On Wed, Feb 12, 2020 at 08:37:30AM +0000, Liu, Yi L wrote:
> > From: Peter Xu <peterx@xxxxxxxxxx>
> > Sent: Wednesday, February 12, 2020 7:36 AM
> > To: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> > Subject: Re: [RFC v3 16/25] intel_iommu: add PASID cache management
> > infrastructure
> >
> > On Wed, Jan 29, 2020 at 04:16:47AM -0800, Liu, Yi L wrote:
> > > From: Liu Yi L <yi.l.liu@xxxxxxxxx>
> > >
> > > This patch adds a PASID cache management infrastructure based on
> > > new added structure VTDPASIDAddressSpace, which is used to track
> > > the PASID usage and future PASID tagged DMA address translation
> > > support in vIOMMU.
> > >
> > > struct VTDPASIDAddressSpace {
> > > VTDBus *vtd_bus;
> > > uint8_t devfn;
> > > AddressSpace as;
> > > uint32_t pasid;
> > > IntelIOMMUState *iommu_state;
> > > VTDContextCacheEntry context_cache_entry;
> > > QLIST_ENTRY(VTDPASIDAddressSpace) next;
> > > VTDPASIDCacheEntry pasid_cache_entry;
> > > };
> > >
> > > Ideally, a VTDPASIDAddressSpace instance is created when a PASID
> > > is bound with a DMA AddressSpace. Intel VT-d spec requires guest
> > > software to issue pasid cache invalidation when bind or unbind a
> > > pasid with an address space under caching-mode. However, as
> > > VTDPASIDAddressSpace instances also act as pasid cache in this
> > > implementation, its creation also happens during vIOMMU PASID
> > > tagged DMA translation. The creation in this path will not be
> > > added in this patch since no PASID-capable emulated devices for
> > > now.
> > >
> > > The implementation in this patch manages VTDPASIDAddressSpace
> > > instances per PASID+BDF (lookup and insert will use PASID and
> > > BDF) since Intel VT-d spec allows per-BDF PASID Table. When a
> > > guest bind a PASID with an AddressSpace, QEMU will capture the
> > > guest pasid selective pasid cache invalidation, and allocate
> > > remove a VTDPASIDAddressSpace instance per the invalidation
> > > reasons:
> > >
> > > *) a present pasid entry moved to non-present
> > > *) a present pasid entry to be a present entry
> > > *) a non-present pasid entry moved to present
> > >
> > > vIOMMU emulator could figure out the reason by fetching latest
> > > guest pasid entry.
> > >
> > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> > > Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> > > Cc: Peter Xu <peterx@xxxxxxxxxx>
> > > Cc: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
> > > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> > > Cc: Richard Henderson <rth@xxxxxxxxxxx>
> > > Cc: Eduardo Habkost <ehabkost@xxxxxxxxxx>
> > > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
> > > ---
> > > hw/i386/intel_iommu.c | 367
> > +++++++++++++++++++++++++++++++++++++++++
> > > hw/i386/intel_iommu_internal.h | 14 ++
> > > hw/i386/trace-events | 1 +
> > > include/hw/i386/intel_iommu.h | 36 +++-
> > > 4 files changed, 417 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> > > index 58e7213..c75cb7b 100644
> > > --- a/hw/i386/intel_iommu.c
> > > +++ b/hw/i386/intel_iommu.c
> > > @@ -40,6 +40,7 @@
> > > #include "kvm_i386.h"
> > > #include "migration/vmstate.h"
> > > #include "trace.h"
