diff --git a/lib/CL.jl b/lib/CL.jl
index ea82ae0..a591b79 100644
--- a/lib/CL.jl
+++ b/lib/CL.jl
@@ -19,6 +19,7 @@ include("cmdqueue.jl")
 include("event.jl")
 include("memory.jl")
 include("buffer.jl")
+include("svm.jl")
 include("program.jl")
 include("kernel.jl")
 
diff --git a/lib/buffer.jl b/lib/buffer.jl
index 7e4cccf..3a7ba09 100644
--- a/lib/buffer.jl
+++ b/lib/buffer.jl
@@ -119,13 +119,9 @@ end
 Base.unsafe_copyto!(dst::Buffer, src::Buffer, N; kwargs...) =
     unsafe_copyto!(dst, 1, src, 1, N; kwargs...)
 
-# map a a buffer into the host address space and return a (pinned) array and an event
-function unsafe_map!(b::Buffer{T}, dims::Dims, flags=:rw; offset::Integer=0,
+# map a buffer into the host address space and return a (pinned) array and an event
+function unsafe_map!(b::Buffer{T}, dims::Dims, flags=:rw; offset::Integer=1,
                      blocking::Bool=false, wait_for::Vector{Event}=Event[]) where {T}
-    if length(b) < prod(dims) + offset
-        throw(ArgumentError("Buffer length must be greater than or
-                             equal to prod(dims) + offset"))
-    end
     n_evts  = length(wait_for)
     evt_ids = isempty(wait_for) ? C_NULL : [pointer(evt) for evt in wait_for]
     flags = if flags == :rw
@@ -140,8 +136,9 @@ function unsafe_map!(b::Buffer{T}, dims::Dims, flags=:rw; offset::Integer=0,
     nbytes  = prod(dims) * sizeof(T)
     ret_evt = Ref{cl_event}()
     status  = Ref{Cint}()
+    byteoffset = (offset - 1) * sizeof(T)
     mapped  = clEnqueueMapBuffer(queue(), b, blocking,
-                                 flags, offset, nbytes,
+                                 flags, byteoffset, nbytes,
                                  n_evts, evt_ids, ret_evt, status)
     if status[] != CL_SUCCESS
         throw(CLError(status[]))
@@ -155,7 +152,7 @@ function unsafe_unmap!(b::Buffer{T}, a::Array{T}; wait_for::Vector{Event}=Event[
     n_evts  = length(wait_for)
     evt_ids = isempty(wait_for) ? C_NULL : [pointer(evt) for evt in wait_for]
     ret_evt = Ref{cl_event}()
-    clEnqueueUnmapMemObject(queue(), b, a, n_evts, evt_ids, ret_evt)
+    clEnqueueUnmapMemObject(queue(), b, pointer(a), n_evts, evt_ids, ret_evt)
     return Event(ret_evt[])
 end
 
