cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

pcie.c (37358B)


      1/*
      2 * pcie.c
      3 *
      4 * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
      5 *                    VA Linux Systems Japan K.K.
      6 *
      7 * This program is free software; you can redistribute it and/or modify
      8 * it under the terms of the GNU General Public License as published by
      9 * the Free Software Foundation; either version 2 of the License, or
     10 * (at your option) any later version.
     11 *
     12 * This program is distributed in the hope that it will be useful,
     13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15 * GNU General Public License for more details.
     16 *
     17 * You should have received a copy of the GNU General Public License along
     18 * with this program; if not, see <http://www.gnu.org/licenses/>.
     19 */
     20
     21#include "qemu/osdep.h"
     22#include "qapi/error.h"
     23#include "hw/pci/pci_bridge.h"
     24#include "hw/pci/pcie.h"
     25#include "hw/pci/msix.h"
     26#include "hw/pci/msi.h"
     27#include "hw/pci/pci_bus.h"
     28#include "hw/pci/pcie_regs.h"
     29#include "hw/pci/pcie_port.h"
     30#include "qemu/range.h"
     31
     32//#define DEBUG_PCIE
     33#ifdef DEBUG_PCIE
     34# define PCIE_DPRINTF(fmt, ...)                                         \
     35    fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
     36#else
     37# define PCIE_DPRINTF(fmt, ...) do {} while (0)
     38#endif
     39#define PCIE_DEV_PRINTF(dev, fmt, ...)                                  \
     40    PCIE_DPRINTF("%s:%x "fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
     41
     42
     43/***************************************************************************
     44 * pci express capability helper functions
     45 */
     46
     47static void
     48pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type, uint8_t version)
     49{
     50    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
     51    uint8_t *cmask = dev->cmask + dev->exp.exp_cap;
     52
     53    /* capability register
     54    interrupt message number defaults to 0 */
     55    pci_set_word(exp_cap + PCI_EXP_FLAGS,
     56                 ((type << PCI_EXP_FLAGS_TYPE_SHIFT) & PCI_EXP_FLAGS_TYPE) |
     57                 version);
     58
     59    /* device capability register
     60     * table 7-12:
     61     * roll based error reporting bit must be set by all
     62     * Functions conforming to the ECN, PCI Express Base
     63     * Specification, Revision 1.1., or subsequent PCI Express Base
     64     * Specification revisions.
     65     */
     66    pci_set_long(exp_cap + PCI_EXP_DEVCAP, PCI_EXP_DEVCAP_RBER);
     67
     68    pci_set_long(exp_cap + PCI_EXP_LNKCAP,
     69                 (port << PCI_EXP_LNKCAP_PN_SHIFT) |
     70                 PCI_EXP_LNKCAP_ASPMS_0S |
     71                 QEMU_PCI_EXP_LNKCAP_MLW(QEMU_PCI_EXP_LNK_X1) |
     72                 QEMU_PCI_EXP_LNKCAP_MLS(QEMU_PCI_EXP_LNK_2_5GT));
     73
     74    pci_set_word(exp_cap + PCI_EXP_LNKSTA,
     75                 QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1) |
     76                 QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT));
     77
     78    /* We changed link status bits over time, and changing them across
     79     * migrations is generally fine as hardware changes them too.
     80     * Let's not bother checking.
     81     */
     82    pci_set_word(cmask + PCI_EXP_LNKSTA, 0);
     83}
     84
     85static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
     86{
     87    PCIESlot *s = (PCIESlot *)object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT);
     88    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
     89
     90    /* Skip anything that isn't a PCIESlot */
     91    if (!s) {
     92        return;
     93    }
     94
     95    /* Clear and fill LNKCAP from what was configured above */
     96    pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP,
     97                                 PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
     98    pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
     99                               QEMU_PCI_EXP_LNKCAP_MLW(s->width) |
    100                               QEMU_PCI_EXP_LNKCAP_MLS(s->speed));
    101
    102    /*
    103     * Link bandwidth notification is required for all root ports and
    104     * downstream ports supporting links wider than x1 or multiple link
    105     * speeds.
    106     */
    107    if (s->width > QEMU_PCI_EXP_LNK_X1 ||
    108        s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
    109        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
    110                                   PCI_EXP_LNKCAP_LBNC);
    111    }
    112
    113    if (s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
    114        /*
    115         * Hot-plug capable downstream ports and downstream ports supporting
    116         * link speeds greater than 5GT/s must hardwire PCI_EXP_LNKCAP_DLLLARC
    117         * to 1b.  PCI_EXP_LNKCAP_DLLLARC implies PCI_EXP_LNKSTA_DLLLA, which
    118         * we also hardwire to 1b here.  2.5GT/s hot-plug slots should also
    119         * technically implement this, but it's not done here for compatibility.
    120         */
    121        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
    122                                   PCI_EXP_LNKCAP_DLLLARC);
    123        /* the PCI_EXP_LNKSTA_DLLLA will be set in the hotplug function */
    124
    125        /*
    126         * Target Link Speed defaults to the highest link speed supported by
    127         * the component.  2.5GT/s devices are permitted to hardwire to zero.