> > > +#include "qemu/jhash.h"
> > >
> > > /* context entry operations */
> > > #define VTD_CE_GET_RID2PASID(ce) \
> > > @@ -65,6 +66,8 @@
> > > static void vtd_address_space_refresh_all(IntelIOMMUState *s);
> > > static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier
> > *n);
> > >
> > > +static void vtd_pasid_cache_reset(IntelIOMMUState *s);
> > > +
> > > static void vtd_panic_require_caching_mode(void)
> > > {
> > > error_report("We need to set caching-mode=on for intel-iommu to enable "
> > > @@ -276,6 +279,7 @@ static void vtd_reset_caches(IntelIOMMUState *s)
> > > vtd_iommu_lock(s);
> > > vtd_reset_iotlb_locked(s);
> > > vtd_reset_context_cache_locked(s);
> > > + vtd_pasid_cache_reset(s);
> > > vtd_iommu_unlock(s);
> > > }
> > >
> > > @@ -686,6 +690,11 @@ static inline bool vtd_pe_type_check(X86IOMMUState
> > *x86_iommu,
> > > return true;
> > > }
> > >
> > > +static inline uint16_t vtd_pe_get_domain_id(VTDPASIDEntry *pe)
> > > +{
> > > + return VTD_SM_PASID_ENTRY_DID((pe)->val[1]);
> > > +}
> > > +
> > > static inline bool vtd_pdire_present(VTDPASIDDirEntry *pdire)
> > > {
> > > return pdire->val & 1;
> > > @@ -2393,19 +2402,370 @@ static bool
> > vtd_process_iotlb_desc(IntelIOMMUState *s, VTDInvDesc *inv_desc)
> > > return true;
> > > }
> > >
> > > +static inline void vtd_init_pasid_key(uint32_t pasid,
> > > + uint16_t sid,
> > > + struct pasid_key *key)
> > > +{
> > > + key->pasid = pasid;
> > > + key->sid = sid;
> > > +}
> > > +
> > > +static guint vtd_pasid_as_key_hash(gconstpointer v)
> > > +{
> > > + struct pasid_key *key = (struct pasid_key *)v;
> > > + uint32_t a, b, c;
> > > +
> > > + /* Jenkins hash */
> > > + a = b = c = JHASH_INITVAL + sizeof(*key);
> > > + a += key->sid;
> > > + b += extract32(key->pasid, 0, 16);
> > > + c += extract32(key->pasid, 16, 16);
> > > +
> > > + __jhash_mix(a, b, c);
> > > + __jhash_final(a, b, c);
> > > +
> > > + return c;
> > > +}
> > > +
> > > +static gboolean vtd_pasid_as_key_equal(gconstpointer v1, gconstpointer v2)
> > > +{
> > > + const struct pasid_key *k1 = v1;
> > > + const struct pasid_key *k2 = v2;
> > > +
> > > + return (k1->pasid == k2->pasid) && (k1->sid == k2->sid);
> > > +}
> > > +
> > > +static inline int vtd_dev_get_pe_from_pasid(IntelIOMMUState *s,
> > > + uint8_t bus_num,
> > > + uint8_t devfn,
> > > + uint32_t pasid,
> > > + VTDPASIDEntry *pe)
> > > +{
> > > + VTDContextEntry ce;
> > > + int ret;
> > > + dma_addr_t pasid_dir_base;
> > > +
> > > + if (!s->root_scalable) {
> > > + return -VTD_FR_PASID_TABLE_INV;
> > > + }
> > > +
> > > + ret = vtd_dev_to_context_entry(s, bus_num, devfn, &ce);
> > > + if (ret) {
> > > + return ret;
> > > + }
> > > +
> > > + pasid_dir_base = VTD_CE_GET_PASID_DIR_TABLE(&ce);
> > > + ret = vtd_get_pe_from_pasid_table(s,
> > > + pasid_dir_base, pasid, pe);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static bool vtd_pasid_entry_compare(VTDPASIDEntry *p1, VTDPASIDEntry
> > *p2)
> > > +{
> > > + return !memcmp(p1, p2, sizeof(*p1));
> > > +}
> > > +
> > > +/**
> > > + * This function is used to clear pasid_cache_gen of cached pasid
> > > + * entry in vtd_pasid_as instances. Caller of this function should
> > > + * hold iommu_lock.
