From: Christian Borntraeger <borntraeger@de.ibm.com> To: Christian Borntraeger <borntraeger@de.ibm.com>, Janosch Frank <frankja@linux.vnet.ibm.com>, Andrew Morton <akpm@linux-foundation.org> Cc: KVM <kvm@vger.kernel.org>, Cornelia Huck <cohuck@redhat.com>, David Hildenbrand <david@redhat.com>, Thomas Huth <thuth@redhat.com>, Ulrich Weigand <Ulrich.Weigand@de.ibm.com>, Claudio Imbrenda <imbrenda@linux.ibm.com>, linux-s390 <linux-s390@vger.kernel.org>, Michael Mueller <mimu@linux.ibm.com>, Vasily Gorbik <gor@linux.ibm.com>, Andrea Arcangeli <aarcange@redhat.com>, linux-mm@kvack.org, Will Deacon <will@kernel.org>, Sean Christopherson <sean.j.christopherson@intel.com> Subject: [PATCH v2 39/42] example for future extension: mm:gup/writeback: add callbacks for inaccessible pages: error cases Date: Fri, 14 Feb 2020 17:26:55 -0500 Message-ID: <20200214222658.12946-40-borntraeger@de.ibm.com> (raw) In-Reply-To: <20200214222658.12946-1-borntraeger@de.ibm.com> From: Claudio Imbrenda <imbrenda@linux.ibm.com> This is a potential extension to do error handling if we fail to make the page accessible if we know what others need. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> --- mm/gup.c | 17 ++++++++++++----- mm/page-writeback.c | 6 +++++- 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index a1c15d029f7c..354bcfbd844b 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -193,6 +193,7 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, struct page *page; spinlock_t *ptl; pte_t *ptep, pte; + int ret; /* FOLL_GET and FOLL_PIN are mutually exclusive. */ if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == @@ -250,8 +251,6 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, if (is_zero_pfn(pte_pfn(pte))) { page = pte_page(pte); } else { - int ret; - ret = follow_pfn_pte(vma, address, ptep, flags); page = ERR_PTR(ret); goto out; @@ -259,7 +258,6 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, } if (flags & FOLL_SPLIT && PageTransCompound(page)) { - int ret; get_page(page); pte_unmap_unlock(ptep, ptl); lock_page(page); @@ -276,7 +274,12 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, page = ERR_PTR(-ENOMEM); goto out; } - arch_make_page_accessible(page); + ret = arch_make_page_accessible(page); + if (ret) { + put_page(page); + page = ERR_PTR(ret); + goto out; + } } if (flags & FOLL_TOUCH) { if ((flags & FOLL_WRITE) && @@ -1920,7 +1923,11 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, VM_BUG_ON_PAGE(compound_head(page) != head, page); - arch_make_page_accessible(page); + ret = arch_make_page_accessible(page); + if (ret) { + put_page(head); + goto pte_unmap; + } SetPageReferenced(page); pages[*nr] = page; (*nr)++; diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 4c020e4ae71c..558d7063c117 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2807,7 +2807,11 @@ int __test_set_page_writeback(struct page *page, bool keep_write) inc_zone_page_state(page, NR_ZONE_WRITE_PENDING); } unlock_page_memcg(page); - arch_make_page_accessible(page); + /* + * If writeback has been triggered on a page that cannot be made + * accessible, it is too late. + */ + WARN_ON(arch_make_page_accessible(page)); return ret; } -- 2.25.0
next prev parent reply index Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-14 22:26 [PATCH v2 00/42] KVM: s390: Add support for protected VMs Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 01/42] mm:gup/writeback: add callbacks for inaccessible pages Christian Borntraeger 2020-02-17 9:14 ` David Hildenbrand 2020-02-17 11:10 ` Christian Borntraeger 2020-02-18 8:27 ` David Hildenbrand 2020-02-18 15:46 ` Sean Christopherson 2020-02-18 16:02 ` Will Deacon 2020-02-18 16:15 ` Christian Borntraeger 2020-02-18 21:35 ` Sean Christopherson 2020-02-19 8:31 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 02/42] KVM: s390/interrupt: do not pin adapter interrupt pages Christian Borntraeger 2020-02-17 9:43 ` David Hildenbrand 2020-02-20 12:18 ` David Hildenbrand 2020-02-20 