From bb58b90b1a8f753b582055adaf448214a8e22c31 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 27 Oct 2023 11:21:50 -0700 Subject: KVM: Introduce KVM_SET_USER_MEMORY_REGION2 Introduce a "version 2" of KVM_SET_USER_MEMORY_REGION so that additional information can be supplied without setting userspace up to fail. The padding in the new kvm_userspace_memory_region2 structure will be used to pass a file descriptor in addition to the userspace_addr, i.e. allow userspace to point at a file descriptor and map memory into a guest that is NOT mapped into host userspace. Alternatively, KVM could simply add "struct kvm_userspace_memory_region2" without a new ioctl(), but as Paolo pointed out, adding a new ioctl() makes detection of bad flags a bit more robust, e.g. if the new fd field is guarded only by a flag and not a new ioctl(), then a userspace bug (setting a "bad" flag) would generate out-of-bounds access instead of an -EINVAL error. Cc: Jarkko Sakkinen Reviewed-by: Paolo Bonzini Reviewed-by: Xiaoyao Li Signed-off-by: Sean Christopherson Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Message-Id: <20231027182217.3615211-9-seanjc@google.com> Acked-by: Kai Huang Signed-off-by: Paolo Bonzini --- Documentation/virt/kvm/api.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'Documentation/virt') diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 7025b3751027..9edd9e436bab 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6192,6 +6192,28 @@ to know what fields can be changed for the system register described by ``op0, op1, crn, crm, op2``. KVM rejects ID register values that describe a superset of the features supported by the system. +4.140 KVM_SET_USER_MEMORY_REGION2 +--------------------------------- + +:Capability: KVM_CAP_USER_MEMORY2 +:Architectures: all +:Type: vm ioctl +:Parameters: struct kvm_userspace_memory_region2 (in) +:Returns: 0 on success, -1 on error + +:: + + struct kvm_userspace_memory_region2 { + __u32 slot; + __u32 flags; + __u64 guest_phys_addr; + __u64 memory_size; /* bytes */ + __u64 userspace_addr; /* start of the userspace allocated memory */ + __u64 pad[16]; + }; + +See KVM_SET_USER_MEMORY_REGION. + 5. The kvm_run structure ======================== -- cgit v1.2.3-70-g09d2