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From: Sean Christopherson <seanjc@google.com>
To: Fuad Tabba <tabba@google.com>
Cc: sashiko-reviews@lists.linux.dev,
	 Ackerley Tng via B4 Relay
	<devnull+ackerleytng.google.com@kernel.org>,
	kvm@vger.kernel.org
Subject: Re: [PATCH v8 17/46] KVM: guest_memfd: Advertise KVM_SET_MEMORY_ATTRIBUTES2 ioctl
Date: Mon, 22 Jun 2026 17:27:04 -0700	[thread overview]
Message-ID: <ajnS2NmvfBtgLKky@google.com> (raw)
In-Reply-To: <CA+EHjTzQhOi-qeiNGpn50o_ko2Cp05qzuKwhiZCgLPCyiwWhrw@mail.gmail.com>

On Fri, Jun 19, 2026, Fuad Tabba wrote:
> On Fri, 19 Jun 2026 at 01:53, <sashiko-bot@kernel.org> wrote:
> >
> > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> > - [Medium] Missing compat_ioctl handler for guest_memfd file operations causes KVM_SET_MEMORY_ATTRIBUTES2 to fail with -ENOTTY for 32-bit userspace.
> 
> guest_memfd is gated on 64-bit: x86 selects KVM_GUEST_MEMFD only under
> X86_64 (arch/x86/kvm/Kconfig:50), and arm64 is 64-bit only. Is 32-bit
> userspace with guest_memfd a supported configuration?

Good question, I genuinely have no idea.  My preference would be to do nothing
for now, and wait to add the (AIUI) one-liner "fix" until someone comes along
with a decent use case.

  reply	other threads:[~2026-06-23  0:27 UTC|newest]

