From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 568AAC33CA8 for ; Wed, 8 Jan 2020 20:27:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 231FB20643 for ; Wed, 8 Jan 2020 20:27:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727526AbgAHU1j (ORCPT ); Wed, 8 Jan 2020 15:27:39 -0500 Received: from mga06.intel.com ([134.134.136.31]:45241 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727298AbgAHU1L (ORCPT ); Wed, 8 Jan 2020 15:27:11 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2020 12:27:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,411,1571727600"; d="scan'208";a="211658383" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga007.jf.intel.com with ESMTP; 08 Jan 2020 12:27:06 -0800 From: Sean Christopherson To: Paolo Bonzini Cc: Paul Mackerras , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, syzbot+c9d1fb51ac9d0d10c39d@syzkaller.appspotmail.com, Andrea Arcangeli , Dan Williams , Barret Rhoden , David Hildenbrand , Jason Zeng , Dave Jiang , Liran Alon , linux-nvdimm Subject: [PATCH 09/14] KVM: x86/mmu: Rely on host page tables to find HugeTLB mappings Date: Wed, 8 Jan 2020 12:24:43 -0800 Message-Id: <20200108202448.9669-10-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200108202448.9669-1-sean.j.christopherson@intel.com> References: <20200108202448.9669-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Remove KVM's HugeTLB specific logic and instead rely on walking the host page tables (already done for THP) to identify HugeTLB mappings. Eliminating the HugeTLB-only logic avoids taking mmap_sem and calling find_vma() for all hugepage compatible page faults, and simplifies KVM's page fault code by consolidating all hugepage adjustments into a common helper. Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 84 ++++++++++------------------------ arch/x86/kvm/mmu/paging_tmpl.h | 15 +++--- 2 files changed, 29 insertions(+), 70 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 7d78d1d996ed..68aec984f953 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1286,23 +1286,6 @@ static bool mmu_gfn_lpage_is_disallowed(struct kvm_vcpu *vcpu, gfn_t gfn, return __mmu_gfn_lpage_is_disallowed(gfn, level, slot); } -static int host_mapping_level(struct kvm_vcpu *vcpu, gfn_t gfn) -{ - unsigned long page_size; - int i, ret = 0; - - page_size = kvm_host_page_size(vcpu, gfn); - - for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) { - if (page_size >= KVM_HPAGE_SIZE(i)) - ret = i; - else - break; - } - - return ret; -} - static inline bool memslot_valid_for_gpte(struct kvm_memory_slot *slot, bool no_dirty_log) { @@ -1327,43 +1310,25 @@ gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, return slot; } -static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, - int *max_levelp) +static int max_mapping_level(struct kvm_vcpu *vcpu, gfn_t gfn, + int max_level) { - int host_level, max_level = *max_levelp; struct kvm_memory_slot *slot; if (unlikely(max_level == PT_PAGE_TABLE_LEVEL)) return PT_PAGE_TABLE_LEVEL; - slot = kvm_vcpu_gfn_to_memslot(vcpu, large_gfn); - if (!memslot_valid_for_gpte(slot, true)) { - *max_levelp = PT_PAGE_TABLE_LEVEL; + slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); + if (!memslot_valid_for_gpte(slot, true)) return PT_PAGE_TABLE_LEVEL; - } max_level = min(max_level, kvm_x86_ops->get_lpage_level()); for ( ; max_level > PT_PAGE_TABLE_LEVEL; max_level--) { - if (!__mmu_gfn_lpage_is_disallowed(large_gfn, max_level, slot)) + if (!__mmu_gfn_lpage_is_disallowed(gfn, max_level, slot)) break; } - *max_levelp = max_level; - - if (max_level == PT_PAGE_TABLE_LEVEL) - return PT_PAGE_TABLE_LEVEL; - - /* - * Note, host_mapping_level() does *not* handle transparent huge pages. - * As suggested by "mapping", it reflects the page size established by - * the associated vma, if there is one, i.e. host_mapping_level() will - * return a huge page level if and only if a vma exists and the backing - * implementation for the vma uses huge pages, e.g. hugetlbfs and dax. - * So, do not propagate host_mapping_level() to max_level as KVM can - * still promote the guest mapping to a huge page in the THP case. - */ - host_level = host_mapping_level(vcpu, large_gfn); - return min(host_level, max_level); + return max_level; } /* @@ -3137,7 +3102,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, /* * Other vcpu creates new sp in the window between - * mapping_level() and acquiring mmu-lock. We can + * max_mapping_level() and acquiring mmu-lock. We can * allow guest to retry the access, the mapping can * be fixed if guest refault. */ @@ -3364,24 +3329,23 @@ static int host_pfn_mapping_level(struct kvm_vcpu *vcpu, gfn_t gfn, return level; } -static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, - int max_level, kvm_pfn_t *pfnp, - int *levelp) +static