[Qemu-devel] Re: [PATCH v5 07/14] pcie: helper functions for pcie capability and extended capability

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Oct 19, 2010 at 06:06:34PM +0900, Isaku Yamahata wrote:
> This patch implements helper functions for pci express capability
> and pci express extended capability allocation.
> NOTE: presence detection depends on pci_qdev_init() change.
> 
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
> ---
> Changes v4 -> v5:
> - dropped FLR related members. This will be addressed at the next phase.
> - use pci_xxx_test_and_xxx_mask().
> - drop PCIDevice::written bits. and made related registers writable.
> - eliminated pcie_cap_slot_notify()
> - introduced PCIExpressDevice::hpev_intx

Please also add a comment saying that hpev_intx field defaults to 0,
and needs to be changed by devices that want to use another
interrupt for hotplug events.

> Changes v3 -> v4:
> - various clean up
> - dropped pcie_notify(), pcie_del_capability()
> - use pci_{clear_set, clear}_bit_xxx() helper functions.
> - dropped pci_exp_cap()
> ---
>  Makefile.objs |    1 +
>  hw/pci.h      |    5 +
>  hw/pcie.c     |  540 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/pcie.h     |  107 ++++++++++++
>  qemu-common.h |    1 +
>  5 files changed, 654 insertions(+), 0 deletions(-)
>  create mode 100644 hw/pcie.c
>  create mode 100644 hw/pcie.h
> 
> diff --git a/Makefile.objs b/Makefile.objs
> index 5f5a4c5..eeb5134 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -186,6 +186,7 @@ hw-obj-$(CONFIG_PIIX4) += piix4.o
>  # PCI watchdog devices
>  hw-obj-y += wdt_i6300esb.o
>  
> +hw-obj-y += pcie.o
>  hw-obj-y += msix.o msi.o
>  
>  # PCI network cards
> diff --git a/hw/pci.h b/hw/pci.h
> index 9e2f27d..d6c522b 100644
> --- a/hw/pci.h
> +++ b/hw/pci.h
> @@ -9,6 +9,8 @@
>  /* PCI includes legacy ISA access.  */
>  #include "isa.h"
>  
> +#include "pcie.h"
> +
>  /* PCI bus */
>  
>  #define PCI_DEVFN(slot, func)   ((((slot) & 0x1f) << 3) | ((func) & 0x07))
> @@ -175,6 +177,9 @@ struct PCIDevice {
>      /* Offset of MSI capability in config space */
>      uint8_t msi_cap;
>  
> +    /* PCI Express */
> +    PCIExpressDevice exp;
> +
>      /* Location of option rom */
>      char *romfile;
>      ram_addr_t rom_offset;
> diff --git a/hw/pcie.c b/hw/pcie.c
> new file mode 100644
> index 0000000..53d1fce
> --- /dev/null
> +++ b/hw/pcie.c
> @@ -0,0 +1,540 @@
> +/*
> + * pcie.c
> + *
> + * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
> + *                    VA Linux Systems Japan K.K.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "sysemu.h"
> +#include "pci_bridge.h"
> +#include "pcie.h"
> +#include "msix.h"
> +#include "msi.h"
> +#include "pci_internals.h"
> +#include "pcie_regs.h"
> +
> +//#define DEBUG_PCIE
> +#ifdef DEBUG_PCIE
> +# define PCIE_DPRINTF(fmt, ...)                                         \
> +    fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
> +#else
> +# define PCIE_DPRINTF(fmt, ...) do {} while (0)
> +#endif
> +#define PCIE_DEV_PRINTF(dev, fmt, ...)                                  \
> +    PCIE_DPRINTF("%s:%x "fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
> +
> +
> +/***************************************************************************
> + * pci express capability helper functions
> + */
> +int pcie_cap_init(PCIDevice *dev, uint8_t offset, uint8_t type, uint8_t port)
> +{
> +    int pos;
> +    uint8_t *exp_cap;
> +
> +    assert(pci_is_express(dev));
> +
> +    pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
> +                                 PCI_EXP_VER2_SIZEOF);
> +    if (pos < 0) {
> +        return pos;
> +    }
> +    dev->exp.exp_cap = pos;
> +    exp_cap = dev->config + pos;
> +
> +    /* capability register
> +       interrupt message number defaults to 0 */
> +    pci_set_word(exp_cap + PCI_EXP_FLAGS,
> +                 ((type << PCI_EXP_FLAGS_TYPE_SHIFT) & PCI_EXP_FLAGS_TYPE) |
> +                 PCI_EXP_FLAGS_VER2);
> +
> +    /* device capability register
> +     * table 7-12:
> +     * roll based error reporting bit must be set by all
> +     * Functions conforming to the ECN, PCI Express Base
> +     * Specification, Revision 1.1., or subsequent PCI Express Base
> +     * Specification revisions.
