Extend the memslot definition to provide fd-based private memory support by adding two new fields (private_fd/private_offset). The memslot then can maintain memory for both shared pages and private pages in a single memslot. Shared pages are provided by existing userspace_addr(hva) field and private pages are provided through the new private_fd/private_offset fields.
Since there is no 'hva' concept anymore for private memory so we cannot rely on get_user_pages() to get a pfn, instead we use the newly added memfile_notifier to complete the same job. This new extension is indicated by a new flag KVM_MEM_PRIVATE. Signed-off-by: Yu Zhang <yu.c.zh...@linux.intel.com> Signed-off-by: Chao Peng <chao.p.p...@linux.intel.com> --- include/linux/kvm_host.h | 7 +++++++ include/uapi/linux/kvm.h | 8 ++++++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f079820f52b5..5011ac35bc50 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -458,8 +458,15 @@ struct kvm_memory_slot { u32 flags; short id; u16 as_id; + struct file *private_file; + loff_t private_offset; }; +static inline bool kvm_slot_is_private(const struct kvm_memory_slot *slot) +{ + return slot && (slot->flags & KVM_MEM_PRIVATE); +} + static inline bool kvm_slot_dirty_track_enabled(const struct kvm_memory_slot *slot) { return slot->flags & KVM_MEM_LOG_DIRTY_PAGES; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index fbfd70d965c6..5d6dceb1b93e 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -103,6 +103,13 @@ struct kvm_userspace_memory_region { __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 padding[5]; +}; + /* * The bit 0 ~ bit 15 of kvm_memory_region::flags are visible for userspace, * other bits are reserved for kvm internal use which are defined in @@ -110,6 +117,7 @@ struct kvm_userspace_memory_region { */ #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) #define KVM_MEM_READONLY (1UL << 1) +#define KVM_MEM_PRIVATE (1UL << 2) /* for KVM_IRQ_LINE */ struct kvm_irq_level { -- 2.17.1