From: Joao Martins <joao.m.martins@oracle.com> To: linux-nvdimm@lists.01.org Cc: Alex Williamson <alex.williamson@redhat.com>, Cornelia Huck <cohuck@redhat.com>, kvm@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org, Liran Alon <liran.alon@oracle.com>, Nikita Leshenko <nikita.leshchenko@oracle.com>, Barret Rhoden <brho@google.com>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, Matthew Wilcox <willy@infradead.org>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Subject: [PATCH RFC 02/10] mm: Handle pmd entries in follow_pfn() Date: Fri, 10 Jan 2020 19:03:05 +0000 [thread overview] Message-ID: <20200110190313.17144-3-joao.m.martins@oracle.com> (raw) In-Reply-To: <20200110190313.17144-1-joao.m.martins@oracle.com> When follow_pfn hits a pmd_huge() it won't return a valid PFN given it's usage of follow_pte(). Fix that up to pass a @pmdpp and thus allow callers to get the pmd pointer. If we encounter such a huge page, we calculate the pfn offset to the PMD accordingly. This allows KVM to handle 2M hugepage pfns on VM_PFNMAP vmas. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- mm/memory.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index cfc3668bddeb..db99684d2cb3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4366,6 +4366,7 @@ EXPORT_SYMBOL(follow_pte_pmd); int follow_pfn(struct vm_area_struct *vma, unsigned long address, unsigned long *pfn) { + pmd_t *pmdpp = NULL; int ret = -EINVAL; spinlock_t *ptl; pte_t *ptep; @@ -4373,10 +4374,14 @@ int follow_pfn(struct vm_area_struct *vma, unsigned long address, if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) return ret; - ret = follow_pte(vma->vm_mm, address, &ptep, &ptl); + ret = follow_pte_pmd(vma->vm_mm, address, NULL, + &ptep, &pmdpp, &ptl); if (ret) return ret; - *pfn = pte_pfn(*ptep); + if (pmdpp) + *pfn = pmd_pfn(*pmdpp) + ((address & ~PMD_MASK) >> PAGE_SHIFT); + else + *pfn = pte_pfn(*ptep); pte_unmap_unlock(ptep, ptl); return 0; } -- 2.17.1 _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
WARNING: multiple messages have this Message-ID (diff)
From: Joao Martins <joao.m.martins@oracle.com> To: linux-nvdimm@lists.01.org Cc: Dan Williams <dan.j.williams@intel.com>, Vishal Verma <vishal.l.verma@intel.com>, Dave Jiang <dave.jiang@intel.com>, Ira Weiny <ira.weiny@intel.com>, Alex Williamson <alex.williamson@redhat.com>, Cornelia Huck <cohuck@redhat.com>, kvm@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org, Liran Alon <liran.alon@oracle.com>, Nikita Leshenko <nikita.leshchenko@oracle.com>, Barret Rhoden <brho@google.com>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, Matthew Wilcox <willy@infradead.org>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Subject: [PATCH RFC 02/10] mm: Handle pmd entries in follow_pfn() Date: Fri, 10 Jan 2020 19:03:05 +0000 [thread overview] Message-ID: <20200110190313.17144-3-joao.m.martins@oracle.com> (raw) In-Reply-To: <20200110190313.17144-1-joao.m.martins@oracle.com> When follow_pfn hits a pmd_huge() it won't return a valid PFN given it's usage of follow_pte(). Fix that up to pass a @pmdpp and thus allow callers to get the pmd pointer. If we encounter such a huge page, we calculate the pfn offset to the PMD accordingly. This allows KVM to handle 2M hugepage pfns on VM_PFNMAP vmas. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- mm/memory.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index cfc3668bddeb..db99684d2cb3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4366,6 +4366,7 @@ EXPORT_SYMBOL(follow_pte_pmd); int follow_pfn(struct vm_area_struct *vma, unsigned long address, unsigned long *pfn) { + pmd_t *pmdpp = NULL; int ret = -EINVAL; spinlock_t *ptl; pte_t *ptep; @@ -4373,10 +4374,14 @@ int follow_pfn(struct vm_area_struct *vma, unsigned long address, if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) return ret; - ret = follow_pte(vma->vm_mm, address, &ptep, &ptl); + ret = follow_pte_pmd(vma->vm_mm, address, NULL, + &ptep, &pmdpp, &ptl); if (ret) return ret; - *pfn = pte_pfn(*ptep); + if (pmdpp) + *pfn = pmd_pfn(*pmdpp) + ((address & ~PMD_MASK) >> PAGE_SHIFT); + else + *pfn = pte_pfn(*ptep); pte_unmap_unlock(ptep, ptl); return 0; } -- 2.17.1