> > > + */
> > > +static gboolean vtd_flush_pasid(gpointer key, gpointer value,
> > > + gpointer user_data)
> > > +{
> > > + VTDPASIDCacheInfo *pc_info = user_data;
> > > + VTDPASIDAddressSpace *vtd_pasid_as = value;
> > > + IntelIOMMUState *s = vtd_pasid_as->iommu_state;
> > > + VTDPASIDCacheEntry *pc_entry = &vtd_pasid_as->pasid_cache_entry;
> > > + VTDBus *vtd_bus = vtd_pasid_as->vtd_bus;
> > > + VTDPASIDEntry pe;
> > > + uint16_t did;
> > > + uint32_t pasid;
> > > + uint16_t devfn;
> > > + int ret;
> > > +
> > > + did = vtd_pe_get_domain_id(&pc_entry->pasid_entry);
> > > + pasid = vtd_pasid_as->pasid;
> > > + devfn = vtd_pasid_as->devfn;
> > > +
> > > + if (!(pc_entry->pasid_cache_gen == s->pasid_cache_gen)) {
> > > + return false;
> > > + }
> > > +
> > > + switch (pc_info->flags & VTD_PASID_CACHE_INFO_MASK) {
> > > + case VTD_PASID_CACHE_PASIDSI:
> > > + if (pc_info->pasid != pasid) {
> > > + return false;
> > > + }
> > > + /* Fall through */
> >
> > Why fall through?
>
> For VTD_PASID_CACHE_PASIDSI, it implies domain selective, so it
> requires to check did just as VTD_PASID_CACHE_DOMSI.
Ah right. :)
>
> >
> > > + case VTD_PASID_CACHE_DOMSI:
> > > + if (pc_info->domain_id != did) {
> > > + return false;
> > > + }
> > > + /* Fall through */
> >
> > Same here.
>
> If code comes to here, it means the necessary checks are passed. Should
> add a break here. However, as the below case does nothing and just calls
> break. So I let the code fall through.
Yes this is fine too.
>
> >
> > > + case VTD_PASID_CACHE_GLOBAL:
> > > + break;
> > > + default:
> >
> > Nevee reach here right? If so we can abort.
>
> yes, should never reach here.
>
> > > + return false;
> > > + }
> > > +
> > > + /*
> > > + * pasid cache invalidation may indicate a present pasid
> > > + * entry to present pasid entry modification. To cover such
> > > + * case, vIOMMU emulator needs to fetch latest guest pasid
> > > + * entry and check cached pasid entry, then update pasid
> > > + * cache and send pasid bind/unbind to host properly.
> > > + */
> > > + ret = vtd_dev_get_pe_from_pasid(s,
> > > + pci_bus_num(vtd_bus->bus), devfn, pasid, &pe);
> > > + if (ret) {
> > > + /*
> > > + * No valid pasid entry in guest memory. e.g. pasid entry
> > > + * was modified to be either all-zero or non-present. Either
> > > + * case means existing pasid cache should be removed.
> > > + */
> > > + goto remove;
> > > + }
> > > + /* Compare cached pasid entry and latest pasid entry */
> > > + if (!vtd_pasid_entry_compare(&pe, &pc_entry->pasid_entry)) {
> > > + /* pasid entry was updated, thus update the pasid cache */
> > > + pc_entry->pasid_entry = pe;
> > > + pc_entry->pasid_cache_gen = s->pasid_cache_gen;
> > > + /*
> > > + * TODO:
> > > + * - send pasid bind to host for passthru devices
> > > + * - when pasid-base-iotlb(piotlb) infrastructure is ready,
> > > + * should invalidate QEMU piotlb togehter with this change.
> > > + */
> > > + }
> > > + return false;
> > > +remove:
> > > + /*
> > > + * TODO:
> > > + * - send pasid unbind to host for passthru devices
> > > + * - when pasid-base-iotlb(piotlb) infrastructure is ready,
> > > + * should invalidate QEMU piotlb togehter with this change.
