[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v9 5/8] remove remaining uses of iommu_legacy_map/unmap
From: Paul Durrant <pdurrant@xxxxxxxxxx> The 'legacy' functions do implicit flushing so amend the callers to do the appropriate flushing. Unfortunately, because of the structure of the P2M code, we cannot remove the per-CPU 'iommu_dont_flush_iotlb' global and the optimization it facilitates. Checking of this flag is now done only in relevant callers of iommu_iotlb_flush(). Also, 'iommu_dont_flush_iotlb' is now declared as bool (rather than bool_t) and setting/clearing it are no longer pointlessly gated on is_iommu_enabled() returning true. (Arguably it is also pointless to gate the call to iommu_iotlb_flush() on that condition - since it is a no-op in that case - but the if clause allows the scope of a stack variable to be restricted). NOTE: The code in memory_add() now sets 'ret' if iommu_map() or iommu_iotlb_flush() fails. Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx> --- Cc: Jan Beulich <jbeulich@xxxxxxxx> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Cc: Wei Liu <wl@xxxxxxx> Cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx> Cc: George Dunlap <george.dunlap@xxxxxxxxxx> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> Cc: Julien Grall <julien@xxxxxxx> Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> Cc: Jun Nakajima <jun.nakajima@xxxxxxxxx> Cc: Kevin Tian <kevin.tian@xxxxxxxxx> v9: - Moved check of 'iommu_dont_flush_iotlb' out of iommu_iotlb_flush() and into callers to avoid re-introducing a problem on Arm - Dropped Jan's R-b due to change v6: - Fix formatting problem in memory_add() v5: - Re-base - Removed failure case on overflow of unsigned int as it is no longer necessary v3: - Same as v2; elected to implement batch flushing in the grant table code as a subsequent patch v2: - Shorten the diff (mainly because of a prior patch introducing automatic flush-on-fail into iommu_map() and iommu_unmap()) --- xen/arch/x86/mm.c | 24 +++++++++++++++++------- xen/arch/x86/mm/p2m-ept.c | 21 +++++++++++++-------- xen/arch/x86/mm/p2m-pt.c | 16 ++++++++++++---- xen/arch/x86/mm/p2m.c | 25 +++++++++++++++++-------- xen/arch/x86/x86_64/mm.c | 20 +++++++------------- xen/common/grant_table.c | 29 ++++++++++++++++++++++------- xen/common/memory.c | 7 +++---- xen/drivers/passthrough/iommu.c | 23 ----------------------- xen/include/xen/iommu.h | 21 +++++---------------- 9 files changed, 96 insertions(+), 90 deletions(-) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 9447dabc50..fec8a19920 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -2441,10 +2441,16 @@ static int cleanup_page_mappings(struct page_info *page) if ( d && unlikely(need_iommu_pt_sync(d)) && is_pv_domain(d) ) { - int rc2 = iommu_legacy_unmap(d, _dfn(mfn), 1u << PAGE_ORDER_4K); + unsigned int flush_flags = 0; + int err; + + err = iommu_unmap(d, _dfn(mfn), 1ul << PAGE_ORDER_4K, &flush_flags); + if ( !err && !this_cpu(iommu_dont_flush_iotlb) ) + err = iommu_iotlb_flush(d, _dfn(mfn), 1ul << PAGE_ORDER_4K, + flush_flags); if ( !rc ) - rc = rc2; + rc = err; } if ( likely(!is_special_page(page)) ) @@ -2966,14 +2972,18 @@ static int _get_page_type(struct page_info *page, unsigned long type, if ( d && unlikely(need_iommu_pt_sync(d)) && is_pv_domain(d) ) { mfn_t mfn = page_to_mfn(page); + dfn_t