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intel-iommu: drop VTDBus

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We introduce VTDBus structure as an intermediate step for searching
the address space. This works well with SID based matching/lookup. But
when we want to support SID plus PASID based address space lookup,
this intermediate steps turns out to be a burden. So the patch simply
drops the VTDBus structure and use the PCIBus and devfn as the key for
the g_hash_table(). This simplifies the codes and the future PASID
extension.

To prevent being slower for past vtd_find_as_from_bus_num() callers, a
vtd_as cache indexed by the bus number is introduced to store the last
recent search result of a vtd_as belongs to a specific bus.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221028061436.30093-3-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
This commit is contained in:
Jason Wang 2022-10-28 14:14:34 +08:00 committed by Michael S. Tsirkin
parent fb1d084b44
commit da8d439c80
2 changed files with 118 additions and 127 deletions
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234
hw/i386/intel_iommu.c
View File

@ -61,6 +61,16 @@
} \
}
/*
* PCI bus number (or SID) is not reliable since the device is usaully
* initalized before guest can configure the PCI bridge
* (SECONDARY_BUS_NUMBER).
*/
struct vtd_as_key {
PCIBus *bus;
uint8_t devfn;
};
static void vtd_address_space_refresh_all(IntelIOMMUState *s);
static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n);
@ -210,6 +220,27 @@ static guint vtd_uint64_hash(gconstpointer v)
return (guint)*(const uint64_t *)v;
}
static gboolean vtd_as_equal(gconstpointer v1, gconstpointer v2)
{
const struct vtd_as_key *key1 = v1;
const struct vtd_as_key *key2 = v2;
return (key1->bus == key2->bus) && (key1->devfn == key2->devfn);
}
/*
* Note that we use pointer to PCIBus as the key, so hashing/shifting
* based on the pointer value is intended. Note that we deal with
* collisions through vtd_as_equal().
*/
static guint vtd_as_hash(gconstpointer v)
{
const struct vtd_as_key *key = v;
guint value = (guint)(uintptr_t)key->bus;
return (guint)(value << 8 | key->devfn);
}
static gboolean vtd_hash_remove_by_domain(gpointer key, gpointer value,
gpointer user_data)
{
@ -248,22 +279,14 @@ static gboolean vtd_hash_remove_by_page(gpointer key, gpointer value,
static void vtd_reset_context_cache_locked(IntelIOMMUState *s)
{
VTDAddressSpace *vtd_as;
VTDBus *vtd_bus;
GHashTableIter bus_it;
uint32_t devfn_it;
GHashTableIter as_it;
trace_vtd_context_cache_reset();
g_hash_table_iter_init(&bus_it, s->vtd_as_by_busptr);
g_hash_table_iter_init(&as_it, s->vtd_address_spaces);
while (g_hash_table_iter_next (&bus_it, NULL, (void**)&vtd_bus)) {
for (devfn_it = 0; devfn_it < PCI_DEVFN_MAX; ++devfn_it) {
vtd_as = vtd_bus->dev_as[devfn_it];
if (!vtd_as) {
continue;
}
vtd_as->context_cache_entry.context_cache_gen = 0;
}
while (g_hash_table_iter_next(&as_it, NULL, (void **)&vtd_as)) {
vtd_as->context_cache_entry.context_cache_gen = 0;
}
s->context_cache_gen = 1;
}
@ -993,32 +1016,6 @@ static bool vtd_slpte_nonzero_rsvd(uint64_t slpte, uint32_t level)
return slpte & rsvd_mask;
}
/* Find the VTD address space associated with a given bus number */
static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState *s, uint8_t bus_num)
{
VTDBus *vtd_bus = s->vtd_as_by_bus_num[bus_num];
GHashTableIter iter;
if (vtd_bus) {
return vtd_bus;
}
/*
* Iterate over the registered buses to find the one which
* currently holds this bus number and update the bus_num
* lookup table.
