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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 , Vlastimil Babka , 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 References: <20260618-gmem-inplace-conversion-v8-0-9d2959357853@google.com> <20260618-gmem-inplace-conversion-v8-17-9d2959357853@google.com> <584a8f9a-1538-4f8b-b576-75ef0fa961c7@intel.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/25/2026 4:26 AM, Ackerley Tng wrote: > Xiaoyao Li writes: > >> On 7/2/2026 12:09 AM, Sean Christopherson wrote: >>> On Wed, Jul 01, 2026, Xiaoyao Li wrote: >>>> On 6/19/2026 8:31 AM, Ackerley Tng via B4 Relay wrote: >>>>> @@ -4969,6 +4973,11 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) >>>>> return 1; >>>>> case KVM_CAP_GUEST_MEMFD_FLAGS: >>>>> return kvm_gmem_get_supported_flags(kvm); >>>>> + case KVM_CAP_GUEST_MEMFD_MEMORY_ATTRIBUTES: >>>>> + if (!gmem_in_place_conversion || !kvm_supports_private_mem(kvm)) >>>>> + return 0; >>>>> + >>>>> + return KVM_MEMORY_ATTRIBUTE_PRIVATE; >>>>> #endif >>>>> default: >>>>> break; >>>> >>>> this looks inconsistent with the >>>> >>>> case KVM_SET_MEMORY_ATTRIBUTES2: >>>> if (!gmem_in_place_conversion) >>>> return -ENOTTY; >>>> >>>> Well, the check of >>>> >>>> if (!kvm_arch_has_private_mem(f->kvm)) >>>> return -EINVAL; >>>> >>>> is buried in the following kvm_gmem_set_attributes(). How about moving of >>>> kvm_arch_has_private_mem() check to put it along with >>>> gmem_in_place_conversion check in kvm_gmem_ioctl() in Patch 13? >>> >>> Me confused, patch 13 already adds the kvm_arch_has_private_mem() in >>> kvm_gmem_set_attributes(). >> >> I wanted to make the check in KVM_SET_MEMORY_ATTRIBUTES2 in Patch 13 >> like something below: >> >> case KVM_SET_MEMORY_ATTRIBUTES2: >> if (!gmem_in_place_conversion || !kvm_arch_has_private_mem(f->kvm)) >> return -EXXX; >> >> and finally, with the introduction of kvm_supports_private_mem() in this >> patch, it becomes: >> >> case KVM_SET_MEMORY_ATTRIBUTES2: >> if (!gmem_in_place_conversion || !kvm_supports_private_mem(f->kvm)) >> return -EXXX; >> > > Is the request here to make KVM_SET_MEMORY_ATTRIBUTES2 return -ENOTTY > instead of -EINVAL? kvm_gmem_set_attributes() also checks for > !kvm_arch_has_private_mem() and returns -EINVAL. Not really. I want both "KVM_CAP_GUEST_MEMFD_MEMORY_ATTRIBUTES" and "KVM_SET_MEMORY_ATTRIBUTES2 on gmem" to check gmem_in_place_conversion and kvm_supports_private_mem() in the same if(), or side by side if two different return code is desired. Because the current code somewhat confused me on why KVM_CAP_GUEST_MEMFD_MEMORY_ATTRIBUTES checks two conditions while KVM_SET_MEMORY_ATTRIBUTES2 on gmem only checks gmem_in_place_conversion. Only later did I realize that KVM_SET_MEMORY_ATTRIBUTES2 on gmem also checks kvm_supports_private_mem(), but buried in the following handling. > I'm about to post v9, which squashes the patches as Sean > suggested. Please review v9 instead to see if this concern is already > addressed :) sure.