From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3544E261B9E; Fri, 7 Aug 2026 21:52:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786139568; cv=none; b=Sh6sK5/g6ULeHXnGAO41uQe+KA6bz7FFxrGs9NIa5nz5YNKEBT3s1lPjn5fmBOSjGRgmuuviwTqLYKSXUa7rnCdu0RTvgSs7ZY1imawlocJ9LXPt6wVjGTBoU4Qx0xKkjpfIxqMBe+9NUNoGkmi8A53t7pgCYjFB7NP7bpa3HIc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786139568; c=relaxed/simple; bh=VRY21HbGe+yrXyu21+xEN17//OmuhC1bDdv0JvaqW4Q=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=KMKpqQwjgFTT6XIy8C4hy3FQxU5OqndWWcJedCaehpsK+EzXlUVwwPun+XCnShrSt45fV5uwK/CiX8O0wRoPEbcdaacZcWTt8576gZ6ATCKA8klEnLsUZ83osIHX/P4T1plM+WgQlF7O1AY7L0tSJoxnGV/oo1fwok8ng2TLuwM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hZZDe9nA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hZZDe9nA" Received: by smtp.kernel.org (Postfix) with ESMTPS id C2B7DC19425; Fri, 7 Aug 2026 21:52:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1786139567; bh=VRY21HbGe+yrXyu21+xEN17//OmuhC1bDdv0JvaqW4Q=; h=From:Subject:Date:To:Cc:Reply-To:From; b=hZZDe9nAPE71x/6W7qTfborur/rgdxBksXQgjdrTG3UHLpXU11vEEA23dZdDkNNHx b3A0fwJJPTPufkBeG98p4hsOJqIP1tZwdiP/axVkaO2v5+aMubb2i9/93QN8Eu/dJs LDRae5YVEPxuiT4Y7GsXrJQOldgWnSY6M1iMcJGDcqVIFdT5SFCb0WqtCl50iEgxm/ Nqrct6gzS6gvM4IADtdqEbSl/Eri2Bhc1Zd0sKJ+cs28/guc7ex55IlHrBV9VXMpAO lg9aU+X37pFrgdtoQnR3LbbGfDPU6chvOtFOYCsgBDKg1APWgTUxLwS+lRceNsHs4r h8KJpEBMT58+w== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96420C5ACD3; Fri, 7 Aug 2026 21:52:47 +0000 (UTC) From: Ackerley Tng via B4 Relay Subject: [PATCH v10 00/41] guest_memfd: In-place conversion support Date: Fri, 07 Aug 2026 14:52:39 -0700 Message-Id: <20260807-gmem-inplace-conversion-v10-0-2fc18ee6d3ba@google.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAKhTdmoC/33SzW6DMAwA4Fepcl624JC/nfYe0w4hcSBagS4w1 Kni3RfaSXRC9OjI/uxYvpABU8SBvB4uJOEUh9h3OSjY04G4xnY10ujzAwEGkgEIWrfY0tidjtY hdX03YVqKaOWZrzw3SnBLcvUpYYjnK/3+kePKDkirZDvXLN7n1L50eB6X1CYOY59+rkNMfCm4t eMF3203ccqoCK4Aqxg6bd7qvq+P+Oz6liz9pvIOArkPlRnCnBbQCBaC30BihUrQ+5DIkNeSaee CswAbSK6QYGofkhkyha2E1VVhbLmB1B0EsA+pDEFgwWJppOBsA+kVksWDr+llIg9GGC6UFnwDm RVSj3ZkMsRFMBYdWPT/dzTfzibh13c+xPHvdub5F8bP7JKmAgAA X-Change-ID: 20260225-gmem-inplace-conversion-bd0dbd39753a To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , tarunsahu@google.com, Jason Gunthorpe , Vlastimil Babka , Baoquan He Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng , Xiaoyao Li , Fuad Tabba , "Vlastimil Babka (SUSE)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1786139564; l=7969; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=VRY21HbGe+yrXyu21+xEN17//OmuhC1bDdv0JvaqW4Q=; b=1MMm0tJlW1y4Emo2ScsHjlWOO+GuUKmskR1J2fwzVgT2PGgtiz+v6uJrsvDDPE/XdsXrfLDJw o+0+DbabpMKAo/92iXSHQw01z3E1wx+Iu+a6Vsp3cbzsxoCge5e4wd4 X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com This is v10 of guest_memfd in-place conversion support, which addresses comments on v9. Please find the motivation for this series from v8 and before. v9 is based on kvm-x86/next, with a cherry-picked version of David's GUP fix [1], and a cherry-picked version of David's refactoring patch [2]. Here's everything stitched together for your convenience: https://github.com/googleprodkernel/linux-cc/commits/guest_memfd-inplace-conversion-v10 