> > > + */
> > > + return true;
> > > +}
> > > +
> > > static int vtd_pasid_cache_dsi(IntelIOMMUState *s, uint16_t domain_id)
> > > {
> > > + VTDPASIDCacheInfo pc_info;
> > > +
> > > + trace_vtd_pasid_cache_dsi(domain_id);
> > > +
> > > + pc_info.flags = VTD_PASID_CACHE_DOMSI;
> > > + pc_info.domain_id = domain_id;
> > > +
> > > + /*
> > > + * Loop all existing pasid caches and update them.
> > > + */
> > > + vtd_iommu_lock(s);
> > > + g_hash_table_foreach_remove(s->vtd_pasid_as,
> > > + vtd_flush_pasid, &pc_info);
> > > +
> > > + /*
> > > + * TODO: Domain selective PASID cache invalidation
> > > + * flushes all the pasid caches within a domain. To
> > > + * be safe, after invalidating the pasid caches, emulator
> > > + * needs to replay the pasid bindings by walking guest
> > > + * pasid dir and pasid table.
> >
> > Better spell out on what special case we're handling here: When the
> > guest setup a new PASID entry then send a PASID DSI.
>
> oh, yes. will add it in new version. :-)
>
> >
> > > + */
> > > + vtd_iommu_unlock(s);
> > > return 0;
> > > }
> > >
> > > +/**
> > > + * This function finds or adds a VTDPASIDAddressSpace for a device
> > > + * when it is bound to a pasid. Caller of this function should hold
> > > + * iommu_lock.
> > > + */
> > > +static VTDPASIDAddressSpace *vtd_add_find_pasid_as(IntelIOMMUState *s,
> > > + VTDBus *vtd_bus,
> > > + int devfn,
> > > + uint32_t pasid,
> > > + bool allocate)
> > > +{
> > > + struct pasid_key key;
> > > + struct pasid_key *new_key;
> > > + VTDPASIDAddressSpace *vtd_pasid_as;
> > > + uint16_t sid;
> > > +
> > > + sid = vtd_make_source_id(pci_bus_num(vtd_bus->bus), devfn);
> > > + vtd_init_pasid_key(pasid, sid, &key);
> > > + vtd_pasid_as = g_hash_table_lookup(s->vtd_pasid_as, &key);
> > > +
> > > + if (!vtd_pasid_as && allocate) {
> > > + new_key = g_malloc0(sizeof(*new_key));
> > > + vtd_init_pasid_key(pasid, sid, new_key);
> > > + /*
> > > + * Initiate the vtd_pasid_as structure.
> > > + *
> > > + * This structure here is used to track the guest pasid
> > > + * binding and also serves as pasid-cache mangement entry.
> > > + *
> > > + * TODO: in future, if wants to support the SVA-aware DMA
> > > + * emulation, the vtd_pasid_as should have include
> > > + * AddressSpace to support DMA emulation.
> > > + */
> > > + vtd_pasid_as = g_malloc0(sizeof(VTDPASIDAddressSpace));
> > > + vtd_pasid_as->iommu_state = s;
> > > + vtd_pasid_as->vtd_bus = vtd_bus;
> > > + vtd_pasid_as->devfn = devfn;
> > > + vtd_pasid_as->context_cache_entry.context_cache_gen = 0;
> > > + vtd_pasid_as->pasid = pasid;
> > > + vtd_pasid_as->pasid_cache_entry.pasid_cache_gen = 0;
> > > + g_hash_table_insert(s->vtd_pasid_as, new_key, vtd_pasid_as);
> > > + }
> > > + return vtd_pasid_as;
> > > +}
> > > +
> > > + /**
> > > + * This function updates the pasid entry cached in &vtd_pasid_as.
> > > + * Caller of this function should hold iommu_lock.
