v86/src/virtio.js

1495 lines
45 KiB
JavaScript

"use strict";
// http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html
const VIRTIO_PCI_VENDOR_ID = 0x1AF4;
// Identifies vendor-specific PCI capability.
const VIRTIO_PCI_CAP_VENDOR = 0x09;
// Length (bytes) of VIRTIO_PCI_CAP linked list entry.
const VIRTIO_PCI_CAP_LENGTH = 16;
// Capability types.
const VIRTIO_PCI_CAP_COMMON_CFG = 1;
const VIRTIO_PCI_CAP_NOTIFY_CFG = 2;
const VIRTIO_PCI_CAP_ISR_CFG = 3;
const VIRTIO_PCI_CAP_DEVICE_CFG = 4;
const VIRTIO_PCI_CAP_PCI_CFG = 5;
// Status bits (device_status values).
const VIRTIO_STATUS_ACKNOWLEDGE = 1;
const VIRTIO_STATUS_DRIVER = 2;
const VIRTIO_STATUS_DRIVER_OK = 4;
const VIRTIO_STATUS_FEATURES_OK = 8;
const VIRTIO_STATUS_DEVICE_NEEDS_RESET = 64;
const VIRTIO_STATUS_FAILED = 128;
// ISR bits (isr_status values).
const VIRTIO_ISR_QUEUE = 1;
const VIRTIO_ISR_DEVICE_CFG = 2;
// Feature bits (bit positions).
const VIRTIO_F_RING_INDIRECT_DESC = 28;
const VIRTIO_F_RING_EVENT_IDX = 29;
const VIRTIO_F_VERSION_1 = 32;
// Queue struct sizes.
// Size (bytes) of the virtq_desc struct per queue size.
const VIRTQ_DESC_ENTRYSIZE = 16;
// Size (bytes) of the virtq_avail struct ignoring ring entries.
const VIRTQ_AVAIL_BASESIZE = 6;
// Size (bytes) of the virtq_avail struct per queue size.
const VIRTQ_AVAIL_ENTRYSIZE = 2;
// Size (bytes) of the virtq_used struct ignoring ring entries.
const VIRTQ_USED_BASESIZE = 6;
// Size (bytes) of the virtq_desc struct per queue size.
const VIRTQ_USED_ENTRYSIZE = 8;
// Mask for wrapping the idx field of the virtq_used struct so that the value
// naturally overflows after 65535 (idx is a word).
const VIRTQ_IDX_MASK = 0xFFFF;
// Queue flags.
const VIRTQ_DESC_F_NEXT = 1;
const VIRTQ_DESC_F_WRITE = 2;
const VIRTQ_DESC_F_INDIRECT = 4;
const VIRTQ_AVAIL_F_NO_INTERRUPT = 1;
const VIRTQ_USED_F_NO_NOTIFY = 1;
// Closure Compiler Types.
/**
* @typedef {!Array<{
* bytes: number,
* name: string,
* read: function():number,
* write: function(number)
* }>}
*/
var VirtIO_CapabilityStruct;
/**
* @typedef {
* {
* type: number,
* bar: number,
* port: number,
* use_mmio: boolean,
* offset: number,
* extra: Uint8Array,
* struct: VirtIO_CapabilityStruct,
* }}
*/
var VirtIO_CapabilityInfo;
/**
* @typedef {
* {
* size_supported: number,
* notify_offset: number,
* }}
*/
var VirtQueue_Options;
/**
* @typedef {
* {
* initial_port: number,
* queues: !Array<VirtQueue_Options>,
* features: !Array<number>,
* on_driver_ok: function(),
* }}
*/
var VirtIO_CommonCapabilityOptions;
/**
* @typedef {
* {
* initial_port: number,
* single_handler: boolean,
* handlers: !Array<function()>,
* }}
*/
var VirtIO_NotificationCapabilityOptions;
/**
* @typedef {
* {
* initial_port: number,
* }}
*/
var VirtIO_ISRCapabilityOptions;
/**
* @typedef {
* {
* initial_port: number,
* struct: VirtIO_CapabilityStruct,
* }}
*/
var VirtIO_DeviceSpecificCapabilityOptions;
/**
* @typedef {
* {
* name: string,
* pci_id: number,
* device_id: number,
* subsystem_device_id: number,
* common: VirtIO_CommonCapabilityOptions,
* notification: VirtIO_NotificationCapabilityOptions,
* isr_status: VirtIO_ISRCapabilityOptions,
* device_specific: (undefined | VirtIO_DeviceSpecificCapabilityOptions),
* }}
*/
var VirtIO_Options;
/**
* @constructor
* @param {CPU} cpu
* @param {VirtIO_Options} options
*/
function VirtIO(cpu, options)
{
const io = cpu.io;
/** @const @type {CPU} */
this.cpu = cpu;
/** @const @type {PCI} */
this.pci = cpu.devices.pci;
this.device_id = options.device_id;
this.pci_space =
[
// Vendor ID
VIRTIO_PCI_VENDOR_ID & 0xFF, VIRTIO_PCI_VENDOR_ID >> 8,
// Device ID
options.device_id & 0xFF, options.device_id >> 8,
// Command
0x07, 0x05,
// Status - enable capabilities list
0x10, 0x00,
// Revision ID
0x01,
// Prof IF, Subclass, Class code
0x00, 0x02, 0x00,
// Cache line size
0x00,
// Latency Timer
0x00,
// Header Type
0x00,
// Built-in self test
0x00,
// BAR0
0x01, 0xa8, 0x00, 0x00,
// BAR1
0x00, 0x10, 0xbf, 0xfe,
// BAR2
0x00, 0x00, 0x00, 0x00,
// BAR3
0x00, 0x00, 0x00, 0x00,
// BAR4
0x00, 0x00, 0x00, 0x00,
// BAR5
0x00, 0x00, 0x00, 0x00,
// CardBus CIS pointer
0x00, 0x00, 0x00, 0x00,
// Subsystem vendor ID
VIRTIO_PCI_VENDOR_ID & 0xFF, VIRTIO_PCI_VENDOR_ID >> 8,
// Subsystem ID
options.subsystem_device_id & 0xFF, options.subsystem_device_id >> 8,
// Expansion ROM base address
0x00, 0x00, 0x00, 0x00,
// Capabilities pointer
0x40,
// Reserved
0x00, 0x00, 0x00,
// Reserved
0x00, 0x00, 0x00, 0x00,
// Interrupt line
0x00,
// Interrupt pin
0x01,
// Min grant
0x00,
// Max latency
0x00,
];
// Prevent sparse arrays by preallocating.
