From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zoltan Kiss Subject: Re: [PATCH] xen/grant-table: Refactor gnttab_[un]map_refs to avoid m2p_override Date: Mon, 10 Mar 2014 17:14:02 +0000 Message-ID: <531DF2DA.20209@citrix.com> References: <1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Stefano Stabellini , David Vrabel , Russell King , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: Jeremy Fitzhardinge , Matt Wilson , x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Anthony Liguori , xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org, =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= List-Id: virtualization@lists.linuxfoundation.org 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 > Suggested-by: Anthony Liguori > Suggested-by: David Vrabel > Suggested-by: Stefano Stabellini > --- > 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); > > From mboxrd@z Thu Jan 1 00:00:00 1970 From: zoltan.kiss@citrix.com (Zoltan Kiss) Date: Mon, 10 Mar 2014 17:14:02 +0000 Subject: [PATCH] xen/grant-table: Refactor gnttab_[un]map_refs to avoid m2p_override In-Reply-To: <1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com> References: <1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com> Message-ID: <531DF2DA.20209@citrix.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > Suggested-by: Anthony Liguori > Suggested-by: David Vrabel > Suggested-by: Stefano Stabellini > --- > 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); > > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754530AbaCJROK (ORCPT ); Mon, 10 Mar 2014 13:14:10 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:42650 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754508AbaCJROH (ORCPT ); Mon, 10 Mar 2014 13:14:07 -0400 X-IronPort-AV: E=Sophos;i="4.97,625,1389744000"; d="scan'208";a="108408416" Message-ID: <531DF2DA.20209@citrix.com> Date: Mon, 10 Mar 2014 17:14:02 +0000 From: Zoltan Kiss User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Stefano Stabellini , David Vrabel , Russell King , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" CC: Jeremy Fitzhardinge , Matt Wilson , Anthony Liguori , =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= , , , , , Subject: Re: [PATCH] xen/grant-table: Refactor gnttab_[un]map_refs to avoid m2p_override References: <1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com> In-Reply-To: <1393516530-9145-1-git-send-email-zoltan.kiss@citrix.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.133] X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > Suggested-by: Anthony Liguori > Suggested-by: David Vrabel > Suggested-by: Stefano Stabellini > --- > 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); > >