> > > + */
> > > +static inline void vtd_fill_in_pe_cache(
> > > + VTDPASIDAddressSpace *vtd_pasid_as, VTDPASIDEntry *pe)
> > > +{
> > > + IntelIOMMUState *s = vtd_pasid_as->iommu_state;
> > > + VTDPASIDCacheEntry *pc_entry = &vtd_pasid_as->pasid_cache_entry;
> > > +
> > > + pc_entry->pasid_entry = *pe;
> > > + pc_entry->pasid_cache_gen = s->pasid_cache_gen;
> > > +}
> > > +
> > > static int vtd_pasid_cache_psi(IntelIOMMUState *s,
> > > uint16_t domain_id, uint32_t pasid)
> > > {
> > > + VTDPASIDCacheInfo pc_info;
> > > + VTDPASIDEntry pe;
> > > + VTDBus *vtd_bus;
> > > + int bus_n, devfn;
> > > + VTDPASIDAddressSpace *vtd_pasid_as;
> > > + VTDIOMMUContext *vtd_icx;
> > > +
> > > + /* PASID selective implies a DID selective */
> > > + pc_info.flags = VTD_PASID_CACHE_PASIDSI;
> > > + pc_info.domain_id = domain_id;
> > > + pc_info.pasid = pasid;
> > > +
> > > + /*
> > > + * Regards to a pasid selective pasid cache invalidation (PSI),
> > > + * it could be either cases of below:
> > > + * a) a present pasid entry moved to non-present
> > > + * b) a present pasid entry to be a present entry
> > > + * c) a non-present pasid entry moved to present
> > > + *
> > > + * Here the handling of a PSI is:
> > > + * 1) loop all the exisitng vtd_pasid_as instances to update them
> > > + * according to the latest guest pasid entry in pasid table.
> > > + * this will make sure affected existing vtd_pasid_as instances
> > > + * cached the latest pasid entries. Also, during the loop, the
> > > + * host should be notified if needed. e.g. pasid unbind or pasid
> > > + * update. Should be able to cover case a) and case b).
> > > + *
> > > + * 2) loop all devices to cover case c)
> > > + * However, it is not good to always loop all devices. In this
> > > + * implementation. We do it in this ways:
> > > + * - For devices which have VTDIOMMUContext instances,
> > > + * we loop them and check if guest pasid entry exists. If yes,
> > > + * it is case c), we update the pasid cache and also notify
> > > + * host.
> > > + * - For devices which have no VTDIOMMUContext
> > > + * instances, it is not necessary to create pasid cache at
> > > + * this phase since it could be created when vIOMMU do DMA
> > > + * address translation. This is not implemented yet since
> > > + * no PASID-capable emulated devices today. If we have it
> > > + * in future, the pasid cache shall be created there.
> > > + */
> > > +
> > > + vtd_iommu_lock(s);
> > > + g_hash_table_foreach_remove(s->vtd_pasid_as,
> > > + vtd_flush_pasid, &pc_info);
> > > +
> > > + QLIST_FOREACH(vtd_icx, &s->vtd_dev_icx_list, next) {
> > > + vtd_bus = vtd_icx->vtd_bus;
> > > + devfn = vtd_icx->devfn;
> > > + bus_n = pci_bus_num(vtd_bus->bus);
> > > +
> > > + /* Step 1: fetch vtd_pasid_as and check if it is valid */
> > > + vtd_pasid_as = vtd_add_find_pasid_as(s, vtd_bus,
> > > + devfn, pasid, true);
> >
> > I feel like you wanted to pass "false" here for "allocate".
>
> emmm, yeah. It was "false" in draft code as step 1 is only to check if
> a valid vtd_pasid_as exists. And in step 3, it needs to call
> vtd_add_find_pasid_as() with "allocate" be "true". In vtd_add_find_pasid_as(),
> it will try search vtd_pasid_as first and then allocate a new one. In such
> logic, there will be two vtd_add_find_pasid_as() callig and means two hash
> table searching.
>
> So I mofified it to be "true" to save a vtd_add_find_pasid_as() calling. If
> a vtd_pasid_as is valid, its pasid_cache_gen will be equal to s->pasid_cache_gen.