this.pci_space = this.pci_space.concat(v86util.zeros(256 - this.pci_space.length));
// Remaining PCI space is appended by capabilities further below.
this.pci_id = options.pci_id;
// PCI bars gets filled in by capabilities further below.
this.pci_bars = [];
this.name = options.name;
// Feature bits grouped in dwords, dword selected by decive_feature_select.
this.device_feature_select = 0;
this.driver_feature_select = 0;
// Unspecified upper bound. Assume 4*32=128 bits.
this.device_feature = new Uint32Array(4);
this.driver_feature = new Uint32Array(4);
for(const f of options.common.features)
{
dbg_assert(f >= 0,
"VirtIO device<" + this.name + "> feature bit numbers must be non-negative");
dbg_assert(f < 128,
"VirtIO device<" + this.name + "> feature bit numbers assumed less than 128 in implementation");
// Feature bits are grouped in 32 bits.
this.device_feature[f >>> 5] |= 1 << (f & 0x1F);
this.driver_feature[f >>> 5] |= 1 << (f & 0x1F);
}
dbg_assert(options.common.features.includes(VIRTIO_F_VERSION_1),
"VirtIO device<" + this.name + "> only non-transitional devices are supported");
// Indicates whether driver_feature bits is subset of device_feature bits.
this.features_ok = true;
this.device_status = 0;
this.config_has_changed = false;
this.config_generation = 0;
/** @type {!Array<VirtQueue>} */
this.queues = [];
for(const queue_options of options.common.queues)
{
this.queues.push(new VirtQueue(cpu, this, queue_options));
}
this.queue_select = 0;
this.queue_selected = this.queues[0];
this.isr_status = 0;
// Verify notification options.
if(DEBUG)
{
const offsets = new Set();
for(const offset of this.queues.map(q => q.notify_offset))
{
const effective_offset = options.notification.single_handler ? 0 : offset;
offsets.add(effective_offset);
dbg_assert(options.notification.handlers[effective_offset],
"VirtIO device<" + this.name + "> every queue's notifier must exist");
}
for(const [index, handler] of options.notification.handlers.entries())
{
dbg_assert(!handler || offsets.has(index),
"VirtIO device<" + this.name +"> no defined notify handler should be unused");
}
}
/** @type {!Array<VirtIO_CapabilityInfo>} */
const capabilities = [];
capabilities.push(this.create_common_capability(options.common));
capabilities.push(this.create_notification_capability(options.notification));
capabilities.push(this.create_isr_capability(options.isr_status));
if(options.device_specific)
{
capabilities.push(this.create_device_specific_capability(options.device_specific));
}
this.init_capabilities(capabilities);
cpu.devices.pci.register_device(this);
this.reset();
}
/**
* @param {VirtIO_CommonCapabilityOptions} options
* @return {VirtIO_CapabilityInfo}
*/
VirtIO.prototype.create_common_capability = function(options)
{
return {
type: VIRTIO_PCI_CAP_COMMON_CFG,
bar: 0,
port: options.initial_port,
use_mmio: false,
offset: 0,
extra: new Uint8Array(0),
struct:
[
{
bytes: 4,
name: "device_feature_select",
read: () => this.device_feature_select,
write: data =>
{
this.device_feature_select = data;
},
},
{
bytes: 4,
name: "device_feature",
read: () => this.device_feature[this.device_feature_select] || 0,
write: data => { /* read only */ },
},
{
bytes: 4,
name: "driver_feature_select",
read: () => this.driver_feature_select,
write: data =>
{
this.driver_feature_select = data;
},
},
{
bytes: 4,
name: "driver_feature",
read: () => this.driver_feature[this.driver_feature_select] || 0,
write: data =>
{
const supported_feature = this.device_feature[this.driver_feature_select];
if(this.driver_feature_select < this.driver_feature.length)
{
// Note: only set subset of device_features is set.
