On Thu, Jun 20, 2019 at 09:04:43PM +0800, Peter Xu wrote: > On Thu, Jun 20, 2019 at 08:59:55PM +0800, Peter Xu wrote: > > On Thu, Jun 20, 2019 at 10:35:29AM +0200, Paolo Bonzini wrote: > > > On 20/06/19 06:02, Peter Xu wrote: > > > > Seems workable, to be explicit - we can even cut it into chunks with > > > > different size to be efficient. > > > > > > Yes, this is not hard (completely untested): > > > > > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > > index 44b1231157..541538bc6c 100644 > > > --- a/hw/i386/intel_iommu.c > > > +++ b/hw/i386/intel_iommu.c > > > @@ -3388,39 +3388,34 @@ static void > > > vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) > > > } > > > > > > assert(start <= end); > > > - size = end - start; > > > + while (end > start) { > > > + size = end - start; > > > + /* Only keep the lowest bit of either size or start. */ > > > + size = MIN(size & -size, start & -start); > > > > I feel like this can be problematic. I'm imaging: > > > > start=0x1000_0000, size=0x1000_1000 > > > > This will get size=0x1000 but actually we can do size=0x1000_0000 as > > the first. > > > > > + /* Should not happen, but limit to address width too just in > > > case */ > > > + size = MIN(size, 1ULL << s->aw_bits); > > > > > > - 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; > > > - } > > > + assert((start & (size - 1)) == 0); > > > > > > - 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; > > > + entry.target_as = &address_space_memory; > > > + entry.iova = start; > > > + /* This field is meaningless for unmap */ > > > + entry.translated_addr = 0; > > > + entry.perm = IOMMU_NONE; > > > + entry.addr_mask = size - 1; > > > > (some of the fields can be moved out of loop because they are > > constants) > > > > > > > > - trace_vtd_as_unmap_whole(pci_bus_num(as->bus), > > > - VTD_PCI_SLOT(as->devfn), > > > - VTD_PCI_FUNC(as->devfn), > > > - entry.iova, size); > > > + trace_vtd_as_unmap_whole(pci_bus_num(as->bus), > > > + VTD_PCI_SLOT(as->devfn), > > > + VTD_PCI_FUNC(as->devfn), > > > + entry.iova, size); > > > > Can move this out because this is a trace only so we don't have > > restriction on mask? > > > > > > > > - map.iova = entry.iova; > > > - map.size = entry.addr_mask; > > > - iova_tree_remove(as->iova_tree, &map); > > > + map.iova = entry.iova; > > > + map.size = entry.addr_mask; > > > + iova_tree_remove(as->iova_tree, &map); > > > > Same here? > > > > > > > > - memory_region_notify_one(n, &entry); > > > + memory_region_notify_one(n, &entry); > > > + start += size; > > > + } > > > } > > > > > > static void vtd_address_space_unmap_all(IntelIOMMUState *s) > > > > > > > > > Yan, > > > > > > if something like this works for you, let me know and I will submit it > > > as a proper patch. > > > > > > Paolo > > > > Since during review I'm thinking how to generate a correct sequence of > > these masks... here's my try below with above issues fixed... :) > > > > I've tried compile but not tested. Yan can test it, or I can do it > > too tomorrow after I find some machines. > > > > Thanks, > > > > ------------------------------------------------------------ > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > index 44b1231157..cfbd225f0a 100644 > > --- a/hw/i386/intel_iommu.c > > +++ b/hw/i386/intel_iommu.c > > @@ -3363,11 +3363,32 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState > > *s, PCIBus *bus, int devfn) > > return vtd_dev_as; > > } > > > > +static uint64_t vtd_get_next_mask(uint64_t start, uint64_t size, int gaw) > > +{ > > + /* Tries to find smallest mask from start first */ > > + uint64_t rmask = start & -start, max_mask = 1ULL << gaw; > > + > > + assert(size && gaw > 0 && gaw < 64); > > + > > + /* Zero start, or too big */ > > + if (!rmask || rmask > max_mask) { > > + rmask = max_mask; > > + } > > + > > + /* If the start mask worked, then use it */ > > + if (rmask <= size) { > > + return rmask; > > + } > > + > > + /* 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 +3409,28 @@ static void vtd_address_space_unmap(VTDAddressSpace > > *as, IOMMUNotifier *n) > > } > > > > assert(start <= end); > > - size = end - start; > > - > > - 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; > > - } > > - > > + size = remain = end - start; > > entry.target_as = &address_space_memory; > > - /* Adjust iova for the size */ > > - entry.iova = n->start & ~(size - 1); > > + entry.perm = IOMMU_NONE; > > /* This field is meaningless for unmap */ > > entry.translated_addr = 0; > > - entry.perm = IOMMU_NONE; > > - entry.addr_mask = size - 1; > > + > > + while (remain) { > > + uint64_t mask = vtd_get_next_mask(start, remain, s->aw_bits); > > + > > + entry.iova = start; > > + entry.addr_mask = mask - 1; > > + memory_region_notify_one(n, &entry); > > Sorry, I at least missed these lines: > > start += mask; > remain -= mask; > > > + } > > > > 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) > > ------------------------------------------------------------ > > > > Regards, > > > > -- > > Peter Xu > > Regards, > > -- > Peter Xu
hi Peter and Paolo, I tested with code and it's fine in my side. It's base on your version with some minor modifications, such as size is now (end - start + 1) now. Thanks Yan +static uint64_t vtd_get_next_mask(uint64_t start, uint64_t size, int gaw) +{ + /* Tries to find smallest mask from start first */ + uint64_t rmask = start & -start, max_mask = 1ULL << gaw; + assert(size && gaw > 0 && gaw < 64); + /* Zero start, or too big */ + if (!rmask || rmask > max_mask) { + rmask = max_mask; + } + /* If the start mask worked, then use it */ + if (rmask <= size) { + return rmask; + } + + /* 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; @@ -3380,48 +3398,46 @@ static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) * VT-d spec), otherwise we need to consider overflow of 64 bits. */ - if (end > VTD_ADDRESS_SIZE(s->aw_bits)) { + if (end > VTD_ADDRESS_SIZE(s->aw_bits) - 1) { /* * Don't need to unmap regions that is bigger than the whole * VT-d supported address space size */ - end = VTD_ADDRESS_SIZE(s->aw_bits); + end = VTD_ADDRESS_SIZE(s->aw_bits) - 1; } assert(start <= end); - size = end - start; - 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; - } + size = remain = end - start + 1; entry.target_as = &address_space_memory; - /* Adjust iova for the size */ - entry.iova = n->start & ~(size - 1); + + entry.perm = IOMMU_NONE; /* This field is meaningless for unmap */ entry.translated_addr = 0; - entry.perm = IOMMU_NONE; - entry.addr_mask = size - 1; + + while (remain >= VTD_PAGE_SIZE) { + uint64_t mask = vtd_get_next_mask(start, remain, s->aw_bits); + + entry.iova = start; + entry.addr_mask = mask - 1; + memory_region_notify_one(n, &entry); + start += mask; + remain -= mask; + } + + if (remain) { + warn_report("Unmapping unaligned range %lx-%lx", start, end); + } trace_vtd_as_unmap_whole(pci_bus_num(as->bus), VTD_PCI_SLOT(as->devfn), VTD_PCI_FUNC(as->devfn), - entry.iova, size); - - map.iova = entry.iova; - map.size = entry.addr_mask; + n->start, size); + 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) -- 2.7.4