From patchwork Fri Nov 14 21:54:44 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mario Smarduch X-Patchwork-Id: 5309691 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3C1EFC11AC for ; Fri, 14 Nov 2014 21:59:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2FE00200E0 for ; Fri, 14 Nov 2014 21:59:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 225D320145 for ; Fri, 14 Nov 2014 21:59:56 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XpOq1-0005g8-M6; Fri, 14 Nov 2014 21:55:29 +0000 Received: from mailout2.w2.samsung.com ([211.189.100.12] helo=usmailout2.samsung.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XpOpz-0005UN-8B for linux-arm-kernel@lists.infradead.org; Fri, 14 Nov 2014 21:55:28 +0000 Received: from uscpsbgex4.samsung.com (u125.gpu85.samsung.co.kr [203.254.195.125]) by mailout2.w2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NF100B9SU7SUP30@mailout2.w2.samsung.com> for linux-arm-kernel@lists.infradead.org; Fri, 14 Nov 2014 16:55:04 -0500 (EST) X-AuditID: cbfec37d-b7f3b6d000005695-27-54667a372ed6 Received: from usmmp1.samsung.com ( [203.254.195.77]) by uscpsbgex4.samsung.com (USCPEXMTA) with SMTP id 41.AA.22165.73A76645; Fri, 14 Nov 2014 16:55:04 -0500 (EST) Received: from sisasmtp.sisa.samsung.com ([105.144.21.116]) by usmmp1.samsung.com (Oracle Communications Messaging Server 7u4-27.01(7.0.4.27.0) 64bit (built Aug 30 2012)) with ESMTP id <0NF10097BU7RX450@usmmp1.samsung.com>; Fri, 14 Nov 2014 16:55:03 -0500 (EST) Received: from mjsmard-530U3C-530U4C-532U3C.sisa.samsung.com (105.144.129.79) by SISAEX02SJ.sisa.samsung.com (105.144.21.116) with Microsoft SMTP Server (TLS) id 14.3.123.3; Fri, 14 Nov 2014 13:55:03 -0800 From: Mario Smarduch To: marc.zyngier@arm.com, christoffer.dall@linaro.org Subject: [RESEND PATCH v14 7/7] KVM: arm: page logging 2nd stage fault handling Date: Fri, 14 Nov 2014 13:54:44 -0800 Message-id: <1416002084-9928-1-git-send-email-m.smarduch@samsung.com> X-Mailer: git-send-email 1.7.9.5 MIME-version: 1.0 X-Originating-IP: [105.144.129.79] X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPLMWRmVeSWpSXmKPExsVy+t9hX12LqrQQg4ft7Bbvl/UwWrx4/Y/R Ys7UQouPp46zW2x6fI3V4u+df2wWk95sY3Jg91gzbw2jx51re9g8zm9aw+yxeUm9x+dNcgGs UVw2Kak5mWWpRfp2CVwZ33//Yivo1KpoWvSJqYFxoVIXIyeHhICJxL9HK1khbDGJC/fWs3Ux cnEICSxjlHi/fQEThNPLJLFj8XpGCOcio8T/s0tYQFrYBHQl9t/byA5iiwiYSvx7+w6sg1lg O6PEgo29YEXCAv4Sr3bsBZrLwcEioCpx+oIjSJhXwFWia3cPI0hYQkBBYs4kG4iwoMSPyfdY QMLMAhISzz+DHSoE1Ljt5nNGiEOVJKYdvso+gVFgFpKOWQgdCxiZVjGKlRYnFxQnpadWmOgV J+YWl+al6yXn525ihARy7Q7G+19tDjEKcDAq8fBWpqSGCLEmlhVX5h5ilOBgVhLhXZKbFiLE m5JYWZValB9fVJqTWnyIkYmDU6qB0f5a1IHQy+9fJW73j3BierY7Oj9lw5x3cZt1NY83mpuK s37g0/l+oHbaUWXBNm2Liz4Snx/s/uXc9GjRU3GxTdsclwQpP9t9d+f/zzktU8PvfrXWq1z0 c2qIRVcvx9ezGx9Z3giv6cv2fanU9F6efV3Q8WOzFmaH3XeZvd4uzrx5mWzcv+WqpUosxRmJ hlrMRcWJAElBfQxCAgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141114_135527_375710_C4F5485B X-CRM114-Status: GOOD ( 13.03 ) X-Spam-Score: -4.9 (----) Cc: kvm@vger.kernel.org, steve.capper@arm.com, catalin.marinas@arm.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Mario Smarduch X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds support for handling 2nd stage page faults during migration, it disables faulting in huge pages, and dissolves huge pages to page tables. In case migration is canceled huge pages are used again. Resending to addresse Marc's comments to simplify stage2_set_pte() handling of logging, and mapping device memory - flags. Reviewed-by: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Mario Smarduch --- arch/arm/kvm/mmu.c | 61 +++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 53 insertions(+), 8 deletions(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 8137455..d29de77 