    128         */
    129        pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKCTL2,
    130                                     PCI_EXP_LNKCTL2_TLS);
    131        pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKCTL2,
    132                                   QEMU_PCI_EXP_LNKCAP_MLS(s->speed) &
    133                                   PCI_EXP_LNKCTL2_TLS);
    134    }
    135
    136    /*
    137     * 2.5 & 5.0GT/s can be fully described by LNKCAP, but 8.0GT/s is
    138     * actually a reference to the highest bit supported in this register.
    139     * We assume the device supports all link speeds.
    140     */
    141    if (s->speed > QEMU_PCI_EXP_LNK_5GT) {
    142        pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP2, ~0U);
    143        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
    144                                   PCI_EXP_LNKCAP2_SLS_2_5GB |
    145                                   PCI_EXP_LNKCAP2_SLS_5_0GB |
    146                                   PCI_EXP_LNKCAP2_SLS_8_0GB);
    147        if (s->speed > QEMU_PCI_EXP_LNK_8GT) {
    148            pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
    149                                       PCI_EXP_LNKCAP2_SLS_16_0GB);
    150        }
    151    }
    152}
    153
    154int pcie_cap_init(PCIDevice *dev, uint8_t offset,
    155                  uint8_t type, uint8_t port,
    156                  Error **errp)
    157{
    158    /* PCIe cap v2 init */
    159    int pos;
    160    uint8_t *exp_cap;
    161
    162    assert(pci_is_express(dev));
    163
    164    pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
    165                             PCI_EXP_VER2_SIZEOF, errp);
    166    if (pos < 0) {
    167        return pos;
    168    }
    169    dev->exp.exp_cap = pos;
    170    exp_cap = dev->config + pos;
    171
    172    /* Filling values common with v1 */
    173    pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER2);
    174
    175    /* Fill link speed and width options */
    176    pcie_cap_fill_slot_lnk(dev);
    177
    178    /* Filling v2 specific values */
    179    pci_set_long(exp_cap + PCI_EXP_DEVCAP2,
    180                 PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);
    181
    182    pci_set_word(dev->wmask + pos + PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_EETLPPB);
    183
    184    if (dev->cap_present & QEMU_PCIE_EXTCAP_INIT) {
    185        /* read-only to behave like a 'NULL' Extended Capability Header */
    186        pci_set_long(dev->wmask + PCI_CONFIG_SPACE_SIZE, 0);
    187    }
    188
    189    return pos;
    190}
    191
    192int pcie_cap_v1_init(PCIDevice *dev, uint8_t offset, uint8_t type,
    193                     uint8_t port)
    194{
    195    /* PCIe cap v1 init */
    196    int pos;
    197    Error *local_err = NULL;
    198
    199    assert(pci_is_express(dev));
    200
    201    pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
    202                             PCI_EXP_VER1_SIZEOF, &local_err);
    203    if (pos < 0) {
    204        error_report_err(local_err);
    205        return pos;
    206    }
    207    dev->exp.exp_cap = pos;
    208
    209    pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER1);
    210
    211    return pos;
    212}
    213
    214static int
    215pcie_endpoint_cap_common_init(PCIDevice *dev, uint8_t offset, uint8_t cap_size)
    216{
    217    uint8_t type = PCI_EXP_TYPE_ENDPOINT;
    218    Error *local_err = NULL;
    219    int ret;
    220
    221    /*
    222     * Windows guests will report Code 10, device cannot start, if
    223     * a regular Endpoint type is exposed on a root complex.  These
    224     * should instead be Root Complex Integrated Endpoints.
