On Thu, Sep 15, 2022 at 10:29:07PM +0800, Chao Peng wrote: > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index abd7c32126ce..c1fac1e9f820 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -1319,7 +1319,7 @@ yet and must be cleared on entry. > :Capability: KVM_CAP_USER_MEMORY > :Architectures: all > :Type: vm ioctl > -:Parameters: struct kvm_userspace_memory_region (in) > +:Parameters: struct kvm_userspace_memory_region(_ext) (in) > :Returns: 0 on success, -1 on error > > :: > @@ -1332,9 +1332,18 @@ yet and must be cleared on entry. > __u64 userspace_addr; /* start of the userspace allocated memory */ > }; > > + struct kvm_userspace_memory_region_ext { > + struct kvm_userspace_memory_region region; > + __u64 private_offset; > + __u32 private_fd; > + __u32 pad1; > + __u64 pad2[14]; > + }; > + > /* for kvm_memory_region::flags */ > #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) > #define KVM_MEM_READONLY (1UL << 1) > + #define KVM_MEM_PRIVATE (1UL << 2) > > This ioctl allows the user to create, modify or delete a guest physical > memory slot. Bits 0-15 of "slot" specify the slot id and this value > @@ -1365,12 +1374,27 @@ It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr > be identical. This allows large pages in the guest to be backed by large > pages in the host. > > -The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and > -KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of > -writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to > -use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, > -to make a new slot read-only. In this case, writes to this memory will be > -posted to userspace as KVM_EXIT_MMIO exits. > +kvm_userspace_memory_region_ext includes all the kvm_userspace_memory_region > +fields. It also includes additional fields for some specific features. See > +below description of flags field for more information. It's recommended to use > +kvm_userspace_memory_region_ext in new userspace code. Better say "kvm_userspace_memory_region_ext includes all fields of kvm_userspace_memory_region struct, while also adds additional fields ..." > + > +The flags field supports below flags: s/below/following/ > + > +- KVM_MEM_LOG_DIRTY_PAGES can be set to instruct KVM to keep track of writes to > + memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to use it. > + Better say "... For more details, see KVM_GET_DIRTY_LOG." > +- KVM_MEM_READONLY can be set, if KVM_CAP_READONLY_MEM capability allows it, to > + make a new slot read-only. In this case, writes to this memory will be posted > + to userspace as KVM_EXIT_MMIO exits. > + Better say "if KVM_CAP_READONLY_MEM allows, KVM_MEM_READONLY makes a new slot read-only ..." > +- KVM_MEM_PRIVATE can be set to indicate a new slot has private memory backed by > + a file descirptor(fd) and the content of the private memory is invisible to > + userspace. In this case, userspace should use private_fd/private_offset in > + kvm_userspace_memory_region_ext to instruct KVM to provide private memory to > + guest. Userspace should guarantee not to map the same pfn indicated by > + private_fd/private_offset to different gfns with multiple memslots. Failed to > + do this may result undefined behavior. > For the lists above, s/can be set/ Thanks. -- An old man doll... just what I always wanted! - Clara