Thread overview: 97+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-19  0:31 [PATCH v8 00/46] guest_memfd: In-place conversion support Ackerley Tng via B4 Relay
2026-06-19  0:31 ` [PATCH v8 01/46] KVM: guest_memfd: Introduce per-gmem attributes, use to guard user mappings Ackerley Tng via B4 Relay
2026-06-22  9:08   ` Binbin Wu
2026-06-23  1:37     ` Sean Christopherson
2026-06-23  2:14       ` Binbin Wu
2026-06-19  0:31 ` [PATCH v8 02/46] KVM: Rename KVM_GENERIC_MEMORY_ATTRIBUTES to KVM_VM_MEMORY_ATTRIBUTES Ackerley Tng via B4 Relay
2026-06-23  2:48   ` Binbin Wu
2026-06-19  0:31 ` [PATCH v8 03/46] KVM: Move KVM_VM_MEMORY_ATTRIBUTES config definition to x86 Ackerley Tng via B4 Relay
2026-06-23  2:48   ` Binbin Wu
2026-06-19  0:31 ` [PATCH v8 04/46] KVM: Decouple kvm_has_arch_private_mem from CONFIG_KVM_VM_MEMORY_ATTRIBUTES Ackerley Tng via B4 Relay
2026-06-19  8:10   ` Fuad Tabba
2026-06-23  2:51   ` Binbin Wu
2026-06-19  0:31 ` [PATCH v8 05/46] KVM: Make CONFIG_KVM_VM_MEMORY_ATTRIBUTES selectable Ackerley Tng via B4 Relay
2026-06-19  8:12   ` Fuad Tabba
2026-06-19 12:51   ` Julian Braha
2026-06-23  0:16     ` Sean Christopherson
2026-06-19  0:31 ` [PATCH v8 06/46] KVM: Enumerate support for PRIVATE memory iff kvm_arch_has_private_mem is defined Ackerley Tng via B4 Relay
2026-06-23  3:10   ` Binbin Wu
2026-06-19  0:31 ` [PATCH v8 07/46] KVM: Rename memory attribute APIs to prepare for in-place gmem conversion Ackerley Tng via B4 Relay
2026-06-19  0:55   ` sashiko-bot
2026-06-19  8:17     ` Fuad Tabba
2026-06-19  8:16   ` Fuad Tabba
2026-06-23  4:55   ` Binbin Wu
2026-06-19  0:31 ` [PATCH v8 08/46] KVM: Provide generic interface for checking memory private/shared status Ackerley Tng via B4 Relay
2026-06-19  0:51   ` sashiko-bot
2026-06-19  8:19   ` Fuad Tabba
2026-06-19  8:21     ` Fuad Tabba
2026-06-19  9:57       ` Suzuki K Poulose
2026-06-19  0:31 ` [PATCH v8 09/46] KVM: guest_memfd: Introduce function to check GFN " Ackerley Tng via B4 Relay
2026-06-19  0:49   ` sashiko-bot
2026-06-19  8:24     ` Fuad Tabba
2026-06-19  8:25   ` Fuad Tabba
2026-06-19  0:31 ` [PATCH v8 10/46] KVM: guest_memfd: Wire up core private/shared attribute interfaces Ackerley Tng via B4 Relay
2026-06-19  8:34   ` Fuad Tabba
2026-06-19  0:31 ` [PATCH v8 11/46] KVM: Consolidate private memory and guest_memfd ifdeffery in kvm_host.h Ackerley Tng via B4 Relay
2026-06-19 11:02   ` Fuad Tabba
2026-06-19  0:31 ` [PATCH v8 12/46] KVM: guest_memfd: Only prepare folios for private pages Ackerley Tng via B4 Relay
2026-06-19  0:31 ` [PATCH v8 13/46] KVM: guest_memfd: Add base support for KVM_SET_MEMORY_ATTRIBUTES2 Ackerley Tng via B4 Relay
2026-06-19  9:25   ` Fuad Tabba
2026-06-23  0:22     ` Sean Christopherson
2026-06-19  0:31 ` [PATCH v8 14/46] KVM: guest_memfd: Ensure pages are not in use before conversion Ackerley Tng via B4 Relay
2026-06-19  0:31 ` [PATCH v8 15/46] KVM: guest_memfd: Call arch invalidate hooks on conversion Ackerley Tng via B4 Relay
2026-06-19 10:09   ` Fuad Tabba
2026-06-23  1:15     ` Sean Christopherson
2026-06-19  0:31 ` [PATCH v8 16/46] KVM: guest_memfd: Return early if range already has requested attributes Ackerley Tng via B4 Relay
2026-06-19  0:31 ` [PATCH v8 17/46] KVM: guest_memfd: Advertise KVM_SET_MEMORY_ATTRIBUTES2 ioctl Ackerley Tng via B4 Relay
2026-06-19  0:53   ` sashiko-bot
2026-06-19 10:35     ` Fuad Tabba
2026-06-23  0:27       ` Sean Christopherson [this message]
2026-06-19 10:35   ` Fuad Tabba
2026-06-19  0:31 ` [PATCH v8 18/46] KVM: guest_memfd: Handle lru_add fbatch refcounts during conversion safety check Ackerley Tng via B4 Relay
2026-06-19  0:31 ` [PATCH v8 19/46] KVM: guest_memfd: Use actual size for invalidation in kvm_gmem_release() Ackerley Tng via B4 Relay
2026-06-19  0:49   ` sashiko-bot
2026-06-19 10:46   ` Fuad Tabba
2026-06-19  0:31 ` [PATCH v8 20/46] KVM: guest_memfd: Determine invalidation filter from memory attributes Ackerley Tng via B4 Relay
2026-06-19  0:31 ` [PATCH v8 21/46] KVM: guest_memfd: Zero page while getting pfn Ackerley Tng via B4 Relay
2026-06-19 10:51   ` Fuad Tabba
2026-06-19  0:31 ` [PATCH v8 22/46] KVM: SEV: Make 'uaddr' parameter optional for KVM_SEV_SNP_LAUNCH_UPDATE Ackerley Tng via B4 Relay
2026-06-19 11:01   ` Fuad Tabba
2026-06-19  0:32 ` [PATCH v8 23/46] KVM: TDX: Make source page optional for KVM_TDX_INIT_MEM_REGION Ackerley Tng via B4 Relay
2026-06-19  0:58   ` sashiko-bot
2026-06-19 11:09   ` Fuad Tabba
2026-06-22  7:18     ` Yan Zhao
2026-06-23  1:24     ` Sean Christopherson
2026-06-22  6:57   ` Yan Zhao
2026-06-23  1:22     ` Sean Christopherson
2026-06-19  0:32 ` [PATCH v8 24/46] KVM: guest_memfd: Make in-place conversion the default Ackerley Tng via B4 Relay
2026-06-19  0:58   ` sashiko-bot
2026-06-22  4:53   ` Yan Zhao
2026-06-19  0:32 ` [PATCH v8 25/46] KVM: guest_memfd: Enable INIT_SHARED on guest_memfd for x86 Coco VMs Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 26/46] KVM: selftests: Create gmem fd before "regular" fd when adding memslot Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 27/46] KVM: selftests: Rename guest_memfd{,_offset} to gmem_{fd,offset} Ackerley Tng via B4 Relay
2026-06-19  0:56   ` sashiko-bot
2026-06-19  0:32 ` [PATCH v8 28/46] KVM: selftests: Add support for mmap() on guest_memfd in core library Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 29/46] KVM: selftests: Add selftests global for guest memory attributes capability Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 30/46] KVM: selftests: Add helpers for calling ioctls on guest_memfd Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 31/46] KVM: selftests: Test basic single-page conversion flow Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 32/46] KVM: selftests: Test conversion flow when INIT_SHARED Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 33/46] KVM: selftests: Test conversion precision in guest_memfd Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 34/46] KVM: selftests: Test conversion before allocation Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 35/46] KVM: selftests: Convert with allocated folios in different layouts Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 36/46] KVM: selftests: Test that truncation does not change shared/private status Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 37/46] KVM: selftests: Test that shared/private status is consistent across processes Ackerley Tng via B4 Relay
2026-06-19  1:02   ` sashiko-bot
2026-06-19  0:32 ` [PATCH v8 38/46] KVM: selftests: Add helpers to pin pages with CONFIG_GUP_TEST Ackerley Tng via B4 Relay
2026-06-19  3:02   ` sashiko-bot
2026-06-19  0:32 ` [PATCH v8 39/46] KVM: selftests: Test conversion with elevated page refcount Ackerley Tng via B4 Relay
2026-06-19  1:07   ` sashiko-bot
2026-06-19  0:32 ` [PATCH v8 40/46] KVM: selftests: Reset shared memory after hole-punching Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 41/46] KVM: selftests: Provide function to look up guest_memfd details from gpa Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 42/46] KVM: selftests: Provide common function to set memory attributes Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 43/46] KVM: selftests: Check fd/flags provided to mmap() when setting up memslot Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 44/46] KVM: selftests: Make TEST_EXPECT_SIGBUS thread-safe Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 45/46] KVM: selftests: Update private_mem_conversions_test to mmap() guest_memfd Ackerley Tng via B4 Relay
2026-06-19  0:32 ` [PATCH v8 46/46] KVM: selftests: Update private memory exits test to work with per-gmem attributes Ackerley Tng via B4 Relay
2026-06-19 12:28 ` [PATCH v8 00/46] guest_memfd: In-place conversion support Garg, Shivank
2026-06-23  2:39 ` Xiaoyao Li

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