| Message ID | 1489375798-19518-2-git-send-email-jasowang@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 13/03/2017 04:29, Jason Wang wrote: > 96a8821d2141 ("virtio: unbreak virtio-pci with IOMMU after caching ring > translations") tries to make IOMMU works with virtio memory region > cache, but it requires IOMMU to be created before any virtio > devices. This is sub optimal, fixing this by introduce a bus master > container to make sure address space can be initialized during device > registering, and then we can safely set alias and make > bus_master_enable_region as its subregion during bus master > initialization. > > Cc: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > hw/pci/pci.c | 9 +++++++-- > include/hw/pci/pci.h | 1 + > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 273f1e4..ad46390 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -88,8 +88,8 @@ static void pci_init_bus_master(PCIDevice *pci_dev) > OBJECT(pci_dev), "bus master", > dma_as->root, 0, memory_region_size(dma_as->root)); > memory_region_set_enabled(&pci_dev->bus_master_enable_region, false); > - address_space_init(&pci_dev->bus_master_as, > - &pci_dev->bus_master_enable_region, pci_dev->name); > + memory_region_add_subregion(&pci_dev->bus_master_container_region, 0, > + &pci_dev->bus_master_enable_region); > } > > static void pcibus_machine_done(Notifier *notifier, void *data) > @@ -995,6 +995,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, > pci_dev->devfn = devfn; > pci_dev->requester_id_cache = pci_req_id_cache_get(pci_dev); > > + memory_region_init(&pci_dev->bus_master_container_region, OBJECT(pci_dev), > + "bus master container", UINT64_MAX); > + address_space_init(&pci_dev->bus_master_as, > + &pci_dev->bus_master_container_region, pci_dev->name); > + > if (qdev_hotplug) { > pci_init_bus_master(pci_dev); > } > diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h > index 9349acb..713ede0 100644 > --- a/include/hw/pci/pci.h > +++ b/include/hw/pci/pci.h > @@ -284,6 +284,7 @@ struct PCIDevice { > char name[64]; > PCIIORegion io_regions[PCI_NUM_REGIONS]; > AddressSpace bus_master_as; > + MemoryRegion bus_master_container_region; > MemoryRegion bus_master_enable_region; > > /* do not access the following fields */ > Series Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
On 03/13/2017 05:29 AM, Jason Wang wrote: > 96a8821d2141 ("virtio: unbreak virtio-pci with IOMMU after caching ring > translations") tries to make IOMMU works with virtio memory region > cache, but it requires IOMMU to be created before any virtio > devices. This is sub optimal, fixing this by introduce a bus master > container to make sure address space can be initialized during device > registering, and then we can safely set alias and make > bus_master_enable_region as its subregion during bus master > initialization. > > Cc: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > hw/pci/pci.c | 9 +++++++-- > include/hw/pci/pci.h | 1 + > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 273f1e4..ad46390 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -88,8 +88,8 @@ static void pci_init_bus_master(PCIDevice *pci_dev) > OBJECT(pci_dev), "bus master", > dma_as->root, 0, memory_region_size(dma_as->root)); > memory_region_set_enabled(&pci_dev->bus_master_enable_region, false); > - address_space_init(&pci_dev->bus_master_as, > - &pci_dev->bus_master_enable_region, pci_dev->name); > + memory_region_add_subregion(&pci_dev->bus_master_container_region, 0, > + &pci_dev->bus_master_enable_region); Hi Jason, The patch looks good to me, I only have one question: On hot-unplug, shouldn't we remove the "new" sub-region ? Thanks, Marcel > } > > static void pcibus_machine_done(Notifier *notifier, void *data) > @@ -995,6 +995,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, > pci_dev->devfn = devfn; > pci_dev->requester_id_cache = pci_req_id_cache_get(pci_dev); > > + memory_region_init(&pci_dev->bus_master_container_region, OBJECT(pci_dev), > + "bus master container", UINT64_MAX); > + address_space_init(&pci_dev->bus_master_as, > + &pci_dev->bus_master_container_region, pci_dev->name); > + > if (qdev_hotplug) { > pci_init_bus_master(pci_dev); > } > diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h > index 9349acb..713ede0 100644 > --- a/include/hw/pci/pci.h > +++ b/include/hw/pci/pci.h > @@ -284,6 +284,7 @@ struct PCIDevice { > char name[64]; > PCIIORegion io_regions[PCI_NUM_REGIONS]; > AddressSpace bus_master_as; > + MemoryRegion bus_master_container_region; > MemoryRegion bus_master_enable_region; > > /* do not access the following fields */ >
