Re: [RFC PATCH v11 06/29] KVM: Introduce KVM_SET_USER_MEMORY_REGION2
From: Quentin Perret <hidden>
Date: 2023-07-28 09:28:31
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-fsdevel, linux-mips, linux-mm, linux-riscv, linuxppc-dev, lkml
On Tuesday 18 Jul 2023 at 16:44:49 (-0700), Sean Christopherson wrote:
quoted hunk ↗ jump to hunk
--- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h@@ -95,6 +95,16 @@ struct kvm_userspace_memory_region { __u64 userspace_addr; /* start of the userspace allocated memory */ }; +/* for KVM_SET_USER_MEMORY_REGION2 */ +struct kvm_userspace_memory_region2 { + __u32 slot; + __u32 flags; + __u64 guest_phys_addr; + __u64 memory_size; + __u64 userspace_addr; + __u64 pad[16];
Should we replace that pad[16] with: __u64 size; where 'size' is the size of the structure as seen by userspace? This is used in other UAPIs (see struct sched_attr for example) and is a bit more robust for future extensions (e.g. an 'old' kernel can correctly reject a newer version of the struct with additional fields it doesn't know about if that makes sense, etc).