// Required in our implementation for is_feature_negotiated().
this.driver_feature[this.driver_feature_select] = data & supported_feature;
}
// Check that driver features is an inclusive subset of device features.
const invalid_bits = data & ~supported_feature;
this.features_ok = this.features_ok && !invalid_bits;
},
},
{
bytes: 2,
name: "msix_config",
read: () =>
{
dbg_log("No msi-x capability supported.", LOG_VIRTIO);
return 0xFFFF;
},
write: data =>
{
dbg_log("No msi-x capability supported.", LOG_VIRTIO);
},
},
{
bytes: 2,
name: "num_queues",
read: () => this.queues.length,
write: data => { /* read only */ },
},
{
bytes: 1,
name: "device_status",
read: () => this.device_status,
write: data =>
{
if(data === 0)
{
dbg_log("Reset device<" + this.name + ">", LOG_VIRTIO);
this.reset();
}
else if(data & VIRTIO_STATUS_FAILED)
{
dbg_log("Warning: Device<" + this.name + "> status failed", LOG_VIRTIO);
}
else
{
dbg_log("Device<" + this.name +"> status: " +
((data & VIRTIO_STATUS_ACKNOWLEDGE) ? "ACKNOWLEDGE " : "") +
((data & VIRTIO_STATUS_DRIVER) ? "DRIVER " : "") +
((data & VIRTIO_STATUS_DRIVER_OK) ? "DRIVER_OK" : "") +
((data & VIRTIO_STATUS_FEATURES_OK) ? "FEATURES_OK " : "") +
((data & VIRTIO_STATUS_DEVICE_NEEDS_RESET) ? "DEVICE_NEEDS_RESET" : ""),
LOG_VIRTIO);
}
if((data & ~this.device_status & VIRTIO_STATUS_DRIVER_OK) &&
(this.device_status & VIRTIO_STATUS_DEVICE_NEEDS_RESET))
{
// We couldn't notify NEEDS_RESET earlier because DRIVER_OK was not set.
// Now it has been set, notify now.
this.notify_config_changes();
}
// Don't set FEATURES_OK if our device doesn't support requested features.
if(!this.features_ok)
{
if(DEBUG && (data & VIRTIO_STATUS_FEATURES_OK))
{
dbg_log("Removing FEATURES_OK", LOG_VIRTIO);
}
data &= ~VIRTIO_STATUS_FEATURES_OK;
}
this.device_status = data;
if(data & ~this.device_status & VIRTIO_STATUS_DRIVER_OK)
{
options.on_driver_ok();
}
},
},
{
bytes: 1,
name: "config_generation",
read: () => this.config_generation,
write: data => { /* read only */ },
},
{
bytes: 2,
name: "queue_select",
read: () => this.queue_select,
write: data =>
{
this.queue_select = data;
if(this.queue_select < this.queues.length)
{
this.queues_selected = this.queues[this.queue_select];
}
else
{
// Allow queue_select >= num_queues.
this.queue_selected = null;
// Drivers can then detect that the queue is not available
// using the below fields.
}
},
},
{
bytes: 2,
name: "queue_size",
read: () => this.queue_selected ? this.queue_selected.size : 0,
write: data =>
{
if(!this.queue_selected)
{
return;
}
if(data & data - 1)
{
dbg_log("Warning: dev<" + this.name +"> " +
"Given queue size was not a power of 2. " +
"Rounding up to next power of 2.", LOG_VIRTIO);
data = 1 << (v86util.int_log2(data - 1) + 1);
}
if(data > this.queue_selected.size_supported)
{
dbg_log("Warning: dev<" + this.name +"> " +
"Trying to set queue size greater than supported. " +
"Clamping to supported size.", LOG_VIRTIO);
data = this.queue_selected.size_supported;
}
this.queue_selected.set_size(data);
},
},
{
bytes: 2,
name: "queue_msix_vector",
read: () =>
{
dbg_log("No msi-x capability supported.", LOG_VIRTIO);
return 0xFFFF;
},
write: data =>
{
dbg_log("No msi-x capability supported.", LOG_VIRTIO);
},
},
{
bytes: 2,
name: "queue_enable",
read: () => this.queue_selected ? this.queue_selected.enabled | 0 : 0,
write: data =>
{
if(!this.queue_selected)
{
return;
}
if(data === 1)
{
if(this.queue_selected.is_configured())
{
this.queue_selected.enable();
}
else
{
dbg_log("Driver bug: tried enabling unconfigured queue", LOG_VIRTIO);
}
}
else if(data === 0)
{
dbg_log("Driver bug: tried writing 0 to queue_enable", LOG_VIRTIO);
}
},
},
{
bytes: 2,
name: "queue_notify_off",
read: () => this.queue_selected ? this.queue_selected.notify_offset : 0,
write: data => { /* read only */ },
},
{
bytes: 4,
name: "queue_desc (low dword)",
read: () => this.queue_selected ? this.queue_selected.desc_addr : 0,
write: data =>
{
if(this.queue_selected) this.queue_selected.desc_addr = data;
},
},
{
bytes: 4,
name: "queue_desc (high dword)",
read: () => 0,
write: data =>
{
dbg_log("Warning: High dword of 64 bit queue_desc ignored", LOG_VIRTIO);
},
},
{
bytes: 4,
name: "queue_avail (low dword)",
read: () => this.queue_selected ? this.queue_selected.avail_addr : 0,
write: data =>
{
if(this.queue_selected) this.queue_selected.avail_addr = data;
},
},
{
bytes: 4,
name: "queue_avail (high dword)",
read: () => 0,
write: data =>
{
dbg_log("Warning: High dword of 64 bit queue_avail ignored", LOG_VIRTIO);
},
},
{
bytes: 4,
name: "queue_used (low dword)",
read: () => this.queue_selected ? this.queue_selected.used_addr : 0,
write: data =>
{
if(this.queue_selected) this.queue_selected.used_addr = data;
},
},
{
bytes: 4,
name: "queue_used (high dword)",
read: () => 0,
write: data =>
{
dbg_log("Warning: High dword of 64 bit queue_used ignored", LOG_VIRTIO);
},
},
],
};
};
/**
* @param {VirtIO_NotificationCapabilityOptions} options
* @return {VirtIO_CapabilityInfo}
*/
VirtIO.prototype.create_notification_capability = function(options)
{
const notify_struct = [];
let notify_off_multiplier;
if(options.single_handler)
{
dbg_assert(options.handlers.length === 1,
"VirtIO device<" + this.name + "> too many notify handlers specified: expected single handler");
// Forces all queues to use the same address for notifying.
