struct domain *d, set_gpfn_from_mfn(mfn_x(page_to_mfn(page)), INVALID_M2P_ENTRY); - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); /* The incremented type count pins as writable or read-only. */ page->u.inuse.type_info = @@ -502,7 +502,7 @@ void share_xen_page_with_guest(struct page_info *page, struct domain *d, page_list_add_tail(page, &d->xenpage_list); } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); } void make_cr3(struct vcpu *v, mfn_t mfn) @@ -3584,11 +3584,11 @@ long do_mmuext_op( { bool drop_ref; - spin_lock(&pg_owner->page_alloc_lock); + nrspin_lock(&pg_owner->page_alloc_lock); drop_ref = (pg_owner->is_dying && test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info)); - spin_unlock(&pg_owner->page_alloc_lock); + nrspin_unlock(&pg_owner->page_alloc_lock); if ( drop_ref ) { pin_drop: @@ -4411,7 +4411,7 @@ int steal_page( * that it might be upon return from alloc_domheap_pages with * MEMF_no_owner set. */ - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); BUG_ON(page->u.inuse.type_info & (PGT_count_mask | PGT_locked | PGT_pinned)); @@ -4423,7 +4423,7 @@ int steal_page( if ( !(memflags & MEMF_no_refcount) && !domain_adjust_tot_pages(d, -1) ) drop_dom_ref = true; - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); if ( unlikely(drop_dom_ref) ) put_domain(d); diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c index 1720079fd9..fa4e56a4df 100644 --- a/xen/arch/x86/mm/mem_sharing.c +++ b/xen/arch/x86/mm/mem_sharing.c @@ -746,11 +746,11 @@ static int page_make_private(struct domain *d, struct page_info *page) if ( !get_page(page, dom_cow) ) return -EINVAL; - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); if ( d->is_dying ) { - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); put_page(page); return -EBUSY; } @@ -758,7 +758,7 @@ static int page_make_private(struct domain *d, struct page_info *page) expected_type = (PGT_shared_page | PGT_validated | PGT_locked | 2); if ( page->u.inuse.type_info != expected_type ) { - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); put_page(page); return -EEXIST; } @@ -775,7 +775,7 @@ static int page_make_private(struct domain *d, struct page_info *page) if ( domain_adjust_tot_pages(d, 1) == 1 ) get_knownalive_domain(d); page_list_add_tail(page, &d->page_list); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); put_page(page); diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c index 9e5ad68df2..61a91f5a94 100644 --- a/xen/arch/x86/mm/p2m-pod.c +++ b/xen/arch/x86/mm/p2m-pod.c @@ -27,7 +27,7 @@ static inline void lock_page_alloc(struct p2m_domain *p2m) { page_alloc_mm_pre_lock(p2m->domain); - spin_lock(&(p2m->domain->page_alloc_lock)); + nrspin_lock(&(p2m->domain->page_alloc_lock)); page_alloc_mm_post_lock(p2m->domain, p2m->domain->arch.page_alloc_unlock_level); } @@ -35,7 +35,7 @@ static inline void lock_page_alloc(struct p2m_domain *p2m) static inline void unlock_page_alloc(struct p2m_domain *p2m) { page_alloc_mm_unlock(p2m->domain->arch.page_alloc_unlock_level); - spin_unlock(&(p2m->domain->page_alloc_lock)); + nrspin_unlock(&(p2m->domain->page_alloc_lock)); } /* diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c index 6eb446e437..f188f09b8e 100644 --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -2226,7 +2226,7 @@ void audit_p2m(struct domain *d, /* Audit part two: walk the domain's page allocation list, checking * the m2p entries. */ - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_for_each ( page, &d->page_list ) { mfn = mfn_x(page_to_mfn(page)); @@ -2278,7 +2278,7 @@ void audit_p2m(struct