*/
g_hash_table_iter_init(&iter, s->vtd_as_by_busptr);
while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) {
if (pci_bus_num(vtd_bus->bus) == bus_num) {
s->vtd_as_by_bus_num[bus_num] = vtd_bus;
return vtd_bus;
}
}
return NULL;
}
/* Given the @iova, get relevant @slptep. @slpte_level will be the last level
* of the translation, can be used for deciding the size of large page.
*/
@ -1632,26 +1629,15 @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
static void vtd_switch_address_space_all(IntelIOMMUState *s)
{
VTDAddressSpace *vtd_as;
GHashTableIter iter;
VTDBus *vtd_bus;
int i;
g_hash_table_iter_init(&iter, s->vtd_as_by_busptr);
while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) {
for (i = 0; i < PCI_DEVFN_MAX; i++) {
if (!vtd_bus->dev_as[i]) {
continue;
}
vtd_switch_address_space(vtd_bus->dev_as[i]);
}
g_hash_table_iter_init(&iter, s->vtd_address_spaces);
while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_as)) {
vtd_switch_address_space(vtd_as);
}
}
static inline uint16_t vtd_make_source_id(uint8_t bus_num, uint8_t devfn)
{
return ((bus_num & 0xffUL) << 8) | (devfn & 0xffUL);
}
static const bool vtd_qualified_faults[] = {
[VTD_FR_RESERVED] = false,
[VTD_FR_ROOT_ENTRY_P] = false,
@ -1686,18 +1672,37 @@ static inline bool vtd_is_interrupt_addr(hwaddr addr)
return VTD_INTERRUPT_ADDR_FIRST <= addr && addr <= VTD_INTERRUPT_ADDR_LAST;
}
static gboolean vtd_find_as_by_sid(gpointer key, gpointer value,
gpointer user_data)
{
struct vtd_as_key *as_key = (struct vtd_as_key *)key;
uint16_t target_sid = *(uint16_t *)user_data;
uint16_t sid = PCI_BUILD_BDF(pci_bus_num(as_key->bus), as_key->devfn);
return sid == target_sid;
}
static VTDAddressSpace *vtd_get_as_by_sid(IntelIOMMUState *s, uint16_t sid)
{
uint8_t bus_num = PCI_BUS_NUM(sid);
VTDAddressSpace *vtd_as = s->vtd_as_cache[bus_num];
if (vtd_as &&
(sid == PCI_BUILD_BDF(pci_bus_num(vtd_as->bus), vtd_as->devfn))) {
return vtd_as;
}
vtd_as = g_hash_table_find(s->vtd_address_spaces, vtd_find_as_by_sid, &sid);
s->vtd_as_cache[bus_num] = vtd_as;
return vtd_as;
}
static void vtd_pt_enable_fast_path(IntelIOMMUState *s, uint16_t source_id)
{
VTDBus *vtd_bus;
VTDAddressSpace *vtd_as;
bool success = false;
vtd_bus = vtd_find_as_from_bus_num(s, VTD_SID_TO_BUS(source_id));
if (!vtd_bus) {
goto out;
}
vtd_as = vtd_bus->dev_as[VTD_SID_TO_DEVFN(source_id)];
vtd_as = vtd_get_as_by_sid(s, source_id);
if (!vtd_as) {
goto out;
}
@ -1733,7 +1738,7 @@ static bool vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus,
VTDContextCacheEntry *cc_entry;
uint64_t slpte, page_mask;
uint32_t level;
uint16_t source_id = vtd_make_source_id(bus_num, devfn);
uint16_t source_id = PCI_BUILD_BDF(bus_num, devfn);
int ret_fr;
bool is_fpd_set = false;
bool reads = true;
@ -1905,11 +1910,10 @@ static void vtd_context_device_invalidate(IntelIOMMUState *s,
uint16_t source_id,
uint16_t func_mask)
{
GHashTableIter as_it;
uint16_t mask;
VTDBus *vtd_bus;
VTDAddressSpace *vtd_as;
uint8_t bus_n, devfn;
uint16_t devfn_it;
trace_vtd_inv_desc_cc_devices(source_id, func_mask);
@ -1932,32 +1936,31 @@ static void vtd_context_device_invalidate(IntelIOMMUState *s,
mask = ~mask;
bus_n = VTD_SID_TO_BUS(source_id);
vtd_bus = vtd_find_as_from_bus_num(s, bus_n);
if (vtd_bus) {
devfn = VTD_SID_TO_DEVFN(source_id);
for (devfn_it = 0; devfn_it < PCI_DEVFN_MAX; ++devfn_it) {
vtd_as = vtd_bus->dev_as[devfn_it];
if (vtd_as && ((devfn_it & mask) == (devfn & mask))) {
trace_vtd_inv_desc_cc_device(bus_n, VTD_PCI_SLOT(devfn_it),
VTD_PCI_FUNC(devfn_it));
vtd_iommu_lock(s);
vtd_as->context_cache_entry.context_cache_gen = 0;
vtd_iommu_unlock(s);
/*
* Do switch address space when needed, in case if the
* device passthrough bit is switched.