notify_off_multiplier = 0;
}
else
{
notify_off_multiplier = 2;
}
for(const [i, handler] of options.handlers.entries())
{
notify_struct.push(
{
bytes: 2,
name: "notify" + i,
read: () => 0xFFFF,
write: handler || (data => {}),
});
}
return {
type: VIRTIO_PCI_CAP_NOTIFY_CFG,
bar: 1,
port: options.initial_port,
use_mmio: false,
offset: 0,
extra: new Uint8Array(
[
notify_off_multiplier & 0xFF,
(notify_off_multiplier >> 8) & 0xFF,
(notify_off_multiplier >> 16) & 0xFF,
notify_off_multiplier >> 24,
]),
struct: notify_struct,
};
};
/**
* @param {VirtIO_ISRCapabilityOptions} options
* @return {VirtIO_CapabilityInfo}
*/
VirtIO.prototype.create_isr_capability = function(options)
{
return {
type: VIRTIO_PCI_CAP_ISR_CFG,
bar: 2,
port: options.initial_port,
use_mmio: false,
offset: 0,
extra: new Uint8Array(0),
struct:
[
{
bytes: 1,
name: "isr_status",
read: () =>
{
const isr_status = this.isr_status;
this.lower_irq();
return isr_status;
},
write: data => { /* read only */ },
},
],
};
};
/**
* @param {VirtIO_DeviceSpecificCapabilityOptions} options
* @return {VirtIO_CapabilityInfo}
*/
VirtIO.prototype.create_device_specific_capability = function(options)
{
dbg_assert(~options.offset & 0x3,
"VirtIO device<" + this.name + "> device specific cap offset must be 4-byte aligned");
return {
type: VIRTIO_PCI_CAP_DEVICE_CFG,
bar: 3,
port: options.initial_port,
use_mmio: false,
offset: 0,
extra: new Uint8Array(0),
struct: options.struct,
};
};
/**
* Writes capabilities into pci_space and hook up IO/MMIO handlers.
* Call only within constructor.
* @param {!Array<VirtIO_CapabilityInfo>} capabilities
*/
VirtIO.prototype.init_capabilities = function(capabilities)
{
// Next available offset for capabilities linked list.
let cap_next = this.pci_space[0x34] = 0x40;
// Current offset.
let cap_ptr = cap_next;
for(const cap of capabilities)
{
const cap_len = VIRTIO_PCI_CAP_LENGTH + cap.extra.length;
cap_ptr = cap_next;
cap_next = cap_ptr + cap_len;
dbg_assert(cap_next <= 256,
"VirtIO device<" + this.name + "> can't fit all capabilities into 256byte configspace");
dbg_assert(0 <= cap.bar && cap.bar < 6,
"VirtIO device<" + this.name + "> capability invalid bar number");
let bar_size = cap.struct.reduce((bytes, field) => bytes + field.bytes, 0);
bar_size += cap.offset;
// Round up to next power of 2,
// Minimum 16 bytes for its size to be detectable in general (esp. mmio).
bar_size = bar_size < 16 ? 16 : 1 << (v86util.int_log2(bar_size - 1) + 1);
dbg_assert((cap.port & (bar_size - 1)) === 0,
"VirtIO device<" + this.name + "> capability port should be aligned to pci bar size");
this.pci_bars[cap.bar] =
{
size: bar_size,
};
this.pci_space[cap_ptr] = VIRTIO_PCI_CAP_VENDOR;
this.pci_space[cap_ptr + 1] = cap_next;
this.pci_space[cap_ptr + 2] = cap_len;
this.pci_space[cap_ptr + 3] = cap.type;
this.pci_space[cap_ptr + 4] = cap.bar;
this.pci_space[cap_ptr + 5] = 0; // Padding.
this.pci_space[cap_ptr + 6] = 0; // Padding.
this.pci_space[cap_ptr + 7] = 0; // Padding.