> +     */
> +    pci_set_long(exp_cap + PCI_EXP_DEVCAP, PCI_EXP_DEVCAP_RBER);
> +
> +    pci_set_long(exp_cap + PCI_EXP_LNKCAP,
> +                 (port << PCI_EXP_LNKCAP_PN_SHIFT) |
> +                 PCI_EXP_LNKCAP_ASPMS_0S |
> +                 PCI_EXP_LNK_MLW_1 |
> +                 PCI_EXP_LNK_LS_25);
> +
> +    pci_set_word(exp_cap + PCI_EXP_LNKSTA,
> +                 PCI_EXP_LNK_MLW_1 | PCI_EXP_LNK_LS_25);
> +
> +    pci_set_long(exp_cap + PCI_EXP_DEVCAP2,
> +                 PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);
> +
> +    pci_set_word(dev->wmask + pos, PCI_EXP_DEVCTL2_EETLPPB);
> +    return pos;
> +}
> +
> +void pcie_cap_exit(PCIDevice *dev)
> +{
> +    pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER2_SIZEOF);
> +}
> +
> +uint8_t pcie_cap_get_type(const PCIDevice *dev)
> +{
> +    uint32_t pos = dev->exp.exp_cap;
> +    assert(pos > 0);
> +    return (pci_get_word(dev->config + pos + PCI_EXP_FLAGS) &
> +            PCI_EXP_FLAGS_TYPE) >> PCI_EXP_FLAGS_TYPE_SHIFT;
> +}
> +
> +/* MSI/MSI-X */
> +/* pci express interrupt message number */
> +/* 7.8.2 PCI Express Capabilities Register: Interrupt Message Number */
> +void pcie_cap_flags_set_vector(PCIDevice *dev, uint8_t vector)
> +{
> +    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
> +    assert(vector < 32);
> +    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_FLAGS, PCI_EXP_FLAGS_IRQ);
> +    pci_word_test_and_set_mask(exp_cap + PCI_EXP_FLAGS,
> +                               vector << PCI_EXP_FLAGS_IRQ_SHIFT);
> +}
> +
> +uint8_t pcie_cap_flags_get_vector(PCIDevice *dev)
> +{
> +    return (pci_get_word(dev->config + dev->exp.exp_cap + PCI_EXP_FLAGS) &
> +            PCI_EXP_FLAGS_IRQ) >> PCI_EXP_FLAGS_IRQ_SHIFT;
> +}
> +
> +void pcie_cap_deverr_init(PCIDevice *dev)
> +{
> +    uint32_t pos = dev->exp.exp_cap;
> +    pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP,
> +                               PCI_EXP_DEVCAP_RBER);
> +    pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL,
> +                               PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
> +                               PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
> +    pci_long_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_DEVSTA,
> +                               PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED |
> +                               PCI_EXP_DEVSTA_URD | PCI_EXP_DEVSTA_URD);
> +}
> +
> +void pcie_cap_deverr_reset(PCIDevice *dev)
> +{
> +    uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
> +    pci_long_test_and_clear_mask(devctl,
> +                                 PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
> +                                 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
> +}
> +
> +/*
> + * A PCI Express Hot-Plug Event has occured, so update slot status register
> + * and notify OS of the event if necessary.