domain *d, P2M_PRINTK("OK: mfn=%#lx, gfn=%#lx, p2mfn=%#lx\n", mfn, gfn, mfn_x(p2mfn)); } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); pod_unlock(p2m); p2m_unlock(p2m); diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c index 86c4c22cac..5b33a1bf9d 100644 --- a/xen/arch/x86/tboot.c +++ b/xen/arch/x86/tboot.c @@ -205,14 +205,14 @@ static void tboot_gen_domain_integrity(const uint8_t key[TB_KEY_SIZE], continue; printk("MACing Domain %u\n", d->domain_id); - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_for_each(page, &d->page_list) { void *pg = __map_domain_page(page); vmac_update(pg, PAGE_SIZE, &ctx); unmap_domain_page(pg); } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); if ( is_iommu_enabled(d) && is_vtd ) { diff --git a/xen/common/domctl.c b/xen/common/domctl.c index f5a71ee5f7..cb62b18a9d 100644 --- a/xen/common/domctl.c +++ b/xen/common/domctl.c @@ -621,14 +621,14 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl) { uint64_t new_max = op->u.max_mem.max_memkb >> (PAGE_SHIFT - 10); - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); /* * NB. We removed a check that new_max >= current tot_pages; this means * that the domain will now be allowed to "ratchet" down to new_max. In * the meantime, while tot > max, all new allocations are disallowed. */ d->max_pages = min(new_max, (uint64_t)(typeof(d->max_pages))-1); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); break; } diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index 5721eab225..54163d51ea 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -2376,7 +2376,7 @@ gnttab_transfer( mfn = page_to_mfn(page); } - spin_lock(&e->page_alloc_lock); + nrspin_lock(&e->page_alloc_lock); /* * Check that 'e' will accept the page and has reservation @@ -2387,7 +2387,7 @@ gnttab_transfer( unlikely(domain_tot_pages(e) >= e->max_pages) || unlikely(!(e->tot_pages + 1)) ) { - spin_unlock(&e->page_alloc_lock); + nrspin_unlock(&e->page_alloc_lock); if ( e->is_dying ) gdprintk(XENLOG_INFO, "Transferee d%d is dying\n", @@ -2411,7 +2411,7 @@ gnttab_transfer( * safely drop the lock and re-aquire it later to add page to the * pagelist. */ - spin_unlock(&e->page_alloc_lock); + nrspin_unlock(&e->page_alloc_lock); okay = gnttab_prepare_for_transfer(e, d, gop.ref); /* @@ -2427,9 +2427,9 @@ gnttab_transfer( * Need to grab this again to safely free our "reserved" * page in the page total */ - spin_lock(&e->page_alloc_lock); + nrspin_lock(&e->page_alloc_lock); drop_dom_ref = !domain_adjust_tot_pages(e, -1); - spin_unlock(&e->page_alloc_lock); + nrspin_unlock(&e->page_alloc_lock); if ( okay /* i.e. e->is_dying due to the surrounding if() */ ) gdprintk(XENLOG_INFO, "Transferee d%d is now dying\n", diff --git a/xen/common/memory.c b/xen/common/memory.c index b3b05c2ec0..b4593f5f45 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -770,10 +770,10 @@ static long memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg) (1UL << in_chunk_order)) - (j * (1UL << exch.out.extent_order))); - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); drop_dom_ref = (dec_count && !domain_adjust_tot_pages(d, -dec_count)); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); if ( drop_dom_ref ) put_domain(d); diff --git a/xen/common/numa.c b/xen/common/numa.c index f454c4d894..47b1d0b5a8 100644 --- a/xen/common/numa.c +++ b/xen/common/numa.c @@ -718,13 +718,13 @@ static void cf_check dump_numa(unsigned char key) memset(page_num_node, 0, sizeof(page_num_node)); - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_for_each ( page, &d->page_list ) { i = page_to_nid(page); page_num_node[i]++; } - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); for_each_online_node ( i ) printk(" Node %u: %u\n", i, page_num_node[i]); diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 8c6a3d9274..a25c00a7d4 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -515,7 +515,7 @@ int domain_set_outstanding_pages(struct domain *d, unsigned long pages) * must always take the global heap_lock rather than only in the much * rarer case that d->outstanding_pages is non-zero */ - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); spin_lock(&heap_lock); /* pages==0 means "unset" the claim. */ @@ -561,7 +561,7 @@ int domain_set_outstanding_pages(struct domain *d, unsigned long pages) out: spin_unlock(&heap_lock); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); return ret; } @@ -2343,7 +2343,7 @@ int assign_pages( int rc = 0; unsigned int i; - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); if ( unlikely(d->is_dying) ) { @@ -2425,7 +2425,7 @@ int assign_pages( } out: - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); return rc; } @@ -2906,9 +2906,9 @@ mfn_t acquire_reserved_page(struct domain *d, unsigned int memflags) ASSERT_ALLOC_CONTEXT(); /* Acquire a page from reserved page list(resv_page_list). */ - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page = page_list_remove_head(&d->resv_page_list); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); if ( unlikely(!page) ) return INVALID_MFN; @@ -2927,9 +2927,9 @@ mfn_t acquire_reserved_page(struct domain *d, unsigned int memflags) */ unprepare_staticmem_pages(page, 1, false); fail: - spin_lock(&d->page_alloc_lock); + nrspin_lock(&d->page_alloc_lock); page_list_add_tail(page, &d->resv_page_list); - spin_unlock(&d->page_alloc_lock); + nrspin_unlock(&d->page_alloc_lock); return INVALID_MFN; } #endif diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index 1db2bbdb6a..8d05c57f69 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -369,9 +369,9 @@ long read_console_ring(struct xen_sysctl_readconsole *op) if ( op->clear ) { - spin_lock_irq(&console_lock); + nrspin_lock_irq(&console_lock); conringc = p - c > conring_size ? p - conring_size : c; - spin_unlock_irq(&console_lock); + nrspin_unlock_irq(&console_lock); } op->count = sofar; @@ -639,7 +639,7 @@ static long guest_console_write(XEN_GUEST_HANDLE_PARAM(char) buffer, if ( is_hardware_domain(cd) ) { /* Use direct console output as it could be interactive */ - spin_lock_irq(&console_lock); + nrspin_lock_irq(&console_lock); console_serial_puts(kbuf, kcount); video_puts(kbuf, kcount); @@ -660,7 +660,7 @@ static long guest_console_write(XEN_GUEST_HANDLE_PARAM(char) buffer, tasklet_schedule(¬ify_dom0_con_ring_tasklet); } - spin_unlock_irq(&console_lock); + nrspin_unlock_irq(&console_lock); } else { @@ -1027,9 +1027,9 @@ void __init console_init_preirq(void) pv_console_set_rx_handler(serial_rx); /* HELLO WORLD --- start-of-day banner text. */ - spin_lock(&console_lock); + nrspin_lock(&console_lock); __putstr(xen_banner()); - spin_unlock(&console_lock); + nrspin_unlock(&console_lock); printk("Xen version %d.%d%s (%s@%s) (%s) %s %s\n", xen_major_version(), xen_minor_version(), xen_extra_version(), xen_compile_by(), xen_compile_domain(), xen_compiler(), @@ -1066,13 +1066,13 @@ void __init console_init_ring(void) } opt_conring_size = PAGE_SIZE << order; - spin_lock_irqsave(&console_lock, flags); + nrspin_lock_irqsave(&console_lock, flags); for ( i = conringc ; i != conringp; i++ ) ring[i & (opt_conring_size - 1)] = conring[i & (conring_size - 1)]; conring = ring; smp_wmb(); /* Allow users of console_force_unlock() to see larger buffer. */ conring_size = opt_conring_size; - spin_unlock_irqrestore(&console_lock, flags); + nrspin_unlock_irqrestore(&console_lock, flags); printk("Allocated console ring of %u KiB.