From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43418) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cVD0g-0000Mb-On for qemu-devel@nongnu.org; Sun, 22 Jan 2017 02:56:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cVD0d-0006un-ME for qemu-devel@nongnu.org; Sun, 22 Jan 2017 02:56:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60722) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cVD0d-0006uj-DB for qemu-devel@nongnu.org; Sun, 22 Jan 2017 02:56:19 -0500 References: <1484917736-32056-1-git-send-email-peterx@redhat.com> <1484917736-32056-16-git-send-email-peterx@redhat.com> From: Jason Wang Message-ID: Date: Sun, 22 Jan 2017 15:56:10 +0800 MIME-Version: 1.0 In-Reply-To: <1484917736-32056-16-git-send-email-peterx@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH RFC v4 15/20] intel_iommu: provide its own replay() callback List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu , qemu-devel@nongnu.org Cc: tianyu.lan@intel.com, kevin.tian@intel.com, mst@redhat.com, jan.kiszka@siemens.com, alex.williamson@redhat.com, bd.aviv@gmail.com On 2017=E5=B9=B401=E6=9C=8820=E6=97=A5 21:08, Peter Xu wrote: > The default replay() don't work for VT-d since vt-d will have a huge > default memory region which covers address range 0-(2^64-1). This will > normally consumes a lot of time (which looks like a dead loop). > > The solution is simple - we don't walk over all the regions. Instead, w= e > jump over the regions when we found that the page directories are empty= . > It'll greatly reduce the time to walk the whole region. > > To achieve this, we provided a page walk helper to do that, invoking > corresponding hook function when we found an page we are interested in. > vtd_page_walk_level() is the core logic for the page walking. It's > interface is designed to suite further use case, e.g., to invalidate a > range of addresses. > > Signed-off-by: Peter Xu > --- > hw/i386/intel_iommu.c | 216 +++++++++++++++++++++++++++++++++++++++++= +++++++-- > hw/i386/trace-events | 7 ++ > include/exec/memory.h | 2 + > 3 files changed, 220 insertions(+), 5 deletions(-) > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index 6f5f68a..f9c5142 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -598,6 +598,22 @@ static inline uint32_t vtd_get_agaw_from_context_e= ntry(VTDContextEntry *ce) > return 30 + (ce->hi & VTD_CONTEXT_ENTRY_AW) * 9; > } > =20 > +static inline uint64_t vtd_iova_limit(VTDContextEntry *ce) > +{ > + uint32_t ce_agaw =3D vtd_get_agaw_from_context_entry(ce); > + return 1ULL << MIN(ce_agaw, VTD_MGAW); > +} > + > +/* Return true if IOVA passes range check, otherwise false. */ > +static inline bool vtd_iova_range_check(uint64_t iova, VTDContextEntry= *ce) > +{ > + /* > + * Check if @iova is above 2^X-1, where X is the minimum of MGAW > + * in CAP_REG and AW in context-entry. > + */ > + return !(iova & ~(vtd_iova_limit(ce) - 1)); > +} > + > static const uint64_t vtd_paging_entry_rsvd_field[] =3D { > [0] =3D ~0ULL, > /* For not large page */ > @@ -633,13 +649,9 @@ static int vtd_gpa_to_slpte(VTDContextEntry *ce, u= int64_t iova, bool is_write, > uint32_t level =3D vtd_get_level_from_context_entry(ce); > uint32_t offset; > uint64_t slpte; > - uint32_t ce_agaw =3D vtd_get_agaw_from_context_entry(ce); > uint64_t access_right_check; > =20 > - /* Check if @iova is above 2^X-1, where X is the minimum of MGAW > - * in CAP_REG and AW in