| Message ID | 1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
David/Stefano, can you take a look, and ack if you are happy with this? I could build it on ARM and a backported version on 3.10 have seen quite a lot of testing recently. Zoli On 27/02/14 15:55, Zoltan Kiss wrote: > (This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override > during mapping") > > The grant mapping API does m2p_override unnecessarily: only gntdev needs it, > for blkback and future netback patches it just cause a lock contention, as > those pages never go to userspace. Therefore this series does the following: > - the bulk of the original function (everything after the mapping hypercall) > is moved to arch-dependent set/clear_foreign_p2m_mapping > - the "if (xen_feature(XENFEAT_auto_translated_physmap))" brach goes to ARM > - therefore the ARM function could be much smaller, the m2p_override stubs > could be also removed > - on x86 the set_phys_to_machine calls were moved up to this new funcion > from m2p_override functions > - and m2p_override functions are only called when there is a kmap_ops param > > It also removes a stray space from arch/x86/include/asm/xen/page.h. > > Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> > Suggested-by: Anthony Liguori <aliguori@amazon.com> > Suggested-by: David Vrabel <david.vrabel@citrix.com> > Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > --- > arch/arm/include/asm/xen/page.h | 15 ++--- > arch/arm/xen/p2m.c | 32 +++++++++++ > arch/x86/include/asm/xen/page.h | 11 +++- > arch/x86/xen/p2m.c | 121 ++++++++++++++++++++++++++++++++++----- > drivers/xen/grant-table.c | 73 +---------------------- > 5 files changed, 156 insertions(+), 96 deletions(-) > > diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h > index e0965ab..cf4f3e8 100644 > --- a/arch/arm/include/asm/xen/page.h > +++ b/arch/arm/include/asm/xen/page.h > @@ -97,16 +97,13 @@ static inline pte_t *lookup_address(unsigned long address, unsigned int *level) > return NULL; > } > > -static inline int m2p_add_override(unsigned long mfn, struct page *page, > - struct gnttab_map_grant_ref *kmap_op) > -{ > - return 0; > -} > +extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count); > > -static inline int m2p_remove_override(struct page *page, bool clear_pte) > -{ > - return 0; > -} > +extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count); > > bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); > bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn, > diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c > index b31ee1b2..9c48778 100644 > --- a/arch/arm/xen/p2m.c > +++ b/arch/arm/xen/p2m.c > @@ -146,6 +146,38 @@ unsigned long __mfn_to_pfn(unsigned long mfn) > } > EXPORT_SYMBOL_GPL(__mfn_to_pfn); > > +int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count); > +{ > + int i; > + > + for (i = 0; i < count; i++) { > + if (map_ops[i].status) > + continue; > + set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, > + map_ops[i].dev_bus_addr >> PAGE_SHIFT); > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); > + > +int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count); > +{ > + int i; > + > + for (i = 0; i < count; i++) { > + set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, > + INVALID_P2M_ENTRY); > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); > + > bool __set_phys_to_machine_multi(unsigned long pfn, > unsigned long mfn, unsigned long nr_pages) > { > diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h > index 3e276eb..c949923 100644 > --- a/arch/x86/include/asm/xen/page.h > +++ b/arch/x86/include/asm/xen/page.h > @@ -49,10 +49,17 @@ extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); > extern unsigned long set_phys_range_identity(unsigned long pfn_s, > unsigned long pfn_e); > > +extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count); > extern int m2p_add_override(unsigned long mfn, struct page *page, > struct gnttab_map_grant_ref *kmap_op); > +extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count); > extern int m2p_remove_override(struct page *page, > - struct gnttab_map_grant_ref *kmap_op); > + struct gnttab_map_grant_ref *kmap_op, > + unsigned long mfn); > extern struct page *m2p_find_override(unsigned long mfn); > extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); > > @@ -121,7 +128,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) > pfn = m2p_find_override_pfn(mfn, ~0); > } > > - /* > + /* > * pfn is ~0 if there are no entries in the m2p for mfn or if the > * entry doesn't map back to the mfn and m2p_override doesn't have a > * valid entry for it. > diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c > index 696c694..85e5d78 100644 > --- a/arch/x86/xen/p2m.c > +++ b/arch/x86/xen/p2m.c > @@ -881,6 +881,65 @@ static unsigned long mfn_hash(unsigned long mfn) > return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT); > } > > +int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count) > +{ > + int i, ret = 0; > + bool lazy = false; > + pte_t *pte; > + > + if (xen_feature(XENFEAT_auto_translated_physmap)) > + return 0; > + > + if (kmap_ops && > + !in_interrupt() && > + paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { > + arch_enter_lazy_mmu_mode(); > + lazy = true; > + } > + > + for (i = 0; i < count; i++) { > + unsigned long mfn, pfn; > + > + /* Do not add to override if the map failed. */ > + if (map_ops[i].status) > + continue; > + > + if (map_ops[i].flags & GNTMAP_contains_pte) { > + pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + > + (map_ops[i].host_addr & ~PAGE_MASK)); > + mfn = pte_mfn(*pte); > + } else { > + mfn = PFN_DOWN(map_ops[i].dev_bus_addr); > + } > + pfn = page_to_pfn(pages[i]); > + > + WARN_ON(PagePrivate(pages[i])); > + SetPagePrivate(pages[i]); > + set_page_private(pages[i], mfn); > + pages[i]->index = pfn_to_mfn(pfn); > + > + if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) { > + ret = -ENOMEM; > + goto out; > + } > + > + if (kmap_ops) { > + ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]); > + if (ret) > + goto out; > + } > + } > + > +out: > + if (lazy) > + arch_leave_lazy_mmu_mode(); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); > + > /* Add an MFN override for a particular page */ > int m2p_add_override(unsigned long mfn, struct page *page, > struct gnttab_map_grant_ref *kmap_op) > @@ -899,13 +958,6 @@ int m2p_add_override(unsigned long mfn, struct page *page, > "m2p_add_override: pfn %lx not mapped", pfn)) > return -EINVAL; > } > - WARN_ON(PagePrivate(page)); > - SetPagePrivate(page); > - set_page_private(page, mfn); > - page->index = pfn_to_mfn(pfn); > - > - if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) > - return -ENOMEM; > > if (kmap_op != NULL) { > if (!PageHighMem(page)) { > @@ -943,20 +995,62 @@ int m2p_add_override(unsigned long mfn, struct page *page, > return 0; > } > EXPORT_SYMBOL_GPL(m2p_add_override); > + > +int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, > + struct gnttab_map_grant_ref *kmap_ops, > + struct page **pages, unsigned int count) > +{ > + int i, ret = 0; > + bool lazy = false; > + > + if (xen_feature(XENFEAT_auto_translated_physmap)) > + return 0; > + > + if (kmap_ops && > + !in_interrupt() && > + paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { > + arch_enter_lazy_mmu_mode(); > + lazy = true; > + } > + > + for (i = 0; i < count; i++) { > + unsigned long mfn = get_phys_to_machine(page_to_pfn(pages[i])); > + unsigned long pfn = page_to_pfn(pages[i]); > + > + if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) { > + ret = -EINVAL; > + goto out; > + } > + > + set_page_private(pages[i], INVALID_P2M_ENTRY); > + WARN_ON(!PagePrivate(pages[i])); > + ClearPagePrivate(pages[i]); > + set_phys_to_machine(pfn, pages[i]->index); > + > + if (kmap_ops) > + ret = m2p_remove_override(pages[i], &kmap_ops[i], mfn); > + if (ret) > + goto out; > + } > + > +out: > + if (lazy) > + arch_leave_lazy_mmu_mode(); > + return ret; > +} > +EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); > + > int m2p_remove_override(struct page *page, > - struct gnttab_map_grant_ref *kmap_op) > + struct gnttab_map_grant_ref *kmap_op, > + unsigned long mfn) > { > unsigned long flags; > - unsigned long mfn; > unsigned long pfn; > unsigned long uninitialized_var(address); > unsigned level; > pte_t *ptep = NULL; > > pfn = page_to_pfn(page); > - mfn = get_phys_to_machine(pfn); > - if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) > - return -EINVAL; > > if (!PageHighMem(page)) { > address = (unsigned long)__va(pfn << PAGE_SHIFT); > @@ -970,10 +1064,7 @@ int m2p_remove_override(struct page *page, > spin_lock_irqsave(&m2p_override_lock, flags); > list_del(&page->lru); > spin_unlock_irqrestore(&m2p_override_lock, flags); > - WARN_ON(!PagePrivate(page)); > - ClearPagePrivate(page); > > - set_phys_to_machine(pfn, page->index); > if (kmap_op != NULL) { > if (!PageHighMem(page)) { > struct multicall_space mcs; > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index b84e3ab..6d325bd 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c > @@ -933,9 +933,6 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, > struct page **pages, unsigned int count) > { > int i, ret; > - bool lazy = false; > - pte_t *pte; > - unsigned long mfn; > > ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); > if (ret) > @@ -947,45 +944,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, > gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, > &map_ops[i].status, __func__); > > - /* this