13:31 ` Christian Borntraeger 2020-02-20 13:34 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 03/42] s390/protvirt: introduce host side setup Christian Borntraeger 2020-02-17 9:53 ` David Hildenbrand 2020-02-17 11:11 ` Christian Borntraeger 2020-02-17 11:13 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 04/42] s390/protvirt: add ultravisor initialization Christian Borntraeger 2020-02-17 9:57 ` David Hildenbrand 2020-02-17 11:13 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 05/42] s390/mm: provide memory management functions for protected KVM guests Christian Borntraeger 2020-02-17 10:21 ` David Hildenbrand 2020-02-17 11:28 ` Christian Borntraeger 2020-02-17 12:07 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 06/42] s390/mm: add (non)secure page access exceptions handlers Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 07/42] KVM: s390: protvirt: Add UV debug trace Christian Borntraeger 2020-02-17 10:41 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 08/42] KVM: s390: add new variants of UV CALL Christian Borntraeger 2020-02-17 10:42 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 09/42] KVM: s390: protvirt: Add initial vm and cpu lifecycle handling Christian Borntraeger 2020-02-17 10:56 ` David Hildenbrand 2020-02-17 12:04 ` Christian Borntraeger 2020-02-17 12:09 ` David Hildenbrand 2020-02-17 14:53 ` [PATCH 0/2] example changes Christian Borntraeger 2020-02-17 14:53 ` [PATCH 1/2] lock changes Christian Borntraeger 2020-02-17 14:53 ` [PATCH 2/2] merge vm/cpu create Christian Borntraeger 2020-02-17 15:00 ` Janosch Frank 2020-02-17 15:02 ` Christian Borntraeger 2020-02-19 11:02 ` Christian Borntraeger 2020-02-17 19:18 ` [PATCH 0/2] example changes David Hildenbrand 2020-02-18 8:09 ` [PATCH v2 09/42] KVM: s390: protvirt: Add initial vm and cpu lifecycle handling Christian Borntraeger 2020-02-18 8:39 ` [PATCH v2.1] " Christian Borntraeger 2020-02-18 9:12 ` David Hildenbrand 2020-02-18 21:18 ` Christian Borntraeger 2020-02-19 8:32 ` David Hildenbrand 2020-02-19 11:01 ` Christian Borntraeger 2020-02-18 9:56 ` David Hildenbrand 2020-02-18 20:26 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 10/42] KVM: s390: protvirt: Add KVM api documentation Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 11/42] KVM: s390: protvirt: Secure memory is not mergeable Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 12/42] KVM: s390/mm: Make pages accessible before destroying the guest Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 13/42] KVM: s390: protvirt: Handle SE notification interceptions Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 14/42] KVM: s390: protvirt: Instruction emulation Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 15/42] KVM: s390: protvirt: Add interruption injection controls Christian Borntraeger 2020-02-17 10:59 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 16/42] KVM: s390: protvirt: Implement interruption injection Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 17/42] KVM: s390: protvirt: Add SCLP interrupt handling Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 18/42] KVM: s390: protvirt: Handle spec exception loops Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 19/42] KVM: s390: protvirt: Add new gprs location handling Christian Borntraeger 2020-02-17 11:01 ` David Hildenbrand 2020-02-17 11:33 ` Christian Borntraeger 2020-02-17 14:37 ` Janosch Frank 2020-02-14 22:26 ` [PATCH v2 20/42] KVM: S390: protvirt: Introduce instruction data area bounce buffer Christian Borntraeger 2020-02-17 11:08 ` David Hildenbrand 2020-02-17 14:47 ` Janosch Frank 2020-02-17 15:00 ` Christian Borntraeger 2020-02-17 15:38 ` Janosch Frank 2020-02-17 16:58 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 21/42] KVM: s390: protvirt: handle secure guest prefix pages Christian Borntraeger 2020-02-17 11:11 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 22/42] KVM: s390/mm: handle guest unpin events Christian