    225     */
    226    if (pci_bus_is_express(pci_get_bus(dev))
    227        && pci_bus_is_root(pci_get_bus(dev))) {
    228        type = PCI_EXP_TYPE_RC_END;
    229    }
    230
    231    if (cap_size == PCI_EXP_VER1_SIZEOF) {
    232        return pcie_cap_v1_init(dev, offset, type, 0);
    233    } else {
    234        ret = pcie_cap_init(dev, offset, type, 0, &local_err);
    235
    236        if (ret < 0) {
    237            error_report_err(local_err);
    238        }
    239
    240        return ret;
    241    }
    242}
    243
    244int pcie_endpoint_cap_init(PCIDevice *dev, uint8_t offset)
    245{
    246    return pcie_endpoint_cap_common_init(dev, offset, PCI_EXP_VER2_SIZEOF);
    247}
    248
    249int pcie_endpoint_cap_v1_init(PCIDevice *dev, uint8_t offset)
    250{
    251    return pcie_endpoint_cap_common_init(dev, offset, PCI_EXP_VER1_SIZEOF);
    252}
    253
    254void pcie_cap_exit(PCIDevice *dev)
    255{
    256    pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER2_SIZEOF);
    257}
    258
    259void pcie_cap_v1_exit(PCIDevice *dev)
    260{
    261    pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER1_SIZEOF);
    262}
    263
    264uint8_t pcie_cap_get_type(const PCIDevice *dev)
    265{
    266    uint32_t pos = dev->exp.exp_cap;
    267    assert(pos > 0);
    268    return (pci_get_word(dev->config + pos + PCI_EXP_FLAGS) &
    269            PCI_EXP_FLAGS_TYPE) >> PCI_EXP_FLAGS_TYPE_SHIFT;
    270}
    271
    272/* MSI/MSI-X */
    273/* pci express interrupt message number */
    274/* 7.8.2 PCI Express Capabilities Register: Interrupt Message Number */
    275void pcie_cap_flags_set_vector(PCIDevice *dev, uint8_t vector)
    276{
    277    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
    278    assert(vector < 32);
    279    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_FLAGS, PCI_EXP_FLAGS_IRQ);
    280    pci_word_test_and_set_mask(exp_cap + PCI_EXP_FLAGS,
    281                               vector << PCI_EXP_FLAGS_IRQ_SHIFT);
    282}
    283
    284uint8_t pcie_cap_flags_get_vector(PCIDevice *dev)
    285{
    286    return (pci_get_word(dev->config + dev->exp.exp_cap + PCI_EXP_FLAGS) &
    287            PCI_EXP_FLAGS_IRQ) >> PCI_EXP_FLAGS_IRQ_SHIFT;
    288}
    289
    290void pcie_cap_deverr_init(PCIDevice *dev)
    291{
    292    uint32_t pos = dev->exp.exp_cap;
    293    pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP,
    294                               PCI_EXP_DEVCAP_RBER);
    295    pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL,
    296                               PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
    297                               PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
    298    pci_long_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_DEVSTA,
    299                               PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED |
    300                               PCI_EXP_DEVSTA_FED | PCI_EXP_DEVSTA_URD);
    301}
    302
    303void pcie_cap_deverr_reset(PCIDevice *dev)
    304{
    305    uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
    306    pci_long_test_and_clear_mask(devctl,
    307                                 PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
    308                                 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
    309}
    310
    311void pcie_cap_lnkctl_init(PCIDevice *dev)
    312{
    313    uint32_t pos = dev->exp.exp_cap;
    314    pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_LNKCTL,
    315                               PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES);
    316}
    317
    318void pcie_cap_lnkctl_reset(PCIDevice *dev)
    319{
    320    uint8_t *lnkctl = dev->config + dev->exp.exp_cap + PCI_EXP_LNKCTL;
    321    pci_long_test_and_clear_mask(lnkctl,
    322                                 PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES);
    323}
    324
    325static void hotplug_event_update_event_status(PCIDevice *dev)
    326{
    327    uint32_t pos = dev->exp.exp_cap;
    328    uint8_t *exp_cap = dev->config + pos;
    329    uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
    330    uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
    331
    332    dev->exp.hpev_notified = (sltctl & PCI_EXP_SLTCTL_HPIE) &&
    333        (sltsta & sltctl & PCI_EXP_HP_EV_SUPPORTED);
    334}
    335
    336static void hotplug_event_notify(PCIDevice *dev)
    337{
    338    bool prev = dev->exp.hpev_notified;
    339
    340    hotplug_event_update_event_status(dev);
    341
    342    if (prev == dev->exp.hpev_notified) {
    343        return;
    344    }
    345
    346    /* Note: the logic above does not take into account whether interrupts
    347     * are masked. The result is that interrupt will be sent when it is
    348     * subsequently unmasked. This appears to be legal: Section 6.7.3.4:
    349     * The Port may optionally send an MSI when there are hot-plug events that
    350     * occur while interrupt generation is disabled, and interrupt generation is
    351     * subsequently enabled. */
    352    if (msix_enabled(dev)) {
    353        msix_notify(dev, pcie_cap_flags_get_vector(dev));
    354    } else if (msi_enabled(dev)) {
    355        msi_notify(dev, pcie_cap_flags_get_vector(dev));
    356    } else {
    357        pci_set_irq(dev, dev->exp.hpev_notified);
    358    }
    359}
    360
    361static void hotplug_event_clear(PCIDevice *dev)
    362{
    363    hotplug_event_update_event_status(dev);
    364    if (!msix_enabled(dev) && !msi_enabled(dev) && !dev->exp.hpev_notified) {
    365        pci_irq_deassert(dev);
    366    }
    367}
    368
    369/*
    370 * A PCI Express Hot-Plug Event has occurred, so update slot status register
    371 * and notify OS of the event if necessary.
    372 *
    373 * 6.7.3 PCI Express Hot-Plug Events
    374 * 6.7.3.4 Software Notification of Hot-Plug Events
    375 */
    376static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
    377{
    378    /* Minor optimization: if nothing changed - no event is needed. */
    379    if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
    380                                   PCI_EXP_SLTSTA, event) == event) {
    381        return;
    382    }
    383    hotplug_event_notify(dev);
    384}
    385
    386static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev,
    387                                      Error **errp)
    388{
    389    uint8_t *exp_cap = hotplug_dev->config + hotplug_dev->exp.exp_cap;
    390    uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
    391
    392    PCIE_DEV_PRINTF(PCI_DEVICE(dev), "hotplug state: 0x%x\n", sltsta);
    393    if (sltsta & PCI_EXP_SLTSTA_EIS) {
    394        /* the slot is electromechanically locked.