is basically a nop on x86 */ > - if (xen_feature(XENFEAT_auto_translated_physmap)) { > - for (i = 0; i < count; i++) { > - if (map_ops[i].status) > - continue; > - set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, > - map_ops[i].dev_bus_addr >> PAGE_SHIFT); > - } > - return ret; > - } > - > - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { > - arch_enter_lazy_mmu_mode(); > - lazy = true; > - } > - > - for (i = 0; i < count; i++) { > - /* Do not add to override if the map failed. */ > - if (map_ops[i].status) > - continue; > - > - if (map_ops[i].flags & GNTMAP_contains_pte) { > - pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + > - (map_ops[i].host_addr & ~PAGE_MASK)); > - mfn = pte_mfn(*pte); > - } else { > - mfn = PFN_DOWN(map_ops[i].dev_bus_addr); > - } > - ret = m2p_add_override(mfn, pages[i], kmap_ops ? > - &kmap_ops[i] : NULL); > - if (ret) > - goto out; > - } > - > - out: > - if (lazy) > - arch_leave_lazy_mmu_mode(); > - > - return ret; > + return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count); > } > EXPORT_SYMBOL_GPL(gnttab_map_refs); > > @@ -993,39 +952,13 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, > struct gnttab_map_grant_ref *kmap_ops, > struct page **pages, unsigned int count) > { > - int i, ret; > - bool lazy = false; > + int ret; > > ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); > if (ret) > return ret; > > - /* this is basically a nop on x86 */ > - if (xen_feature(XENFEAT_auto_translated_physmap)) { > - for (i = 0; i < count; i++) { > - set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, > - INVALID_P2M_ENTRY); > - } > - return ret; > - } > - > - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { > - arch_enter_lazy_mmu_mode(); > - lazy = true; > - } > - > - for (i = 0; i < count; i++) { > - ret = m2p_remove_override(pages[i], kmap_ops ? > - &kmap_ops[i] : NULL); > - if (ret) > - goto out; > - } > - > - out: > - if (lazy) > - arch_leave_lazy_mmu_mode(); > - > - return ret; > + return clear_foreign_p2m_mapping(unmap_ops, kmap_ops, pages, count); > } > EXPORT_SYMBOL_GPL(gnttab_unmap_refs); > >
On 27/02/14 15:55, Zoltan Kiss wrote: > (This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override > during mapping") > > The grant mapping API does m2p_override unnecessarily: only gntdev needs it, > for blkback and future netback patches it just cause a lock contention, as > those pages never go to userspace. Therefore this series does the following: > - the bulk of the original function (everything after the mapping hypercall) > is moved to arch-dependent set/clear_foreign_p2m_mapping > - the "if (xen_feature(XENFEAT_auto_translated_physmap))" brach goes to ARM > - therefore the ARM function could be much smaller, the m2p_override stubs > could be also removed > - on x86 the set_phys_to_machine calls were moved up to this new funcion > from m2p_override functions > - and m2p_override functions are only called when there is a kmap_ops param > > It also removes a stray space from arch/x86/include/asm/xen/page.h. Applied to devel/for-linus-3.15. Thanks. David
On Mon, 10 Mar 2014, David Vrabel wrote: > On 27/02/14 15:55, Zoltan Kiss wrote: > > (This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override > > during mapping") > > > > The grant mapping API does m2p_override unnecessarily: only gntdev needs it, > > for blkback and future netback patches it just cause a lock contention, as > > those pages never go to userspace. Therefore this series does the following: > > - the bulk of the original function (everything after the mapping hypercall) > > is moved to arch-dependent set/clear_foreign_p2m_mapping > > - the "if (xen_feature(XENFEAT_auto_translated_physmap))" brach goes to ARM > > - therefore the ARM function could be much smaller, the m2p_override stubs > > could be also removed > > - on x86 the set_phys_to_machine calls were moved up to this new funcion > > from m2p_override functions > > - and m2p_override functions are only called when there is a kmap_ops param > > > > It also removes a stray space from arch/x86/include/asm/xen/page.h. > > Applied to devel/for-linus-3.15. The patch breaks the ARM build: arch/arm/xen/p2m.c:152:1: error: expected identifier or '(' before '{' token { ^ arch/arm/xen/p2m.c:169:1: error: expected identifier or '(' before '{' token { ^
diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index e0965ab..cf4f3e8 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -97,16 +97,13 @@ static inline pte_t *lookup_address(unsigned long address, unsigned int *level) return NULL; } -static inline int m2p_add_override(unsigned long mfn, struct page *page, - struct gnttab_map_grant_ref *kmap_op) -{ - return 0; -} +extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); -static inline int m2p_remove_override(struct page *page, bool clear_pte) -{ - return 0; -} +extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn, diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c index b31ee1b2..9c48778 100644 --- a/arch/arm/xen/p2m.c +++ b/arch/arm/xen/p2m.c @@ -146,6 +146,38 @@ unsigned long __mfn_to_pfn(unsigned long mfn) } EXPORT_SYMBOL_GPL(__mfn_to_pfn); +int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); +{ + int i; + + for (i = 0; i < count; i++) { + if (map_ops[i].status) + continue; + set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, + map_ops[i].dev_bus_addr >> PAGE_SHIFT); + } + + return 0; +} +EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); + +int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); +{ + int i; + + for (i = 0; i < count; i++) { + set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, + INVALID_P2M_ENTRY); + } + + return 0; +} +EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); + bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn, unsigned long nr_pages) { diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 3e276eb..c949923 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -49,10 +49,17 @@ extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); extern unsigned long set_phys_range_identity(unsigned long pfn_s, unsigned long pfn_e); +extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); extern int m2p_add_override(unsigned long mfn, struct page *page, struct gnttab_map_grant_ref *kmap_op); +extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); extern int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op); + struct gnttab_map_grant_ref *kmap_op, + unsigned long mfn); extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); @@ -121,7 +128,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) pfn = m2p_find_override_pfn(mfn, ~0); } - /* + /* * pfn is ~0 if there are no entries in the m2p for mfn or if the * entry doesn't map back to the mfn and m2p_override doesn't have a * valid entry for it. diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 696c694..85e5d78 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -881,6 +881,65 @@ static unsigned long mfn_hash(unsigned long mfn) return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT); } +int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count) +{ + int i, ret = 0; + bool lazy = false; + pte_t *pte; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return 0; + + if (kmap_ops && + !in_interrupt() && + paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { + arch_enter_lazy_mmu_mode(); + lazy = true; + } + + for (i = 0; i < count; i++) { + unsigned long mfn, pfn; + + /* Do not add to override if the map failed. */ + if (map_ops[i].status) + continue; + + if (map_ops[i].flags & GNTMAP_contains_pte) { + pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + + (map_ops[i].host_addr & ~PAGE_MASK)); + mfn = pte_mfn(*pte); + } else { + mfn = PFN_DOWN(map_ops[i].dev_bus_addr); + } + pfn = page_to_pfn(pages[i]); + + WARN_ON(PagePrivate(pages[i])); + SetPagePrivate(pages[i]); + set_page_private(pages[i], mfn); + pages[i]->index = pfn_to_mfn(pfn); + + if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) { + ret = -ENOMEM; + goto out; + } + + if (kmap_ops) { + ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]); + if (ret) + goto out; + } + } + +out: + if (lazy) + arch_leave_lazy_mmu_mode(); + + return ret; +} +EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); + /* Add an MFN override for a particular page */ int m2p_add_override(unsigned long mfn, struct page *page, struct gnttab_map_grant_ref *kmap_op) @@ -899,13 +958,6 @@ int m2p_add_override(unsigned long mfn, struct page *page, "m2p_add_override: pfn %lx not mapped", pfn)) return -EINVAL; } - WARN_ON(PagePrivate(page)); - SetPagePrivate(page); - set_page_private(page, mfn); - page->index = pfn_to_mfn(pfn); - - if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) - return -ENOMEM; if (kmap_op != NULL) { if (!PageHighMem(page)) { @@ -943,20 +995,62 @@ int m2p_add_override(unsigned long mfn, struct page *page, return 0; } EXPORT_SYMBOL_GPL(m2p_add_override); + +int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count) +{ + int i, ret = 0; + bool lazy = false; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return 0; + + if (kmap_ops && + !in_interrupt() && + paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { + arch_enter_lazy_mmu_mode(); + lazy = true; + } + + for (i = 0; i < count; i++) { + unsigned long mfn = get_phys_to_machine(page_to_pfn(pages[i])); + unsigned long pfn = page_to_pfn(pages[i]); + + if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) { + ret = -EINVAL; + goto