context-entry. > - */ > - if (iova & ~((1ULL << MIN(ce_agaw, VTD_MGAW)) - 1)) { > + if (!vtd_iova_range_check(iova, ce)) { > trace_vtd_err("IOVA exceeds limits"); > return -VTD_FR_ADDR_BEYOND_MGAW; > } > @@ -681,6 +693,168 @@ static int vtd_gpa_to_slpte(VTDContextEntry *ce, = uint64_t iova, bool is_write, > } > } > =20 > +typedef int (*vtd_page_walk_hook)(IOMMUTLBEntry *entry, void *private)= ; > + > +/** > + * vtd_page_walk_level - walk over specific level for IOVA range > + * > + * @addr: base GPA addr to start the walk > + * @start: IOVA range start address > + * @end: IOVA range end address (start <=3D addr < end) > + * @hook_fn: hook func to be called when detected page > + * @private: private data to be passed into hook func > + * @read: whether parent level has read permission > + * @write: whether parent level has write permission > + * @skipped: accumulated skipped ranges What's the usage for this parameter? Looks like it was never used in=20 this series. > + * @notify_unmap: whether we should notify invalid entries > + */ > +static int vtd_page_walk_level(dma_addr_t addr, uint64_t start, > + uint64_t end, vtd_page_walk_hook hook_f= n, > + void *private, uint32_t level, > + bool read, bool write, uint64_t *skippe= d, > + bool notify_unmap) > +{ > + bool read_cur, write_cur, entry_valid; > + uint32_t offset; > + uint64_t slpte; > + uint64_t subpage_size, subpage_mask; > + IOMMUTLBEntry entry; > + uint64_t iova =3D start; > + uint64_t iova_next; > + uint64_t skipped_local =3D 0; > + int ret =3D 0; > + > + trace_vtd_page_walk_level(addr, level, start, end); > + > + subpage_size =3D 1ULL << vtd_slpt_level_shift(level); > + subpage_mask =3D vtd_slpt_level_page_mask(level); > + > + while (iova < end) { > + iova_next =3D (iova & subpage_mask) + subpage_size; > + > + offset =3D vtd_iova_level_offset(iova, level); > + slpte =3D vtd_get_slpte(addr, offset); > + > + /* > + * When one of the following case happens, we assume the whole > + * range is invalid: > + * > + * 1. read block failed Don't get the meaning (and don't see any code relate to this comment). > + * 3. reserved area non-zero > + * 2. both read & write flag are not set Should be 1,2,3? And the above comment is conflict with the code at=20 least when notify_unmap is true. > + */ > + > + if (slpte =3D=3D (uint64_t)-1) { If this is true, vtd_slpte_nonzero_rsvd(slpte) should be true too I think= ? > + trace_vtd_page_walk_skip_read(iova, iova_next); > + skipped_local++; > + goto next; > + } > + > + if (vtd_slpte_nonzero_rsvd(slpte, level)) { > + trace_vtd_page_walk_skip_reserve(iova, iova_next); > + skipped_local++; > + goto next; > + } > + > + /* Permissions are stacked with parents' */ > + read_cur =3D read && (slpte & VTD_SL_R); > + write_cur =3D write && (slpte & VTD_SL_W); > + > + /* > + * As long as we have either read/write permission, this is > + * a valid entry. The rule works for both page or page tables. > + */ > + entry_valid =3D read_cur | write_cur; > + > + if (vtd_is_last_slpte(slpte, level)) { > + entry.target_as =3D &address_space_memory; > + entry.iova =3D iova & subpage_mask; > + /* > + * This might be meaningless addr if (!read_cur && > + * !write_cur), but after all this field will be > + * meaningless in that case, so let's share the code to > + * generate the IOTLBs no matter it's an MAP or UNMAP > + */ > + entry.translated_addr =3D vtd_get_slpte_addr(slpte); > + entry.addr_mask =3D ~subpage_mask; > + entry.perm =3D IOMMU_ACCESS_FLAG(read_cur, write_cur); > + if (!entry_valid && !notify_unmap) { > + trace_vtd_page_walk_skip_perm(iova, iova_next); > + skipped_local++; > + goto next; > + } Under which case should we care about unmap here (better with a comment=20 I think)? > + trace_vtd_page_walk_one(level, entry.iova, entry.translate= d_addr, > + entry.addr_mask, entry.perm); > + if (hook_fn) { > + ret =3D hook_fn(&entry, private); For better performance, we could try to merge adjacent mappings here. I=20 think both vfio and vhost support this and it can save a lot of ioctls. > + if (ret < 0) { > + error_report("Detected error in page walk hook " > + "function, stop walk."); > + return ret; > + } > + } > + } else { > + if (!entry_valid) { > + trace_vtd_page_walk_skip_perm(iova, iova_next); > + skipped_local++; > + goto next; > + } > + trace_vtd_page_walk_level(vtd_get_slpte_addr(slpte), level= - 1, > + iova, MIN(iova_next, end)); This looks duplicated? > + ret =3D vtd_page_walk_level(vtd_get_slpte_addr(slpte), iov= a, > + MIN(iova_next, end), hook_fn, pr= ivate, > + level - 1, read_cur, write_cur, > + &skipped_local, notify_unmap); > + if (ret < 0) { > + error_report("Detected page walk error on addr 0x%"PRI= x64 > + " level %"PRIu32", stop walk.", addr, lev= el - 1); Guest triggered, so better use debug macro or tracepoint. > + return ret; > + } > + } > + > +next: > + iova =3D iova_next; > + } > + > + if (skipped) { > + *skipped +=3D skipped_local; > + } > + > + return 0; > +} > + > +/** > + * vtd_page_walk - walk specific IOVA range, and call the hook > + * > + * @ce: context entry to walk upon > + * @start: IOVA address to start the walk > + * @end: IOVA range end address (start <=3D addr < end) > + * @hook_fn: the hook that to be called for each detected area > + * @private: private data for the hook function > + */ > +static int vtd_page_walk(VTDContextEntry *ce, uint64_t start, uint64_t= end, > + vtd_page_walk_hook hook_fn, void *private) > +{ > + dma_addr_t addr =3D vtd_get_slpt_base_from_context(ce); > + uint32_t level =3D vtd_get_level_from_context_entry(ce); > + > + if (!vtd_iova_range_check(start, ce)) { > + error_report("IOVA start 0x%"PRIx64 " end 0x%"PRIx64" exceeds = limits", > + start, end); Guest triggered, better use debug macro or tracepoint. > + return -VTD_FR_ADDR_BEYOND_MGAW; > + } > + > + if (!vtd_iova_range_check(end, ce)) { > + /* Fix end so that it reaches the maximum */ > + end =3D vtd_iova_limit(ce); > + } > + > + trace_vtd_page_walk_level(addr, level, start, end); Duplicated with the tracepoint in vtd_page_walk_level() too? > + > + return vtd_page_walk_level(addr, start, end, hook_fn, private, > + level, true, true, NULL, false); > +} > + > /* Map a device to its corresponding domain (context-entry) */ > static int vtd_dev_to_context_entry(IntelIOMMUState *s, uint8_t bus_n= um, > uint8_t devfn, VTDContextEntry *c= e) > @@ -2395,6 +2569,37 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState= *s, PCIBus *bus, int devfn) > return vtd_dev_as; > } > =20 > +static int vtd_replay_hook(IOMMUTLBEntry *entry, void *private) > +{ > + memory_region_notify_one((IOMMUNotifier *)private, entry); > + return 0; > +} > + > +static void vtd_iommu_replay(MemoryRegion *mr, IOMMUNotifier *n) > +{ > + VTDAddressSpace *vtd_as =3D container_of(mr, VTDAddressSpace, iomm= u); > + IntelIOMMUState *s =3D