    395         * This error is propagated up to qdev and then to HMP/QMP.
    396         */
    397        error_setg_errno(errp, EBUSY, "slot is electromechanically locked");
    398    }
    399}
    400
    401void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
    402                               Error **errp)
    403{
    404    PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
    405    uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
    406    uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);
    407
    408    /* Check if hot-plug is disabled on the slot */
    409    if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) {
    410        error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'",
    411                         DEVICE(hotplug_pdev)->id);
    412        return;
    413    }
    414
    415    pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp);
    416}
    417
    418void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
    419                           Error **errp)
    420{
    421    PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
    422    uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
    423    PCIDevice *pci_dev = PCI_DEVICE(dev);
    424    uint32_t lnkcap = pci_get_long(exp_cap + PCI_EXP_LNKCAP);
    425
    426    /* Don't send event when device is enabled during qemu machine creation:
    427     * it is present on boot, no hotplug event is necessary. We do send an
    428     * event when the device is disabled later. */
    429    if (!dev->hotplugged) {
    430        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
    431                                   PCI_EXP_SLTSTA_PDS);
    432        if (pci_dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA ||
    433            (lnkcap & PCI_EXP_LNKCAP_DLLLARC)) {
    434            pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
    435                                       PCI_EXP_LNKSTA_DLLLA);
    436        }
    437        return;
    438    }
    439
    440    /* To enable multifunction hot-plug, we just ensure the function
    441     * 0 added last. When function 0 is added, we set the sltsta and
    442     * inform OS via event notification.
    443     */
    444    if (pci_get_function_0(pci_dev)) {
    445        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
    446                                   PCI_EXP_SLTSTA_PDS);
    447        if (pci_dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA ||
    448            (lnkcap & PCI_EXP_LNKCAP_DLLLARC)) {
    449            pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
    450                                       PCI_EXP_LNKSTA_DLLLA);
    451        }
    452        pcie_cap_slot_event(hotplug_pdev,
    453                            PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
    454    }
    455}
    456
    457void pcie_cap_slot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
    458                             Error **errp)
    459{
    460    qdev_unrealize(dev);
    461}
    462
    463static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
    464{
    465    HotplugHandler *hotplug_ctrl = qdev_get_hotplug_handler(DEVICE(dev));
    466
    467    if (dev->partially_hotplugged) {
    468        dev->qdev.pending_deleted_event = false;
    469        return;
    470    }
    471    hotplug_handler_unplug(hotplug_ctrl, DEVICE(dev), &error_abort);
    472    object_unparent(OBJECT(dev));
    473}
    474
    475void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
    476                                     DeviceState *dev, Error **errp)
    477{
    478    Error *local_err = NULL;
    479    PCIDevice *pci_dev = PCI_DEVICE(dev);
    480    PCIBus *bus = pci_get_bus(pci_dev);
    481    PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
    482    uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
    483    uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);
    484
    485    /* Check if hot-unplug is disabled on the slot */
    486    if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) {
    487        error_setg(errp, "Hot-unplug failed: "
    488                         "unsupported by the port device '%s'",
    489                         DEVICE(hotplug_pdev)->id);
    490        return;
    491    }
    492
    493    pcie_cap_slot_plug_common(hotplug_pdev, dev, &local_err);
    494    if (local_err) {
    495        error_propagate(errp, local_err);
    496        return;
    497    }
    498
    499    dev->pending_deleted_event = true;
    500
    501    /* In case user cancel the operation of multi-function hot-add,
    502     * remove the function that is unexposed to guest individually,
    503     * without interaction with guest.
    504     */
    505    if (pci_dev->devfn &&
    506        !bus->devices[0]) {
    507        pcie_unplug_device(bus, pci_dev, NULL);
    508
    509        return;
    510    }
    511
    512    pcie_cap_slot_push_attention_button(hotplug_pdev);
    513}
    514
    515/* pci express slot for pci express root/downstream port
    516   PCI express capability slot registers */
    517void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
    518{
    519    uint32_t pos = dev->exp.exp_cap;
    520
    521    pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
    522                               PCI_EXP_FLAGS_SLOT);
    523
    524    pci_long_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCAP,
    525                                 ~PCI_EXP_SLTCAP_PSN);
    526    pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
    527                               (s->slot << PCI_EXP_SLTCAP_PSN_SHIFT) |
    528                               PCI_EXP_SLTCAP_EIP |
    529                               PCI_EXP_SLTCAP_PIP |
    530                               PCI_EXP_SLTCAP_AIP |
    531                               PCI_EXP_SLTCAP_ABP);
    532
    533    /*
    534     * Enable native hot-plug on all hot-plugged bridges unless
    535     * hot-plug is disabled on the slot.
