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From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Fuad Tabba <tabba@google.com>,
	kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-mm@kvack.org, kvmarm@lists.linux.dev
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Subject: Re: [PATCH v15 19/21] KVM: Introduce the KVM capability KVM_CAP_GMEM_MMAP
Date: Fri, 18 Jul 2025 14:14:17 +0800	[thread overview]
Message-ID: <0f31ab50-e30a-40d5-96ae-ee54742d98f9@intel.com> (raw)
In-Reply-To: <20250717162731.446579-20-tabba@google.com>

On 7/18/2025 12:27 AM, Fuad Tabba wrote:
> Introduce the new KVM capability KVM_CAP_GMEM_MMAP. This capability
> signals to userspace that a KVM instance supports host userspace mapping
> of guest_memfd-backed memory.
> 
> The availability of this capability is determined per architecture, and
> its enablement for a specific guest_memfd instance is controlled by the
> GUEST_MEMFD_FLAG_MMAP flag at creation time.
> 
> Update the KVM API documentation to detail the KVM_CAP_GMEM_MMAP
> capability, the associated GUEST_MEMFD_FLAG_MMAP, and provide essential
> information regarding support for mmap in guest_memfd.
> 
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Reviewed-by: Shivank Garg <shivankg@amd.com>
> Signed-off-by: Fuad Tabba <tabba@google.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

Though I have comments on some patches, the general functionality for 
x86 seems to be work. I plan to do a POC with QEMU to test non-coco VM 
with guest_memfd with mmap support as the memory backend.