this.pci_space[cap_ptr + 8] = cap.offset & 0xFF;
this.pci_space[cap_ptr + 9] = (cap.offset >>> 8) & 0xFF;
this.pci_space[cap_ptr + 10] = (cap.offset >>> 16) & 0xFF;
this.pci_space[cap_ptr + 11] = cap.offset >>> 24;
this.pci_space[cap_ptr + 12] = bar_size & 0xFF;
this.pci_space[cap_ptr + 13] = (bar_size >>> 8) & 0xFF;
this.pci_space[cap_ptr + 14] = (bar_size >>> 16) & 0xFF;
this.pci_space[cap_ptr + 15] = bar_size >>> 24;
for(const [i, extra_byte] of cap.extra.entries())
{
this.pci_space[cap_ptr + 16 + i] = extra_byte;
}
const bar_offset = 0x10 + 4 * cap.bar;
this.pci_space[bar_offset] = (cap.port & 0xFE) | !cap.use_mmio;
this.pci_space[bar_offset + 1] = (cap.port >>> 8) & 0xFF;
this.pci_space[bar_offset + 2] = (cap.port >>> 16) & 0xFF;
this.pci_space[bar_offset + 3] = (cap.port >>> 24) & 0xFF;
let port = cap.port + cap.offset;
for(const field of cap.struct)
{
let read = field.read;
let write = field.write;
if(DEBUG)
{
read = () =>
{
const val = field.read();
dbg_log("Device<" + this.name + "> " +
"cap[" + cap.type + "] " +
"read[" + field.name + "] " +
"=> " + h(val, field.bytes * 8),
LOG_VIRTIO);
return val;
};
write = data =>
{
dbg_log("Device<" + this.name + "> " +
"cap[" + cap.type + "] " +
"write[" + field.name + "] " +
"<= " + h(data, field.bytes * 8),
LOG_VIRTIO);
field.write(data);
};
}
if(cap.use_mmio)
{
dbg_assert(false, "VirtIO device <" + this.name + "> mmio capability not implemented.");
}
else
{
// DSL (2.4 kernel) does these reads
const shim_read8_on_16 = function(addr)
{
dbg_log("Warning: 8-bit read from 16-bit virtio port", LOG_VIRTIO);
return read(addr & ~1) >> ((addr & 1) << 3) & 0xFF;
};
const shim_read8_on_32 = function(addr)
{
dbg_log("Warning: 8-bit read from 32-bit virtio port", LOG_VIRTIO);
return read(addr & ~3) >> ((addr & 3) << 3) & 0xFF;
};
switch(field.bytes)
{
case 4:
this.cpu.io.register_read(port, this, shim_read8_on_32, undefined, read);
this.cpu.io.register_write(port, this, undefined, undefined, write);
break;
case 2:
this.cpu.io.register_read(port, this, shim_read8_on_16, read);
this.cpu.io.register_write(port, this, undefined, write);
break;
case 1:
this.cpu.io.register_read(port, this, read);
this.cpu.io.register_write(port, this, write);
break;
default:
dbg_assert(false,
"VirtIO device <" + this.name + "> invalid capability field width of " +
field.bytes + " bytes");
break;
}
}
port += field.bytes;
}
}
// Terminate linked list with the pci config access capability.
const cap_len = VIRTIO_PCI_CAP_LENGTH + 4;
dbg_assert(cap_next + cap_len <= 256,
"VirtIO device<" + this.name + "> can't fit all capabilities into 256byte configspace");
this.pci_space[cap_next] = VIRTIO_PCI_CAP_VENDOR;
this.pci_space[cap_next + 1] = 0; // cap next (null terminator)
this.pci_space[cap_next + 2] = cap_len;
this.pci_space[cap_next + 3] = VIRTIO_PCI_CAP_PCI_CFG; // cap type
this.pci_space[cap_next + 4] = 0; // bar (written by device)
this.pci_space[cap_next + 5] = 0; // Padding.
this.pci_space[cap_next + 6] = 0; // Padding.
this.pci_space[cap_next + 7] = 0; // Padding.
// Remaining fields are configured by driver when needed.
// offset
this.pci_space[cap_next + 8] = 0;
this.pci_space[cap_next + 9] = 0;
this.pci_space[cap_next + 10] = 0;
this.pci_space[cap_next + 11] = 0;
// bar size
this.pci_space[cap_next + 12] = 0;
this.pci_space[cap_next + 13] = 0;
this.pci_space[cap_next + 14] = 0;
this.pci_space[cap_next + 15] = 0;
// cfg_data
this.pci_space[cap_next + 16] = 0;
this.pci_space[cap_next + 17] = 0;
this.pci_space[cap_next + 18] = 0;
this.pci_space[cap_next + 19] = 0;
//
// TODO
// The pci config access capability is required by spec, but so far, devices
// seem to work well without it.
// This capability provides a cfg_data field (at cap_next + 16 for 4 bytes)
// that acts like a window to the previous bars. The driver writes the bar number,
// offset, and length values in this capability, and the cfg_data field should
// mirror the data referred by the bar, offset and length. Here, length can be
// 1, 2, or 4.
//
// This requires some sort of pci devicespace read and write handlers.
};
VirtIO.prototype.get_state = function()
{
let state = [];
state[0] = this.device_feature_select;
state[1] = this.driver_feature_select;
state[2] = this.device_feature;
state[3] = this.driver_feature;
state[4] = this.features_ok;
state[5] = this.device_status;
state[6] = this.config_has_changed;
state[7] = this.config_generation;
state[8] = this.isr_status;
state[9] = this.queue_select;
state = state.concat(this.queues);
return state;
};
VirtIO.prototype.set_state = function(state)
{
this.device_feature_select = state[0];
this.driver_feature_select = state[1];
this.device_feature = state[2];
this.driver_feature = state[3];
this.features_ok = state[4];
this.device_status = state[5];
this.config_has_changed = state[6];
this.config_generation = state[7];
this.isr_status = state[8];
this.queue_select = state[9];
let i = 0;
for(let queue of state.slice(10))
{
this.queues[i].set_state(queue);
i++;
}
this.queue_selected = this.queues[this.queue_select] || null;
};
VirtIO.prototype.reset = function()
{
this.device_feature_select = 0;
this.driver_feature_select = 0;
this.driver_feature.set(this.device_feature);
this.features_ok = true;
this.device_status = 0;
this.queue_select = 0;
this.queue_selected = this.queues[0];
for(const queue of this.queues)
{
queue.reset();
}
this.config_has_changed = false;
this.config_generation = 0;
this.lower_irq();
};
/**
* Call this when device-specific configuration state changes.