*/
vtd_switch_address_space(vtd_as);
/*
* So a device is moving out of (or moving into) a
* domain, resync the shadow page table.
* This won't bring bad even if we have no such
* notifier registered - the IOMMU notification
* framework will skip MAP notifications if that
* happened.
*/
vtd_sync_shadow_page_table(vtd_as);
}
devfn = VTD_SID_TO_DEVFN(source_id);
g_hash_table_iter_init(&as_it, s->vtd_address_spaces);
while (g_hash_table_iter_next(&as_it, NULL, (void **)&vtd_as)) {
if ((pci_bus_num(vtd_as->bus) == bus_n) &&
(vtd_as->devfn & mask) == (devfn & mask)) {
trace_vtd_inv_desc_cc_device(bus_n, VTD_PCI_SLOT(vtd_as->devfn),
VTD_PCI_FUNC(vtd_as->devfn));
vtd_iommu_lock(s);
vtd_as->context_cache_entry.context_cache_gen = 0;
vtd_iommu_unlock(s);
/*
* Do switch address space when needed, in case if the
* device passthrough bit is switched.
*/
vtd_switch_address_space(vtd_as);
/*
* So a device is moving out of (or moving into) a
* domain, resync the shadow page table.
* This won't bring bad even if we have no such
* notifier registered - the IOMMU notification
* framework will skip MAP notifications if that
* happened.
*/
vtd_sync_shadow_page_table(vtd_as);
}
}
}
@ -2473,18 +2476,13 @@ static bool vtd_process_device_iotlb_desc(IntelIOMMUState *s,
{
VTDAddressSpace *vtd_dev_as;
IOMMUTLBEvent event;
struct VTDBus *vtd_bus;
hwaddr addr;
uint64_t sz;
uint16_t sid;
uint8_t devfn;
bool size;
uint8_t bus_num;
addr = VTD_INV_DESC_DEVICE_IOTLB_ADDR(inv_desc->hi);
sid = VTD_INV_DESC_DEVICE_IOTLB_SID(inv_desc->lo);
devfn = sid & 0xff;
bus_num = sid >> 8;
size = VTD_INV_DESC_DEVICE_IOTLB_SIZE(inv_desc->hi);
if ((inv_desc->lo & VTD_INV_DESC_DEVICE_IOTLB_RSVD_LO) ||
@ -2495,12 +2493,11 @@ static bool vtd_process_device_iotlb_desc(IntelIOMMUState *s,
return false;
}
vtd_bus = vtd_find_as_from_bus_num(s, bus_num);
if (!vtd_bus) {
goto done;
}
vtd_dev_as = vtd_bus->dev_as[devfn];
/*
* Using sid is OK since the guest should have finished the
* initialization of both the bus and device.
*/
vtd_dev_as = vtd_get_as_by_sid(s, sid);
if (!vtd_dev_as) {
goto done;
}
@ -3427,27 +3424,27 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
{
uintptr_t key = (uintptr_t)bus;
VTDBus *vtd_bus = g_hash_table_lookup(s->vtd_as_by_busptr, &key);
/*
* We can't simply use sid here since the bus number might not be
* initialized by the guest.
