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Rework copyDataToVMM to work in both directions

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This commit is contained in:
Sam Tebbs 2020-11-20 00:47:41 +00:00
parent a0c2bf758b
commit 6bbdadfa94
3 changed files with 62 additions and 40 deletions
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2
src/kernel/scheduler.zig
View file

@ -394,7 +394,7 @@ fn rt_user_task(allocator: *Allocator, mem_profile: *const mem.MemProfile) void
} orelse panic(null, "User task VMM didn't allocate space for the user program\n", .{});
if (code_start != 0) panic(null, "User program start address was {} instead of 0\n", .{code_start});
// 5. Copy user_program code over
vmm.kernel_vmm.copyDataToVMM(task_vmm, code[0..code_len], code_start) catch |e| {
vmm.kernel_vmm.copyData(task_vmm, code[0..code_len], code_start, true) catch |e| {
panic(@errorReturnTrace(), "Failed to copy user code: {}\n", .{e});
};
// 6. Schedule it

98
src/kernel/vmm.zig
View file

@ -424,10 +424,11 @@ pub fn VirtualMemoryManager(comptime Payload: type) type {
/// Copy data from an address in a virtual memory manager to an address in another virtual memory manager
///
/// Arguments:
/// IN self: *Self - The virtual memory that owns the data being copied. This must be the VMM currently in use
/// IN to: *const Self - The virtual memory manager that owns the address that the data is being copied to
/// IN data: []const u8 - The data being copied. Must be within memory mapped in `self`
/// IN dest: usize - The address within `to` to copy the data to. The space covered by `dest` and `dest` + `dest.len` must be mapped in `to`
/// IN self: *Self - One of the VMMs to copy between. This should be the currently active VMM
/// IN other: *Self - The second of the VMMs to copy between
/// IN data: []u8 - The being copied from or written to (depending on `from`). Must be mapped within the VMM being copied from/to
/// IN address: usize - The address within `other` that is to be copied from or to
/// IN from: bool - Whether the date should be copied from `self` to `other, or the other way around
///
/// Error: VmmError || pmm.PmmError || Allocator.Error
/// VmmError.NotAllocated - Some or all of the destination isn't mapped
@ -435,18 +436,18 @@ pub fn VirtualMemoryManager(comptime Payload: type) type {
/// Bitmap(u32).Error.OutOfBounds - The address given is outside of the memory managed
/// Allocator.Error.OutOfMemory - There wasn't enough memory available to fulfill the request
///
pub fn copyDataToVMM(self: *Self, to: *const Self, data: []const u8, dest: usize) (bitmap.Bitmap(usize).BitmapError || VmmError || Allocator.Error)!void {
pub fn copyData(self: *Self, other: *const Self, data: []u8, address: usize, from: bool) (bitmap.Bitmap(usize).BitmapError || VmmError || Allocator.Error)!void {
if (data.len == 0) {
return;
}
const start_addr = std.mem.alignBackward(dest, BLOCK_SIZE);
const end_addr = std.mem.alignForward(dest + data.len, BLOCK_SIZE);
if (end_addr >= to.end or start_addr < to.start)
const start_addr = std.mem.alignBackward(address, BLOCK_SIZE);
const end_addr = std.mem.alignForward(address + data.len, BLOCK_SIZE);
if (end_addr >= other.end or start_addr < other.start)
return bitmap.Bitmap(usize).BitmapError.OutOfBounds;
// Find physical blocks for `dest`
// Find physical blocks for the address
var blocks = std.ArrayList(usize).init(self.allocator);
defer blocks.deinit();
var it = to.allocations.iterator();
var it = other.allocations.iterator();
while (it.next()) |allocation| {
const virtual = allocation.key;
const physical = allocation.value.physical.items;
@ -462,11 +463,11 @@ pub fn VirtualMemoryManager(comptime Payload: type) type {