> If not, the vtd_pasid_as is a newly allocated and needs to go through step 2
> and step 3 to fulfill it. Looks like I missed to free the vtd_pasid_as when step
> 2 failed. Will add it if you are fine with the current logic.
I see. Note that vtd_add_find_pasid_as() is fast for no allocation,
because hash lookup is O(1). However I think current approach is ok,
but if with that, we can also:
- Remove the allocate parameter for vtd_add_find_pasid_as(), since it's
always true even in future patches so useless,
- Remove the vtd_pasid_as check right below because it's not needed.
>
>
> > > + if (vtd_pasid_as &&
^^^^^^^^^^^^
> > > + (s->pasid_cache_gen ==
> > > + vtd_pasid_as->pasid_cache_entry.pasid_cache_gen)) {
> > > + /*
> > > + * pasid_cache_gen equals to s->pasid_cache_gen means
> > > + * vtd_pasid_as is valid after the above s->vtd_pasid_as
> > > + * updates. Thus no need for the below steps.
> > > + */
> > > + continue;
> > > + }
> > > +
> > > + /*
> > > + * Step 2: vtd_pasid_as is not valid, it's potentailly a
> > > + * new pasid bind. Fetch guest pasid entry.
> > > + */
> > > + if (vtd_dev_get_pe_from_pasid(s, bus_n, devfn, pasid, &pe)) {
> > > + continue;
> > > + }
> > > +
> > > + /*
> > > + * Step 3: pasid entry exists, update pasid cache
> > > + *
> > > + * Here need to check domain ID since guest pasid entry
> > > + * exists. What needs to do are:
> > > + * - update the pc_entry in the vtd_pasid_as
> > > + * - set proper pc_entry.pasid_cache_gen
> > > + * - pass down the latest guest pasid entry config to host
> > > + * (will be added in later patch)
> > > + */
> > > + if (domain_id == vtd_pe_get_domain_id(&pe)) {
> > > + vtd_fill_in_pe_cache(vtd_pasid_as, &pe);
> > > + }
> > > + }
> > > + vtd_iommu_unlock(s);
> > > return 0;
> > > }
> > >
> > > +/**
> > > + * Caller of this function should hold iommu_lock
> > > + */
> > > +static void vtd_pasid_cache_reset(IntelIOMMUState *s)
> > > +{
> > > + VTDPASIDCacheInfo pc_info;
> > > +
> > > + trace_vtd_pasid_cache_reset();
> > > +
> > > + pc_info.flags = VTD_PASID_CACHE_GLOBAL;
> > > +
> > > + /*
> > > + * Reset pasid cache is a big hammer, so use
> > > + * g_hash_table_foreach_remove which will free
> > > + * the vtd_pasid_as instances.
> > > + */
> > > + g_hash_table_foreach_remove(s->vtd_pasid_as,
> > > + vtd_flush_pasid, &pc_info);
> > > + s->pasid_cache_gen = 1;
> > > +}
> > > +
> > > static int vtd_pasid_cache_gsi(IntelIOMMUState *s)
> > > {
> > > + trace_vtd_pasid_cache_gsi();
> > > +
> > > + vtd_iommu_lock(s);
> > > + vtd_pasid_cache_reset(s);
> >
> > [1]
> >
> > > +
> > > + /*
> > > + * TODO: Global PASID cache invalidation may be
> > > + * flushes all the pasid caches. To be safe, after
> > > + * invalidating the pasid caches, emulator needs
> > > + * to replay the pasid bindings by walking guest
> > > + * pasid dir and pasid table.