  reply	other threads:[~2025-07-18  6:14 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-17 16:27 [PATCH v15 00/21] KVM: Enable host userspace mapping for guest_memfd-backed memory for non-CoCo VMs Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 01/21] KVM: Rename CONFIG_KVM_PRIVATE_MEM to CONFIG_KVM_GMEM Fuad Tabba
2025-07-21 15:17   ` Sean Christopherson
2025-07-21 15:26     ` Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 02/21] KVM: Rename CONFIG_KVM_GENERIC_PRIVATE_MEM to CONFIG_KVM_GENERIC_GMEM_POPULATE Fuad Tabba
2025-07-21 16:44   ` Sean Christopherson
2025-07-21 16:51     ` Fuad Tabba
2025-07-21 17:33       ` Sean Christopherson
2025-07-22  9:29         ` Fuad Tabba
2025-07-22 15:58           ` Sean Christopherson
2025-07-22 16:01             ` Fuad Tabba
2025-07-22 23:42               ` Sean Christopherson
2025-07-23  9:22                 ` Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 03/21] KVM: Introduce kvm_arch_supports_gmem() Fuad Tabba
2025-07-18  1:42   ` Xiaoyao Li
2025-07-21 14:47     ` Sean Christopherson
2025-07-21 14:55     ` Fuad Tabba
2025-07-21 16:44   ` Sean Christopherson
2025-07-17 16:27 ` [PATCH v15 04/21] KVM: x86: Introduce kvm->arch.supports_gmem Fuad Tabba
2025-07-21 16:45   ` Sean Christopherson
2025-07-21 17:00     ` Fuad Tabba
2025-07-21 19:09       ` Sean Christopherson
2025-07-17 16:27 ` [PATCH v15 05/21] KVM: Rename kvm_slot_can_be_private() to kvm_slot_has_gmem() Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 06/21] KVM: Fix comments that refer to slots_lock Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 07/21] KVM: Fix comment that refers to kvm uapi header path Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 08/21] KVM: guest_memfd: Allow host to map guest_memfd pages Fuad Tabba
2025-07-18  2:56   ` Xiaoyao Li
2025-07-17 16:27 ` [PATCH v15 09/21] KVM: guest_memfd: Track guest_memfd mmap support in memslot Fuad Tabba
2025-07-18  3:33   ` Xiaoyao Li
2025-07-17 16:27 ` [PATCH v15 10/21] KVM: x86/mmu: Generalize private_max_mapping_level x86 op to max_mapping_level Fuad Tabba
2025-07-18  6:19   ` Xiaoyao Li
2025-07-21 19:46   ` Sean Christopherson
2025-07-17 16:27 ` [PATCH v15 11/21] KVM: x86/mmu: Allow NULL-able fault in kvm_max_private_mapping_level Fuad Tabba
2025-07-18  5:10   ` Xiaoyao Li
2025-07-21 23:17     ` Sean Christopherson
2025-07-22  5:35       ` Xiaoyao Li
2025-07-22 11:08         ` Fuad Tabba
2025-07-22 14:32           ` Sean Christopherson
2025-07-22 15:30             ` Fuad Tabba
2025-07-22 10:35       ` Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 12/21] KVM: x86/mmu: Consult guest_memfd when computing max_mapping_level Fuad Tabba
2025-07-18  5:32   ` Xiaoyao Li
2025-07-18  5:57     ` Xiaoyao Li
2025-07-17 16:27 ` [PATCH v15 13/21] KVM: x86/mmu: Handle guest page faults for guest_memfd with shared memory Fuad Tabba
2025-07-18  6:09   ` Xiaoyao Li
2025-07-21 16:47   ` Sean Christopherson
2025-07-21 16:56     ` Fuad Tabba
2025-07-22  5:41     ` Xiaoyao Li
2025-07-22  8:43       ` Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 14/21] KVM: x86: Enable guest_memfd mmap for default VM type Fuad Tabba
2025-07-18  6:10   ` Xiaoyao Li
2025-07-21 12:22   ` Xiaoyao Li
2025-07-21 12:41     ` Fuad Tabba
2025-07-21 13:45     ` Vishal Annapurve
2025-07-21 14:42       ` Xiaoyao Li
2025-07-21 14:42       ` Sean Christopherson
2025-07-21 15:07         ` Xiaoyao Li
2025-07-21 17:29           ` Sean Christopherson
2025-07-21 20:33             ` Vishal Annapurve
2025-07-21 22:21               ` Sean Christopherson
2025-07-21 23:50                 ` Vishal Annapurve
2025-07-22 14:35                   ` Sean Christopherson
2025-07-23 14:08                     ` Vishal Annapurve
2025-07-23 14:43                       ` Sean Christopherson
2025-07-23 14:46                         ` David Hildenbrand
2025-07-22 14:28     ` Xiaoyao Li
2025-07-22 14:37       ` Sean Christopherson
2025-07-22 15:31         ` Xiaoyao Li
2025-07-22 15:50           ` David Hildenbrand
2025-07-22 15:54           ` Sean Christopherson
2025-07-17 16:27 ` [PATCH v15 15/21] KVM: arm64: Refactor user_mem_abort() Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 16/21] KVM: arm64: Handle guest_memfd-backed guest page faults Fuad Tabba
2025-07-22 12:31   ` Kunwu Chan
2025-07-23  8:20     ` Marc Zyngier
2025-07-23 11:44       ` Kunwu Chan
2025-07-23  8:26   ` Marc Zyngier
2025-07-17 16:27 ` [PATCH v15 17/21] KVM: arm64: nv: Handle VNCR_EL2-triggered faults backed by guest_memfd Fuad Tabba
2025-07-23  8:29   ` Marc Zyngier
2025-07-17 16:27 ` [PATCH v15 18/21] KVM: arm64: Enable host mapping of shared guest_memfd memory Fuad Tabba
2025-07-23  8:33   ` Marc Zyngier
2025-07-23  9:18     ` Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 19/21] KVM: Introduce the KVM capability KVM_CAP_GMEM_MMAP Fuad Tabba
2025-07-18  6:14   ` Xiaoyao Li [this message]
2025-07-21 17:31   ` Sean Christopherson
2025-07-17 16:27 ` [PATCH v15 20/21] KVM: selftests: Do not use hardcoded page sizes in guest_memfd test Fuad Tabba
2025-07-17 16:27 ` [PATCH v15 21/21] KVM: selftests: guest_memfd mmap() test when mmap is supported Fuad Tabba

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