linux-kernel - [PATCH v2 3/5] mm: userfaultfd: allow to register continue for guest

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250402160721.97596-4-kalyazin@amazon.com>
Date: Wed, 2 Apr 2025 16:07:19 +0000
From: Nikita Kalyazin <kalyazin@...zon.com>
To: <akpm@...ux-foundation.org>, <pbonzini@...hat.com>, <shuah@...nel.org>
CC: <kvm@...r.kernel.org>, <linux-kselftest@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
	<lorenzo.stoakes@...cle.com>, <david@...hat.com>, <ryan.roberts@....com>,
	<quic_eberman@...cinc.com>, <jthoughton@...gle.com>, <peterx@...hat.com>,
	<graf@...zon.de>, <jgowans@...zon.com>, <roypat@...zon.co.uk>,
	<derekmn@...zon.com>, <nsaenz@...zon.es>, <xmarcalx@...zon.com>,
	<kalyazin@...zon.com>
Subject: [PATCH v2 3/5] mm: userfaultfd: allow to register continue for guest_memfd

Signed-off-by: Nikita Kalyazin <kalyazin@...zon.com>
---
 include/linux/userfaultfd_k.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 75342022d144..bc184edfbb85 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -212,6 +212,10 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma)
 	return vma->vm_flags & __VM_UFFD_FLAGS;
 }
 
+#ifdef CONFIG_KVM_PRIVATE_MEM
+bool kvm_gmem_vma_is_gmem(struct vm_area_struct *vma);
+#endif
+
 static inline bool vma_can_userfault(struct vm_area_struct *vma,
 				     unsigned long vm_flags,
 				     bool wp_async)
@@ -222,7 +226,11 @@ static inline bool vma_can_userfault(struct vm_area_struct *vma,
 		return false;
 
 	if ((vm_flags & VM_UFFD_MINOR) &&
-	    (!is_vm_hugetlb_page(vma) && !vma_is_shmem(vma)))
+	    (!is_vm_hugetlb_page(vma) && !vma_is_shmem(vma))
+#ifdef CONFIG_KVM_PRIVATE_MEM
+	     && !kvm_gmem_vma_is_gmem(vma)
+#endif
+	    )
 		return false;
 
 	/*
@@ -244,6 +252,9 @@ static inline bool vma_can_userfault(struct vm_area_struct *vma,
 
 	/* By default, allow any of anon|shmem|hugetlb */
 	return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
+#ifdef CONFIG_KVM_PRIVATE_MEM
+	    kvm_gmem_vma_is_gmem(vma) ||
+#endif
 	    vma_is_shmem(vma);
 }
 
-- 
2.47.1