\n", opt_conring_size >> 10); } diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h index ac3bef267a..82ef99d3b6 100644 --- a/xen/include/xen/spinlock.h +++ b/xen/include/xen/spinlock.h @@ -101,6 +101,8 @@ struct lock_profile_qhead { }; #define _LOCK_PROFILE(lockname) { .name = #lockname, .lock = &lockname, } +#define _RLOCK_PROFILE(lockname) { .name = #lockname, .rlock = &lockname, \ + .is_rlock = 1, } #define _LOCK_PROFILE_PTR(name) \ static struct lock_profile * const __lock_profile_##name \ __used_section(".lockprofile.data") = \ @@ -117,10 +119,10 @@ struct lock_profile_qhead { _LOCK_PROFILE_PTR(l) #define DEFINE_RSPINLOCK(l) \ rspinlock_t l = _SPIN_LOCK_UNLOCKED(NULL); \ - static struct lock_profile __lock_profile_data_##l = _LOCK_PROFILE(l); \ + static struct lock_profile __lock_profile_data_##l = _RLOCK_PROFILE(l); \ _LOCK_PROFILE_PTR(l) -#define __spin_lock_init_prof(s, l, locktype) \ +#define __spin_lock_init_prof(s, l, lockptr, locktype, isr) \ do { \ struct lock_profile *prof; \ prof = xzalloc(struct lock_profile); \ @@ -133,13 +135,16 @@ struct lock_profile_qhead { break; \ } \ prof->name = #l; \ - prof->lock = &(s)->l; \ + prof->lockptr = &(s)->l; \ + prof->is_rlock = isr; \ prof->next = (s)->profile_head.elem_q; \ (s)->profile_head.elem_q = prof; \ } while( 0 ) -#define spin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, spinlock_t) -#define rspin_lock_init_prof(s, l) __spin_lock_init_prof(s, l, rspinlock_t) +#define spin_lock_init_prof(s, l) \ + __spin_lock_init_prof(s, l, lock, spinlock_t, 0) +#define rspin_lock_init_prof(s, l) \ + __spin_lock_init_prof(s, l, rlock, rspinlock_t, 1) void _lock_profile_register_struct( int32_t type, struct lock_profile_qhead *qhead, int32_t idx); @@ -174,6 +179,7 @@ struct lock_profile_qhead { }; #endif + typedef union { uint32_t head_tail; struct { @@ -261,4 +267,12 @@ void rspin_unlock_irqrestore(rspinlock_t *lock, unsigned long flags); /* Ensure a lock is quiescent between two critical operations. */ #define spin_barrier(l) _spin_barrier(l) +#define nrspin_trylock(l) spin_trylock(l) +#define nrspin_lock(l) spin_lock(l) +#define nrspin_unlock(l) spin_unlock(l) +#define nrspin_lock_irq(l) spin_lock_irq(l) +#define nrspin_unlock_irq(l) spin_unlock_irq(l) +#define nrspin_lock_irqsave(l, f) spin_lock_irqsave(l, f) +#define nrspin_unlock_irqrestore(l, f) spin_unlock_irqrestore(l, f) + #endif /* __SPINLOCK_H__ */
In order to prepare a type-safe recursive spinlock structure, add explicitly non-recursive locking functions to be used for non-recursive locking of spinlocks, which are used recursively, too. Signed-off-by: Juergen Gross <jgross@suse.com> --- V2: - rename functions (Jan Beulich) - get rid of !! in pcidevs_locked() (Jan Beulich) --- xen/arch/arm/mm.c | 4 ++-- xen/arch/x86/domain.c | 12 ++++++------ xen/arch/x86/mm.c | 12 ++++++------ xen/arch/x86/mm/mem_sharing.c | 8 ++++---- xen/arch/x86/mm/p2m-pod.c | 4 ++-- xen/arch/x86/mm/p2m.c | 4 ++-- xen/arch/x86/tboot.c | 4 ++-- xen/common/domctl.c | 4 ++-- xen/common/grant_table.c | 10 +++++----- xen/common/memory.c | 4 ++-- xen/common/numa.c | 4 ++-- xen/common/page_alloc.c | 16 ++++++++-------- xen/drivers/char/console.c | 16 ++++++++-------- xen/include/xen/spinlock.h | 24 +++++++++++++++++++----- 14 files changed, 70 insertions(+), 56 deletions(-)