*/
struct vtd_as_key key = {
.bus = bus,
.devfn = devfn,
};
VTDAddressSpace *vtd_dev_as;
char name[128];
if (!vtd_bus) {
uintptr_t *new_key = g_malloc(sizeof(*new_key));
*new_key = (uintptr_t)bus;
/* No corresponding free() */
vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \
PCI_DEVFN_MAX);
vtd_bus->bus = bus;
g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus);
}
vtd_dev_as = vtd_bus->dev_as[devfn];
vtd_dev_as = g_hash_table_lookup(s->vtd_address_spaces, &key);
if (!vtd_dev_as) {
struct vtd_as_key *new_key = g_malloc(sizeof(*new_key));
new_key->bus = bus;
new_key->devfn = devfn;
snprintf(name, sizeof(name), "vtd-%02x.%x", PCI_SLOT(devfn),
PCI_FUNC(devfn));
vtd_bus->dev_as[devfn] = vtd_dev_as = g_new0(VTDAddressSpace, 1);
vtd_dev_as = g_new0(VTDAddressSpace, 1);
vtd_dev_as->bus = bus;
vtd_dev_as->devfn = (uint8_t)devfn;
@ -3503,6 +3500,8 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
&vtd_dev_as->nodmar, 0);
vtd_switch_address_space(vtd_dev_as);
g_hash_table_insert(s->vtd_address_spaces, new_key, vtd_dev_as);
}
return vtd_dev_as;
}
@ -3881,7 +3880,6 @@ static void vtd_realize(DeviceState *dev, Error **errp)
QLIST_INIT(&s->vtd_as_with_notifiers);
qemu_mutex_init(&s->iommu_lock);
memset(s->vtd_as_by_bus_num, 0, sizeof(s->vtd_as_by_bus_num));
memory_region_init_io(&s->csrmem, OBJECT(s), &vtd_mem_ops, s,
"intel_iommu", DMAR_REG_SIZE);
@ -3903,8 +3901,8 @@ static void vtd_realize(DeviceState *dev, Error **errp)
/* No corresponding destroy */
s->iotlb = g_hash_table_new_full(vtd_uint64_hash, vtd_uint64_equal,
g_free, g_free);
s->vtd_as_by_busptr = g_hash_table_new_full(vtd_uint64_hash, vtd_uint64_equal,
g_free, g_free);
s->vtd_address_spaces = g_hash_table_new_full(vtd_as_hash, vtd_as_equal,
g_free, g_free);
vtd_init(s);
sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
pci_setup_iommu(bus, vtd_host_dma_iommu, dev);

11
include/hw/i386/intel_iommu.h
View File

@ -58,7 +58,6 @@ typedef struct VTDContextEntry VTDContextEntry;
typedef struct VTDContextCacheEntry VTDContextCacheEntry;
typedef struct VTDAddressSpace VTDAddressSpace;
typedef struct VTDIOTLBEntry VTDIOTLBEntry;
typedef struct VTDBus VTDBus;
typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
@ -111,12 +110,6 @@ struct VTDAddressSpace {
IOVATree *iova_tree; /* Traces mapped IOVA ranges */
};
struct VTDBus {
PCIBus* bus; /* A reference to the bus to provide translation for */
/* A table of VTDAddressSpace objects indexed by devfn */
VTDAddressSpace *dev_as[];
};
struct VTDIOTLBEntry {
uint64_t gfn;
uint16_t domain_id;
@ -253,8 +246,8 @@ struct IntelIOMMUState {
uint32_t context_cache_gen; /* Should be in [1,MAX] */
GHashTable *iotlb; /* IOTLB */
GHashTable *vtd_as_by_busptr; /* VTDBus objects indexed by PCIBus* reference */
VTDBus *vtd_as_by_bus_num[VTD_PCI_BUS_MAX]; /* VTDBus objects indexed by bus number */
GHashTable *vtd_address_spaces; /* VTD address spaces */
VTDAddressSpace *vtd_as_cache[VTD_PCI_BUS_MAX]; /* VTD address space cache */
/* list of registered notifiers */
QLIST_HEAD(, VTDAddressSpace) vtd_as_with_notifiers;