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[Qemu-devel] [PULL 05/12] intel_iommu: Fix unexpected unmaps during glob
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 05/12] intel_iommu: Fix unexpected unmaps during global unmap |
Date: |
Fri, 5 Jul 2019 21:50:32 +0200 |
From: Peter Xu <address@hidden>
This is an replacement work of Yan Zhao's patch:
https://www.mail-archive.com/address@hidden/msg625340.html
vtd_address_space_unmap() will do proper page mask alignment to make
sure each IOTLB message will have correct masks for notification
messages (2^N-1), but sometimes it can be expanded to even supercede
the registered range. That could lead to unexpected UNMAP of already
mapped regions in some other notifiers.
Instead of doing mindless expension of the start address and address
mask, we split the range into smaller ones and guarantee that each
small range will have correct masks (2^N-1) and at the same time we
should also try our best to generate as less IOTLB messages as
possible.
Reported-by: Yan Zhao <address@hidden>
Signed-off-by: Peter Xu <address@hidden>
Reviewed-by: Eric Auger <address@hidden>
Tested-by: Yan Zhao <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/i386/intel_iommu.c | 67 +++++++++++++++++++++++++++++++--------------------
1 file changed, 41 insertions(+), 26 deletions(-)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 719ce19..de86f53 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3363,11 +3363,28 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s,
PCIBus *bus, int devfn)
return vtd_dev_as;
}
+static uint64_t get_naturally_aligned_size(uint64_t start,
+ uint64_t size, int gaw)
+{
+ uint64_t max_mask = 1ULL << gaw;
+ uint64_t alignment = start ? start & -start : max_mask;
+
+ alignment = MIN(alignment, max_mask);
+ size = MIN(size, max_mask);
+
+ if (alignment <= size) {
+ /* Increase the alignment of start */
+ return alignment;
+ } else {
+ /* Find the largest page mask from size */
+ return 1ULL << (63 - clz64(size));
+ }
+}
+
/* Unmap the whole range in the notifier's scope. */
static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n)
{
- IOMMUTLBEntry entry;
- hwaddr size;
+ hwaddr size, remain;
hwaddr start = n->start;
hwaddr end = n->end;
IntelIOMMUState *s = as->iommu_state;
@@ -3388,39 +3405,37 @@ static void vtd_address_space_unmap(VTDAddressSpace
*as, IOMMUNotifier *n)
}
assert(start <= end);
- size = end - start;
+ size = remain = end - start + 1;
- if (ctpop64(size) != 1) {
- /*
- * This size cannot format a correct mask. Let's enlarge it to
- * suite the minimum available mask.
- */
- int n = 64 - clz64(size);
- if (n > s->aw_bits) {
- /* should not happen, but in case it happens, limit it */
- n = s->aw_bits;
- }
- size = 1ULL << n;
+ while (remain >= VTD_PAGE_SIZE) {
+ IOMMUTLBEntry entry;
+ uint64_t mask = get_naturally_aligned_size(start, remain, s->aw_bits);
+
+ assert(mask);
+
+ entry.iova = start;
+ entry.addr_mask = mask - 1;
+ entry.target_as = &address_space_memory;
+ entry.perm = IOMMU_NONE;
+ /* This field is meaningless for unmap */
+ entry.translated_addr = 0;
+
+ memory_region_notify_one(n, &entry);
+
+ start += mask;
+ remain -= mask;
}
- entry.target_as = &address_space_memory;
- /* Adjust iova for the size */
- entry.iova = n->start & ~(size - 1);
- /* This field is meaningless for unmap */
- entry.translated_addr = 0;
- entry.perm = IOMMU_NONE;
- entry.addr_mask = size - 1;
+ assert(!remain);
trace_vtd_as_unmap_whole(pci_bus_num(as->bus),
VTD_PCI_SLOT(as->devfn),
VTD_PCI_FUNC(as->devfn),
- entry.iova, size);
+ n->start, size);
- map.iova = entry.iova;
- map.size = entry.addr_mask;
+ map.iova = n->start;
+ map.size = size;
iova_tree_remove(as->iova_tree, &map);
-
- memory_region_notify_one(n, &entry);
}
static void vtd_address_space_unmap_all(IntelIOMMUState *s)
--
1.8.3.1
- [Qemu-devel] [PULL 00/12] Misc bugfixes for QEMU hard freeze, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 02/12] checkpatch: do not warn for multiline parenthesized returned value, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 01/12] pc: fix possible NULL pointer dereference in pc_machine_get_device_memory_region_size(), Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 03/12] i386/kvm: Fix build with -m32, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 04/12] intel_iommu: Fix incorrect "end" for vtd_address_space_unmap, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 06/12] ioapic: clear irq_eoi when updating the ioapic redirect table entry, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 05/12] intel_iommu: Fix unexpected unmaps during global unmap,
Paolo Bonzini <=
- [Qemu-devel] [PULL 07/12] target/i386: fix feature check in hyperv-stub.c, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 08/12] minikconf: do not include variables from MINIKCONF_ARGS in config-all-devices.mak, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 09/12] target/i386: kvm: Fix when nested state is needed for migration, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 10/12] Makefile: generate header file with the list of devices enabled, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 11/12] hw/i386: Fix linker error when ISAPC is disabled, Paolo Bonzini, 2019/07/05
- [Qemu-devel] [PULL 12/12] ioapic: use irq number instead of vector in ioapic_eoi_broadcast, Paolo Bonzini, 2019/07/05
- Re: [Qemu-devel] [PULL 00/12] Misc bugfixes for QEMU hard freeze, Paolo Bonzini, 2019/07/05
- Re: [Qemu-devel] [PULL 00/12] Misc bugfixes for QEMU hard freeze, Eric Blake, 2019/07/06