> > > + */
> > > + vtd_iommu_unlock(s);
> > > return 0;
> > > }
> > >
> > > @@ -3659,8 +4019,11 @@ static int
> > vtd_icx_register_ds_iommu(IOMMUContext *iommu_ctx,
> > > VTDIOMMUContext *vtd_dev_icx = container_of(iommu_ctx,
> > > VTDIOMMUContext,
> > > iommu_context);
> > > + IntelIOMMUState *s = vtd_dev_icx->iommu_state;
> > >
> > > vtd_dev_icx->dsi_obj = dsi_obj;
> > > + QLIST_INSERT_HEAD(&s->vtd_dev_icx_list, vtd_dev_icx, next);
> > > +
> > > return 0;
> > > }
> > >
> > > @@ -3672,6 +4035,7 @@ static void
> > vtd_icx_unregister_ds_iommu(IOMMUContext *iommu_ctx,
> > > iommu_context);
> > >
> > > vtd_dev_icx->dsi_obj = NULL;
> > > + QLIST_REMOVE(vtd_dev_icx, next);
> > > }
> > >
> > > IOMMUContextOps vtd_iommu_context_ops = {
> > > @@ -4130,6 +4494,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
> > > }
> > >
> > > QLIST_INIT(&s->vtd_as_with_notifiers);
> > > + QLIST_INIT(&s->vtd_dev_icx_list);
> > > 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,
> > > @@ -4155,6 +4520,8 @@ static void vtd_realize(DeviceState *dev, Error **errp)
> > > 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_pasid_as = g_hash_table_new_full(vtd_pasid_as_key_hash,
> > > + vtd_pasid_as_key_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_iommu_ops, dev);
> > > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> > > index 6c03560..18a9e50 100644
> > > --- a/hw/i386/intel_iommu_internal.h
> > > +++ b/hw/i386/intel_iommu_internal.h
> > > @@ -311,6 +311,7 @@ typedef enum VTDFaultReason {
> > > VTD_FR_IR_SID_ERR = 0x26, /* Invalid Source-ID */
> > >
> > > VTD_FR_PASID_TABLE_INV = 0x58, /*Invalid PASID table entry */
> > > + VTD_FR_PASID_ENTRY_P = 0x59, /* The Present(P) field of pasidt-entry is 0
> > */
> > >
> > > /* This is not a normal fault reason. We use this to indicate some faults
> > > * that are not referenced by the VT-d specification.
> > > @@ -485,6 +486,19 @@ struct VTDRootEntry {
> > > };
> > > typedef struct VTDRootEntry VTDRootEntry;
> > >
> > > +struct VTDPASIDCacheInfo {
> > > +#define VTD_PASID_CACHE_GLOBAL (1ULL << 0)
> > > +#define VTD_PASID_CACHE_DOMSI (1ULL << 1)
> > > +#define VTD_PASID_CACHE_PASIDSI (1ULL << 2)
> > > + uint32_t flags;
> > > + uint16_t domain_id;
> > > + uint32_t pasid;
> > > +};
> > > +#define VTD_PASID_CACHE_INFO_MASK (VTD_PASID_CACHE_GLOBAL | \
> > > + VTD_PASID_CACHE_DOMSI | \
> > > + VTD_PASID_CACHE_PASIDSI)
> > > +typedef struct VTDPASIDCacheInfo VTDPASIDCacheInfo;
> > > +
> > > /* Masks for struct VTDRootEntry */
> > > #define VTD_ROOT_ENTRY_P 1ULL
> > > #define VTD_ROOT_ENTRY_CTP (~0xfffULL)
> > > diff --git a/hw/i386/trace-events b/hw/i386/trace-events
> > > index f7cd4e5..87364a3 100644
> > > --- a/hw/i386/trace-events
> > > +++ b/hw/i386/trace-events
> > > @@ -22,6 +22,7 @@ vtd_inv_qi_head(uint16_t head) "read head %d"
> > > vtd_inv_qi_tail(uint16_t head) "write tail %d"
> > > vtd_inv_qi_fetch(void) ""
> > > vtd_context_cache_reset(void) ""
> > > +vtd_pasid_cache_reset(void) ""
> > > vtd_pasid_cache_gsi(void) ""
> > > vtd_pasid_cache_dsi(uint16_t domain) "Domian slective PC invalidation
> > domain 0x%"PRIx16