return VmmError.NotAllocated;
}
// Map them into `self` for some vaddr so they can be accessed from this VMM
// Map them into self for some vaddr so they can be accessed from this VMM
if (self.bmp.setContiguous(blocks.items.len)) |entry| {
const v_start = entry * BLOCK_SIZE + self.start;
defer {
// Unmap virtual blocks from `self` so they can be used in the future
// Unmap virtual blocks from self so they can be used in the future
var v = v_start;
while (v < v_start + blocks.items.len * BLOCK_SIZE) : (v += BLOCK_SIZE) {
// Cannot be out of bounds as it has been set above
@ -490,9 +491,13 @@ pub fn VirtualMemoryManager(comptime Payload: type) type {
};
}
// Copy to vaddr from above
const align_offset = dest - start_addr;
const align_offset = address - start_addr;
var data_copy = @intToPtr([*]u8, v_start + align_offset)[0..data.len];
std.mem.copy(u8, data_copy, data);
if (from) {
std.mem.copy(u8, data_copy, data);
} else {
std.mem.copy(u8, data, data_copy);
}
} else {
return VmmError.OutOfMemory;
}
@ -777,7 +782,7 @@ test "copy" {
std.testing.expectError(VmmError.NotAllocated, mirrored.virtToPhys(alloc4));
}
test "copyDataToVMM" {
test "copyData" {
var vmm = try testInit(100);
defer testDeinit(&vmm);
const alloc1_blocks = 1;
@ -787,23 +792,28 @@ test "copyDataToVMM" {
var vmm_free_entries = vmm.bmp.num_free_entries;
var vmm2_free_entries = vmm2.bmp.num_free_entries;
const buff: []const u8 = &[_]u8{ 10, 11, 12, 13 };
try vmm2.copyDataToVMM(&vmm, buff, alloc);
var buff: [4]u8 = [4]u8{ 10, 11, 12, 13 };
try vmm2.copyData(&vmm, buff[0..buff.len], alloc, true);
// Make sure they are the same
const buff2 = @intToPtr([*]u8, alloc)[0..buff.len];
std.testing.expectEqualSlices(u8, buff, buff2);
var buff2 = @intToPtr([*]u8, alloc)[0..buff.len];
std.testing.expectEqualSlices(u8, buff[0..buff.len], buff2);
std.testing.expectEqual(vmm_free_entries, vmm.bmp.num_free_entries);
std.testing.expectEqual(vmm2_free_entries, vmm2.bmp.num_free_entries);
try vmm2.copyData(&vmm, buff2, alloc, false);
std.testing.expectEqualSlices(u8, buff[0..buff.len], buff2);
std.testing.expectEqual(vmm_free_entries, vmm.bmp.num_free_entries);
std.testing.expectEqual(vmm2_free_entries, vmm2.bmp.num_free_entries);
// Test NotAllocated
std.testing.expectError(VmmError.NotAllocated, vmm2.copyDataToVMM(&vmm, buff, alloc + alloc1_blocks * BLOCK_SIZE));
std.testing.expectError(VmmError.NotAllocated, vmm2.copyData(&vmm, buff[0..buff.len], alloc + alloc1_blocks * BLOCK_SIZE, true));
std.testing.expectEqual(vmm_free_entries, vmm.bmp.num_free_entries);
std.testing.expectEqual(vmm2_free_entries, vmm2.bmp.num_free_entries);
// Test Bitmap.Error.OutOfBounds
std.testing.expectError(bitmap.Bitmap(usize).BitmapError.OutOfBounds, vmm2.copyDataToVMM(&vmm, buff, vmm.end));
std.testing.expectError(bitmap.Bitmap(usize).BitmapError.OutOfBounds, vmm.copyDataToVMM(&vmm2, buff, vmm2.end));
std.testing.expectError(bitmap.Bitmap(usize).BitmapError.OutOfBounds, vmm2.copyData(&vmm, buff[0..buff.len], vmm.end, true));
std.testing.expectError(bitmap.Bitmap(usize).BitmapError.OutOfBounds, vmm.copyData(&vmm2, buff[0..buff.len], vmm2.end, true));
std.testing.expectEqual(vmm_free_entries, vmm.bmp.num_free_entries);
std.testing.expectEqual(vmm2_free_entries, vmm2.bmp.num_free_entries);
}
@ -917,7 +927,7 @@ fn testUnmap(vstart: usize, vend: usize, payload: u8) (Allocator.Error || Mapper
///
pub fn runtimeTests(comptime Payload: type, vmm: *VirtualMemoryManager(Payload), mem_profile: *const mem.MemProfile) void {
rt_correctMapping(Payload, vmm, mem_profile);
rt_copyDataToVMM(vmm);
rt_copyData(vmm);
}
///
@ -964,27 +974,32 @@ fn rt_correctMapping(comptime Payload: type, vmm: *VirtualMemoryManager(Payload)