* Also called when status DEVICE_NEEDS_RESET is set.
*/
VirtIO.prototype.notify_config_changes = function()
{
this.config_has_changed = true;
if(this.device_status & VIRTIO_STATUS_DRIVER_OK)
{
this.raise_irq(VIRTIO_ISR_DEVICE_CFG);
}
else
{
dbg_assert(false,
"VirtIO device<" + this.name + "> attempted to notify driver before DRIVER_OK");
}
};
/**
* To be called after reading any field whose write can trigger notify_config_changes().
*/
VirtIO.prototype.update_config_generation = function()
{
if(this.config_has_changed)
{
this.config_generation++;
this.config_generation &= 0xFF;
this.config_has_changed = false;
}
};
VirtIO.prototype.is_feature_negotiated = function(feature)
{
// Feature bits are grouped in 32 bits.
// Note: earlier we chose not to set invalid features into driver_feature.
return (this.driver_feature[feature >>> 5] & (1 << (feature & 0x1F))) > 0;
};
/**
* Call this if an irrecoverable error has been occured.
* Notifies driver if DRIVER_OK, or when DRIVER_OK gets set.
*/
VirtIO.prototype.needs_reset = function()
{
dbg_log("Device<" + this.name + "> experienced error - requires reset", LOG_VIRTIO);
this.device_status |= VIRTIO_STATUS_DEVICE_NEEDS_RESET;
if(this.device_status & VIRTIO_STATUS_DRIVER_OK)
{
this.notify_config_changes();
}
};
VirtIO.prototype.raise_irq = function(type)
{
dbg_log("Raise irq " + h(type), LOG_VIRTIO);
this.isr_status |= type;
this.pci.raise_irq(this.pci_id);
};
VirtIO.prototype.lower_irq = function()
{
dbg_log("Lower irq ", LOG_VIRTIO);
this.isr_status = 0;
this.pci.lower_irq(this.pci_id);
};
/**
* @constructor
* @param {CPU} cpu
* @param {VirtQueue_Options} options
*/
function VirtQueue(cpu, virtio, options)
{
/** @const @type {CPU} */
this.cpu = cpu;
/** @const @type {VirtIO} */
this.virtio = virtio;
// Number of entries.
this.size = options.size_supported;
this.size_supported = options.size_supported;
this.mask = this.size - 1;
this.enabled = false;
this.notify_offset = options.notify_offset;
this.desc_addr = 0;
this.avail_addr = 0;
this.avail_last_idx = 0;
this.used_addr = 0;
this.num_staged_replies = 0;
this.reset();
}
VirtQueue.prototype.get_state = function()
{
const state = [];
state[0] = this.size;
state[1] = this.size_supported;
state[2] = this.enabled;
state[3] = this.notify_offset;
state[4] = this.desc_addr;
state[5] = this.avail_addr;
state[6] = this.avail_last_idx;
state[7] = this.used_addr;
state[8] = this.num_staged_replies;
return state;
};
VirtQueue.prototype.set_state = function(state)
{
this.size = state[0];
this.size_supported = state[1];
this.enabled = state[2];
this.notify_offset = state[3];
this.desc_addr = state[4];
this.avail_addr = state[5];
this.avail_last_idx = state[6];
this.used_addr = state[7];
this.num_staged_replies = state[8];
this.mask = this.size - 1;
};
VirtQueue.prototype.reset = function()
{
this.enabled = false;
this.desc_addr = 0;
this.avail_addr = 0;
this.avail_last_idx = 0;
this.used_addr = 0;
this.num_staged_replies = 0;
this.set_size(this.size_supported);
};
VirtQueue.prototype.is_configured = function()
{
return this.desc_addr && this.avail_addr && this.used_addr;
};
VirtQueue.prototype.enable = function()
{
dbg_assert(this.is_configured(), "VirtQueue must be configured before enabled");
this.enabled = true;
};
VirtQueue.prototype.set_size = function(size)
{
dbg_assert((size & size - 1) === 0, "VirtQueue size must be power of 2 or zero");
dbg_assert(size <= this.size_supported, "VirtQueue size must be within supported size");
this.size = size;
this.mask = size - 1;
};
/**
* @return {number}
*/
VirtQueue.prototype.count_requests = function()
{
dbg_assert(this.avail_addr, "VirtQueue addresses must be configured before use");
return (this.avail_get_idx() - this.avail_last_idx) & this.mask;
};
/**
* @return {boolean}
*/
VirtQueue.prototype.has_request = function()
{
dbg_assert(this.avail_addr, "VirtQueue addresses must be configured before use");
return (this.avail_get_idx() & this.mask) !== this.avail_last_idx;
};
/**
* @return {VirtQueueBufferChain}
*/
VirtQueue.prototype.pop_request = function()
{
dbg_assert(this.avail_addr, "VirtQueue addresses must be configured before use");
dbg_assert(this.has_request(), "VirtQueue must not pop nonexistent request");
const desc_idx = this.avail_get_entry(this.avail_last_idx);
dbg_log("Pop request: avail_last_idx=" + this.avail_last_idx +
" desc_idx=" + desc_idx, LOG_VIRTIO);
const bufchain = new VirtQueueBufferChain(this, desc_idx);
this.avail_last_idx = this.avail_last_idx + 1 & this.mask;
return bufchain;
};
/**
* Stage a buffer chain into the used ring.