On 13/03/2017 10:38, Marcel Apfelbaum wrote: > On 03/13/2017 05:29 AM, Jason Wang wrote: >> 96a8821d2141 ("virtio: unbreak virtio-pci with IOMMU after caching ring >> translations") tries to make IOMMU works with virtio memory region >> cache, but it requires IOMMU to be created before any virtio >> devices. This is sub optimal, fixing this by introduce a bus master >> container to make sure address space can be initialized during device >> registering, and then we can safely set alias and make >> bus_master_enable_region as its subregion during bus master >> initialization. >> >> Cc: Paolo Bonzini <pbonzini@redhat.com> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> hw/pci/pci.c | 9 +++++++-- >> include/hw/pci/pci.h | 1 + >> 2 files changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/hw/pci/pci.c b/hw/pci/pci.c >> index 273f1e4..ad46390 100644 >> --- a/hw/pci/pci.c >> +++ b/hw/pci/pci.c >> @@ -88,8 +88,8 @@ static void pci_init_bus_master(PCIDevice *pci_dev) >> OBJECT(pci_dev), "bus master", >> dma_as->root, 0, >> memory_region_size(dma_as->root)); >> memory_region_set_enabled(&pci_dev->bus_master_enable_region, >> false); >> - address_space_init(&pci_dev->bus_master_as, >> - &pci_dev->bus_master_enable_region, >> pci_dev->name); >> + >> memory_region_add_subregion(&pci_dev->bus_master_container_region, 0, >> + &pci_dev->bus_master_enable_region); > > Hi Jason, > > The patch looks good to me, I only have one question: > On hot-unplug, shouldn't we remove the "new" sub-region ? It should be done automatically: /* We know the region is not visible in any address space (it * does not have a container and cannot be a root either because * it has no references, so we can blindly clear mr->enabled. * memory_region_set_enabled instead could trigger a transaction * and cause an infinite loop. */ mr->enabled = false; memory_region_transaction_begin(); while (!QTAILQ_EMPTY(&mr->subregions)) { MemoryRegion *subregion = QTAILQ_FIRST(&mr->subregions); memory_region_del_subregion(mr, subregion); } memory_region_transaction_commit(); It's relatively new though (QEMU v2.5+). Paolo > Thanks, > Marcel > >> } >> >> static void pcibus_machine_done(Notifier *notifier, void *data) >> @@ -995,6 +995,11 @@ static PCIDevice >> *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, >> pci_dev->devfn = devfn; >> pci_dev->requester_id_cache = pci_req_id_cache_get(pci_dev); >> >> + memory_region_init(&pci_dev->bus_master_container_region, >> OBJECT(pci_dev), >> + "bus master container", UINT64_MAX); >> + address_space_init(&pci_dev->bus_master_as, >> + &pci_dev->bus_master_container_region, >> pci_dev->name); >> + >> if (qdev_hotplug) { >> pci_init_bus_master(pci_dev); >> } >> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h >> index 9349acb..713ede0 100644 >> --- a/include/hw/pci/pci.h >> +++ b/include/hw/pci/pci.h >> @@ -284,6 +284,7 @@ struct PCIDevice { >> char name[64]; >> PCIIORegion io_regions[PCI_NUM_REGIONS]; >> AddressSpace bus_master_as; >> + MemoryRegion bus_master_container_region; >> MemoryRegion bus_master_enable_region; >> >> /* do not access the following fields */ >> >
On 03/13/2017 11:52 AM, Paolo Bonzini wrote: > > > On 13/03/2017 10:38, Marcel Apfelbaum wrote: >> On 03/13/2017 05:29 AM, Jason Wang wrote: >>> 96a8821d2141 ("virtio: unbreak virtio-pci with IOMMU after caching ring >>> translations") tries to make IOMMU works with virtio memory region >>> cache, but it requires IOMMU to be created before any virtio >>> devices. This is sub optimal, fixing this by introduce a bus master >>> container to make sure address space can be initialized during device >>> registering, and then we can safely set alias and make >>> bus_master_enable_region as its subregion during bus master >>> initialization. >>> >>> Cc: Paolo Bonzini <pbonzini@redhat.com> >>> Signed-off-by: Jason Wang <jasowang@redhat.com> >>> --- >>> hw/pci/pci.c | 9 +++++++-- >>> include/hw/pci/pci.h | 1 + >>> 2 files changed, 8 insertions(+), 2 deletions(-) >>> >>> diff --git a/hw/pci/pci.c b/hw/pci/pci.c >>> index 273f1e4..ad46390 100644 >>> --- a/hw/pci/pci.c >>> +++ b/hw/pci/pci.c >>> @@ -88,8 +88,8 @@ static void pci_init_bus_master(PCIDevice *pci_dev) >>> OBJECT(pci_dev), "bus master", >>> dma_as->root, 0, >>> memory_region_size(dma_as->root)); >>> memory_region_set_enabled(&pci_dev->bus_master_enable_region, >>> false); >>> - address_space_init(&pci_dev->bus_master_as, >>> - &pci_dev->bus_master_enable_region, >>> pci_dev->name); >>> + >>> memory_region_add_subregion(&pci_dev->bus_master_container_region, 0, >>> + &pci_dev->bus_master_enable_region); >> >> Hi Jason, >> >> The patch looks good to me, I only have one question: >> On hot-unplug, shouldn't we remove the "new" sub-region ? > > It should be done automatically: > > /* We know the region is not visible in any address space (it > * does not have a container and cannot be a root either because > * it has no references, so we can blindly clear mr->enabled. > * memory_region_set_enabled instead could trigger a transaction > * and cause an infinite loop. > */ > mr->enabled = false; > memory_region_transaction_begin(); > while (!QTAILQ_EMPTY(&mr->subregions)) { > MemoryRegion *subregion = QTAILQ_FIRST(&mr->subregions); > memory_region_del_subregion(mr, subregion); > } > memory_region_transaction_commit(); > > It's relatively new though (QEMU v2.5+). > Nice! Not that new, but new to me :) Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> Thanks, Marcel > Paolo > >> Thanks, >> Marcel >> >>> } >>> >>> static void pcibus_machine_done(Notifier *notifier, void *data) >>> @@ -995,6 +995,11 @@ static PCIDevice >>> *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, >>> pci_dev->devfn = devfn; >>> pci_dev->requester_id_cache = pci_req_id_cache_get(pci_dev); >>> >>> + memory_region_init(&pci_dev->bus_master_container_region, >>> OBJECT(pci_dev), >>> + "bus master container", UINT64_MAX); >>> + address_space_init(&pci_dev->bus_master_as, >>> + &pci_dev->bus_master_container_region, >>> pci_dev->name); >>> + >>> if (qdev_hotplug) { >>> pci_init_bus_master(pci_dev); >>> } >>> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h >>> index 9349acb..713ede0 100644 >>> --- a/include/hw/pci/pci.h >>> +++ b/include/hw/pci/pci.h >>> @@ -284,6 +284,7 @@ struct PCIDevice { >>> char name[64]; >>> PCIIORegion io_regions[PCI_NUM_REGIONS]; >>> AddressSpace bus_master_as; >>> + MemoryRegion bus_master_container_region; >>> MemoryRegion bus_master_enable_region; >>> >>> /* do not access the following fields */ >>> >>
diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 273f1e4..ad46390 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -88,8 +88,8 @@ static void pci_init_bus_master(PCIDevice *pci_dev) OBJECT(pci_dev), "bus master", dma_as->root, 0, memory_region_size(dma_as->root)); memory_region_set_enabled(&pci_dev->bus_master_enable_region, false); - address_space_init(&pci_dev->bus_master_as, - &pci_dev->bus_master_enable_region, pci_dev->name); + memory_region_add_subregion(&pci_dev->bus_master_container_region, 0, + &pci_dev->bus_master_enable_region); } static void pcibus_machine_done(Notifier *notifier, void *data) @@ -995,6 +995,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, pci_dev->devfn = devfn; pci_dev->requester_id_cache = pci_req_id_cache_get(pci_dev); + memory_region_init(&pci_dev->bus_master_container_region, OBJECT(pci_dev), + "bus master container", UINT64_MAX); + address_space_init(&pci_dev->bus_master_as, + &pci_dev->bus_master_container_region, pci_dev->name); + if (qdev_hotplug) { pci_init_bus_master(pci_dev); } diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h index 9349acb..713ede0 100644 --- a/include/hw/pci/pci.h +++ b/include/hw/pci/pci.h @@ -284,6 +284,7 @@ struct PCIDevice { char name[64]; PCIIORegion io_regions[PCI_NUM_REGIONS]; AddressSpace bus_master_as; + MemoryRegion bus_master_container_region; MemoryRegion bus_master_enable_region; /* do not access the following fields */
96a8821d2141 ("virtio: unbreak virtio-pci with IOMMU after caching ring translations") tries to make IOMMU works with virtio memory region cache, but it requires IOMMU to be created before any virtio devices. This is sub optimal, fixing this by introduce a bus master container to make sure address space can be initialized during device registering, and then we can safely set alias and make bus_master_enable_region as its subregion during bus master initialization. Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- hw/pci/pci.c | 9 +++++++-- include/hw/pci/pci.h | 1 + 2 files changed, 8 insertions(+), 2 deletions(-)