Commit 2b1dbd0d authored by Alex Williamson's avatar Alex Williamson
Browse files

vfio/quirks: Enable ioeventfd quirks to be handled by vfio directly 



With vfio ioeventfd support, we can program vfio-pci to perform a
specified BAR write when an eventfd is triggered.  This allows the
KVM ioeventfd to be wired directly to vfio-pci, entirely avoiding
userspace handling for these events.  On the same micro-benchmark
where the ioeventfd got us to almost 90% of performance versus
disabling the GeForce quirks, this gets us to within 95%.

Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent c958c51d

hw/vfio/pci-quirks.c

+46 −7
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include "qemu/range.h"

#include "qapi/error.h"

#include "qapi/visitor.h"

#include <sys/ioctl.h>

#include "hw/nvram/fw_cfg.h"

#include "pci.h"

#include "trace.h"
@@ -287,12 +288,33 @@ static VFIOQuirk *vfio_quirk_alloc(int nr_mem) 
    return quirk;

}



static void vfio_ioeventfd_exit(VFIOIOEventFD *ioeventfd)

static void vfio_ioeventfd_exit(VFIOPCIDevice *vdev, VFIOIOEventFD *ioeventfd)

{

    QLIST_REMOVE(ioeventfd, next);

    memory_region_del_eventfd(ioeventfd->mr, ioeventfd->addr, ioeventfd->size,

                              true, ioeventfd->data, &ioeventfd->e);

    qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e), NULL, NULL, NULL);



    if (ioeventfd->vfio) {

        struct vfio_device_ioeventfd vfio_ioeventfd;



        vfio_ioeventfd.argsz = sizeof(vfio_ioeventfd);

        vfio_ioeventfd.flags = ioeventfd->size;

        vfio_ioeventfd.data = ioeventfd->data;

        vfio_ioeventfd.offset = ioeventfd->region->fd_offset +

                                ioeventfd->region_addr;

        vfio_ioeventfd.fd = -1;



        if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_IOEVENTFD, &vfio_ioeventfd)) {

            error_report("Failed to remove vfio ioeventfd for %s+0x%"

                         HWADDR_PRIx"[%d]:0x%"PRIx64" (%m)",

                         memory_region_name(ioeventfd->mr), ioeventfd->addr,

                         ioeventfd->size, ioeventfd->data);

        }

    } else {

        qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e),

                            NULL, NULL, NULL);

    }



    event_notifier_cleanup(&ioeventfd->e);

    trace_vfio_ioeventfd_exit(memory_region_name(ioeventfd->mr),

                              (uint64_t)ioeventfd->addr, ioeventfd->size,
@@ -306,7 +328,7 @@ static void vfio_drop_dynamic_eventfds(VFIOPCIDevice *vdev, VFIOQuirk *quirk) 


    QLIST_FOREACH_SAFE(ioeventfd, &quirk->ioeventfds, next, tmp) {

        if (ioeventfd->dynamic) {

            vfio_ioeventfd_exit(ioeventfd);

            vfio_ioeventfd_exit(vdev, ioeventfd);

        }

    }

}
@@ -359,12 +381,29 @@ static VFIOIOEventFD *vfio_ioeventfd_init(VFIOPCIDevice *vdev, 
    ioeventfd->region = region;

    ioeventfd->region_addr = region_addr;



    if (!vdev->no_vfio_ioeventfd) {

        struct vfio_device_ioeventfd vfio_ioeventfd;



        vfio_ioeventfd.argsz = sizeof(vfio_ioeventfd);

        vfio_ioeventfd.flags = ioeventfd->size;

        vfio_ioeventfd.data = ioeventfd->data;

        vfio_ioeventfd.offset = ioeventfd->region->fd_offset +

                                ioeventfd->region_addr;

        vfio_ioeventfd.fd = event_notifier_get_fd(&ioeventfd->e);



        ioeventfd->vfio = !ioctl(vdev->vbasedev.fd,

                                 VFIO_DEVICE_IOEVENTFD, &vfio_ioeventfd);