next prev parent reply other threads:[~2020-01-10 19:07 UTC|newest] Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-10 19:03 [PATCH RFC 00/10] device-dax: Support devices without PFN metadata Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 01/10] mm: Add pmd support for _PAGE_SPECIAL Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-02-03 21:34 ` Matthew Wilcox 2020-02-03 21:34 ` Matthew Wilcox 2020-02-04 16:14 ` Joao Martins 2020-02-04 16:14 ` Joao Martins 2020-01-10 19:03 ` Joao Martins [this message] 2020-01-10 19:03 ` [PATCH RFC 02/10] mm: Handle pmd entries in follow_pfn() Joao Martins 2020-02-03 21:37 ` Matthew Wilcox 2020-02-03 21:37 ` Matthew Wilcox 2020-02-04 16:17 ` Joao Martins 2020-02-04 16:17 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 03/10] mm: Add pud support for _PAGE_SPECIAL Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 04/10] mm: Handle pud entries in follow_pfn() Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 05/10] device-dax: Do not enforce MADV_DONTFORK on mmap() Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 06/10] device-dax: Introduce pfn_flags helper Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 07/10] device-dax: Add support for PFN_SPECIAL flags Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 08/10] dax/pmem: Add device-dax support for PFN_MODE_NONE Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-01-10 19:03 ` [PATCH RFC 09/10] vfio/type1: Use follow_pfn for VM_FPNMAP VMAs Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-02-07 21:08 ` Jason Gunthorpe 2020-02-11 16:23 ` Joao Martins 2020-02-11 16:23 ` Joao Martins 2020-02-11 16:50 ` Jason Gunthorpe 2020-01-10 19:03 ` [PATCH RFC 10/10] nvdimm/e820: add multiple namespaces support Joao Martins 2020-01-10 19:03 ` Joao Martins 2020-02-04 15:28 ` Barret Rhoden 2020-02-04 15:28 ` Barret Rhoden 2020-02-04 16:44 ` Dan Williams 2020-02-04 16:44 ` Dan Williams 2020-02-04 16:44 ` Dan Williams 2020-02-04 18:20 ` Barret Rhoden 2020-02-04 18:20 ` Barret Rhoden 2020-02-04 19:24 ` Joao Martins 2020-02-04 19:24 ` Joao Martins 2020-02-04 21:43 ` Dan Williams 2020-02-04 21:43 ` Dan Williams 2020-02-04 21:43 ` Dan Williams 2020-02-04 21:57 ` Barret Rhoden 2020-02-04 21:57 ` Barret Rhoden 2020-02-04 1:24 ` [PATCH RFC 00/10] device-dax: Support devices without PFN metadata Dan Williams 2020-02-04 1:24 ` Dan Williams 2020-02-04 1:24 ` Dan Williams 2020-02-04 19:07 ` Joao Martins 2020-02-04 19:07 ` Joao Martins
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200110190313.17144-3-joao.m.martins@oracle.com \ --to=joao.m.martins@oracle.com \ --cc=akpm@linux-foundation.org \ --cc=alex.williamson@redhat.com \ --cc=boris.ostrovsky@oracle.com \ --cc=bp@alien8.de \ --cc=brho@google.com \ --cc=cohuck@redhat.com \ --cc=hpa@zytor.com \ --cc=konrad.wilk@oracle.com \ --cc=kvm@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux-nvdimm@lists.01.org \ --cc=liran.alon@oracle.com \ --cc=mingo@redhat.com \ --cc=nikita.leshchenko@oracle.com \ --cc=tglx@linutronix.de \ --cc=willy@infradead.org \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.