Borntraeger 2020-02-17 14:23 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 23/42] KVM: s390: protvirt: Write sthyi data to instruction data area Christian Borntraeger 2020-02-17 14:24 ` David Hildenbrand 2020-02-17 18:40 ` Christian Borntraeger 2020-02-17 19:16 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 24/42] KVM: s390: protvirt: STSI handling Christian Borntraeger 2020-02-18 8:35 ` David Hildenbrand 2020-02-18 8:44 ` Christian Borntraeger 2020-02-18 9:08 ` David Hildenbrand 2020-02-18 9:11 ` Christian Borntraeger 2020-02-18 9:13 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 25/42] KVM: s390: protvirt: disallow one_reg Christian Borntraeger 2020-02-18 8:40 ` David Hildenbrand 2020-02-18 8:57 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 26/42] KVM: s390: protvirt: Do only reset registers that are accessible Christian Borntraeger 2020-02-18 8:42 ` David Hildenbrand 2020-02-18 9:20 ` Christian Borntraeger 2020-02-18 9:28 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 27/42] KVM: s390: protvirt: Only sync fmt4 registers Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 28/42] KVM: s390: protvirt: Add program exception injection Christian Borntraeger 2020-02-18 9:33 ` David Hildenbrand 2020-02-18 9:37 ` Christian Borntraeger 2020-02-18 9:39 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 29/42] KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling Christian Borntraeger 2020-02-18 9:38 ` David Hildenbrand 2020-02-19 12:45 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 30/42] KVM: s390: protvirt: UV calls in support of diag308 0, 1 Christian Borntraeger 2020-02-18 9:44 ` David Hildenbrand 2020-02-19 11:53 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 31/42] KVM: s390: protvirt: Report CPU state to Ultravisor Christian Borntraeger 2020-02-18 9:48 ` David Hildenbrand 2020-02-19 19:36 ` Christian Borntraeger 2020-02-19 19:46 ` Christian Borntraeger 2020-02-20 10:52 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 32/42] KVM: s390: protvirt: Support cmd 5 operation state Christian Borntraeger 2020-02-18 9:50 ` David Hildenbrand 2020-02-19 11:06 ` Christian Borntraeger 2020-02-19 11:08 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 33/42] KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and 112 Christian Borntraeger 2020-02-18 9:53 ` David Hildenbrand 2020-02-18 10:02 ` David Hildenbrand 2020-02-18 10:05 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 34/42] KVM: s390: protvirt: do not inject interrupts after start Christian Borntraeger 2020-02-18 9:53 ` David Hildenbrand 2020-02-18 10:02 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 35/42] KVM: s390: protvirt: Add UV cpu reset calls Christian Borntraeger 2020-02-18 9:54 ` David Hildenbrand 2020-02-14 22:26 ` [PATCH v2 36/42] DOCUMENTATION: Protected virtual machine introduction and IPL Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 37/42] s390/uv: Fix handling of length extensions (already in s390 tree) Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 38/42] s390: protvirt: Add sysfs firmware interface for Ultravisor information Christian Borntraeger 2020-02-14 22:26 ` Christian Borntraeger [this message] 2020-02-18 16:25 ` [PATCH v2 39/42] example for future extension: mm:gup/writeback: add callbacks for inaccessible pages: error cases Will Deacon 2020-02-18 16:30 ` Christian Borntraeger 2020-02-18 16:33 ` Will Deacon 2020-02-14 22:26 ` [PATCH v2 40/42] example for future extension: mm:gup/writeback: add callbacks for inaccessible pages: source indication Christian Borntraeger 2020-02-17 14:15 ` Ulrich Weigand 2020-02-17 14:38 ` Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 41/42] potential fixup for "s390/mm: provide memory management functions for protected KVM guests" Christian Borntraeger 2020-02-14 22:26 ` [PATCH v2 42/42] KVM: s390: rstify new ioctls in api.rst Christian Borntraeger
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