qemu/hw/usb/hcd-xhci-pci.c
Phil Dennis-Jordan bb5b7fced6 hw/usb/hcd-xhci-pci: Use modulo to select MSI vector as per spec
QEMU would crash with a failed assertion if the XHCI controller
attempted to raise the interrupt on an interrupter corresponding
to a MSI vector with a higher index than the highest configured
for the device by the guest driver.

This behaviour is correct on the MSI/PCI side: per PCI 3.0 spec,
devices must ensure they do not send MSI notifications for
vectors beyond the range of those allocated by the system/driver
software. Unlike MSI-X, there is no generic way for handling
aliasing in the case of fewer allocated vectors than requested,
so the specifics are up to device implementors. (Section
6.8.3.4. "Sending Messages")

It turns out the XHCI spec (Implementation Note in section 4.17,
"Interrupters") requires that the host controller signal the MSI
vector with the number computed by taking the interrupter number
modulo the number of enabled MSI vectors.

This change introduces that modulo calculation, fixing the
failed assertion. This makes the device work correctly in MSI mode
with macOS's XHCI driver, which only allocates a single vector.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250112210056.16658-2-phil@philjordan.eu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2025-01-13 17:21:46 +01:00

267 lines
8 KiB
C

/*
* USB xHCI controller with PCI bus emulation
*
* SPDX-FileCopyrightText: 2011 Securiforest
* SPDX-FileContributor: Hector Martin <hector@marcansoft.com>
* SPDX-sourceInfo: Based on usb-ohci.c, emulates Renesas NEC USB 3.0
* SPDX-FileCopyrightText: 2020 Xilinx
* SPDX-FileContributor: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
* SPDX-sourceInfo: Moved the pci specific content for hcd-xhci.c to
* hcd-xhci-pci.c
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/pci/pci.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "hw/pci/msi.h"
#include "hw/pci/msix.h"
#include "hcd-xhci-pci.h"
#include "trace.h"
#include "qapi/error.h"
#define OFF_MSIX_TABLE 0x3000
#define OFF_MSIX_PBA 0x3800
static void xhci_pci_intr_update(XHCIState *xhci, int n, bool enable)
{
XHCIPciState *s = container_of(xhci, XHCIPciState, xhci);
PCIDevice *pci_dev = PCI_DEVICE(s);
if (!msix_enabled(pci_dev)) {
return;
}
if (enable == !!xhci->intr[n].msix_used) {
return;
}
if (enable) {
trace_usb_xhci_irq_msix_use(n);
msix_vector_use(pci_dev, n);
xhci->intr[n].msix_used = true;
} else {
trace_usb_xhci_irq_msix_unuse(n);
msix_vector_unuse(pci_dev, n);
xhci->intr[n].msix_used = false;
}
}
static bool xhci_pci_intr_raise(XHCIState *xhci, int n, bool level)
{
XHCIPciState *s = container_of(xhci, XHCIPciState, xhci);
PCIDevice *pci_dev = PCI_DEVICE(s);
if (n == 0 &&
!(msix_enabled(pci_dev) ||
msi_enabled(pci_dev))) {
pci_set_irq(pci_dev, level);
}
if (msix_enabled(pci_dev) && level) {
msix_notify(pci_dev, n);
return true;
}
if (msi_enabled(pci_dev) && level) {
n %= msi_nr_vectors_allocated(pci_dev);
msi_notify(pci_dev, n);
return true;
}
return false;
}
static void xhci_pci_reset(DeviceState *dev)
{
XHCIPciState *s = XHCI_PCI(dev);
device_cold_reset(DEVICE(&s->xhci));
}
static int xhci_pci_vmstate_post_load(void *opaque, int version_id)
{
XHCIPciState *s = XHCI_PCI(opaque);
PCIDevice *pci_dev = PCI_DEVICE(s);
int intr;
for (intr = 0; intr < s->xhci.numintrs; intr++) {
if (s->xhci.intr[intr].msix_used) {
msix_vector_use(pci_dev, intr);
} else {
msix_vector_unuse(pci_dev, intr);
}
}
return 0;
}
static void usb_xhci_pci_realize(struct PCIDevice *dev, Error **errp)
{
int ret;
Error *err = NULL;
XHCIPciState *s = XHCI_PCI(dev);
dev->config[PCI_CLASS_PROG] = 0x30; /* xHCI */
dev->config[PCI_INTERRUPT_PIN] = 0x01; /* interrupt pin 1 */
dev->config[PCI_CACHE_LINE_SIZE] = 0x10;
dev->config[0x60] = 0x30; /* release number */
object_property_set_link(OBJECT(&s->xhci), "host", OBJECT(s), NULL);
s->xhci.intr_update = xhci_pci_intr_update;
