From: Sean Christopherson <seanjc@google.com>
To: Ackerley Tng <ackerleytng@google.com>
Cc: kvm@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
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vannapurve@google.com, vbabka@suse.cz, willy@infradead.org,
wyihan@google.com, yan.y.zhao@intel.com
Subject: Re: [RFC PATCH v2 09/37] KVM: guest_memfd: Add support for KVM_SET_MEMORY_ATTRIBUTES2
Date: Tue, 17 Feb 2026 15:04:58 -0800 [thread overview]
Message-ID: <aZT0GmwJ-pm93ojg@google.com> (raw)
In-Reply-To: <CAEvNRgFMNywpDRr+WeNsVj=MnsbhZp9H3j0QRDo_eOP+kGCNJw@mail.gmail.com>
On Sat, Feb 14, 2026, Ackerley Tng wrote:
> Sean is against deferring whether to preserve memory to the underlying
> hardware because that is letting (effectively) micro-architectural
> behavior to define KVM's ABI. KVM's uAPI cannot let behavior be
> undefined, or be based on vendor, and maybe even on firmware version.
Concretely, we'll end up with a giant mess if TDX and/or SNP adds support for
preserving contents on conversion.
next prev parent reply other threads:[~2026-02-17 23:05 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-02 22:36 [RFC PATCH v2 00/37] guest_memfd: In-place conversion support Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 01/37] KVM: guest_memfd: Introduce per-gmem attributes, use to guard user mappings Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 02/37] KVM: Rename KVM_GENERIC_MEMORY_ATTRIBUTES to KVM_VM_MEMORY_ATTRIBUTES Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 03/37] KVM: Enumerate support for PRIVATE memory iff kvm_arch_has_private_mem is defined Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 04/37] KVM: Stub in ability to disable per-VM memory attribute tracking Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 05/37] KVM: guest_memfd: Wire up kvm_get_memory_attributes() to per-gmem attributes Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 06/37] KVM: guest_memfd: Update kvm_gmem_populate() to use gmem attributes Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 07/37] KVM: Introduce KVM_SET_MEMORY_ATTRIBUTES2 Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 08/37] KVM: guest_memfd: Enable INIT_SHARED on guest_memfd for x86 Coco VMs Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 09/37] KVM: guest_memfd: Add support for KVM_SET_MEMORY_ATTRIBUTES2 Ackerley Tng
2026-02-14 20:09 ` Ackerley Tng
2026-02-17 23:04 ` Sean Christopherson [this message]
2026-02-19 12:43 ` Fuad Tabba
2026-02-24 10:14 ` Ackerley Tng
2026-02-25 11:00 ` Fuad Tabba
2026-02-26 4:16 ` Ackerley Tng
2026-02-26 8:11 ` Fuad Tabba
2026-03-12 5:44 ` Ackerley Tng
2026-03-12 15:12 ` Fuad Tabba
2026-03-12 15:44 ` Sean Christopherson
2026-03-12 21:59 ` Ackerley Tng
2026-03-13 0:36 ` Sean Christopherson
2026-03-13 8:32 ` Fuad Tabba
2026-03-13 8:31 ` Fuad Tabba
2026-02-02 22:29 ` [RFC PATCH v2 10/37] KVM: guest_memfd: Handle lru_add fbatch refcounts during conversion safety check Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 11/37] KVM: Move KVM_VM_MEMORY_ATTRIBUTES config definition to x86 Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 12/37] KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 13/37] KVM: selftests: Create gmem fd before "regular" fd when adding memslot Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 14/37] KVM: selftests: Rename guest_memfd{,_offset} to gmem_{fd,offset} Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 15/37] KVM: selftests: Add support for mmap() on guest_memfd in core library Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 16/37] KVM: selftests: Add selftests global for guest memory attributes capability Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 17/37] KVM: selftests: Update framework to use KVM_SET_MEMORY_ATTRIBUTES2 Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 18/37] KVM: selftests: Add helpers for calling ioctls on guest_memfd Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 19/37] KVM: selftests: Test using guest_memfd for guest private memory Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 20/37] KVM: selftests: Test basic single-page conversion flow Ackerley Tng
2026-02-02 22:29 ` [RFC PATCH v2 21/37] KVM: selftests: Test conversion flow when INIT_SHARED Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 22/37] KVM: selftests: Test indexing in guest_memfd Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 23/37] KVM: selftests: Test conversion before allocation Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 24/37] KVM: selftests: Convert with allocated folios in different layouts Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 25/37] KVM: selftests: Test precision of conversion Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 26/37] KVM: selftests: Test that truncation does not change shared/private status Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 27/37] KVM: selftests: Test that shared/private status is consistent across processes Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 28/37] KVM: selftests: Test conversion with elevated page refcount Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 29/37] KVM: selftests: Reset shared memory after hole-punching Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 30/37] KVM: selftests: Provide function to look up guest_memfd details from gpa Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 31/37] KVM: selftests: Provide common function to set memory attributes Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 32/37] KVM: selftests: Check fd/flags provided to mmap() when setting up memslot Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 33/37] KVM: selftests: Make TEST_EXPECT_SIGBUS thread-safe Ackerley Tng
2026-02-14 19:49 ` Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 34/37] KVM: selftests: Update private_mem_conversions_test to mmap() guest_memfd Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 35/37] KVM: selftests: Add script to exercise private_mem_conversions_test Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 36/37] KVM: selftests: Update pre-fault test to work with per-guest_memfd attributes Ackerley Tng
2026-02-02 22:30 ` [RFC PATCH v2 37/37] KVM: selftests: Update private memory exits test work with per-gmem attributes Ackerley Tng
2026-02-20 9:09 ` [RFC PATCH v2 00/37] guest_memfd: In-place conversion support Lisa Wang
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