int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, + int max_level, kvm_pfn_t *pfnp) { kvm_pfn_t pfn = *pfnp; - int level = *levelp; kvm_pfn_t mask; + int level; - if (max_level == PT_PAGE_TABLE_LEVEL || level > PT_PAGE_TABLE_LEVEL) - return; + if (max_level == PT_PAGE_TABLE_LEVEL) + return PT_PAGE_TABLE_LEVEL; if (is_error_noslot_pfn(pfn) || kvm_is_reserved_pfn(pfn) || kvm_is_zone_device_pfn(pfn)) - return; + return PT_PAGE_TABLE_LEVEL; level = host_pfn_mapping_level(vcpu, gfn, pfn); if (level == PT_PAGE_TABLE_LEVEL) - return; + return level; level = min(level, max_level); @@ -3389,10 +3353,11 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, * mmu_notifier_retry() was successful and mmu_lock is held, so * the pmd can't be split from under us. */ - *levelp = level; mask = KVM_PAGES_PER_HPAGE(level) - 1; VM_BUG_ON((gfn & mask) != (pfn & mask)); *pfnp = pfn & ~mask; + + return level; } static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it, @@ -3419,20 +3384,19 @@ static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it, } static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write, - int map_writable, int level, int max_level, - kvm_pfn_t pfn, bool prefault, - bool account_disallowed_nx_lpage) + int map_writable, int max_level, kvm_pfn_t pfn, + bool prefault, bool account_disallowed_nx_lpage) { struct kvm_shadow_walk_iterator it; struct kvm_mmu_page *sp; - int ret; + int level, ret; gfn_t gfn = gpa >> PAGE_SHIFT; gfn_t base_gfn = gfn; if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa))) return RET_PF_RETRY; - transparent_hugepage_adjust(vcpu, gfn, max_level, &pfn, &level); + level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn); trace_kvm_mmu_spte_requested(gpa, level, pfn); for_each_shadow_entry(vcpu, gpa, it) { @@ -4206,7 +4170,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, gfn_t gfn = gpa >> PAGE_SHIFT; unsigned long mmu_seq; kvm_pfn_t pfn; - int level, r; + int r; if (page_fault_handle_page_track(vcpu, error_code, gfn)) return RET_PF_EMULATE; @@ -4218,9 +4182,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (lpage_disallowed) max_level = PT_PAGE_TABLE_LEVEL; - level = mapping_level(vcpu, gfn, &max_level); - if (level > PT_PAGE_TABLE_LEVEL) - gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); + max_level = max_mapping_level(vcpu, gfn, max_level); if (fast_page_fault(vcpu, gpa, error_code)) return RET_PF_RETRY; @@ -4240,7 +4202,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, goto out_unlock; if (make_mmu_pages_available(vcpu) < 0) goto out_unlock; - r = __direct_map(vcpu, gpa, write, map_writable, level, max_level, pfn, + r = __direct_map(vcpu, gpa, write, map_writable, max_level, pfn, prefault, is_tdp && lpage_disallowed); out_unlock: diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 0029f7870865..841506a55815 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -613,14 +613,14 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, */ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr, struct guest_walker *gw, - int write_fault, int hlevel, int max_level, + int write_fault, int max_level, kvm_pfn_t pfn, bool map_writable, bool prefault, bool lpage_disallowed) { struct kvm_mmu_page *sp = NULL; struct kvm_shadow_walk_iterator it; unsigned direct_access, access = gw->pt_access; - int top_level, ret; + int top_level, hlevel, ret; gfn_t gfn, base_gfn; direct_access = gw->pte_access; @@ -673,7 +673,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr, gfn = gw->gfn | ((addr & PT_LVL_OFFSET_MASK(gw->level)) >> PAGE_SHIFT); base_gfn = gfn; - transparent_hugepage_adjust(vcpu, gw->gfn, max_level, &pfn, &hlevel); + hlevel = kvm_mmu_hugepage_adjust(vcpu, gw->gfn, max_level, &pfn); trace_kvm_mmu_spte_requested(addr, gw->level, pfn); @@ -775,7 +775,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, struct guest_walker walker; int r; kvm_pfn_t pfn; - int level; unsigned long mmu_seq; bool map_writable, is_self_change_mapping; bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) && @@ -825,9 +824,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, else max_level = walker.level; - level = mapping_level(vcpu, walker.gfn, &max_level); - if (level > PT_PAGE_TABLE_LEVEL) - walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); + max_level = max_mapping_level(vcpu, walker.gfn, max_level); mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb(); @@ -867,8 +864,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); if (make_mmu_pages_available(vcpu) < 0) goto out_unlock; - r = FNAME(fetch)(vcpu, addr, &walker, write_fault, level, max_level, - pfn, map_writable, prefault, lpage_disallowed); + r = FNAME(fetch)(vcpu, addr, &walker, write_fault, max_level, pfn, + map_writable, prefault, lpage_disallowed); kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT); out_unlock: -- 2.24.1