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Hallyn" Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Peng , Fuad Tabba , Jarkko Sakkinen , Yu Zhang , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , Vlastimil Babka , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" References: <20230718234512.1690985-1-seanjc@google.com> <20230718234512.1690985-13-seanjc@google.com> From: Xiaoyao Li In-Reply-To: <20230718234512.1690985-13-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 33C111C002E X-Stat-Signature: ma8iy6mgkce73nyo8wrognpmcb4x78oa X-HE-Tag: 1689864388-353742 X-HE-Meta: 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 MOavTULY mPU2w6ndY7wgvSNtvrZhM9sxoxifGXvCnlZAdgXyfkglXJBwqf8UBK5MtZWBZ5S8T0GvFQj7iyRY6KS8r/jv6IydttbJBLe5om+CuoS8WkCAf85ptorLml4Zl3BxtTlctnKBkUGfbbDUmhWuVTkHn1zj7NKVIgDnTGYmrzfGH68sIsKHNGcoK9hF4la2Fmh/EbkKNScCRGXb0hRgkV72PsV/JwfVYZv4p1k3b9cNV5kXUrkUlUdSnV8jArhrxUnCg0X7v28zBzxLwmLE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 7/19/2023 7:44 AM, Sean Christopherson wrote: > @@ -5134,6 +5167,16 @@ static long kvm_vm_ioctl(struct file *filp, > case KVM_GET_STATS_FD: > r = kvm_vm_ioctl_get_stats_fd(kvm); > break; > + case KVM_CREATE_GUEST_MEMFD: { > + struct kvm_create_guest_memfd guest_memfd; > + > + r = -EFAULT; > + if (copy_from_user(&guest_memfd, argp, sizeof(guest_memfd))) > + goto out; > + > + r = kvm_gmem_create(kvm, &guest_memfd); > + break; > + } Does it need a new CAP to indicate the support of guest_memfd? This is patch series introduces 3 new CAPs and it seems any one of them can serve as the indicator of guest_memfd. +#define KVM_CAP_USER_MEMORY2 230 +#define KVM_CAP_MEMORY_ATTRIBUTES 231 +#define KVM_CAP_VM_TYPES 232 or we just go and try the ioctl, the return value will tell the result?