From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49026) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fLUz6-0001ya-1n for qemu-devel@nongnu.org; Wed, 23 May 2018 10:43:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fLUz5-0000tE-6i for qemu-devel@nongnu.org; Wed, 23 May 2018 10:43:24 -0400 Date: Wed, 23 May 2018 17:43:21 +0300 From: "Michael S. Tsirkin" Message-ID: <1527086545-68024-24-git-send-email-mst@redhat.com> References: <1527086545-68024-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1527086545-68024-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL 23/28] intel-iommu: only do page walk for MAP notifiers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Peter Xu , QEMU Stable , Paolo Bonzini , Richard Henderson , Eduardo Habkost , Marcel Apfelbaum From: Peter Xu For UNMAP-only IOMMU notifiers, we don't need to walk the page tables. Fasten that procedure by skipping the page table walk. That should boost performance for UNMAP-only notifiers like vhost. CC: QEMU Stable Signed-off-by: Peter Xu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/hw/i386/intel_iommu.h | 2 ++ hw/i386/intel_iommu.c | 44 ++++++++++++++++++++++++++++++++++++++----- 2 files changed, 41 insertions(+), 5 deletions(-) diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index 016e74b..156f35e 100644 --- a/include/hw/i386/intel_iommu.h +++ b/include/hw/i386/intel_iommu.h @@ -93,6 +93,8 @@ struct VTDAddressSpace { IntelIOMMUState *iommu_state; VTDContextCacheEntry context_cache_entry; QLIST_ENTRY(VTDAddressSpace) next; + /* Superset of notifier flags that this address space has */ + IOMMUNotifierFlag notifier_flags; }; struct VTDBus { diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 8d4069d..38ccc74 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -138,6 +138,12 @@ static inline void vtd_iommu_unlock(IntelIOMMUState *s) qemu_mutex_unlock(&s->iommu_lock); } +/* Whether the address space needs to notify new mappings */ +static inline gboolean vtd_as_has_map_notifier(VTDAddressSpace *as) +{ + return as->notifier_flags & IOMMU_NOTIFIER_MAP; +} + /* GHashTable functions */ static gboolean vtd_uint64_equal(gconstpointer v1, gconstpointer v2) { @@ -1436,14 +1442,36 @@ static void vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s, VTDAddressSpace *vtd_as; VTDContextEntry ce; int ret; + hwaddr size = (1 << am) * VTD_PAGE_SIZE; QLIST_FOREACH(vtd_as, &(s->vtd_as_with_notifiers), next) { ret = vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus), vtd_as->devfn, &ce); if (!ret && domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) { - vtd_page_walk(&ce, addr, addr + (1 << am) * VTD_PAGE_SIZE, - vtd_page_invalidate_notify_hook, - (void *)&vtd_as->iommu, true, s->aw_bits); + if (vtd_as_has_map_notifier(vtd_as)) { + /* + * As long as we have MAP notifications registered in + * any of our IOMMU notifiers, we need to sync the + * shadow page table. + */ + vtd_page_walk(&ce, addr, addr + size, + vtd_page_invalidate_notify_hook, + (void *)&vtd_as->iommu, true, s->aw_bits); + } else { + /* + * For UNMAP-only notifiers, we don't need to walk the + * page tables. We just deliver the PSI down to + * invalidate caches. + */ + IOMMUTLBEntry entry = { + .target_as = &address_space_memory, + .iova = addr, + .translated_addr = 0, + .addr_mask = size - 1, + .perm = IOMMU_NONE, + }; + memory_region_notify_iommu(&vtd_as->iommu, entry); + } } } } @@ -2383,6 +2411,9 @@ static void vtd_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu, exit(1); } + /* Update per-address-space notifier flags */ + vtd_as->notifier_flags = new; + if (old == IOMMU_NOTIFIER_NONE) { QLIST_INSERT_HEAD(&s->vtd_as_with_notifiers, vtd_as, next); } else if (new == IOMMU_NOTIFIER_NONE) { @@ -2891,8 +2922,11 @@ static void vtd_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n) PCI_FUNC(vtd_as->devfn), VTD_CONTEXT_ENTRY_DID(ce.hi), ce.hi, ce.lo); - vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false, - s->aw_bits); + if (vtd_as_has_map_notifier(vtd_as)) { + /* This is required only for MAP typed notifiers */ + vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false, + s->aw_bits); + } } else { trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn), PCI_FUNC(vtd_as->devfn)); -- MST