vtd_as->iommu_state; > + uint8_t bus_n =3D pci_bus_num(vtd_as->bus); > + VTDContextEntry ce; > + > + if (vtd_dev_to_context_entry(s, bus_n, vtd_as->devfn, &ce) =3D=3D = 0) { > + /* > + * Scanned a valid context entry, walk over the pages and > + * notify when needed. > + */ > + trace_vtd_replay_ce_valid(bus_n, PCI_SLOT(vtd_as->devfn), > + PCI_FUNC(vtd_as->devfn), > + VTD_CONTEXT_ENTRY_DID(ce.hi), > + ce.hi, ce.lo); > + vtd_page_walk(&ce, 0, ~0, vtd_replay_hook, (void *)n); ~0ULL? > + } else { > + trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn), > + PCI_FUNC(vtd_as->devfn)); > + } > + > + return; > +} > + > /* Do the initialization. It will also be called when reset, so pay > * attention when adding new initialization stuff. > */ > @@ -2409,6 +2614,7 @@ static void vtd_init(IntelIOMMUState *s) > =20 > s->iommu_ops.translate =3D vtd_iommu_translate; > s->iommu_ops.notify_flag_changed =3D vtd_iommu_notify_flag_change= d; > + s->iommu_ops.replay =3D vtd_iommu_replay; > s->root =3D 0; > s->root_extended =3D false; > s->dmar_enabled =3D false; > diff --git a/hw/i386/trace-events b/hw/i386/trace-events > index a273980..a3e1a9d 100644 > --- a/hw/i386/trace-events > +++ b/hw/i386/trace-events > @@ -31,6 +31,13 @@ vtd_iotlb_page_update(uint16_t sid, uint64_t addr, u= int64_t slpte, uint16_t doma > vtd_iotlb_cc_hit(uint8_t bus, uint8_t devfn, uint64_t high, uint64_t = low, uint32_t gen) "IOTLB context hit bus 0x%"PRIx8" devfn 0x%"PRIx8" hig= h 0x%"PRIx64" low 0x%"PRIx64" gen %"PRIu32 > vtd_iotlb_cc_update(uint8_t bus, uint8_t devfn, uint64_t high, uint64= _t low, uint32_t gen1, uint32_t gen2) "IOTLB context update bus 0x%"PRIx8= " devfn 0x%"PRIx8" high 0x%"PRIx64" low 0x%"PRIx64" gen %"PRIu32" -> gen = %"PRIu32 > vtd_iotlb_reset(const char *reason) "IOTLB reset (reason: %s)" > +vtd_replay_ce_valid(uint8_t bus, uint8_t dev, uint8_t fn, uint16_t dom= ain, uint64_t hi, uint64_t lo) "replay valid context device %02"PRIx8":%0= 2"PRIx8".%02"PRIx8" domain 0x%"PRIx16" hi 0x%"PRIx64" lo 0x%"PRIx64 > +vtd_replay_ce_invalid(uint8_t bus, uint8_t dev, uint8_t fn) "replay in= valid context device %02"PRIx8":%02"PRIx8".%02"PRIx8 > +vtd_page_walk_level(uint64_t addr, uint32_t level, uint64_t start, uin= t64_t end) "walk (base=3D0x%"PRIx64", level=3D%"PRIu32") iova range 0x%"P= RIx64" - 0x%"PRIx64 > +vtd_page_walk_one(uint32_t level, uint64_t iova, uint64_t gpa, uint64_= t mask, int perm) "detected page level 0x%"PRIx32" iova 0x%"PRIx64" -> gp= a 0x%"PRIx64" mask 0x%"PRIx64" perm %d" > +vtd_page_walk_skip_read(uint64_t iova, uint64_t next) "Page walk skip = iova 0x%"PRIx64" - 0x%"PRIx64" due to unable to read" > +vtd_page_walk_skip_perm(uint64_t iova, uint64_t next) "Page walk skip = iova 0x%"PRIx64" - 0x%"PRIx64" due to perm empty" > +vtd_page_walk_skip_reserve(uint64_t iova, uint64_t next) "Page walk sk= ip iova 0x%"PRIx64" - 0x%"PRIx64" due to rsrv set" > =20 > # hw/i386/amd_iommu.c > amdvi_evntlog_fail(uint64_t addr, uint32_t head) "error: fail to writ= e at addr 0x%"PRIx64" + offset 0x%"PRIx32 > diff --git a/include/exec/memory.h b/include/exec/memory.h > index bb4e654..9fd3232 100644 > --- a/include/exec/memory.h > +++ b/include/exec/memory.h > @@ -59,6 +59,8 @@ typedef enum { > IOMMU_RW =3D 3, > } IOMMUAccessFlags; > =20 > +#define IOMMU_ACCESS_FLAG(r, w) (((r) ? IOMMU_RO : 0) | ((w) ? IOMMU_W= O : 0)) > + > struct IOMMUTLBEntry { > AddressSpace *target_as; > hwaddr iova;