s->xhci.intr_raise = xhci_pci_intr_raise;
if (!qdev_realize(DEVICE(&s->xhci), NULL, errp)) {
return;
}
if (strcmp(object_get_typename(OBJECT(dev)), TYPE_NEC_XHCI) == 0) {
s->xhci.nec_quirks = true;
}
if (s->msi != ON_OFF_AUTO_OFF) {
ret = msi_init(dev, 0x70, s->xhci.numintrs, true, false, &err);
/*
* Any error other than -ENOTSUP(board's MSI support is broken)
* is a programming error
*/
assert(!ret || ret == -ENOTSUP);
if (ret && s->msi == ON_OFF_AUTO_ON) {
/* Can't satisfy user's explicit msi=on request, fail */
error_append_hint(&err, "You have to use msi=auto (default) or "
"msi=off with this machine type.\n");
error_propagate(errp, err);
return;
}
assert(!err || s->msi == ON_OFF_AUTO_AUTO);
/* With msi=auto, we fall back to MSI off silently */
error_free(err);
}
pci_register_bar(dev, 0,
PCI_BASE_ADDRESS_SPACE_MEMORY |
PCI_BASE_ADDRESS_MEM_TYPE_64,
&s->xhci.mem);
if (pci_bus_is_express(pci_get_bus(dev))) {
ret = pcie_endpoint_cap_init(dev, 0xa0);
assert(ret > 0);
}
if (s->msix != ON_OFF_AUTO_OFF) {
/* TODO check for errors, and should fail when msix=on */
msix_init(dev, s->xhci.numintrs,
&s->xhci.mem, 0, OFF_MSIX_TABLE,
&s->xhci.mem, 0, OFF_MSIX_PBA,
0x90, NULL);
}
s->xhci.as = pci_get_address_space(dev);
}
static void usb_xhci_pci_exit(PCIDevice *dev)
{
XHCIPciState *s = XHCI_PCI(dev);
/* destroy msix memory region */
if (dev->msix_table && dev->msix_pba
&& dev->msix_entry_used) {
msix_uninit(dev, &s->xhci.mem, &s->xhci.mem);
}
}
static const VMStateDescription vmstate_xhci_pci = {
.name = "xhci",
.version_id = 1,
.post_load = xhci_pci_vmstate_post_load,
.fields = (const VMStateField[]) {
VMSTATE_PCI_DEVICE(parent_obj, XHCIPciState),
VMSTATE_MSIX(parent_obj, XHCIPciState),
VMSTATE_STRUCT(xhci, XHCIPciState, 1, vmstate_xhci, XHCIState),
VMSTATE_END_OF_LIST()
}
};
static void xhci_instance_init(Object *obj)
{
XHCIPciState *s = XHCI_PCI(obj);
/*
* QEMU_PCI_CAP_EXPRESS initialization does not depend on QEMU command
* line, therefore, no need to wait to realize like other devices
*/
PCI_DEVICE(obj)->cap_present |= QEMU_PCI_CAP_EXPRESS;
object_initialize_child(obj, "xhci-core", &s->xhci, TYPE_XHCI);
qdev_alias_all_properties(DEVICE(&s->xhci), obj);
}
static const Property xhci_pci_properties[] = {
DEFINE_PROP_ON_OFF_AUTO("msi", XHCIPciState, msi, ON_OFF_AUTO_AUTO),
DEFINE_PROP_ON_OFF_AUTO("msix", XHCIPciState, msix, ON_OFF_AUTO_AUTO),
};
static void xhci_class_init(ObjectClass *klass, void *data)
{
PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
device_class_set_legacy_reset(dc, xhci_pci_reset);
dc->vmsd = &vmstate_xhci_pci;
set_bit(DEVICE_CATEGORY_USB, dc->categories);
k->realize = usb_xhci_pci_realize;
k->exit = usb_xhci_pci_exit;
k->class_id = PCI_CLASS_SERIAL_USB;
device_class_set_props(dc, xhci_pci_properties);
}
static const TypeInfo xhci_pci_info = {
.name = TYPE_XHCI_PCI,
.parent = TYPE_PCI_DEVICE,
.instance_size = sizeof(XHCIPciState),
.class_init = xhci_class_init,
.instance_init = xhci_instance_init,
.abstract = true,
.interfaces = (InterfaceInfo[]) {
{ INTERFACE_PCIE_DEVICE },
{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
{ }
},
};
static void qemu_xhci_class_init(ObjectClass *klass, void *data)
{
PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
k->vendor_id = PCI_VENDOR_ID_REDHAT;
k->device_id = PCI_DEVICE_ID_REDHAT_XHCI;
k->revision = 0x01;
}
static void qemu_xhci_instance_init(Object *obj)
{
XHCIPciState *s = XHCI_PCI(obj);
XHCIState *xhci = &s->xhci;
s->msi = ON_OFF_AUTO_OFF;
s->msix = ON_OFF_AUTO_AUTO;
xhci->numintrs = XHCI_MAXINTRS;
xhci->numslots = XHCI_MAXSLOTS;
}
static const TypeInfo qemu_xhci_info = {
.name = TYPE_QEMU_XHCI,
.parent = TYPE_XHCI_PCI,
.class_init = qemu_xhci_class_init,
.instance_init = qemu_xhci_instance_init,
};
static void xhci_register_types(void)
{
type_register_static(&xhci_pci_info);
type_register_static(&qemu_xhci_info);
}
type_init(xhci_register_types)