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From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
	kvmarm@lists.cs.columbia.edu, linux-mm@kvack.org
Cc: Sean Christopherson <seanjc@google.com>,
	Matthew Wilcox <willy@infradead.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Will Deacon <will@kernel.org>,
	Quentin Perret <qperret@google.com>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kernel-team@android.com
Subject: [PATCH v2 4/6] KVM: Remove kvm_is_transparent_hugepage() and PageTransCompoundMap()
Date: Mon, 26 Jul 2021 16:35:50 +0100	[thread overview]
Message-ID: <20210726153552.1535838-5-maz@kernel.org> (raw)
In-Reply-To: <20210726153552.1535838-1-maz@kernel.org>

Now that arm64 has stopped using kvm_is_transparent_hugepage(),
we can remove it, as well as PageTransCompoundMap() which was
only used by the former.

Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/page-flags.h | 37 -------------------------------------
 virt/kvm/kvm_main.c        | 10 ----------
 2 files changed, 47 deletions(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 5922031ffab6..1ace27c4a8e0 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -632,43 +632,6 @@ static inline int PageTransCompound(struct page *page)
 	return PageCompound(page);
 }
 
-/*
- * PageTransCompoundMap is the same as PageTransCompound, but it also
- * guarantees the primary MMU has the entire compound page mapped
- * through pmd_trans_huge, which in turn guarantees the secondary MMUs
- * can also map the entire compound page. This allows the secondary
- * MMUs to call get_user_pages() only once for each compound page and
- * to immediately map the entire compound page with a single secondary
- * MMU fault. If there will be a pmd split later, the secondary MMUs
- * will get an update through the MMU notifier invalidation through
- * split_huge_pmd().
- *
- * Unlike PageTransCompound, this is safe to be called only while
- * split_huge_pmd() cannot run from under us, like if protected by the
- * MMU notifier, otherwise it may result in page->_mapcount check false
- * positives.
- *
- * We have to treat page cache THP differently since every subpage of it
- * would get _mapcount inc'ed once it is PMD mapped.  But, it may be PTE
- * mapped in the current process so comparing subpage's _mapcount to
- * compound_mapcount to filter out PTE mapped case.
- */
-static inline int PageTransCompoundMap(struct page *page)
-{
-	struct page *head;
-
-	if (!PageTransCompound(page))
-		return 0;
-
-	if (PageAnon(page))
-		return atomic_read(&page->_mapcount) < 0;
-
-	head = compound_head(page);
-	/* File THP is PMD mapped and not PTE mapped */
-	return atomic_read(&page->_mapcount) ==
-	       atomic_read(compound_mapcount_ptr(head));
-}
-
 /*
  * PageTransTail returns true for both transparent huge pages
  * and hugetlbfs pages, so it should only be called when it's known
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 986959833d70..956ef6ddce7f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -189,16 +189,6 @@ bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
 	return true;
 }
 
-bool kvm_is_transparent_hugepage(kvm_pfn_t pfn)
-{
-	struct page *page = pfn_to_page(pfn);
-
-	if (!PageTransCompoundMap(page))
-		return false;
-
-	return is_transparent_hugepage(compound_head(page));
-}
-
 /*
  * Switches to specified vcpu, until a matching vcpu_put()
  */
-- 
2.30.2



  parent reply	other threads:[~2021-07-26 15:36 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-26 15:35 [PATCH v2 0/6] KVM: Remove kvm_is_transparent_hugepage() and friends Marc Zyngier
2021-07-26 15:35 ` [PATCH v2 1/6] KVM: arm64: Introduce helper to retrieve a PTE and its level Marc Zyngier
2021-07-27 10:29   ` Quentin Perret
2021-07-27 15:25   ` Alexandru Elisei
2021-07-28 12:17     ` Marc Zyngier
2021-07-26 15:35 ` [PATCH v2 2/6] KVM: arm64: Walk userspace page tables to compute the THP mapping size Marc Zyngier
2021-07-27 15:55   ` Alexandru Elisei
2021-07-26 15:35 ` [PATCH v2 3/6] KVM: arm64: Avoid mapping size adjustment on permission fault Marc Zyngier
2021-07-27 16:00   ` Alexandru Elisei
2021-07-26 15:35 ` Marc Zyngier [this message]
2021-07-26 15:35 ` [PATCH v2 5/6] KVM: arm64: Use get_page() instead of kvm_get_pfn() Marc Zyngier
2021-07-27 17:46   ` Alexandru Elisei
2021-07-26 15:35 ` [PATCH v2 6/6] KVM: Get rid " Marc Zyngier
2021-08-02 13:39 ` [PATCH v2 0/6] KVM: Remove kvm_is_transparent_hugepage() and friends Marc Zyngier

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