> + *
> + * 6.7.3 PCI Express Hot-Plug Events
> + * 6.7.3.4 Software Notification of Hot-Plug Events
> + */
> +static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
> +{
> +    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
> +    uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
> +    uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
> +
> +    PCIE_DEV_PRINTF(dev,
> +                    "sltctl: 0x%02"PRIx16" sltsta: 0x%02"PRIx16" event: %x\n",
> +                    sltctl, sltsta, event);
> +
> +    if (pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA, event)) {
> +        return;
> +    }
> +    sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
> +    PCIE_DEV_PRINTF(dev, "sltsta -> %02"PRIx16"\n", sltsta);
> +
> +    if ((sltctl & PCI_EXP_SLTCTL_HPIE) &&
> +        (sltctl & event & PCI_EXP_HP_EV_SUPPORTED)) {
> +        if (pci_msi_enabled(dev)) {
> +            pci_msi_notify(dev, pcie_cap_flags_get_vector(dev));
> +        } else {
> +            qemu_set_irq(dev->irq[dev->exp.hpev_intx], 1);
> +        }
> +    }
> +}
> +
> +static int pcie_cap_slot_hotplug(DeviceState *qdev,
> +                                 PCIDevice *pci_dev, int state)
> +{
> +    PCIDevice *d = DO_UPCAST(PCIDevice, qdev, qdev);
> +    uint8_t *exp_cap = d->config + d->exp.exp_cap;
> +    uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
> +
> +    if (!pci_dev->qdev.hotplugged) {
> +        assert(state); /* this case only happens at machine creation. */
> +        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
> +                                   PCI_EXP_SLTSTA_PDS);
> +        return 0;
> +    }
> +
> +    PCIE_DEV_PRINTF(pci_dev, "hotplug state: %d\n", state);
> +    if (sltsta & PCI_EXP_SLTSTA_EIS) {
> +        /* the slot is electromechanically locked.
> +         * This error is propagated up to qdev and then to HMP/QMP.
> +         */
> +        return -EBUSY;
> +    }
> +
> +    /* TODO: multifunction hot-plug.
> +     * Right now, only a device of function = 0 is allowed to be
> +     * hot plugged/unplugged.
> +     */
> +    assert(PCI_FUNC(pci_dev->devfn) == 0);
> +
> +    if (state) {
> +        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
> +                                   PCI_EXP_SLTSTA_PDS);
> +        pcie_cap_slot_event(d, PCI_EXP_HP_EV_PDC);
> +    } else {
> +        qdev_free(&pci_dev->qdev);
> +        pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
> +                                     PCI_EXP_SLTSTA_PDS);
> +        pcie_cap_slot_event(d, PCI_EXP_HP_EV_PDC);
> +    }
> +    return 0;
> +}
> +
> +/* pci express slot for pci express root/downstream port
> +   PCI express capability slot registers */
> +void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot)
> +{
> +    uint32_t pos = dev->exp.exp_cap;
> +
> +    pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
> +                               PCI_EXP_FLAGS_SLOT);
> +
> +    pci_long_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCAP,
> +                                 ~PCI_EXP_SLTCAP_PSN);
> +    pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
> +                               (slot << PCI_EXP_SLTCAP_PSN_SHIFT) |
> +                               PCI_EXP_SLTCAP_EIP |
> +                               PCI_EXP_SLTCAP_HPS |
> +                               PCI_EXP_SLTCAP_HPC |
> +                               PCI_EXP_SLTCAP_PIP |
> +                               PCI_EXP_SLTCAP_AIP |
> +                               PCI_EXP_SLTCAP_ABP);
> +
> +    pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
> +                                 PCI_EXP_SLTCTL_PIC |
> +                                 PCI_EXP_SLTCTL_AIC);
> +    pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCTL,
> +                               PCI_EXP_SLTCTL_PIC_OFF |
> +                               PCI_EXP_SLTCTL_AIC_OFF);
> +    pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
> +                               PCI_EXP_SLTCTL_PIC |
> +                               PCI_EXP_SLTCTL_AIC |
> +                               PCI_EXP_SLTCTL_HPIE |
> +                               PCI_EXP_SLTCTL_CCIE |
> +                               PCI_EXP_SLTCTL_PDCE |
> +                               PCI_EXP_SLTCTL_ABPE);
> +    /* Although reading PCI_EXP_SLTCTL_EIC returns always 0,
> +     * make the bit writable here in order to detect 1b is written.
> +     * pcie_cap_slot_write_config() test-and-clear the bit, so
> +     * this bit always returns 0 to the guest.
