From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58830) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxTSv-0008QL-Oj for qemu-devel@nongnu.org; Mon, 10 Apr 2017 03:10:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxTSs-0001p8-HO for qemu-devel@nongnu.org; Mon, 10 Apr 2017 03:10:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13984) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cxTSs-0001om-8b for qemu-devel@nongnu.org; Mon, 10 Apr 2017 03:10:18 -0400 Date: Mon, 10 Apr 2017 15:09:50 +0800 From: Peter Xu Message-ID: <20170410070950.GK3981@pxdev.xzpeter.org> References: <1491562755-23867-1-git-send-email-peterx@redhat.com> <1491562755-23867-2-git-send-email-peterx@redhat.com> <20170410043922.GI27571@umbus> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170410043922.GI27571@umbus> Subject: Re: [Qemu-devel] [PATCH v9 1/9] memory: add section range info for IOMMU notifier List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson , Marcel Apfelbaum Cc: qemu-devel@nongnu.org, tianyu.lan@intel.com, kevin.tian@intel.com, mst@redhat.com, jan.kiszka@siemens.com, jasowang@redhat.com, alex.williamson@redhat.com, bd.aviv@gmail.com On Mon, Apr 10, 2017 at 02:39:22PM +1000, David Gibson wrote: > On Fri, Apr 07, 2017 at 06:59:07PM +0800, Peter Xu wrote: > > In this patch, IOMMUNotifier.{start|end} are introduced to store section > > information for a specific notifier. When notification occurs, we not > > only check the notification type (MAP|UNMAP), but also check whether the > > notified iova range overlaps with the range of specific IOMMU notifier, > > and skip those notifiers if not in the listened range. > > > > When removing an region, we need to make sure we removed the correct > > VFIOGuestIOMMU by checking the IOMMUNotifier.start address as well. > > > > This patch is solving the problem that vfio-pci devices receive > > duplicated UNMAP notification on x86 platform when vIOMMU is there. The > > issue is that x86 IOMMU has a (0, 2^64-1) IOMMU region, which is > > splitted by the (0xfee00000, 0xfeefffff) IRQ region. AFAIK > > this (splitted IOMMU region) is only happening on x86. > > > > This patch also helps vhost to leverage the new interface as well, so > > that vhost won't get duplicated cache flushes. In that sense, it's an > > slight performance improvement. > > > > Suggested-by: David Gibson > > Reviewed-by: Eric Auger > > Reviewed-by: Michael S. Tsirkin > > Acked-by: Alex Williamson > > Signed-off-by: Peter Xu > > --- > > hw/vfio/common.c | 12 +++++++++--- > > hw/virtio/vhost.c | 10 ++++++++-- > > include/exec/memory.h | 19 ++++++++++++++++++- > > memory.c | 9 +++++++++ > > 4 files changed, 44 insertions(+), 6 deletions(-) > > > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > > index f3ba9b9..6b33b9f 100644 > > --- a/hw/vfio/common.c > > +++ b/hw/vfio/common.c > > @@ -478,8 +478,13 @@ static void vfio_listener_region_add(MemoryListener *listener, > > giommu->iommu_offset = section->offset_within_address_space - > > section->offset_within_region; > > giommu->container = container; > > - giommu->n.notify = vfio_iommu_map_notify; > > - giommu->n.notifier_flags = IOMMU_NOTIFIER_ALL; > > + llend = int128_add(int128_make64(section->offset_within_region), > > + section->size); > > + llend = int128_sub(llend, int128_one()); > > + iommu_notifier_init(&giommu->n, vfio_iommu_map_notify, > > + IOMMU_NOTIFIER_ALL, > > + section->offset_within_region, > > + int128_get64(llend)); > > Seems to me it would make sense to put the fiddling around to convert > the MemoryRegionSection into the necessary values would make sense to > go inside iommu_notifier_init(). But will we always get one MemoryRegionSection if we are not in any of the region_{add|del} callback? E.g., what if we want to init an IOMMU notifier that covers just the whole IOMMU region range? Considering above, I would still slightly prefer current interface. > > > QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next); > > > > memory_region_register_iommu_notifier(giommu->iommu, &giommu->n); > > @@ -550,7 +555,8 @@ static void vfio_listener_region_del(MemoryListener *listener, > > VFIOGuestIOMMU *giommu; > > > > QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) { > > - if (giommu->iommu == section->mr) { > > + if (giommu->iommu == section->mr && > > + giommu->n.start == section->offset_within_region) { > > This