* Can call push_reply many times before flushing to batch replies together.
* Note: this reply is not visible to driver until flush_replies is called.
* @param {VirtQueueBufferChain} bufchain
*/
VirtQueue.prototype.push_reply = function(bufchain)
{
dbg_assert(this.used_addr, "VirtQueue addresses must be configured before use");
dbg_assert(this.num_staged_replies < this.size, "VirtQueue replies must not exceed queue size");
const used_idx = this.used_get_idx() + this.num_staged_replies & this.mask;
dbg_log("Push reply: used_idx=" + used_idx +
" desc_idx=" + bufchain.head_idx, LOG_VIRTIO);
this.used_set_entry(used_idx, bufchain.head_idx, bufchain.length_written);
this.num_staged_replies++;
};
/**
* Makes replies visible to driver by updating the used ring idx and
* firing appropriate interrupt if needed.
*/
VirtQueue.prototype.flush_replies = function()
{
dbg_assert(this.used_addr, "VirtQueue addresses must be configured before use");
if(this.num_staged_replies === 0)
{
dbg_log("flush_replies: Nothing to flush", LOG_VIRTIO);
return;
}
dbg_log("Flushing " + this.num_staged_replies + " replies", LOG_VIRTIO);
const old_idx = this.used_get_idx();
const new_idx = old_idx + this.num_staged_replies & VIRTQ_IDX_MASK;
this.used_set_idx(new_idx);
this.num_staged_replies = 0;
if(this.virtio.is_feature_negotiated(VIRTIO_F_RING_EVENT_IDX))
{
const used_event = this.avail_get_used_event();
// Fire irq when idx values associated with the pushed reply buffers
// has reached or gone past used_event.
let has_passed = old_idx <= used_event && used_event < new_idx;
// Has overflowed? Assumes num_staged_replies > 0.
if(new_idx <= old_idx)
{
has_passed = used_event < new_idx || old_idx <= used_event;
}
// Commented out: Workaround for sometimes loading from the filesystem hangs and the emulator stays idle
//if(has_passed)
{
this.virtio.raise_irq(VIRTIO_ISR_QUEUE);
}
}
else
{
if(~this.avail_get_flags() & VIRTQ_AVAIL_F_NO_INTERRUPT)
{
this.virtio.raise_irq(VIRTIO_ISR_QUEUE);
}
}
};
/**
* If using VIRTIO_F_RING_EVENT_IDX, device must tell driver when
* to get notifications or else driver won't notify regularly.
* If not using VIRTIO_F_RING_EVENT_IDX, driver will ignore avail_event
* and notify every request regardless unless NO_NOTIFY is set (TODO implement when needed).
* @param {number} num_skipped_requests Zero = get notified in the next request.
*/
VirtQueue.prototype.notify_me_after = function(num_skipped_requests)
{
dbg_assert(num_skipped_requests >= 0, "Must skip a non-negative number of requests");
// The 16 bit idx field wraps around after 2^16.
const avail_event = this.avail_get_idx() + num_skipped_requests & 0xFFFF;
this.used_set_avail_event(avail_event);
};
/**
* @param {number} table_address The physical address of the start of the desc table.
* @param {number} i
*/
VirtQueue.prototype.get_descriptor = function(table_address, i)
{
return {
addr_low: this.cpu.read32s(table_address + i * VIRTQ_DESC_ENTRYSIZE),
addr_high: this.cpu.read32s(table_address + i * VIRTQ_DESC_ENTRYSIZE + 4),
len: this.cpu.read32s(table_address + i * VIRTQ_DESC_ENTRYSIZE + 8),
flags: this.cpu.read16(table_address + i * VIRTQ_DESC_ENTRYSIZE + 12),
next: this.cpu.read16(table_address + i * VIRTQ_DESC_ENTRYSIZE + 14),
};
};
// Avail ring fields
VirtQueue.prototype.avail_get_flags = function()
{
return this.cpu.read16(this.avail_addr);
};
VirtQueue.prototype.avail_get_idx = function()
{
return this.cpu.read16(this.avail_addr + 2);
};
VirtQueue.prototype.avail_get_entry = function(i)
{
return this.cpu.read16(this.avail_addr + 4 + VIRTQ_AVAIL_ENTRYSIZE * i);
};
VirtQueue.prototype.avail_get_used_event = function()
{
return this.cpu.read16(this.avail_addr + 4 + VIRTQ_AVAIL_ENTRYSIZE * this.size);
};
// Used ring fields
VirtQueue.prototype.used_get_flags = function()
{
return this.cpu.read16(this.used_addr);
};
VirtQueue.prototype.used_set_flags = function(value)
{
this.cpu.write16(this.used_addr, value);
};
VirtQueue.prototype.used_get_idx = function()
{
return this.cpu.read16(this.used_addr + 2);
};
VirtQueue.prototype.used_set_idx = function(value)
{
this.cpu.write16(this.used_addr + 2, value);
};
VirtQueue.prototype.used_set_entry = function(i, desc_idx, length_written)
{
this.cpu.write32(this.used_addr + 4 + VIRTQ_USED_ENTRYSIZE * i, desc_idx);
this.cpu.write32(this.used_addr + 8 + VIRTQ_USED_ENTRYSIZE * i, length_written);
};
VirtQueue.prototype.used_set_avail_event = function(value)
{
this.cpu.write16(this.used_addr + 4 + VIRTQ_USED_ENTRYSIZE * this.size, value);
};
/**
* Traverses through descriptor chain starting at head_id.