> +     */
> +    pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
> +                               PCI_EXP_SLTCTL_EIC);
> +
> +    pci_word_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_SLTSTA,
> +                               PCI_EXP_HP_EV_SUPPORTED);
> +
> +    pci_bus_hotplug(pci_bridge_get_sec_bus(DO_UPCAST(PCIBridge, dev, dev)),
> +                    pcie_cap_slot_hotplug, &dev->qdev);
> +}
> +
> +void pcie_cap_slot_reset(PCIDevice *dev)
> +{
> +    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
> +
> +    PCIE_DEV_PRINTF(dev, "reset\n");
> +
> +    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
> +                                 PCI_EXP_SLTCTL_EIC |
> +                                 PCI_EXP_SLTCTL_PIC |
> +                                 PCI_EXP_SLTCTL_AIC |
> +                                 PCI_EXP_SLTCTL_HPIE |
> +                                 PCI_EXP_SLTCTL_CCIE |
> +                                 PCI_EXP_SLTCTL_PDCE |
> +                                 PCI_EXP_SLTCTL_ABPE);
> +    pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
> +                               PCI_EXP_SLTCTL_PIC_OFF |
> +                               PCI_EXP_SLTCTL_AIC_OFF);
> +
> +    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
> +                                 PCI_EXP_SLTSTA_EIS |/* on reset,
> +                                                        the lock is released */
> +                                 PCI_EXP_SLTSTA_CC |
> +                                 PCI_EXP_SLTSTA_PDC |
> +                                 PCI_EXP_SLTSTA_ABP);
> +}
> +
> +void pcie_cap_slot_write_config(PCIDevice *dev,
> +                                uint32_t addr, uint32_t val, int len,
> +                                uint16_t sltctl_prev)
> +{
> +    uint32_t pos = dev->exp.exp_cap;
> +    uint8_t *exp_cap = dev->config + pos;
> +    uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
> +    uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
> +
> +    PCIE_DEV_PRINTF(dev,
> +                    "addr: 0x%"PRIx32" val: 0x%"PRIx32" len: %d\n"
> +                    "\tsltctl_prev: 0x%02"PRIx16" sltctl: 0x%02"PRIx16
> +                    " sltsta: 0x%02"PRIx16"\n",
> +                    addr, val, len, sltctl_prev, sltctl, sltsta);
> +
> +    /* SLTCTL */
> +    if (ranges_overlap(addr, len, pos + PCI_EXP_SLTCTL, 2)) {
> +        PCIE_DEV_PRINTF(dev, "sltctl: 0x%02"PRIx16" -> 0x%02"PRIx16"\n",
> +                        sltctl_prev, sltctl);
> +        if (pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
> +                                         PCI_EXP_SLTCTL_EIC)) {
> +            sltsta ^= PCI_EXP_SLTSTA_EIS; /* toggle PCI_EXP_SLTSTA_EIS bit */
> +            pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
> +            PCIE_DEV_PRINTF(dev, "PCI_EXP_SLTCTL_EIC: "
> +                            "sltsta -> 0x%02"PRIx16"\n",
> +                            sltsta);
> +        }
> +
> +        /*
> +         * The events control bits might be enabled or disabled,
> +         * Check if the software notificastion condition is satisfied
> +         * or disatisfied.
> +         *
> +         * 6.7.3.4 Software Notification of Hot-plug events
> +         */
> +        if (pci_msi_enabled(dev)) {
> +            bool msi_trigger =
> +                (sltctl & PCI_EXP_SLTCTL_HPIE) &&
> +                ((sltctl_prev ^ sltctl) & sltctl & /* stlctl: 0 -> 1 */
> +                 sltsta & PCI_EXP_HP_EV_SUPPORTED);
> +            if (msi_trigger) {
> +                pci_msi_notify(dev, pcie_cap_flags_get_vector(dev));
> +            }
> +        } else {
> +            int int_level =
> +                (sltctl & PCI_EXP_SLTCTL_HPIE) &&
> +                (sltctl & sltsta & PCI_EXP_HP_EV_SUPPORTED);
> +            qemu_set_irq(dev->irq[dev->exp.hpev_intx], int_level);
> +        }
> +
> +        if (!((sltctl_prev ^ sltctl) & PCI_EXP_SLTCTL_SUPPORTED)) {
> +            PCIE_DEV_PRINTF(dev,
> +                            "sprious command completion slctl "
> +                            "0x%"PRIx16" -> 0x%"PRIx16"\n",
> +                            sltctl_prev, sltctl);
> +        }
> +
> +        /* command completion.