    }



    if (!ioeventfd->vfio) {

        qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e),

                            vfio_ioeventfd_handler, NULL, ioeventfd);

    }



    memory_region_add_eventfd(ioeventfd->mr, ioeventfd->addr, ioeventfd->size,

                              true, ioeventfd->data, &ioeventfd->e);

    trace_vfio_ioeventfd_init(memory_region_name(mr), (uint64_t)addr,

                              size, data);

                              size, data, ioeventfd->vfio);



    return ioeventfd;

}
@@ -1827,7 +1866,7 @@ void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr) 


    QLIST_FOREACH(quirk, &bar->quirks, next) {

        while (!QLIST_EMPTY(&quirk->ioeventfds)) {

            vfio_ioeventfd_exit(QLIST_FIRST(&quirk->ioeventfds));

            vfio_ioeventfd_exit(vdev, QLIST_FIRST(&quirk->ioeventfds));

        }



        for (i = 0; i < quirk->nr_mem; i++) {

hw/vfio/pci.c

+2 −0
Original line number Diff line number Diff line
@@ -3177,6 +3177,8 @@ static Property vfio_pci_dev_properties[] = { 
                     no_geforce_quirks, false),

    DEFINE_PROP_BOOL("x-no-kvm-ioeventfd", VFIOPCIDevice, no_kvm_ioeventfd,

                     false),

    DEFINE_PROP_BOOL("x-no-vfio-ioeventfd", VFIOPCIDevice, no_vfio_ioeventfd,

                     false),

    DEFINE_PROP_UINT32("x-pci-vendor-id", VFIOPCIDevice, vendor_id, PCI_ANY_ID),

    DEFINE_PROP_UINT32("x-pci-device-id", VFIOPCIDevice, device_id, PCI_ANY_ID),

    DEFINE_PROP_UINT32("x-pci-sub-vendor-id", VFIOPCIDevice,

hw/vfio/pci.h

+2 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ typedef struct VFIOIOEventFD { 
    VFIORegion *region;

    hwaddr region_addr;

    bool dynamic; /* Added runtime, removed on device reset */

    bool vfio;

} VFIOIOEventFD;



typedef struct VFIOQuirk {
@@ -163,6 +164,7 @@ typedef struct VFIOPCIDevice { 
    bool no_kvm_msix;

    bool no_geforce_quirks;

    bool no_kvm_ioeventfd;

    bool no_vfio_ioeventfd;

    VFIODisplay *dpy;

} VFIOPCIDevice;

hw/vfio/trace-events

+1 −1
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ vfio_quirk_ati_bonaire_reset_done(const char *name) "%s" 
vfio_quirk_ati_bonaire_reset(const char *name) "%s"

vfio_ioeventfd_exit(const char *name, uint64_t addr, unsigned size, uint64_t data) "%s+0x%"PRIx64"[%d]:0x%"PRIx64

vfio_ioeventfd_handler(const char *name, uint64_t addr, unsigned size, uint64_t data) "%s+0x%"PRIx64"[%d] -> 0x%"PRIx64

vfio_ioeventfd_init(const char *name, uint64_t addr, unsigned size, uint64_t data) "%s+0x%"PRIx64"[%d]:0x%"PRIx64

vfio_ioeventfd_init(const char *name, uint64_t addr, unsigned size, uint64_t data, bool vfio) "%s+0x%"PRIx64"[%d]:0x%"PRIx64" vfio:%d"

vfio_pci_igd_bar4_write(const char *name, uint32_t index, uint32_t data, uint32_t base) "%s [0x%03x] 0x%08x -> 0x%08x"

vfio_pci_igd_bdsm_enabled(const char *name, int size) "%s %dMB"

vfio_pci_igd_opregion_enabled(const char *name) "%s"