diff options
author | Peter Xu <peterx@redhat.com> | 2018-05-18 15:25:12 +0800 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2018-05-23 17:33:57 +0300 |
commit | 4f8a62a933a79094e44bc1b16b63bb23e62d67b4 (patch) | |
tree | 4b1488663090cc8f14e65e57b380a91395b8bdff /hw | |
parent | 1d9efa73e12ddf361ea997c2d532cc4afa6674d1 (diff) |
intel-iommu: only do page walk for MAP notifiers
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 <qemu-stable@nongnu.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r-- | hw/i386/intel_iommu.c | 44 |
1 files changed, 39 insertions, 5 deletions
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 8d4069de9f..38ccc741f9 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)); |