> +         * Real hardware might take a while to complete
> +         * requested command because physical movement would be involved
> +         * like locking the electromechanical lock.
> +         * However in our case, command is completed instantaneously above,
> +         * so send a command completion event right now.
> +         *
> +         * 6.7.3.2 Command Completed Events
> +         */
> +        /* set command completed bit */
> +        pcie_cap_slot_event(dev, PCI_EXP_HP_EV_CCI);
> +    }
> +}
> +
> +void pcie_cap_slot_push_attention_button(PCIDevice *dev)
> +{
> +    pcie_cap_slot_event(dev, PCI_EXP_HP_EV_ABP);
> +}
> +
> +/* root control/capabilities/status. PME isn't emulated for now */
> +void pcie_cap_root_init(PCIDevice *dev)
> +{
> +    pci_set_word(dev->wmask + dev->exp.exp_cap + PCI_EXP_RTCTL,
> +                 PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
> +                 PCI_EXP_RTCTL_SEFEE);
> +}
> +
> +void pcie_cap_root_reset(PCIDevice *dev)
> +{
> +    pci_set_word(dev->config + dev->exp.exp_cap + PCI_EXP_RTCTL, 0);
> +}
> +
> +/*
> + * TODO: implement FLR:
> + * Right now sets the bit which indicates FLR is supported.
> + */
> +/* function level reset(FLR) */
> +void pcie_cap_flr_init(PCIDevice *dev)
> +{
> +    pci_long_test_and_set_mask(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCAP,
> +                               PCI_EXP_DEVCAP_FLR);
> +
> +    /* Although reading BCR_FLR returns always 0,
> +     * the bit is made writable here in order to detect the 1b is written
> +     * pcie_cap_flr_write_config() test-and-clear the bit, so
> +     * this bit always returns 0 to the guest.
> +     */
> +    pci_word_test_and_set_mask(dev->wmask + dev->exp.exp_cap + PCI_EXP_DEVCTL,
> +                               PCI_EXP_DEVCTL_BCR_FLR);
> +}
> +
> +void pcie_cap_flr_write_config(PCIDevice *dev,
> +                               uint32_t addr, uint32_t val, int len)
> +{
> +    uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
> +    if (pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR)) {
> +        /* TODO: implement FLR */
> +    }
> +}
> +
> +/* Alternative Routing-ID Interpretation (ARI) */
> +/* ari forwarding support for down stream port */
> +void pcie_cap_ari_init(PCIDevice *dev)
> +{
> +    uint32_t pos = dev->exp.exp_cap;
> +    pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP2,
> +                               PCI_EXP_DEVCAP2_ARI);
> +    pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL2,
> +                               PCI_EXP_DEVCTL2_ARI);
> +}
> +
> +void pcie_cap_ari_reset(PCIDevice *dev)
> +{
> +    uint8_t *devctl2 = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2;
> +    pci_long_test_and_clear_mask(devctl2, PCI_EXP_DEVCTL2_ARI);
> +}
> +
> +bool pcie_cap_is_ari_enabled(const PCIDevice *dev)
> +{
> +    if (!pci_is_express(dev)) {
> +        return false;
> +    }
> +    if (!dev->exp.exp_cap) {
> +        return false;
> +    }
> +
> +    return pci_get_long(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2) &
> +        PCI_EXP_DEVCTL2_ARI;
> +}
> +
> +/**************************************************************************
> + * pci express extended capability allocation functions
> + * uint16_t ext_cap_id (16 bit)
> + * uint8_t cap_ver (4 bit)
> + * uint16_t cap_offset (12 bit)
> + * uint16_t ext_cap_size
> + */
> +
> +static uint16_t pcie_find_capability_list(PCIDevice *dev, uint16_t cap_id,
> +                                          uint16_t *prev_p)
> +{
> +    uint16_t prev = 0;
> +    uint16_t next;
> +    uint32_t header = pci_get_long(dev->config + PCI_CONFIG_SPACE_SIZE);
> +
> +    if (!header) {
> +        /* no extended capability */
> +        next = 0;
