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intel-iommu: only do page walk for MAP notifiers

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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>
This commit is contained in:
Peter Xu 2018-05-18 15:25:12 +08:00 committed by Michael S. Tsirkin
parent 1d9efa73e1
commit 4f8a62a933
2 changed files with 41 additions and 5 deletions
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44
hw/i386/intel_iommu.c
View File

@ -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));

2
include/hw/i386/intel_iommu.h
View File

@ -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 {