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AJvYcCUsqfFMUYVDecl+Dl8EzITFUrcBh170jB8EzC+p6+xHyMSA2GWlcuMA5Exf97xRWHFuXjUSKbQ74g==@kvack.org X-Gm-Message-State: AOJu0YwvOUbfVQ1/MngqM7Yq1PLJkzPfqsUy7F6oI3MqIRPLvT0Jz4ui aqvad/AwwlI8neTi9vOfQ9Vh0JrYnqBeTlr62Xv4w4gulDgjrObWPcs+T6xH1/VFZ5cuTIxGueg JvjEfUNACWpPS0FOMEaMQWxzdtcGJV5puGU3mWqC1 X-Gm-Gg: ASbGncux6BjFSdkC7jNcosIOnnHA5aFeQGpr2EHObsa2dt1fk+pn9JrRUtCfjcUxZZ+ jeDCPBuMflfJtB/ZXdgwJp8XRS8wFRvfoc4cEoR0hKxQwhD6C81IfayEULN1YyC46p9Xn9vGKUl wMpncl4ezoz/Fr1ABHssM5GbBQTjjjdidmHzqpyJEivsPKeuwIpmDncdxpgbP704J8v5KQ5MC8r 5RoNjgBGQoA4/kw1+iwfIQ4m0xCtQUyoZkB X-Google-Smtp-Source: AGHT+IG34MfGj/Zl62zVn178UZKzeSI18O6et/oIgJa6CLuO77Ce5w+YXMKKyouWv/4JvQ+6pdezBz48FGUKIecZjcI= X-Received: by 2002:a05:622a:1aa0:b0:4a9:b6e1:15a with SMTP id d75a77b69052e-4ab954d8746mr2391171cf.24.1752663946223; Wed, 16 Jul 2025 04:05:46 -0700 (PDT) MIME-Version: 1.0 References: <20250715093350.2584932-1-tabba@google.com> <20250715093350.2584932-3-tabba@google.com> <418ddbbd-c25e-4047-9317-c05735e02807@intel.com> <778ca011-1b2f-4818-80c6-ac597809ec77@redhat.com> <6927a67b-cd2e-45f1-8e6b-019df7a7417e@intel.com> In-Reply-To: <6927a67b-cd2e-45f1-8e6b-019df7a7417e@intel.com> From: Fuad Tabba Date: Wed, 16 Jul 2025 12:05:09 +0100 X-Gm-Features: Ac12FXwLnudqPBETDUTkvUad_Ou8IyTTedPM6CDydpNfw0kKmZr9XGnTtqO-hwY Message-ID: Subject: Re: [PATCH v14 02/21] KVM: Rename CONFIG_KVM_GENERIC_PRIVATE_MEM to CONFIG_KVM_GENERIC_GMEM_POPULATE To: Xiaoyao Li Cc: David Hildenbrand , kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev, pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 8E004180004 X-Stat-Signature: i6n5yqduh7un3cokzhn89zq5zfie7tmd X-Rspam-User: X-HE-Tag: 1752663947-930084 X-HE-Meta: U2FsdGVkX1/GjYRMN4YXxmQB8aHVBQvQZGwCvDyDajudT4g9EwZrqHeTK077u/FqaJ042+UtKrnJIn4JVjwuj+kunid2VLyI/zy6Ga/VqMTtCTINxvAWakT2le+BLY6jABZbcBpj6Xkq5KA75VFpNES+wkNumJXIZ3F/KAfdrvKXe6aEc90RWMJ5Lk1zRG+eHKKrdO5EBLl//YIJ/gWqDw16JVx1R5eRccE5JEaTuO31cjDoLMKhyhvOEEObRrHHN0vAXyyEsyf0jHUJBag8mw2UIdZpv9CD1kPulm8lWTyAX2Dm9zNPN44gCLx2A+PfGAw9W1CtgOpUoO3zBKJA3QPHR2uZ2rM07nwXsAtIU8TR21QEZuxxwrWo7SBqsf7DiTQIvk3U5nLSs1lc7ciWxYQzVw3hwodsUv6hAlD+svK0L5GXdxDxYmn9+5csze0Cloclz6m4m69JfuUHbpaVaK4RTXTUKgcqFyZP/gkDmoy6xxr4Cdm7NF/WCoPINFyKlLauBL6yS3wiOrZhNkAoYpspQKTcl097Ce371xSH1q8wVdwf6Np1Y7qsrLqxEhzjhk5NThTN3N5vqZN+iizUF75aFml45kjY1Ai3KfUZG78WcJxdlR2sUfFaLBRgC3ALCa14bOgkO9XW/TLZSiJt6uZldM0JB3Om5yIU5kvzjGmByesy3leZ1g9OX+G9AaVH+GCXNtq1D7oKBX1LwouwgEeVwb3QhUrcHkczPCC8++yUqqIzKEs4u7PBbT+gbCu+/uwIP0m4TH3f84ACjS1fKjlSKd8Bs9fytzuVrk3PAVIQ+oySN8H5pLMzjJa5+GTCobRCzEym4mVM3vAzk+wT4r2n659+ZO6sNbrmqihaXw7JahmFzq68BRIdGC0WtHFa+qT4gQbAk6N0jyIYNPRLu7O70S/LX4R9+4pB+IoomEzIiqOuzwwmR8or/PdFOc6B1C0z0B1uwIr47WFhYtL 9rUuzNsi