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Enforce some sane limits on block device request sizes and throttle throughput.

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This commit is contained in:
Florian Nücke
2020-09-26 02:55:47 +02:00
parent 78b853308a
commit 5d6fab0dac
1 changed files with 50 additions and 5 deletions
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55
src/main/java/li/cil/circuity/vm/device/virtio/VirtIOBlockDevice.java
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@@ -59,6 +59,23 @@ public final class VirtIOBlockDevice extends AbstractVirtIODevice implements Ste
private static final int VIRTIO_BLK_CFG_CAPACITY_OFFSET = 0;
private static final int VIRTIO_BLK_CFG_CAPACITYH_OFFSET = 4;
private static final int VIRTIO_BLK_CFG_SIZE_MAX_OFFSET = 8;
private static final int VIRTIO_BLK_CFG_SEG_MAX_OFFSET = 12;
private static final int VIRTIO_BLK_CFG_GEOMETRY_CYLINDERS_OFFSET = 16;
private static final int VIRTIO_BLK_CFG_GEOMETRY_HEADS_OFFSET = 18;
private static final int VIRTIO_BLK_CFG_GEOMETRY_SECTORS_OFFSET = 19;
private static final int VIRTIO_BLK_CFG_BLK_SIZE_OFFSET = 20;
private static final int VIRTIO_BLK_CFG_TOPOLOGY_PHYSICAL_BLOCK_EXP_OFFSET = 24;
private static final int VIRTIO_BLK_CFG_TOPOLOGY_ALIGNMENT_OFFSET_OFFSET = 25;
private static final int VIRTIO_BLK_CFG_TOPOLOGY_MIN_IO_SIZE_OFFSET = 26;
private static final int VIRTIO_BLK_CFG_TOPOLOGY_OPT_IO_SIZE_OFFSET = 28;
private static final int VIRTIO_BLK_CFG_WRITEBACK_OFFSET = 32;
private static final int VIRTIO_BLK_CFG_MAX_DISCARD_SECTORS_OFFSET = 36;
private static final int VIRTIO_BLK_CFG_MAX_DISCARD_SEG_OFFSET = 40;
private static final int VIRTIO_BLK_CFG_DISCARD_SECTOR_ALIGNMENT_OFFSET = 44;
private static final int VIRTIO_BLK_CFG_MAX_WRITE_ZEROES_SECTORS_OFFSET = 48;
private static final int VIRTIO_BLK_CFG_MAX_WRITE_ZEROES_SEG_OFFSET = 52;
private static final int VIRTIO_BLK_CFG_WRITE_ZEROES_MAY_UNMAP_OFFSET = 56;
private static final int VIRTIO_BLK_T_IN = 0;
private static final int VIRTIO_BLK_T_OUT = 1;
@@ -72,17 +89,22 @@ public final class VirtIOBlockDevice extends AbstractVirtIODevice implements Ste
private static final int VIRTQ_REQUEST = 0;
private static final int BYTES_PER_CYCLE = 32;
private static final int MAX_SEGMENT_SIZE = 32 * 512;
private static final int MAX_SEGMENT_COUNT = 64;
private static final int BYTES_PER_THOUSAND_CYCLES = 32;
private static final ThreadLocal<ByteBuffer> requestHeaderBuffer = new ThreadLocal<>();
private final BlockDevice block;
private int remainingByteProcessingQuota;
public VirtIOBlockDevice(final MemoryMap memoryMap, final BlockDevice block) {
super(memoryMap, VirtIODeviceSpec.builder(VirtIODeviceType.VIRTIO_DEVICE_ID_BLOCK_DEVICE)
.configSpaceSize(56)
.queueCount(1)
.features(block.isReadonly() ? VIRTIO_BLK_F_RO : 0)
.features((block.isReadonly() ? VIRTIO_BLK_F_RO : 0) |
VIRTIO_BLK_F_SIZE_MAX |
VIRTIO_BLK_F_SEG_MAX)
.build());
this.block = block;
}
@@ -98,14 +120,17 @@ public final class VirtIOBlockDevice extends AbstractVirtIODevice implements Ste
return;
}
if (remainingByteProcessingQuota <= 0) {
remainingByteProcessingQuota += Math.max(1, cycles * BYTES_PER_THOUSAND_CYCLES / 1000);
}
try {
int remainingBytes = cycles * BYTES_PER_CYCLE;
while (remainingBytes > 0) {
while (remainingByteProcessingQuota > 0) {
final int processedBytes = processRequest();
if (processedBytes < 0) {
break;
}
remainingBytes -= processedBytes;
remainingByteProcessingQuota -= processedBytes;
}
} catch (final VirtIODeviceException | MemoryAccessException e) {
error();
@@ -151,6 +176,12 @@ public final class VirtIOBlockDevice extends AbstractVirtIODevice implements Ste
case VIRTIO_BLK_CFG_CAPACITYH_OFFSET: {
return (int) (capacityToSectorCount(block.getCapacity()) >>> 32);
}
case VIRTIO_BLK_CFG_SIZE_MAX_OFFSET: {
return MAX_SEGMENT_SIZE;
}
case VIRTIO_BLK_CFG_SEG_MAX_OFFSET: {
return MAX_SEGMENT_COUNT;
}
}
return super.loadConfig(offset, sizeLog2);
}
@@ -219,6 +250,13 @@ public final class VirtIOBlockDevice extends AbstractVirtIODevice implements Ste
throw new VirtIODeviceException();
}
// Ensure driver respects virtio_blk_config.size_max and virtio_blk_config.seg_max.
if (chain.writableBytes() > MAX_SEGMENT_COUNT * MAX_SEGMENT_SIZE) {
chain.skip(chain.writableBytes() - 1);
chain.put((byte) VIRTIO_BLK_S_IOERR);
break;
}
final long offset = sector * VIRTIO_BLK_SECTOR_SIZE;
int status = VIRTIO_BLK_S_OK;
try {
@@ -242,6 +280,13 @@ public final class VirtIOBlockDevice extends AbstractVirtIODevice implements Ste
throw new VirtIODeviceException();
}
// Ensure driver respects virtio_blk_config.size_max and virtio_blk_config.seg_max.
if (chain.readableBytes() > MAX_SEGMENT_COUNT * MAX_SEGMENT_SIZE) {
chain.skip(chain.readableBytes());
chain.put((byte) VIRTIO_BLK_S_IOERR);
break;
}
final long offset = sector * VIRTIO_BLK_SECTOR_SIZE;
int status = VIRTIO_BLK_S_OK;
try {