> +        goto out;
> +    }
> +    for (next = PCI_CONFIG_SPACE_SIZE; next;
> +         prev = next, next = PCI_EXT_CAP_NEXT(header)) {
> +
> +        assert(next >= PCI_CONFIG_SPACE_SIZE);
> +        assert(next <= PCIE_CONFIG_SPACE_SIZE - 8);
> +
> +        header = pci_get_long(dev->config + next);
> +        if (PCI_EXT_CAP_ID(header) == cap_id) {
> +            break;
> +        }
> +    }
> +
> +out:
> +    if (prev_p) {
> +        *prev_p = prev;
> +    }
> +    return next;
> +}
> +
> +uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id)
> +{
> +    return pcie_find_capability_list(dev, cap_id, NULL);
> +}
> +
> +static void pcie_ext_cap_set_next(PCIDevice *dev, uint16_t pos, uint16_t next)
> +{
> +    uint16_t header = pci_get_long(dev->config + pos);
> +    assert(!(next & (PCI_EXT_CAP_ALIGN - 1)));
> +    header = (header & ~PCI_EXT_CAP_NEXT_MASK) |
> +        ((next << PCI_EXT_CAP_NEXT_SHIFT) & PCI_EXT_CAP_NEXT_MASK);
> +    pci_set_long(dev->config + pos, header);
> +}
> +
> +/*
> + * caller must supply valid (offset, size) * such that the range shouldn't
> + * overlap with other capability or other registers.
> + * This function doesn't check it.
> + */
> +void pcie_add_capability(PCIDevice *dev,
> +                         uint16_t cap_id, uint8_t cap_ver,
> +                         uint16_t offset, uint16_t size)
> +{
> +    uint32_t header;
> +    uint16_t next;
> +
> +    assert(offset >= PCI_CONFIG_SPACE_SIZE);
> +    assert(offset < offset + size);
> +    assert(offset + size < PCIE_CONFIG_SPACE_SIZE);
> +    assert(size >= 8);
> +    assert(pci_is_express(dev));
> +
> +    if (offset == PCI_CONFIG_SPACE_SIZE) {
> +        header = pci_get_long(dev->config + offset);
> +        next = PCI_EXT_CAP_NEXT(header);
> +    } else {
> +        uint16_t prev;
> +
> +        /* 0 is reserved cap id. use internally to find the last capability
> +           in the linked list */
> +        next = pcie_find_capability_list(dev, 0, &prev);
> +
> +        assert(prev >= PCI_CONFIG_SPACE_SIZE);
> +        assert(next == 0);
> +        pcie_ext_cap_set_next(dev, prev, offset);
> +    }
> +    pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, next));
> +
> +    /* Make capability read-only by default */
> +    memset(dev->wmask + offset, 0, size);
> +    memset(dev->w1cmask + offset, 0, size);
> +    /* Check capability by default */
> +    memset(dev->cmask + offset, 0xFF, size);
> +}
> +
> +/**************************************************************************
> + * pci express extended capability helper functions
> + */
> +
> +/* ARI */
> +void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn)
> +{
> +    pcie_add_capability(dev, PCI_EXT_CAP_ID_ARI, PCI_ARI_VER,
> +                        offset, PCI_ARI_SIZEOF);
> +    pci_set_long(dev->config + offset + PCI_ARI_CAP, PCI_ARI_CAP_NFN(nextfn));
> +}
> diff --git a/hw/pcie.h b/hw/pcie.h
> new file mode 100644
> index 0000000..68327d8
> --- /dev/null
> +++ b/hw/pcie.h
> @@ -0,0 +1,107 @@
> +/*
> + * pcie.h
> + *
> + * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
> + *                    VA Linux Systems Japan K.K.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef QEMU_PCIE_H
> +#define QEMU_PCIE_H
> +
> +#include "hw.h"
> +#include "pci_regs.h"
> +#include "pcie_regs.h"
> +
> +typedef enum {
> +    /* for attention and power indicator */
> +    PCI_EXP_HP_IND_RESERVED     = PCI_EXP_SLTCTL_IND_RESERVED,
> +    PCI_EXP_HP_IND_ON           = PCI_EXP_SLTCTL_IND_ON,
> +    PCI_EXP_HP_IND_BLINK        = PCI_EXP_SLTCTL_IND_BLINK,
> +    PCI_EXP_HP_IND_OFF          = PCI_EXP_SLTCTL_IND_OFF,
> +} PCIExpressIndicator;
> +
> +typedef enum {
> +    /* these bits must match the bits in Slot Control/Status registers.