    536     */
    537    if (s->hotplug &&
    538        (s->native_hotplug || DEVICE(dev)->hotplugged)) {
    539        pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
    540                                   PCI_EXP_SLTCAP_HPS |
    541                                   PCI_EXP_SLTCAP_HPC);
    542    }
    543
    544    if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
    545        pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
    546                                   PCI_EXP_SLTCAP_PCP);
    547        pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
    548                                     PCI_EXP_SLTCTL_PCC);
    549        pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
    550                                   PCI_EXP_SLTCTL_PCC);
    551    }
    552
    553    pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
    554                                 PCI_EXP_SLTCTL_PIC |
    555                                 PCI_EXP_SLTCTL_AIC);
    556    pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCTL,
    557                               PCI_EXP_SLTCTL_PIC_OFF |
    558                               PCI_EXP_SLTCTL_AIC_OFF);
    559    pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
    560                               PCI_EXP_SLTCTL_PIC |
    561                               PCI_EXP_SLTCTL_AIC |
    562                               PCI_EXP_SLTCTL_HPIE |
    563                               PCI_EXP_SLTCTL_CCIE |
    564                               PCI_EXP_SLTCTL_PDCE |
    565                               PCI_EXP_SLTCTL_ABPE);
    566    /* Although reading PCI_EXP_SLTCTL_EIC returns always 0,
    567     * make the bit writable here in order to detect 1b is written.
    568     * pcie_cap_slot_write_config() test-and-clear the bit, so
    569     * this bit always returns 0 to the guest.
    570     */
    571    pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
    572                               PCI_EXP_SLTCTL_EIC);
    573
    574    pci_word_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_SLTSTA,
    575                               PCI_EXP_HP_EV_SUPPORTED);
    576
    577    dev->exp.hpev_notified = false;
    578
    579    qbus_set_hotplug_handler(BUS(pci_bridge_get_sec_bus(PCI_BRIDGE(dev))),
    580                             OBJECT(dev));
    581}
    582
    583void pcie_cap_slot_reset(PCIDevice *dev)
    584{
    585    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
    586    uint8_t port_type = pcie_cap_get_type(dev);
    587
    588    assert(port_type == PCI_EXP_TYPE_DOWNSTREAM ||
    589           port_type == PCI_EXP_TYPE_ROOT_PORT);
    590
    591    PCIE_DEV_PRINTF(dev, "reset\n");
    592
    593    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
    594                                 PCI_EXP_SLTCTL_EIC |
    595                                 PCI_EXP_SLTCTL_PIC |
    596                                 PCI_EXP_SLTCTL_AIC |
    597                                 PCI_EXP_SLTCTL_HPIE |
    598                                 PCI_EXP_SLTCTL_CCIE |
    599                                 PCI_EXP_SLTCTL_PDCE |
    600                                 PCI_EXP_SLTCTL_ABPE);
    601    pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
    602                               PCI_EXP_SLTCTL_AIC_OFF);
    603
    604    if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
    605        /* Downstream ports enforce device number 0. */
    606        bool populated = pci_bridge_get_sec_bus(PCI_BRIDGE(dev))->devices[0];
    607        uint16_t pic;
    608
    609        if (populated) {
    610            pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
    611                                         PCI_EXP_SLTCTL_PCC);
    612        } else {
    613            pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
    614                                       PCI_EXP_SLTCTL_PCC);
    615        }
    616
    617        pic = populated ? PCI_EXP_SLTCTL_PIC_ON : PCI_EXP_SLTCTL_PIC_OFF;
    618        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL, pic);
    619    }
    620
    621    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
    622                                 PCI_EXP_SLTSTA_EIS |/* on reset,
    623                                                        the lock is released */
    624                                 PCI_EXP_SLTSTA_CC |
    625                                 PCI_EXP_SLTSTA_PDC |
    626                                 PCI_EXP_SLTSTA_ABP);
    627
    628    hotplug_event_update_event_status(dev);
    629}
    630
    631void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slt_ctl, uint16_t *slt_sta)
    632{
    633    uint32_t pos = dev->exp.exp_cap;
    634    uint8_t *exp_cap = dev->config + pos;
    635    *slt_ctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
    636    *slt_sta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
    637}
    638
    639void pcie_cap_slot_write_config(PCIDevice *dev,
    640                                uint16_t old_slt_ctl, uint16_t old_slt_sta,
    641                                uint32_t addr, uint32_t val, int len)
    642{
    643    uint32_t pos = dev->exp.exp_cap;
    644    uint8_t *exp_cap = dev->config + pos;
    645    uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
    646    uint32_t lnkcap = pci_get_long(exp_cap + PCI_EXP_LNKCAP);
    647
    648    if (ranges_overlap(addr, len, pos + PCI_EXP_SLTSTA, 2)) {
    649        /*
    650         * Guests tend to clears all bits during init.
    651         * If they clear bits that weren't set this is racy and will lose events:
    652         * not a big problem for manual button presses, but a problem for us.
    653         * As a work-around, detect this and revert status to what it was
    654         * before the write.