@@ -167,10 +164,11 @@ function unsafe_fill!(b::Buffer{T}, pattern::T, offset::Integer, N::Integer;
     ret_evt = Ref{cl_event}()
     nbytes = N * sizeof(T)
     nbytes_pattern = sizeof(T)
+    byteoffset = (offset - 1) * sizeof(T)
     @assert nbytes_pattern > 0
     clEnqueueFillBuffer(queue(), b, [pattern],
-                        nbytes_pattern, offset, nbytes,
+                        nbytes_pattern, byteoffset, nbytes,
                         n_evts, evt_ids, ret_evt)
     @return_event ret_evt[]
 end
-unsafe_fill!(b::Buffer, pattern, N::Integer) = unsafe_fill!(b, pattern, 0, N)
+unsafe_fill!(b::Buffer, pattern, N::Integer) = unsafe_fill!(b, pattern, 1, N)
diff --git a/lib/svm.jl b/lib/svm.jl
new file mode 100644
index 0000000..a8612b9
--- /dev/null
+++ b/lib/svm.jl
@@ -0,0 +1,112 @@
+mutable struct SVMBuffer{T}
+    ptr::Ptr{T}
+    len::Int
+
+    function SVMBuffer{T}(len::Integer, typ::Symbol=:rw;
+                          fine_grained=false, alignment=nothing) where {T}
+        flags = if typ == :rw
+            CL_MEM_READ_WRITE
+        elseif typ == :r
+            CL_MEM_READ_ONLY
+        elseif typ == :w
+            CL_MEM_WRITE_ONLY
+        else
+            throw(ArgumentError("Invalid access type"))
+        end
+
+        if fine_grained
+            flags |= CL_MEM_SVM_FINE_GRAIN_BUFFER
+        end
+
+        ptr = clSVMAlloc(context(), flags, len * sizeof(T), something(alignment, 0))
+        obj = new{T}(ptr, len)
+        finalizer(obj) do x
+            # TODO: asynchronous free using clEnqueueSVMFree?
+            clSVMFree(context(), x)
+        end
+
+        return obj
+    end
+end
+
+Base.unsafe_convert(::Type{Ptr{T}}, x::SVMBuffer) where {T} = convert(Ptr{T}, x.ptr)
+@inline function Base.pointer(x::SVMBuffer{T}, i::Integer=1) where T
+    Base.unsafe_convert(Ptr{T}, x) + (i-1)*sizeof(T)
+end
+
+Base.ndims(b::SVMBuffer) = 1
+Base.eltype(b::SVMBuffer{T}) where {T} = T
+Base.length(b::SVMBuffer{T}) where {T} = b.len
+Base.sizeof(b::SVMBuffer{T}) where {T} = b.len * sizeof(T)
+
+
+## memory operations
+
+# these generally only make sense for coarse-grained SVM buffers;
+# fine-grained buffers can just be used directly.
+
+# copy from and to SVM buffers
+for (srcty, dstty) in [(:Array, :SVMBuffer), (:SVMBuffer, :Array), (:SVMBuffer, :SVMBuffer)]
+    @eval begin
+        function Base.unsafe_copyto!(dst::$dstty{T}, dst_off::Int, src::$srcty{T}, src_off::Int,
+                                     N::Int; blocking::Bool=false,
+                                     wait_for::Vector{Event}=Event[]) where T
+            nbytes = N * sizeof(T)
+            n_evts  = length(wait_for)
+            evt_ids = isempty(wait_for) ? C_NULL : [pointer(evt) for evt in wait_for]
+            ret_evt = Ref{cl_event}()
+            clEnqueueSVMMemcpy(queue(), blocking, pointer(dst, dst_off),
+                               pointer(src, src_off), nbytes, n_evts, evt_ids, ret_evt)
+            @return_nanny_event(ret_evt[], dst)
+        end
+        Base.unsafe_copyto!(dst::$dstty, src::$srcty, N; kwargs...) =
+            unsafe_copyto!(dst, 1, src, 1, N; kwargs...)
+    end
+end
+
+# map an SVM buffer into the host address space and return a (pinned) array and an event
+function unsafe_map!(b::SVMBuffer{T}, dims::Dims, flags=:rw; offset::Integer=1,
+                     blocking::Bool=false, wait_for::Vector{Event}=Event[]) where {T}
+    n_evts  = length(wait_for)
+    evt_ids = isempty(wait_for) ? C_NULL : [pointer(evt) for evt in wait_for]
+    flags = if flags == :rw
+        CL_MAP_READ | CL_MAP_WRITE
+    elseif flags == :r
+        CL_MAP_READ
+    elseif flags == :w
+        CL_MAP_WRITE
+    else
+        throw(ArgumentError("enqueue_unmap can have flags of :r, :w, or :rw, got :$flags"))
+    end
+    nbytes  = prod(dims) * sizeof(T)
+    ret_evt = Ref{cl_event}()
+    clEnqueueSVMMap(queue(), blocking, flags, pointer(b, offset), nbytes,
+                    n_evts, evt_ids, ret_evt)
+
+    return unsafe_wrap(Array, pointer(b, offset), dims; own=false), Event(ret_evt[])
+end
+
+# unmap a buffer, return an event
+function unsafe_unmap!(b::SVMBuffer{T}, a::Array{T}; wait_for::Vector{Event}=Event[]) where {T}
+    n_evts  = length(wait_for)
+    evt_ids = isempty(wait_for) ? C_NULL : [pointer(evt) for evt in wait_for]
+    ret_evt = Ref{cl_event}()
+    clEnqueueSVMUnmap(queue(), pointer(a), n_evts, evt_ids, ret_evt)
+    return Event(ret_evt[])
+end
+
+# fill a buffer with a pattern, returning an event
+function unsafe_fill!(b::SVMBuffer{T}, pattern::T, offset::Integer, N::Integer;
+                      wait_for::Vector{Event}=Event[]) where {T}
+    n_evts  = length(wait_for)
+    evt_ids = isempty(wait_for) ? C_NULL : [pointer(evt) for evt in wait_for]
+    ret_evt = Ref{cl_event}()
+    nbytes = N * sizeof(T)
+    nbytes_pattern = sizeof(T)
+    @assert nbytes_pattern > 0
+    clEnqueueSVMMemFill(queue(), pointer(b, offset), [pattern],
+                        nbytes_pattern, nbytes,
+                        n_evts, evt_ids, ret_evt)
+    @return_event ret_evt[]
+end
+unsafe_fill!(b::SVMBuffer, pattern, N::Integer) = unsafe_fill!(b, pattern, 1, N)
diff --git a/test/buffer.jl b/test/buffer.jl
index f9e8418..ba02b9b 100644
--- a/test/buffer.jl
+++ b/test/buffer.jl
@@ -60,3 +60,46 @@
         @test arr == [42,42,42]
     end
 end
+
+
+@testset "SVMBuffer" begin
+    # simple buffer
+    let buf = cl.SVMBuffer{Int}(1)
+        @test ndims(buf) == 1
+        @test eltype(buf) == Int
+        @test length(buf) == 1
+        @test sizeof(buf) == sizeof(Int)
+    end
+
+    # memory copy
+    let buf = cl.SVMBuffer{Int}(1)
+        unsafe_copyto!(buf, [42], 1; blocking=true)
+
+        arr = [0]
+        cl.unsafe_copyto!(arr, buf, 1; blocking=true)
+        @test arr == [42]
+    end
+
+    # memory map
+    let buf = cl.SVMBuffer{Int}(1)
+        unsafe_copyto!(buf, [42], 1; blocking=true)
+
+        arr, evt = cl.unsafe_map!(buf, (1,), :rw)
+        wait(evt)
+        @test arr[] == 42
+        arr[] = 100
+        cl.unsafe_unmap!(buf, arr) |> wait
+
+        res = [0]
+        cl.unsafe_copyto!(res, buf, 1; blocking=true)
+        @test res == [100]
+    end
+
+    # fill
+    let buf = cl.SVMBuffer{Int}(3)
+        cl.unsafe_fill!(buf, 42, 3)
+        arr = Vector{Int}(undef, 3)
+        unsafe_copyto!(arr, buf, 3; blocking=true)
+        @test arr == [42,42,42]
+    end
+end