}
///
/// Test copying data to another VMM
/// Test copying data to and from another VMM
///
/// Arguments:
/// IN vmm: *VirtualMemoryManager() - The VMM to copy from
/// IN vmm: *VirtualMemoryManager() - The active VMM to test
///
fn rt_copyDataToVMM(vmm: *VirtualMemoryManager(arch.VmmPayload)) void {
fn rt_copyData(vmm: *VirtualMemoryManager(arch.VmmPayload)) void {
const expected_free_entries = vmm.bmp.num_free_entries;
// Mirror the VMM
var vmm2 = vmm.copy() catch |e| {
panic(@errorReturnTrace(), "Failed to mirror VMM: {}\n", .{e});
};
// Allocate within secondary VMM
const addr = vmm2.alloc(1, .{ .kernel = true, .cachable = true, .writable = true }) catch |e| {
panic(@errorReturnTrace(), "Failed to allocate within the secondary VMM in rt_copyDataToVMM: {}\n", .{e});
} orelse panic(@errorReturnTrace(), "Failed to get an allocation within the secondary VMM in rt_copyDataToVMM\n", .{});
panic(@errorReturnTrace(), "Failed to allocate within the secondary VMM in rt_copyData: {}\n", .{e});
} orelse panic(@errorReturnTrace(), "Failed to get an allocation within the secondary VMM in rt_copyData\n", .{});
defer vmm2.free(addr) catch |e| {
panic(@errorReturnTrace(), "Failed to free the allocation in secondary VMM: {}\n", .{e});
};
const expected_free_entries2 = vmm2.bmp.num_free_entries;
const expected_free_pmm_entries = pmm.blocksFree();
// Copy an arbitrary buffer into the allocation
const buff = &[_]u8{ 4, 5, 9, 123, 90, 67 };
vmm.copyDataToVMM(&vmm2, buff, addr) catch |e| {
panic(@errorReturnTrace(), "Failed to copy data to secondary VMM in rt_copyDataToVMM: {}\n", .{e});
// Try copying to vmm2
var buff: [6]u8 = [_]u8{ 4, 5, 9, 123, 90, 67 };
vmm.copyData(&vmm2, buff[0..buff.len], addr, true) catch |e| {
panic(@errorReturnTrace(), "Failed to copy data to secondary VMM in rt_copyData: {}\n", .{e});
};
// Make sure the function cleaned up
if (vmm.bmp.num_free_entries != expected_free_entries) {
@ -999,12 +1014,19 @@ fn rt_copyDataToVMM(vmm: *VirtualMemoryManager(arch.VmmPayload)) void {
// Make sure that the data at the allocated address is correct
// Since vmm2 is a mirror of vmm, this address should be mapped by the CPU's MMU
const buff2 = @intToPtr([*]u8, addr)[0..buff.len];
if (!std.mem.eql(u8, buff, buff2)) {
panic(@errorReturnTrace(), "buff2 is not the same as buff in rt_copyDataToVMM\n", .{});
const dest_buff = @intToPtr([*]u8, addr)[0..buff.len];
if (!std.mem.eql(u8, buff[0..buff.len], dest_buff)) {
panic(@errorReturnTrace(), "Data copied to vmm2 doesn't have the expected values\n", .{});
}
// Free the secondary VMM
vmm2.free(addr) catch |e| {
panic(@errorReturnTrace(), "Failed to free the allocation in secondary VMM: {}\n", .{e});
// Now try copying the same buffer from vmm2
var buff2 = vmm.allocator.alloc(u8, buff.len) catch |e| {
panic(@errorReturnTrace(), "Failed to allocate a test buffer in rt_copyData: {}\n", .{e});
};
vmm.copyData(&vmm2, buff2, addr, false) catch |e| {
panic(@errorReturnTrace(), "Failed to copy data from secondary VMM in rt_copyData: {}\n", .{e});
};
if (!std.mem.eql(u8, buff[0..buff.len], buff2)) {
panic(@errorReturnTrace(), "Data copied from vmm2 doesn't have the expected values\n", .{});
}
}

2
test/mock/kernel/vmm_mock.zig
View file

@ -47,7 +47,7 @@ pub fn VirtualMemoryManager(comptime Payload: type) type {
return VmmError.NotAllocated;
}
pub fn copyDataToVMM(self: *Self, to: *const Self, data: []const u8, dest: usize) (bitmap.Bitmap(usize).BitmapError || VmmError || Allocator.Error)!void {}
pub fn copyData(self: *Self, other: *Self, data: []const u8, dest: usize, from_self: bool) (bitmap.Bitmap(usize).BitmapError || VmmError || Allocator.Error)!void {}
};
}