I tested v10 with CoCo selftests on top of the branch above: https://github.com/googleprodkernel/linux-cc/commits/guest_memfd-inplace-conversion-coco-selftests-v10 Tested with both CONFIG_KVM_VM_MEMORY_ATTRIBUTES enabled and disabled: + tools/testing/selftests/kvm/guest_memfd_test.c + tools/testing/selftests/kvm/pre_fault_memory_test.c + tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c + tools/testing/selftests/kvm/x86/private_mem_conversions_test.c + tools/testing/selftests/kvm/x86/private_mem_kvm_exits_test.c + The TDX and SNP conversions selftests in https://github.com/googleprodkernel/linux-cc/commits/guest_memfd-inplace-conversion-coco-selftests-v10 [1] https://lore.kernel.org/all/20260731-check_and_migrate_movable_folios-v1-1-e0002d7b791e@kernel.org/ ("mm/gup: fix always draining LRU caches in collect_longterm_unpinnable_folios()") [2] https://lore.kernel.org/all/20260806-lru_cache_drain_for_folio-v1-1-c6287d295e99@kernel.org/ ("mm/gup: factor out LRU cache draining for folio into lru_cache_drain_for_folio()") Older series: v9: https://lore.kernel.org/r/20260728-gmem-inplace-conversion-v9-0-35f9aec2aed2@google.com v8: https://lore.kernel.org/r/20260618-gmem-inplace-conversion-v8-0-9d2959357853@google.com v7: https://lore.kernel.org/r/20260522-gmem-inplace-conversion-v7-0-2f0fae496530@google.com v6: https://lore.kernel.org/r/20260507-gmem-inplace-conversion-v6-0-91ab5a8b19a4@google.com RFC v5: https://lore.kernel.org/r/20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com RFC v4: https://lore.kernel.org/all/20260326-gmem-inplace-conversion-v4-0-e202fe950ffd@google.com/T/ RFC v3: https://lore.kernel.org/r/20260313-gmem-inplace-conversion-v3-0-5fc12a70ec89@google.com/T/ RFC v2: https://lore.kernel.org/all/cover.1770071243.git.ackerleytng@google.com/T/ RFC v1: https://lore.kernel.org/all/cover.1760731772.git.ackerleytng@google.com/T/ Previous versions of this feature, part of other series, are available at: + https://lore.kernel.org/all/bd163de3118b626d1005aa88e71ef2fb72f0be0f.1726009989.git.ackerleytng@google.com/ + https://lore.kernel.org/all/20250117163001.2326672-6-tabba@google.com/ + https://lore.kernel.org/all/b784326e9ccae6a08388f1bf39db70a2204bdc51.1747264138.git.ackerleytng@google.com/ Signed-off-by: Ackerley Tng --- Ackerley Tng (21): KVM: guest_memfd: Filter both shared and private when invalidating KVM: guest_memfd: Add base support for KVM_SET_MEMORY_ATTRIBUTES2 KVM: guest_memfd: Ensure pages are not in use before conversion KVM: guest_memfd: Call arch make_shared callback for to-shared conversion KVM: guest_memfd: Return early if range already has requested attributes KVM: guest_memfd: Handle lru_add fbatch refcounts during conversion safety check KVM: guest_memfd: Zero page while getting pfn KVM: TDX: Make source page optional for KVM_TDX_INIT_MEM_REGION KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes KVM: selftests: Test basic single-page conversion flow KVM: selftests: Test conversion flow when INIT_SHARED KVM: selftests: Test conversion precision in guest_memfd KVM: selftests: Test conversion before allocation KVM: selftests: Convert with allocated folios in different layouts KVM: selftests: Test that