    655         *
    656         * Note: in theory this can be detected as a duplicate button press
    657         * which cancels the previous press. Does not seem to happen in
    658         * practice as guests seem to only have this bug during init.
    659         */
    660#define PCIE_SLOT_EVENTS (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | \
    661                          PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | \
    662                          PCI_EXP_SLTSTA_CC)
    663
    664        if (val & ~old_slt_sta & PCIE_SLOT_EVENTS) {
    665            sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (old_slt_sta & PCIE_SLOT_EVENTS);
    666            pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
    667        }
    668        hotplug_event_clear(dev);
    669    }
    670
    671    if (!ranges_overlap(addr, len, pos + PCI_EXP_SLTCTL, 2)) {
    672        return;
    673    }
    674
    675    if (pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
    676                                     PCI_EXP_SLTCTL_EIC)) {
    677        sltsta ^= PCI_EXP_SLTSTA_EIS; /* toggle PCI_EXP_SLTSTA_EIS bit */
    678        pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
    679        PCIE_DEV_PRINTF(dev, "PCI_EXP_SLTCTL_EIC: "
    680                        "sltsta -> 0x%02"PRIx16"\n",
    681                        sltsta);
    682    }
    683
    684    /*
    685     * If the slot is populated, power indicator is off and power
    686     * controller is off, it is safe to detach the devices.
    687     *
    688     * Note: don't detach if condition was already true:
    689     * this is a work around for guests that overwrite
    690     * control of powered off slots before powering them on.
    691     */
    692    if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
    693        (val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF &&
    694        (!(old_slt_ctl & PCI_EXP_SLTCTL_PCC) ||
    695        (old_slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) {
    696        PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
    697        pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
    698                            pcie_unplug_device, NULL);
    699
    700        pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
    701                                     PCI_EXP_SLTSTA_PDS);
    702        if (dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA ||
    703            (lnkcap & PCI_EXP_LNKCAP_DLLLARC)) {
    704            pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
    705                                         PCI_EXP_LNKSTA_DLLLA);
    706        }
    707        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
    708                                       PCI_EXP_SLTSTA_PDC);
    709    }
    710
    711    hotplug_event_notify(dev);
    712
    713    /* 
    714     * 6.7.3.2 Command Completed Events
    715     *
    716     * Software issues a command to a hot-plug capable Downstream Port by
    717     * issuing a write transaction that targets any portion of the Port’s Slot
    718     * Control register. A single write to the Slot Control register is
    719     * considered to be a single command, even if the write affects more than
    720     * one field in the Slot Control register. In response to this transaction,
    721     * the Port must carry out the requested actions and then set the
    722     * associated status field for the command completed event. */
    723
    724    /* Real hardware might take a while to complete requested command because
    725     * physical movement would be involved like locking the electromechanical
    726     * lock.  However in our case, command is completed instantaneously above,
    727     * so send a command completion event right now.
    728     */
    729    pcie_cap_slot_event(dev, PCI_EXP_HP_EV_CCI);
    730}
    731
    732int pcie_cap_slot_post_load(void *opaque, int version_id)
    733{
    734    PCIDevice *dev = opaque;
    735    hotplug_event_update_event_status(dev);
    736    return 0;
    737}
    738
    739void pcie_cap_slot_push_attention_button(PCIDevice *dev)
    740{
    741    pcie_cap_slot_event(dev, PCI_EXP_HP_EV_ABP);
    742}
    743
    744/* root control/capabilities/status. PME isn't emulated for now */
    745void pcie_cap_root_init(PCIDevice *dev)
    746{
    747    pci_set_word(dev->wmask + dev->exp.exp_cap + PCI_EXP_RTCTL,
    748                 PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
    749                 PCI_EXP_RTCTL_SEFEE);
    750}
    751
    752void pcie_cap_root_reset(PCIDevice *dev)
    753{
    754    pci_set_word(dev->config + dev->exp.exp_cap + PCI_EXP_RTCTL, 0);
    755}
    756
    757/* function level reset(FLR) */
    758void pcie_cap_flr_init(PCIDevice *dev)
    759{
    760    pci_long_test_and_set_mask(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCAP,
    761                               PCI_EXP_DEVCAP_FLR);
    762
    763    /* Although reading BCR_FLR returns always 0,
    764     * the bit is made writable here in order to detect the 1b is written
    765     * pcie_cap_flr_write_config() test-and-clear the bit, so
    766     * this bit always returns 0 to the guest.