lY7HTDqwzabFpuCG0kaaQVJi6LgQx4wu9yufm8H/jbGu/RcC6Irn0uZ/Vd23rseAcILi8yZiRZ+1VJaPGhxzPa0oXy/ZSoONVGkgt3DJze16yE48cfcfbzG+jzWFKUa2ND4hx3AWfoSjMrbKiuVARxLsHBhgdOcNSeyFD2VLRBY3JOR5llUOAQzP10L+ycziUvdXWPRWp3ovzubwdqfqzgBdOlzKMaNkFSAhzOxmrhknI6yLQ2tEZNtotDT3ESA6EZXi7z5nP1Ow812CaJGThkSzs39e82o+EBZS7NBe1jPECjSlSXHyNWnTeJzhnKZFQFxDvPm7G2t44U3nuhlm4Ekp5Qw== 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: List-Subscribe: List-Unsubscribe: On Wed, 16 Jul 2025 at 12:02, Xiaoyao Li wrote: > > On 7/16/2025 6:25 PM, David Hildenbrand wrote: > > On 16.07.25 10:31, Xiaoyao Li wrote: > >> On 7/16/2025 4:11 PM, Fuad Tabba wrote: > >>> On Wed, 16 Jul 2025 at 05:09, Xiaoyao Li wrote: > >>>> On 7/15/2025 5:33 PM, Fuad Tabba wrote: > >>>>> The original name was vague regarding its functionality. This Kconfig > >>>>> option specifically enables and gates the kvm_gmem_populate() > >>>>> function, > >>>>> which is responsible for populating a GPA range with guest data. > >>>> Well, I disagree. > >>>> > >>>> The config KVM_GENERIC_PRIVATE_MEM was introduced by commit > >>>> 89ea60c2c7b5 > >>>> ("KVM: x86: Add support for "protected VMs" that can utilize private > >>>> memory"), which is a convenient config for vm types that requires > >>>> private memory support, e.g., SNP, TDX, and KVM_X86_SW_PROTECTED_VM. > >>>> > >>>> It was commit e4ee54479273 ("KVM: guest_memfd: let kvm_gmem_populate() > >>>> operate only on private gfns") that started to use > >>>> CONFIG_KVM_GENERIC_PRIVATE_MEM gates kvm_gmem_populate() function. But > >>>> CONFIG_KVM_GENERIC_PRIVATE_MEM is not for kvm_gmem_populate() only. > >>>> > >>>> If using CONFIG_KVM_GENERIC_PRIVATE_MEM to gate kvm_gmem_populate() is > >>>> vague and confusing, we can introduce KVM_GENERIC_GMEM_POPULATE to gate > >>>> kvm_gmem_populate() and select KVM_GENERIC_GMEM_POPULATE under > >>>> CONFIG_KVM_GENERIC_PRIVATE_MEM. > >>>> > >>>> Directly replace CONFIG_KVM_GENERIC_PRIVATE_MEM with > >>>> KVM_GENERIC_GMEM_POPULATE doesn't look correct to me. > >>> I'll quote David's reply to an earlier version of this patch [*]: > >> > >> It's not related to my concern. > >> > >> My point is that CONFIG_KVM_GENERIC_PRIVATE_MEM is used for selecting > >> the private memory support. Rename it to KVM_GENERIC_GMEM_POPULATE is > >> not correct. > > > > It protects a function that is called kvm_gmem_populate(). > > > > Can we stop the nitpicking? > > I don't think it's nitpicking. > > Could you loot into why it was named as KVM_GENERIC_PRIVATE_MEM in the > first place, and why it was picked to protect kvm_gmem_populate()? That is, in part, the point of this patch. This flag protects kvm_gmem_populate(), and the name didn't reflect that. Now it does. It is the only thing it protects. Cheers, /fuad