truncation does not change shared/private status KVM: selftests: Add helpers to pin pages with CONFIG_GUP_TEST KVM: selftests: Test conversion with elevated page refcount KVM: selftests: Reset shared memory after hole-punching KVM: selftests: Provide function to look up guest_memfd details from gpa KVM: selftests: Make TEST_EXPECT_SIGBUS thread-safe KVM: selftests: Update private_mem_conversions_test to mmap() guest_memfd David Hildenbrand (Arm) (1): mm/gup: factor out LRU cache draining for folio into lru_cache_drain_for_folio() Michael Roth (1): KVM: SEV: Make 'uaddr' parameter optional for KVM_SEV_SNP_LAUNCH_UPDATE Sean Christopherson (18): KVM: guest_memfd: Use kvm_mem_is_private() when populating guest_memfd memory KVM: guest_memfd: Introduce per-gmem attributes, use to guard user mappings KVM: Rename KVM_GENERIC_MEMORY_ATTRIBUTES to KVM_VM_MEMORY_ATTRIBUTES KVM: Enumerate support for PRIVATE memory iff kvm_arch_has_private_mem is defined KVM: Rename memory attribute APIs to prepare for in-place gmem conversion KVM: Provide generic interface for checking memory private/shared status KVM: guest_memfd: Stub in ability to enable in-place shared<=>private conversion KVM: Consolidate private memory and guest_memfd ifdeffery in kvm_host.h KVM: Move KVM_VM_MEMORY_ATTRIBUTES config definition to x86 KVM: guest_memfd: Enable INIT_SHARED on guest_memfd for x86 Coco VMs KVM: selftests: Create gmem fd before "regular" fd when adding memslot KVM: selftests: Rename guest_memfd{,_offset} to gmem_{fd,offset} KVM: selftests: Add support for mmap() on guest_memfd in core library KVM: selftests: Add selftests global for guest memory attributes capability KVM: selftests: Add helpers for calling ioctls on guest_memfd KVM: selftests: Test that shared/private status is consistent across processes KVM: selftests: Provide common function to set memory attributes KVM: selftests: Update private memory exits test to work with per-gmem attributes Documentation/virt/kvm/api.rst | 78 +++- .../virt/kvm/x86/amd-memory-encryption.rst | 14 +- Documentation/virt/kvm/x86/intel-tdx.rst | 4 + arch/x86/include/asm/kvm-x86-ops.h | 2 +- arch/x86/include/asm/kvm_host.h | 6 +- arch/x86/kvm/Kconfig | 15 +- arch/x86/kvm/mmu/mmu.c | 16 +- arch/x86/kvm/svm/sev.c | 11 +- arch/x86/kvm/vmx/tdx.c | 8 +- arch/x86/kvm/x86.c | 20 +- include/linux/kvm_host.h | 76 +-- include/linux/swap.h | 11 +- include/trace/events/kvm.h | 6 +- include/uapi/linux/kvm.h | 16 + mm/gup.c | 15 +- mm/swap.c | 48 ++ tools/testing/selftests/kvm/Makefile.kvm | 1 + tools/testing/selftests/kvm/include/kvm_util.h | 139 +++++- tools/testing/selftests/kvm/include/test_util.h | 34 +- tools/testing/selftests/kvm/lib/kvm_util.c | 164 ++++--- tools/testing/selftests/kvm/lib/test_util.c | 7 - .../kvm/x86/guest_memfd_conversions_test.c | 512 +++++++++++++++++++++ .../kvm/x86/private_mem_conversions_test.c | 53 ++- .../selftests/kvm/x86/private_mem_kvm_exits_test.c | 36 +- virt/kvm/Kconfig | 3 - virt/kvm/guest_memfd.c | 450 ++++++++++++++++-- virt/kvm/kvm_main.c | 92 ++-- 27 files changed, 1574 insertions(+), 263 deletions(-) --- base-commit: 4217d4987bbe33e331764a752721f781123b2e07 change-id: 20260225-gmem-inplace-conversion-bd0dbd39753a Best regards, -- Ackerley Tng