out; + } + + set_page_private(pages[i], INVALID_P2M_ENTRY); + WARN_ON(!PagePrivate(pages[i])); + ClearPagePrivate(pages[i]); + set_phys_to_machine(pfn, pages[i]->index); + + if (kmap_ops) + ret = m2p_remove_override(pages[i], &kmap_ops[i], mfn); + if (ret) + goto out; + } + +out: + if (lazy) + arch_leave_lazy_mmu_mode(); + return ret; +} +EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); + int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op) + struct gnttab_map_grant_ref *kmap_op, + unsigned long mfn) { unsigned long flags; - unsigned long mfn; unsigned long pfn; unsigned long uninitialized_var(address); unsigned level; pte_t *ptep = NULL; pfn = page_to_pfn(page); - mfn = get_phys_to_machine(pfn); - if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) - return -EINVAL; if (!PageHighMem(page)) { address = (unsigned long)__va(pfn << PAGE_SHIFT); @@ -970,10 +1064,7 @@ int m2p_remove_override(struct page *page, spin_lock_irqsave(&m2p_override_lock, flags); list_del(&page->lru); spin_unlock_irqrestore(&m2p_override_lock, flags); - WARN_ON(!PagePrivate(page)); - ClearPagePrivate(page); - set_phys_to_machine(pfn, page->index); if (kmap_op != NULL) { if (!PageHighMem(page)) { struct multicall_space mcs; diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index b84e3ab..6d325bd 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -933,9 +933,6 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, struct page **pages, unsigned int count) { int i, ret; - bool lazy = false; - pte_t *pte; - unsigned long mfn; ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); if (ret) @@ -947,45 +944,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, &map_ops[i].status, __func__); - /* this is basically a nop on x86 */ - if (xen_feature(XENFEAT_auto_translated_physmap)) { - for (i = 0; i < count; i++) { - if (map_ops[i].status) - continue; - set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, - map_ops[i].dev_bus_addr >> PAGE_SHIFT); - } - return ret; - } - - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { - arch_enter_lazy_mmu_mode(); - lazy = true; - } - - for (i = 0; i < count; i++) { - /* Do not add to override if the map failed. */ - if (map_ops[i].status) - continue; - - if (map_ops[i].flags & GNTMAP_contains_pte) { - pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + - (map_ops[i].host_addr & ~PAGE_MASK)); - mfn = pte_mfn(*pte); - } else { - mfn = PFN_DOWN(map_ops[i].dev_bus_addr); - } - ret = m2p_add_override(mfn, pages[i], kmap_ops ? - &kmap_ops[i] : NULL); - if (ret) - goto out; - } - - out: - if (lazy) - arch_leave_lazy_mmu_mode(); - - return ret; + return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count); } EXPORT_SYMBOL_GPL(gnttab_map_refs); @@ -993,39 +952,13 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count) { - int i, ret; - bool lazy = false; + int ret; ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); if (ret) return ret; - /* this is basically a nop on x86 */ - if (xen_feature(XENFEAT_auto_translated_physmap)) { - for (i = 0; i < count; i++) { - set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, - INVALID_P2M_ENTRY); - } - return ret; - } - - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { - arch_enter_lazy_mmu_mode(); - lazy = true; - } - - for (i = 0; i < count; i++) { - ret = m2p_remove_override(pages[i], kmap_ops ? - &kmap_ops[i] : NULL); - if (ret) - goto out; - } - - out: - if (lazy) - arch_leave_lazy_mmu_mode(); - - return ret; + return clear_foreign_p2m_mapping(unmap_ops, kmap_ops, pages, count); } EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
(This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override during mapping") The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the bulk of the original function (everything after the mapping hypercall) is moved to arch-dependent set/clear_foreign_p2m_mapping - the "if (xen_feature(XENFEAT_auto_translated_physmap))" brach goes to ARM - therefore the ARM function could be much smaller, the m2p_override stubs could be also removed - on x86 the set_phys_to_machine calls were moved up to this new funcion from m2p_override functions - and m2p_override functions are only called when there is a kmap_ops param It also removes a stray space from arch/x86/include/asm/xen/page.h. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Suggested-by: Anthony Liguori <aliguori@amazon.com> Suggested-by: David Vrabel <david.vrabel@citrix.com> Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> --- arch/arm/include/asm/xen/page.h | 15 ++--- arch/arm/xen/p2m.c | 32 +++++++++++ arch/x86/include/asm/xen/page.h | 11 +++- arch/x86/xen/p2m.c | 121 ++++++++++++++++++++++++++++++++++----- drivers/xen/grant-table.c | 73 +---------------------- 5 files changed, 156 insertions(+), 96 deletions(-)