From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58986) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fBCPW-0004BA-B1 for qemu-devel@nongnu.org; Wed, 25 Apr 2018 00:52:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fBCPT-0007JL-7q for qemu-devel@nongnu.org; Wed, 25 Apr 2018 00:52:06 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58550 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fBCPT-0007IV-3K for qemu-devel@nongnu.org; Wed, 25 Apr 2018 00:52:03 -0400 From: Peter Xu Date: Wed, 25 Apr 2018 12:51:23 +0800 Message-Id: <20180425045129.17449-5-peterx@redhat.com> In-Reply-To: <20180425045129.17449-1-peterx@redhat.com> References: <20180425045129.17449-1-peterx@redhat.com> Subject: [Qemu-devel] [PATCH 04/10] 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: "Michael S . Tsirkin" , Alex Williamson , Jintack Lim , peterx@redhat.com, Jason Wang For UNMAP-only IOMMU notifiers, we don't really 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. Signed-off-by: Peter Xu --- include/hw/i386/intel_iommu.h | 2 ++ hw/i386/intel_iommu.c | 43 ++++++++++++++++++++++++++++++++++++++----- 2 files changed, 40 insertions(+), 5 deletions(-) diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index 1a8ba8e415..486e205e79 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 e4ee211dde..1c252414a9 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_notify_mappings(VTDAddressSpace *as) +{ + return as->notifier_flags & IOMMU_NOTIFIER_MAP; +} + /* GHashTable functions */ static gboolean vtd_uint64_equal(gconstpointer v1, gconstpointer v2) { @@ -1427,14 +1433,35 @@ 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->notifiers_list), 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_notify_mappings(vtd_as)) { + /* + * For MAP-inclusive notifiers, we need to walk the + * page table 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); + } } } } @@ -2374,6 +2401,9 @@ 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) { /* Insert new ones */ QLIST_INSERT_HEAD(&s->notifiers_list, vtd_as, next); @@ -2884,8 +2914,11 @@ 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_notify_mappings(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)); -- 2.14.3