dfn = _dfn(mfn_x(mfn)); + unsigned int flush_flags = 0; if ( (x & PGT_type_mask) == PGT_writable_page ) - rc = iommu_legacy_unmap(d, _dfn(mfn_x(mfn)), - 1ul << PAGE_ORDER_4K); + rc = iommu_unmap(d, dfn, 1ul << PAGE_ORDER_4K, &flush_flags); else - rc = iommu_legacy_map(d, _dfn(mfn_x(mfn)), mfn, - 1ul << PAGE_ORDER_4K, - IOMMUF_readable | IOMMUF_writable); + rc = iommu_map(d, dfn, mfn, 1ul << PAGE_ORDER_4K, + IOMMUF_readable | IOMMUF_writable, &flush_flags); + + if ( !rc && !this_cpu(iommu_dont_flush_iotlb) ) + rc = iommu_iotlb_flush(d, dfn, 1ul << PAGE_ORDER_4K, + flush_flags); if ( unlikely(rc) ) { diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c index 12cf38f6eb..71473fd31d 100644 --- a/xen/arch/x86/mm/p2m-ept.c +++ b/xen/arch/x86/mm/p2m-ept.c @@ -842,15 +842,20 @@ out: if ( rc == 0 && p2m_is_hostp2m(p2m) && need_modify_vtd_table ) { - if ( iommu_use_hap_pt(d) ) - rc = iommu_iotlb_flush(d, _dfn(gfn), 1ul << order, - (iommu_flags ? IOMMU_FLUSHF_added : 0) | - (vtd_pte_present ? IOMMU_FLUSHF_modified - : 0)); - else if ( need_iommu_pt_sync(d) ) + unsigned int flush_flags = 0; + + if ( need_iommu_pt_sync(d) ) rc = iommu_flags ? - iommu_legacy_map(d, _dfn(gfn), mfn, 1ul << order, iommu_flags) : - iommu_legacy_unmap(d, _dfn(gfn), 1ul << order); + iommu_map(d, _dfn(gfn), mfn, 1ul << order, iommu_flags, + &flush_flags) : + iommu_unmap(d, _dfn(gfn), 1ul << order, &flush_flags); + else if ( iommu_use_hap_pt(d) ) + flush_flags = + (iommu_flags ? IOMMU_FLUSHF_added : 0) | + (vtd_pte_present ? IOMMU_FLUSHF_modified : 0); + + if ( !rc && !this_cpu(iommu_dont_flush_iotlb) ) + rc = iommu_iotlb_flush(d, _dfn(gfn), 1ul << order, flush_flags); } unmap_domain_page(table); diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c index 3af51be78e..96cacb6748 100644 --- a/xen/arch/x86/mm/p2m-pt.c +++ b/xen/arch/x86/mm/p2m-pt.c @@ -678,10 +678,18 @@ p2m_pt_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t mfn, if ( need_iommu_pt_sync(p2m->domain) && (iommu_old_flags != iommu_pte_flags || old_mfn != mfn_x(mfn)) ) - rc = iommu_pte_flags - ? iommu_legacy_map(d, _dfn(gfn), mfn, 1ul << page_order, - iommu_pte_flags) - : iommu_legacy_unmap(d, _dfn(gfn), 1ul << page_order); + { + unsigned int flush_flags = 0; + + rc = iommu_pte_flags ? + iommu_map(d, _dfn(gfn), mfn, 1ul << page_order, iommu_pte_flags, + &flush_flags) : + iommu_unmap(d, _dfn(gfn), 1ul << page_order, &flush_flags); + + if ( !rc && !this_cpu(iommu_dont_flush_iotlb) ) + rc = iommu_iotlb_flush(d, _dfn(gfn), 1ul << page_order, + flush_flags); + } /* * Free old intermediate tables if necessary. This has to be the diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c index 928344be30..01ff92862d 100644 --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -1350,11 +1350,15 @@ int set_identity_p2m_entry(struct domain *d, unsigned long gfn_l, if ( !paging_mode_translate(p2m->domain) ) { - if ( !is_iommu_enabled(d) ) - return 0; - return iommu_legacy_map(d, _dfn(gfn_l), _mfn(gfn_l), - 1ul << PAGE_ORDER_4K, - IOMMUF_readable | IOMMUF_writable); + unsigned int flush_flags = 0; + + ret = iommu_map(d, _dfn(gfn_l), _mfn(gfn_l), 1ul << PAGE_ORDER_4K, + IOMMUF_readable | IOMMUF_writable, &flush_flags); + if ( !ret ) + ret = iommu_iotlb_flush(d, _dfn(gfn_l), 1ul << PAGE_ORDER_4K, + flush_flags); + + return ret; } gfn_lock(p2m, gfn, 0); @@ -1442,9 +1446,14 @@ int clear_identity_p2m_entry(struct domain *d, unsigned long gfn_l) if ( !paging_mode_translate(d) ) { - if ( !is_iommu_enabled(d) ) - return 0; - return iommu_legacy_unmap(d, _dfn(gfn_l), 1ul << PAGE_ORDER_4K); + unsigned int flush_flags = 0; + + ret = iommu_unmap(d, _dfn(gfn_l), 1ul << PAGE_ORDER_4K, &flush_flags); + if ( !ret ) + ret = iommu_iotlb_flush(d, _dfn(gfn_l), 1ul << PAGE_ORDER_4K, + flush_flags); + + return ret; } gfn_lock(p2m, gfn, 0); diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c index bce1561e1a..7e9d165449 100644 --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -1284,21 +1284,15 @@ int memory_add(unsigned long spfn, unsigned long epfn, unsigned int pxm) !iommu_use_hap_pt(hardware_domain) && !need_iommu_pt_sync(hardware_domain) ) { - for ( i = spfn; i < epfn; i++ ) - if ( iommu_legacy_map(hardware_domain, _dfn(i), _mfn(i), - 1ul << PAGE_ORDER_4K, - IOMMUF_readable | IOMMUF_writable) ) - break; - if ( i != epfn ) - { - while (i-- > old_max) - /* If statement to satisfy __must_check. */ - if ( iommu_legacy_unmap(hardware_domain, _dfn(i), - 1ul << PAGE_ORDER_4K) ) - continue; + unsigned int flush_flags = 0; + unsigned long n = epfn - spfn; + ret = iommu_map(hardware_domain, _dfn(i), _mfn(i), n, + IOMMUF_readable | IOMMUF_writable, &flush_flags); + if ( !ret ) + ret = iommu_iotlb_flush(hardware_domain, _dfn(i), n, flush_flags); + if ( ret ) goto destroy_m2p; - } } /* We can't revert any more */ diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index a5d3ed8bda..beb6b2d40d 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -1225,11 +1225,22 @@ map_grant_ref( kind = IOMMUF_readable; else kind = 0; - if ( kind && iommu_legacy_map(ld, _dfn(mfn_x(mfn)), mfn, 1, kind) ) + + if ( kind ) { - double_gt_unlock(lgt, rgt); - rc = GNTST_general_error; - goto undo_out; + dfn_t dfn = _dfn(mfn_x(mfn)); + unsigned int flush_flags = 0; + int err; + + err = iommu_map(ld, dfn, mfn, 1, kind, &flush_flags); + if ( !err ) + err = iommu_iotlb_flush(ld, dfn, 1, flush_flags); + if ( err ) + { + double_gt_unlock(lgt, rgt); + rc = GNTST_general_error; + goto undo_out; + } } } @@ -1473,19 +1484,23 @@ unmap_common( if ( rc == GNTST_okay && gnttab_need_iommu_mapping(ld) ) { unsigned int kind; + dfn_t dfn = _dfn(mfn_x(op->mfn)); + unsigned int flush_flags = 0; int err = 0; double_gt_lock(lgt, rgt); kind = mapkind(lgt, rd, op->mfn); if ( !kind ) - err = iommu_legacy_unmap(ld, _dfn(mfn_x(op->mfn)), 1); + err = iommu_unmap(ld, dfn, 1, &flush_flags); else if ( !(kind & MAPKIND_WRITE) ) - err = iommu_legacy_map(ld, _dfn(mfn_x(op->mfn)), op->mfn, 1, - IOMMUF_readable); + err = iommu_map(ld, dfn, op->mfn, 1, IOMMUF_readable, + &flush_flags); double_gt_unlock(lgt, rgt); + if ( !err ) + err = iommu_iotlb_flush(ld, dfn, 1, flush_flags); if ( err ) rc = GNTST_general_error; } diff --git a/xen/common/memory.c b/xen/common/memory.c index 714077c1e5..fedbd9019e 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -824,8 +824,7 @@ int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp, xatp->gpfn += start; xatp->size -= start; - if ( is_iommu_enabled(d) ) - this_cpu(iommu_dont_flush_iotlb) = 1; + this_cpu(iommu_dont_flush_iotlb) = true; while ( xatp->size > done ) { @@ -845,12 +844,12 @@ int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp, } } + this_cpu(iommu_dont_flush_iotlb) = false; + if ( is_iommu_enabled(d) ) { int ret; - this_cpu(iommu_dont_flush_iotlb) = 0; - ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done, IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified); if ( unlikely(ret) && rc >= 0 ) diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c index 87f9a857bb..a9da4d2b06 100644 --- a/xen/drivers/passthrough/iommu.c +++ b/xen/drivers/passthrough/iommu.c @@ -282,18 +282,6 @@ int iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn, return rc; } -int iommu_legacy_map(struct domain *d, dfn_t dfn, mfn_t mfn, - unsigned long page_count, unsigned int flags) -{ - unsigned int flush_flags = 0; - int rc = iommu_map(d, dfn, mfn, page_count, flags, &flush_flags); - - if ( !this_cpu(iommu_dont_flush_iotlb) && !rc ) - rc = iommu_iotlb_flush(d, dfn, page_count, flush_flags); - - return rc; -} - int iommu_unmap(struct domain *d, dfn_t dfn, unsigned long page_count, unsigned int *flush_flags) { @@ -338,17 +326,6 @@ int iommu_unmap(struct domain *d, dfn_t dfn, unsigned long page_count, return rc; } -int iommu_legacy_unmap(struct domain *d, dfn_t dfn, unsigned long page_count) -{ - unsigned int flush_flags = 0; - int rc = iommu_unmap(d, dfn, page_count, &flush_flags); - - if ( !this_cpu(iommu_dont_flush_iotlb) && !rc ) - rc = iommu_iotlb_flush(d, dfn, page_count, flush_flags); - - return rc; -} - int iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn, unsigned int *flags) { diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h index 13f68dc93d..a2eefe8582 100644 --- a/xen/include/xen/iommu.h +++ b/xen/include/xen/iommu.h @@ -151,16 +151,8 @@ int __must_check iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn, int __must_check iommu_unmap(struct domain *d, dfn_t dfn, unsigned long page_count, unsigned int *flush_flags); - -int __must_check iommu_legacy_map(struct domain *d, dfn_t dfn, mfn_t mfn, - unsigned long page_count, - unsigned int flags); -int __must_check iommu_legacy_unmap(struct domain *d, dfn_t dfn, - unsigned long page_count); - int __must_check iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn, unsigned int *flags); - int __must_check iommu_iotlb_flush(struct domain *d, dfn_t dfn, unsigned long page_count, unsigned int flush_flags); @@ -369,15 +361,12 @@ void iommu_dev_iotlb_flush_timeout(struct domain *d, struct pci_dev *pdev); /* * The purpose of the iommu_dont_flush_iotlb optional cpu flag is to - * avoid unecessary iotlb_flush in the low level IOMMU code. - * - * iommu_map_page/iommu_unmap_page must flush the iotlb but somethimes - * this operation can be really expensive. This flag will be set by the - * caller to notify the low level IOMMU code to avoid the iotlb flushes. - * iommu_iotlb_flush/iommu_iotlb_flush_all will be explicitly called by - * the caller. + * avoid unnecessary IOMMU flushing while updating the P2M. + * Setting the value to true will cause iommu_iotlb_flush() to return without + * actually performing a flush. A batch flush must therefore be done by the + * calling code after setting the value back to false. */ -DECLARE_PER_CPU(bool_t, iommu_dont_flush_iotlb); +DECLARE_PER_CPU(bool, iommu_dont_flush_iotlb); extern struct spinlock iommu_pt_cleanup_lock; extern struct page_list_head iommu_pt_cleanup_list; -- 2.20.1
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