* Provides means to read/write to buffers represented by the descriptors.
* @constructor
* @param {VirtQueue} virtqueue
* @param {number} head_idx
*/
function VirtQueueBufferChain(virtqueue, head_idx)
{
/** @const @type {CPU} */
this.cpu = virtqueue.cpu;
/** @const @type {VirtIO} */
this.virtio = virtqueue.virtio;
this.head_idx = head_idx;
this.read_buffers = [];
// Pointers for sequential consumption via get_next_blob.
this.read_buffer_idx = 0;
this.read_buffer_offset = 0;
this.length_readable = 0;
this.write_buffers = [];
// Pointers for sequential write via set_next_blob.
this.write_buffer_idx = 0;
this.write_buffer_offset = 0;
this.length_written = 0;
this.length_writable = 0;
// Traverse chain to discover buffers.
// - There shouldn't be an excessive amount of descriptor elements.
let table_address = virtqueue.desc_addr;
let desc_idx = head_idx;
let chain_length = 0;
let chain_max = virtqueue.size;
let writable_region = false;
const has_indirect_feature = this.virtio.is_feature_negotiated(VIRTIO_F_RING_INDIRECT_DESC);
dbg_log("<<< Descriptor chain start", LOG_VIRTIO);
do
{
const desc = virtqueue.get_descriptor(table_address, desc_idx);
dbg_log("descriptor: idx=" + desc_idx + " addr=" + h(desc.addr_high, 8) + ":" + h(desc.addr_low, 8) +
" len=" + h(desc.len, 8) + " flags=" + h(desc.flags, 4) + " next=" + h(desc.next, 4), LOG_VIRTIO);
if(has_indirect_feature && (desc.flags & VIRTQ_DESC_F_INDIRECT))
{
if(DEBUG && (desc.flags & VIRTQ_DESC_F_NEXT))
{
dbg_log("Driver bug: has set VIRTQ_DESC_F_NEXT flag in an indirect table descriptor", LOG_VIRTIO);
}
// Carry on using indirect table, starting at first entry.
table_address = desc.addr_low;
desc_idx = 0;
chain_length = 0;
chain_max = desc.len / VIRTQ_DESC_ENTRYSIZE;
dbg_log("start indirect", LOG_VIRTIO);
continue;
}
if(desc.flags & VIRTQ_DESC_F_WRITE)
{
writable_region = true;
this.write_buffers.push(desc);
this.length_writable += desc.len;
}
else
{
if(writable_region)
{
dbg_log("Driver bug: readonly buffer after writeonly buffer within chain", LOG_VIRTIO);
break;
}
this.read_buffers.push(desc);
this.length_readable += desc.len;
}
chain_length++;
if(chain_length > chain_max)
{
dbg_log("Driver bug: descriptor chain cycle detected", LOG_VIRTIO);
break;
}
if(desc.flags & VIRTQ_DESC_F_NEXT)
{
desc_idx = desc.next;
}
else
{
break;
}
}
while(true);
dbg_log("Descriptor chain end >>>", LOG_VIRTIO);
}
/**
* Reads the next blob of memory represented by the buffer chain into dest_buffer.
* @param {Uint8Array} dest_buffer
* @return {number} Number of bytes successfully read.
*/
VirtQueueBufferChain.prototype.get_next_blob = function(dest_buffer)
{
let dest_offset = 0;
let remaining = dest_buffer.length;
while(remaining)
{
if(this.read_buffer_idx === this.read_buffers.length)
{
dbg_log("Device<" + this.virtio.name + "> Read more than device-readable buffers has", LOG_VIRTIO);
break;
}
const buf = this.read_buffers[this.read_buffer_idx];
const read_address = buf.addr_low + this.read_buffer_offset;
let read_length = buf.len - this.read_buffer_offset;
if(read_length > remaining)
{
read_length = remaining;
this.read_buffer_offset += remaining;
}
else
{
this.read_buffer_idx++;
this.read_buffer_offset = 0;
}
dest_buffer.set(this.cpu.read_blob(read_address, read_length), dest_offset);
dest_offset += read_length;
remaining -= read_length;
}
return dest_offset;
};
/**
* Appends contents of src_buffer into the memory represented by the buffer chain.
* @param {Uint8Array} src_buffer
* @return {number} Number of bytes successfully written.
*/
VirtQueueBufferChain.prototype.set_next_blob = function(src_buffer)
{
let src_offset = 0;
let remaining = src_buffer.length;
while(remaining)
{
if(this.write_buffer_idx === this.write_buffers.length)
{
dbg_log("Device<" + this.virtio.name + "> Write more than device-writable capacity", LOG_VIRTIO);
break;
}
const buf = this.write_buffers[this.write_buffer_idx];
const write_address = buf.addr_low + this.write_buffer_offset;
let write_length = buf.len - this.write_buffer_offset;
if(write_length > remaining)
{
write_length = remaining;
this.write_buffer_offset += remaining;
}
else
{
this.write_buffer_idx++;
this.write_buffer_offset = 0;
}
const src_end = src_offset + write_length;
this.cpu.write_blob(src_buffer.subarray(src_offset, src_end), write_address);
src_offset += write_length;
remaining -= write_length;
}
this.length_written += src_offset;
return src_offset;
};