> > > vtd_pasid_cache_psi(uint16_t domain, uint32_t pasid) "PASID slective PC
> > invalidation domain 0x%"PRIx16" pasid 0x%"PRIx32
> > > diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> > > index 4158116..3cc4b74 100644
> > > --- a/include/hw/i386/intel_iommu.h
> > > +++ b/include/hw/i386/intel_iommu.h
> > > @@ -69,6 +69,8 @@ typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
> > > typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
> > > typedef struct VTDPASIDEntry VTDPASIDEntry;
> > > typedef struct VTDIOMMUContext VTDIOMMUContext;
> > > +typedef struct VTDPASIDCacheEntry VTDPASIDCacheEntry;
> > > +typedef struct VTDPASIDAddressSpace VTDPASIDAddressSpace;
> > >
> > > /* Context-Entry */
> > > struct VTDContextEntry {
> > > @@ -101,6 +103,31 @@ struct VTDPASIDEntry {
> > > uint64_t val[8];
> > > };
> > >
> > > +struct pasid_key {
> > > + uint32_t pasid;
> > > + uint16_t sid;
> > > +};
> > > +
> > > +struct VTDPASIDCacheEntry {
> > > + /*
> > > + * The cache entry is obsolete if
> > > + * pasid_cache_gen!=IntelIOMMUState.pasid_cache_gen
> > > + */
> > > + uint32_t pasid_cache_gen;
> > > + struct VTDPASIDEntry pasid_entry;
> > > +};
> > > +
> > > +struct VTDPASIDAddressSpace {
> > > + VTDBus *vtd_bus;
> > > + uint8_t devfn;
> > > + AddressSpace as;
> > > + uint32_t pasid;
> > > + IntelIOMMUState *iommu_state;
> > > + VTDContextCacheEntry context_cache_entry;
> > > + QLIST_ENTRY(VTDPASIDAddressSpace) next;
> > > + VTDPASIDCacheEntry pasid_cache_entry;
> >
> > In vtd_pasid_cache_gsi() [1], you directly reset pasid_cache_gen for
> > each pasid address space. You never increase
> > pasid_cache_entry.pasid_cache_gen. Then IIUC the gen will always be
> > either 0 or 1. And...
> >
> > > +};
> > > +
> > > struct VTDAddressSpace {
> > > PCIBus *bus;
> > > uint8_t devfn;
> > > @@ -122,6 +149,7 @@ struct VTDIOMMUContext {
> > > uint8_t devfn;
> > > IOMMUContext iommu_context;
> > > DualStageIOMMUObject *dsi_obj;
> > > + QLIST_ENTRY(VTDIOMMUContext) next;
> > > IntelIOMMUState *iommu_state;
> > > };
> > >
> > > @@ -272,9 +300,14 @@ struct IntelIOMMUState {
> > >
> > > 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_pasid_as; /* VTDPASIDAddressSpace instances */
> > > + uint32_t pasid_cache_gen; /* Should be in [1,MAX] */
> >
> > ... This should always be 1.
> > IIUC you can drop both of the pasid_cache_gen, because in this whole
> > patchset you'll remove the pasid hash entry when it is invalidated,
> > right? Then if the hash entry is there, it must be valid. When it's
> > out-dated, it'll be removed from the hash.
>
> Oh, yes it is. However, it's not my intetion. I'd like to let [1] to
> increase the s->pasid_cache_gen instead of justing zero it. I think it
> will save some time as loop hash table takes time. Thanks for catching
> it. :-)
OK that's fine too. Then remember to conditionally reset it:
static int vtd_pasid_cache_gsi(IntelIOMMUState *s)
{
trace_vtd_pasid_cache_gsi();
vtd_iommu_lock(s);
s->pasid_cache_gen++;
if (s->pasid_cache_gen >= THRESHOLD) {
vtd_pasid_cache_reset(s);
}
vtd_iommu_unlock(s);
return 0;
}
Thanks,
--
Peter Xu