    767     */
    768    pci_word_test_and_set_mask(dev->wmask + dev->exp.exp_cap + PCI_EXP_DEVCTL,
    769                               PCI_EXP_DEVCTL_BCR_FLR);
    770}
    771
    772void pcie_cap_flr_write_config(PCIDevice *dev,
    773                               uint32_t addr, uint32_t val, int len)
    774{
    775    uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
    776    if (pci_get_word(devctl) & PCI_EXP_DEVCTL_BCR_FLR) {
    777        /* Clear PCI_EXP_DEVCTL_BCR_FLR after invoking the reset handler
    778           so the handler can detect FLR by looking at this bit. */
    779        pci_device_reset(dev);
    780        pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR);
    781    }
    782}
    783
    784/* Alternative Routing-ID Interpretation (ARI)
    785 * forwarding support for root and downstream ports
    786 */
    787void pcie_cap_arifwd_init(PCIDevice *dev)
    788{
    789    uint32_t pos = dev->exp.exp_cap;
    790    pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP2,
    791                               PCI_EXP_DEVCAP2_ARI);
    792    pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL2,
    793                               PCI_EXP_DEVCTL2_ARI);
    794}
    795
    796void pcie_cap_arifwd_reset(PCIDevice *dev)
    797{
    798    uint8_t *devctl2 = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2;
    799    pci_long_test_and_clear_mask(devctl2, PCI_EXP_DEVCTL2_ARI);
    800}
    801
    802bool pcie_cap_is_arifwd_enabled(const PCIDevice *dev)
    803{
    804    if (!pci_is_express(dev)) {
    805        return false;
    806    }
    807    if (!dev->exp.exp_cap) {
    808        return false;
    809    }
    810
    811    return pci_get_long(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2) &
    812        PCI_EXP_DEVCTL2_ARI;
    813}
    814
    815/**************************************************************************
    816 * pci express extended capability list management functions
    817 * uint16_t ext_cap_id (16 bit)
    818 * uint8_t cap_ver (4 bit)
    819 * uint16_t cap_offset (12 bit)
    820 * uint16_t ext_cap_size
    821 */
    822
    823/* Passing a cap_id value > 0xffff will return 0 and put end of list in prev */
    824static uint16_t pcie_find_capability_list(PCIDevice *dev, uint32_t cap_id,
    825                                          uint16_t *prev_p)
    826{
    827    uint16_t prev = 0;
    828    uint16_t next;
    829    uint32_t header = pci_get_long(dev->config + PCI_CONFIG_SPACE_SIZE);
    830
    831    if (!header) {
    832        /* no extended capability */
    833        next = 0;
    834        goto out;
    835    }
    836    for (next = PCI_CONFIG_SPACE_SIZE; next;
    837         prev = next, next = PCI_EXT_CAP_NEXT(header)) {
    838
    839        assert(next >= PCI_CONFIG_SPACE_SIZE);
    840        assert(next <= PCIE_CONFIG_SPACE_SIZE - 8);
    841
    842        header = pci_get_long(dev->config + next);
    843        if (PCI_EXT_CAP_ID(header) == cap_id) {
    844            break;
    845        }
    846    }
    847
    848out:
    849    if (prev_p) {
    850        *prev_p = prev;
    851    }
    852    return next;
    853}
    854
    855uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id)
    856{
    857    return pcie_find_capability_list(dev, cap_id, NULL);
    858}
    859
    860static void pcie_ext_cap_set_next(PCIDevice *dev, uint16_t pos, uint16_t next)
    861{
    862    uint32_t header = pci_get_long(dev->config + pos);
    863    assert(!(next & (PCI_EXT_CAP_ALIGN - 1)));
    864    header = (header & ~PCI_EXT_CAP_NEXT_MASK) |
    865        ((next << PCI_EXT_CAP_NEXT_SHIFT) & PCI_EXT_CAP_NEXT_MASK);
    866    pci_set_long(dev->config + pos, header);
    867}
    868
    869/*
    870 * Caller must supply valid (offset, size) such that the range wouldn't
    871 * overlap with other capability or other registers.
    872 * This function doesn't check it.
    873 */
    874void pcie_add_capability(PCIDevice *dev,
    875                         uint16_t cap_id, uint8_t cap_ver,
    876                         uint16_t offset, uint16_t size)
    877{
    878    assert(offset >= PCI_CONFIG_SPACE_SIZE);
    879    assert(offset < offset + size);
    880    assert(offset + size <= PCIE_CONFIG_SPACE_SIZE);
    881    assert(size >= 8);
    882    assert(pci_is_express(dev));
    883
    884    if (offset != PCI_CONFIG_SPACE_SIZE) {
    885        uint16_t prev;
    886
    887        /*
    888         * 0xffffffff is not a valid cap id (it's a 16 bit field). use
    889         * internally to find the last capability in the linked list.
    890         */
    891        pcie_find_capability_list(dev, 0xffffffff, &prev);
    892        assert(prev >= PCI_CONFIG_SPACE_SIZE);
    893        pcie_ext_cap_set_next(dev, prev, offset);
    894    }
    895    pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, 0));
    896
    897    /* Make capability read-only by default */
    898    memset(dev->wmask + offset, 0, size);
    899    memset(dev->w1cmask + offset, 0, size);
    900    /* Check capability by default */
    901    memset(dev->cmask + offset, 0xFF, size);
    902}
    903
    904/*
    905 * Sync the PCIe Link Status negotiated speed and width of a bridge with the
    906 * downstream device.  If downstream device is not present, re-write with the
    907 * Link Capability fields.  If downstream device reports invalid width or
    908 * speed, replace with minimum values (LnkSta fields are RsvdZ on VFs but such
    909 * values interfere with PCIe native hotplug detecting new devices).  Limit
    910 * width and speed to bridge capabilities for compatibility.  Use config_read
    911 * to access the downstream device since it could be an assigned device with
    912 * volatile link information.
