Added an irq type VFIO_IRQ_TYPE_REMAP_BAR_REGION to dynamically query and remap BAR regions.
QEMU decodes the index of the BARs by reading cnt of eventfd. If bit n is set, the corresponding BAR will be requeried and its subregions will be remapped according to the its new flags. rely on [1] "vfio: Add a funtion to return a specific irq capabilities" [1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg621645.html Signed-off-by: Yan Zhao <yan.y.z...@intel.com> --- hw/vfio/common.c | 50 ++++++++++++++++++++++++ hw/vfio/pci.c | 90 +++++++++++++++++++++++++++++++++++++++++++ hw/vfio/pci.h | 2 + include/hw/vfio/vfio-common.h | 2 + linux-headers/linux/vfio.h | 11 ++++++ 5 files changed, 155 insertions(+) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index a041c3b..cf24293 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1284,6 +1284,56 @@ void vfio_region_unmap(VFIORegion *region) } } +/* + * re-query a region's flags, + * and update its mmap'd subregions. + * It does not support change a region's size. + */ +void vfio_region_reset_mmap(VFIODevice *vbasedev, VFIORegion *region, int index) +{ + struct vfio_region_info *new; + + if (!region->mem) { + return; + } + + if (vfio_get_region_info(vbasedev, index, &new)) { + goto out; + } + + if (region->size != new->size) { + error_report("vfio: resetting of region size is not supported"); + goto out; + } + + if (region->flags == new->flags) { + goto out; + } + + /* ummap old mmap'd subregions, if any */ + vfio_region_unmap(region); + region->nr_mmaps = 0; + g_free(region->mmaps); + region->mmaps = NULL; + + /* setup new mmap'd subregions*/ + region->flags = new->flags; + if (vbasedev->no_mmap || + !(region->flags & VFIO_REGION_INFO_FLAG_MMAP)) { + goto out; + } + + if (vfio_setup_region_sparse_mmaps(region, new)) { + region->nr_mmaps = 1; + region->mmaps = g_new0(VFIOMmap, region->nr_mmaps); + region->mmaps[0].offset = 0; + region->mmaps[0].size = region->size; + } + vfio_region_mmap(region); +out: + g_free(new); +} + void vfio_region_exit(VFIORegion *region) { int i; diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index c70f153..12998c5 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2883,6 +2883,94 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev) vdev->req_enabled = false; } +static void vfio_remap_bar_notifier_handler(void *opaque) +{ + VFIOPCIDevice *vdev = opaque; + uint64_t bars; + ssize_t ret; + int i; + + ret = read(vdev->remap_bar_notifier.rfd, &bars, sizeof(bars)); + if (ret != sizeof(bars)) { + return; + } + for (i = 0; i < PCI_ROM_SLOT; i++) { + VFIORegion *region = &vdev->bars[i].region; + + if (!test_bit(i, &bars)) { + continue; + } + + vfio_region_reset_mmap(&vdev->vbasedev, region, i); + } + + /* write 0 to notify kernel that we're done */ + bars = 0; + write(vdev->remap_bar_notifier.wfd, &bars, sizeof(bars)); +} + +static void vfio_register_remap_bar_notifier(VFIOPCIDevice *vdev) +{ + int ret; + struct vfio_irq_info *irq; + Error *err = NULL; + int32_t fd; + + ret = vfio_get_dev_irq_info(&vdev->vbasedev, + VFIO_IRQ_TYPE_REMAP_BAR_REGION, + VFIO_IRQ_SUBTYPE_REMAP_BAR_REGION, + &irq); + if (ret) { + return; + } + ret = event_notifier_init(&vdev->remap_bar_notifier, 0); + if (ret) { + error_report("vfio: Failed to init event notifier for remap bar irq"); + return; + } + + fd = event_notifier_get_fd(&vdev->remap_bar_notifier); + qemu_set_fd_handler(fd, vfio_remap_bar_notifier_handler, NULL, vdev); + + if (vfio_set_irq_signaling(&vdev->vbasedev, irq->index, 0, + VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) { + error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); + qemu_set_fd_handler(fd, NULL, NULL, vdev); + event_notifier_cleanup(&vdev->remap_bar_notifier); + } else { + vdev->remap_bar_enabled = true; + } +}; + +static void vfio_unregister_remap_bar_notifier(VFIOPCIDevice *vdev) +{ + struct vfio_irq_info *irq; + Error *err = NULL; + int ret; + + if (!vdev->remap_bar_enabled) { + return; + } + + ret = vfio_get_dev_irq_info(&vdev->vbasedev, + VFIO_IRQ_TYPE_REMAP_BAR_REGION, + VFIO_IRQ_SUBTYPE_REMAP_BAR_REGION, + &irq); + if (ret) { + return; + } + + if (vfio_set_irq_signaling(&vdev->vbasedev, irq->index, 0, + VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) { + error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); + } + qemu_set_fd_handler(event_notifier_get_fd(&vdev->remap_bar_notifier), + NULL, NULL, vdev); + event_notifier_cleanup(&vdev->req_notifier); + + vdev->remap_bar_enabled = false; +} + static void vfio_realize(PCIDevice *pdev, Error **errp) { VFIOPCIDevice *vdev = PCI_VFIO(pdev); @@ -3194,6 +3282,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) vfio_register_err_notifier(vdev); vfio_register_req_notifier(vdev); + vfio_register_remap_bar_notifier(vdev); vfio_setup_resetfn_quirk(vdev); return; @@ -3235,6 +3324,7 @@ static void vfio_exitfn(PCIDevice *pdev) vfio_unregister_req_notifier(vdev); vfio_unregister_err_notifier(vdev); + vfio_unregister_remap_bar_notifier(vdev); pci_device_set_intx_routing_notifier(&vdev->pdev, NULL); if (vdev->irqchip_change_notifier.notify) { kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier); diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h index b148c93..5a1e564 100644 --- a/hw/vfio/pci.h +++ b/hw/vfio/pci.h @@ -134,6 +134,7 @@ typedef struct VFIOPCIDevice { PCIHostDeviceAddress host; EventNotifier err_notifier; EventNotifier req_notifier; + EventNotifier remap_bar_notifier; int (*resetfn)(struct VFIOPCIDevice *); uint32_t vendor_id; uint32_t device_id; @@ -157,6 +158,7 @@ typedef struct VFIOPCIDevice { uint8_t nv_gpudirect_clique; bool pci_aer; bool req_enabled; + bool remap_bar_enabled; bool has_flr; bool has_pm_reset; bool rom_read_failed; diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index a6283b7..1c16790 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -188,6 +188,8 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region, int vfio_region_mmap(VFIORegion *region); void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled); void vfio_region_unmap(VFIORegion *region); +void vfio_region_reset_mmap(VFIODevice *vbasedev, + VFIORegion *region, int index); void vfio_region_exit(VFIORegion *region); void vfio_region_finalize(VFIORegion *region); void vfio_reset_handler(void *opaque); diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h index 2598a84..2344ca6 100644 --- a/linux-headers/linux/vfio.h +++ b/linux-headers/linux/vfio.h @@ -703,6 +703,17 @@ struct vfio_irq_info_cap_type { __u32 subtype; /* type specific */ }; +/* Bar Region Query IRQ TYPE */ +#define VFIO_IRQ_TYPE_REMAP_BAR_REGION (1) + +/* sub-types for VFIO_IRQ_TYPE_REMAP_BAR_REGION */ +/* + * This irq notifies userspace to re-query BAR region and remaps the + * subregions. + */ +#define VFIO_IRQ_SUBTYPE_REMAP_BAR_REGION (0) + + /** * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set) * -- 2.7.4