test should be sufficient, but I'd be a bit more comfortable if > there was a test and assert() that the end matches as well. I also > wonder if remove-matching-notifier helper would be useful here. > Although vhost doesn't appear to ever remove, so maybe it's premature. Oh... vhost does remove it, but I just forgot to touch it up :( ... Thanks for pointing out. Marcel, if this is the only comment, would you mind squash below change into current patch? Thanks, ----8<---- diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 185b95b..0001e60 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -771,7 +771,8 @@ static void vhost_iommu_region_del(MemoryListener *listener, } QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { - if (iommu->mr == section->mr) { + if (iommu->mr == section->mr && + iommu->n.start == section->offset_within_region) { memory_region_unregister_iommu_notifier(iommu->mr, &iommu->n); QLIST_REMOVE(iommu, iommu_next); ---->8---- > > > memory_region_unregister_iommu_notifier(giommu->iommu, > > &giommu->n); > > QLIST_REMOVE(giommu, giommu_next); > > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > > index 613494d..185b95b 100644 > > --- a/hw/virtio/vhost.c > > +++ b/hw/virtio/vhost.c > > @@ -736,14 +736,20 @@ static void vhost_iommu_region_add(MemoryListener *listener, > > struct vhost_dev *dev = container_of(listener, struct vhost_dev, > > iommu_listener); > > struct vhost_iommu *iommu; > > + Int128 end; > > > > if (!memory_region_is_iommu(section->mr)) { > > return; > > } > > > > iommu = g_malloc0(sizeof(*iommu)); > > - iommu->n.notify = vhost_iommu_unmap_notify; > > - iommu->n.notifier_flags = IOMMU_NOTIFIER_UNMAP; > > + end = int128_add(int128_make64(section->offset_within_region), > > + section->size); > > + end = int128_sub(end, int128_one()); > > + iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, > > + IOMMU_NOTIFIER_UNMAP, > > + section->offset_within_region, > > + int128_get64(end)); > > iommu->mr = section->mr; > > iommu->iommu_offset = section->offset_within_address_space - > > section->offset_within_region; > > diff --git a/include/exec/memory.h b/include/exec/memory.h > > index f20b191..0840c89 100644 > > --- a/include/exec/memory.h > > +++ b/include/exec/memory.h > > @@ -77,13 +77,30 @@ typedef enum { > > > > #define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP) > > > > +struct IOMMUNotifier; > > +typedef void (*IOMMUNotify)(struct IOMMUNotifier *notifier, > > + IOMMUTLBEntry *data); > > + > > struct IOMMUNotifier { > > - void (*notify)(struct IOMMUNotifier *notifier, IOMMUTLBEntry *data); > > + IOMMUNotify notify; > > IOMMUNotifierFlag notifier_flags; > > + /* Notify for address space range start <= addr <= end */ > > + hwaddr start; > > + hwaddr end; > > QLIST_ENTRY(IOMMUNotifier) node; > > }; > > typedef struct IOMMUNotifier IOMMUNotifier; > > > > +static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn, > > + IOMMUNotifierFlag flags, > > + hwaddr start, hwaddr end) > > +{ > > + n->notify = fn; > > + n->notifier_flags = flags; > > + n->start = start; > > + n->end = end; > > +} > > + > > /* New-style MMIO accessors can indicate that the transaction failed. > > * A zero (MEMTX_OK) response means success; anything else is a failure > > * of some kind. The memory subsystem will bitwise-OR together results > > diff --git a/memory.c b/memory.c > > index 4c95aaf..75ac595 100644 > > --- a/memory.c > > +++ b/memory.c > > @@ -1606,6 +1606,7 @@ void memory_region_register_iommu_notifier(MemoryRegion *mr, > > > > /* We need to register for at least one bitfield */ > > assert(n->notifier_flags != IOMMU_NOTIFIER_NONE); > > + assert(n->start <= n->end); > > QLIST_INSERT_HEAD(&mr->iommu_notify, n, node); > > memory_region_update_iommu_notify_flags(mr); > > } > > @@ -1667,6 +1668,14 @@ void memory_region_notify_iommu(MemoryRegion *mr, > > } > > > > QLIST_FOREACH(iommu_notifier, &mr->iommu_notify, node) { > > + /* > > + * Skip the notification if the notification does not overlap > > + * with registered range. > > + */ > > + if (iommu_notifier->start > entry.iova + entry.addr_mask + 1 || > > + iommu_notifier->end < entry.iova) { > > + continue; > > + } > > if (iommu_notifier->notifier_flags & request_flags) { > > iommu_notifier->notify(iommu_notifier, &entry); > > } > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson -- peterx