    913 */
    914void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
    915{
    916    PCIBridge *br = PCI_BRIDGE(bridge_dev);
    917    PCIBus *bus = pci_bridge_get_sec_bus(br);
    918    PCIDevice *target = bus->devices[0];
    919    uint8_t *exp_cap = bridge_dev->config + bridge_dev->exp.exp_cap;
    920    uint16_t lnksta, lnkcap = pci_get_word(exp_cap + PCI_EXP_LNKCAP);
    921
    922    if (!target || !target->exp.exp_cap) {
    923        lnksta = lnkcap;
    924    } else {
    925        lnksta = target->config_read(target,
    926                                     target->exp.exp_cap + PCI_EXP_LNKSTA,
    927                                     sizeof(lnksta));
    928
    929        if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) {
    930            lnksta &= ~PCI_EXP_LNKSTA_NLW;
    931            lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW;
    932        } else if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
    933            lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
    934        }
    935
    936        if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) {
    937            lnksta &= ~PCI_EXP_LNKSTA_CLS;
    938            lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS;
    939        } else if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
    940            lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
    941        }
    942    }
    943
    944    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
    945                                 PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
    946    pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta &
    947                               (PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW));
    948}
    949
    950/**************************************************************************
    951 * pci express extended capability helper functions
    952 */
    953
    954/* ARI */
    955void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn)
    956{
    957    pcie_add_capability(dev, PCI_EXT_CAP_ID_ARI, PCI_ARI_VER,
    958                        offset, PCI_ARI_SIZEOF);
    959    pci_set_long(dev->config + offset + PCI_ARI_CAP, (nextfn & 0xff) << 8);
    960}
    961
    962void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num)
    963{
    964    static const int pci_dsn_ver = 1;
    965    static const int pci_dsn_cap = 4;
    966
    967    pcie_add_capability(dev, PCI_EXT_CAP_ID_DSN, pci_dsn_ver, offset,
    968                        PCI_EXT_CAP_DSN_SIZEOF);
    969    pci_set_quad(dev->config + offset + pci_dsn_cap, ser_num);
    970}
    971
    972void pcie_ats_init(PCIDevice *dev, uint16_t offset, bool aligned)
    973{
    974    pcie_add_capability(dev, PCI_EXT_CAP_ID_ATS, 0x1,
    975                        offset, PCI_EXT_CAP_ATS_SIZEOF);
    976
    977    dev->exp.ats_cap = offset;
    978
    979    /* Invalidate Queue Depth 0 */
    980    if (aligned) {
    981        pci_set_word(dev->config + offset + PCI_ATS_CAP,
    982                     PCI_ATS_CAP_PAGE_ALIGNED);
    983    }
    984    /* STU 0, Disabled by default */
    985    pci_set_word(dev->config + offset + PCI_ATS_CTRL, 0);
    986
    987    pci_set_word(dev->wmask + dev->exp.ats_cap + PCI_ATS_CTRL, 0x800f);
    988}
    989
    990/* ACS (Access Control Services) */
    991void pcie_acs_init(PCIDevice *dev, uint16_t offset)
    992{
    993    bool is_downstream = pci_is_express_downstream_port(dev);
    994    uint16_t cap_bits = 0;
    995
    996    /* For endpoints, only multifunction devs may have an ACS capability: */
    997    assert(is_downstream ||
    998           (dev->cap_present & QEMU_PCI_CAP_MULTIFUNCTION) ||
    999           PCI_FUNC(dev->devfn));
   1000
   1001    pcie_add_capability(dev, PCI_EXT_CAP_ID_ACS, PCI_ACS_VER, offset,
   1002                        PCI_ACS_SIZEOF);
   1003    dev->exp.acs_cap = offset;
   1004
   1005    if (is_downstream) {
   1006        /*
   1007         * Downstream ports must implement SV, TB, RR, CR, UF, and DT (with
   1008         * caveats on the latter four that we ignore for simplicity).
   1009         * Endpoints may also implement a subset of ACS capabilities,
   1010         * but these are optional if the endpoint does not support
   1011         * peer-to-peer between functions and thus omitted here.
   1012         */
   1013        cap_bits = PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
   1014            PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT;
   1015    }
   1016
   1017    pci_set_word(dev->config + offset + PCI_ACS_CAP, cap_bits);
   1018    pci_set_word(dev->wmask + offset + PCI_ACS_CTRL, cap_bits);
   1019}
   1020
   1021void pcie_acs_reset(PCIDevice *dev)
   1022{
   1023    if (dev->exp.acs_cap) {
   1024        pci_set_word(dev->config + dev->exp.acs_cap + PCI_ACS_CTRL, 0);
   1025    }
   1026}