> +     * PCI_EXP_HP_EV_xxx = PCI_EXP_SLTCTL_xxxE = PCI_EXP_SLTSTA_xxx
> +     *
> +     * Not all the bits of slot control register match with the ones of
> +     * slot status. Not some bits of slot status register is used to
> +     * show status, not to report event occurence.
> +     * So such bits must be masked out when checking the software
> +     * notification condition.
> +     */
> +    PCI_EXP_HP_EV_ABP           = PCI_EXP_SLTCTL_ABPE,
> +                                        /* attention button pressed */
> +    PCI_EXP_HP_EV_PDC           = PCI_EXP_SLTCTL_PDCE,
> +                                        /* presence detect changed */
> +    PCI_EXP_HP_EV_CCI           = PCI_EXP_SLTCTL_CCIE,
> +                                        /* command completed */
> +
> +    PCI_EXP_HP_EV_SUPPORTED     = PCI_EXP_HP_EV_ABP |
> +                                  PCI_EXP_HP_EV_PDC |
> +                                  PCI_EXP_HP_EV_CCI,
> +                                                /* supported event mask  */
> +
> +    /* events not listed aren't supported */
> +} PCIExpressHotPlugEvent;
> +
> +struct PCIExpressDevice {
> +    /* Offset of express capability in config space */
> +    uint8_t exp_cap;
> +
> +    /* TODO FLR */
> +
> +    /* SLOT */
> +    unsigned int hpev_intx;     /* INTx for hot plug event */
> +};
> +
> +/* PCI express capability helper functions */
> +int pcie_cap_init(PCIDevice *dev, uint8_t offset, uint8_t type, uint8_t port);
> +void pcie_cap_exit(PCIDevice *dev);
> +uint8_t pcie_cap_get_type(const PCIDevice *dev);
> +void pcie_cap_flags_set_vector(PCIDevice *dev, uint8_t vector);
> +uint8_t pcie_cap_flags_get_vector(PCIDevice *dev);
> +
> +void pcie_cap_deverr_init(PCIDevice *dev);
> +void pcie_cap_deverr_reset(PCIDevice *dev);
> +
> +void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot);
> +void pcie_cap_slot_reset(PCIDevice *dev);
> +void pcie_cap_slot_write_config(PCIDevice *dev,
> +                                uint32_t addr, uint32_t val, int len,
> +                                uint16_t sltctl_prev);
> +void pcie_cap_slot_push_attention_button(PCIDevice *dev);
> +
> +void pcie_cap_root_init(PCIDevice *dev);
> +void pcie_cap_root_reset(PCIDevice *dev);
> +
> +void pcie_cap_flr_init(PCIDevice *dev);
> +void pcie_cap_flr_write_config(PCIDevice *dev,
> +                           uint32_t addr, uint32_t val, int len);
> +
> +void pcie_cap_ari_init(PCIDevice *dev);
> +void pcie_cap_ari_reset(PCIDevice *dev);
> +bool pcie_cap_is_ari_enabled(const PCIDevice *dev);
> +
> +/* PCI express extended capability helper functions */
> +uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id);
> +void pcie_add_capability(PCIDevice *dev,
> +                         uint16_t cap_id, uint8_t cap_ver,
> +                         uint16_t offset, uint16_t size);
> +
> +void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn);
> +
> +#endif /* QEMU_PCIE_H */
> diff --git a/qemu-common.h b/qemu-common.h
> index d735235..6d9ee26 100644
> --- a/qemu-common.h
> +++ b/qemu-common.h
> @@ -219,6 +219,7 @@ typedef struct PCIHostState PCIHostState;
>  typedef struct PCIExpressHost PCIExpressHost;
>  typedef struct PCIBus PCIBus;
>  typedef struct PCIDevice PCIDevice;
> +typedef struct PCIExpressDevice PCIExpressDevice;
>  typedef struct PCIBridge PCIBridge;
>  typedef struct SerialState SerialState;
>  typedef struct IRQState *qemu_irq;
> -- 
> 1.7.1.1