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -47,6 +47,18 @@ static phys_addr_t hyp_idmap_vector; #define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x)) #define kvm_pud_huge(_x) pud_huge(_x) +#define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0) +#define KVM_S2PTE_FLAG_LOGGING_ACTIVE (1UL << 1) + +static bool kvm_get_logging_state(struct kvm_memory_slot *memslot) +{ +#ifdef CONFIG_ARM + return !!memslot->dirty_bitmap; +#else + return false; +#endif +} + static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { /* @@ -626,10 +638,13 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache } static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, - phys_addr_t addr, const pte_t *new_pte, bool iomap) + phys_addr_t addr, const pte_t *new_pte, + unsigned long flags) { pmd_t *pmd; pte_t *pte, old_pte; + unsigned long iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP; + unsigned long logging_active = flags & KVM_S2PTE_FLAG_LOGGING_ACTIVE; /* Create stage-2 page table mapping - Level 1 */ pmd = stage2_get_pmd(kvm, cache, addr); @@ -641,6 +656,18 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, return 0; } + /* + * While dirty memory logging, clear PMD entry for huge page and split + * into smaller pages, to track dirty memory at page granularity. + */ + if (logging_active && kvm_pmd_huge(*pmd)) { + phys_addr_t ipa = pmd_pfn(*pmd) << PAGE_SHIFT; + + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, ipa); + put_page(virt_to_page(pmd)); + } + /* Create stage-2 page mappings - Level 2 */ if (pmd_none(*pmd)) { if (!cache) @@ -693,7 +720,8 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, if (ret) goto out; spin_lock(&kvm->mmu_lock); - ret = stage2_set_pte(kvm, &cache, addr, &pte, true); + ret = stage2_set_pte(kvm, &cache, addr, &pte, + KVM_S2PTE_FLAG_IS_IOMAP); spin_unlock(&kvm->mmu_lock); if (ret) goto out; @@ -908,6 +936,10 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, struct vm_area_struct *vma; pfn_t pfn; pgprot_t mem_type = PAGE_S2; + unsigned long logging_active = 0; + + if (kvm_get_logging_state(memslot)) + logging_active = KVM_S2PTE_FLAG_LOGGING_ACTIVE; write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu)); if (fault_status == FSC_PERM && !write_fault) { @@ -918,7 +950,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, /* Let's check if we will get back a huge page backed by hugetlbfs */ down_read(¤t->mm->mmap_sem); vma = find_vma_intersection(current->mm, hva, hva + 1); - if (is_vm_hugetlb_page(vma)) { + if (is_vm_hugetlb_page(vma) && !logging_active) { hugetlb = true; gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; } else { @@ -964,7 +996,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, spin_lock(&kvm->mmu_lock); if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; - if (!hugetlb && !force_pte) + if (!hugetlb && !force_pte && !logging_active) hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); if (hugetlb) { @@ -978,16 +1010,21 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { pte_t new_pte = pfn_pte(pfn, mem_type); + unsigned long flags = logging_active; + + if (mem_type == PAGE_S2_DEVICE) + flags |= KVM_S2PTE_FLAG_IS_IOMAP; + if (writable) { kvm_set_s2pte_writable(&new_pte); kvm_set_pfn_dirty(pfn); } coherent_cache_guest_page(vcpu, hva, PAGE_SIZE); - ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, - mem_type == PAGE_S2_DEVICE); + ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); } - + if (write_fault) + mark_page_dirty(kvm, gfn); out_unlock: spin_unlock(&kvm->mmu_lock); kvm_release_pfn_clean(pfn); @@ -1137,7 +1174,15 @@ static void kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data) { pte_t *pte = (pte_t *)data; - stage2_set_pte(kvm, NULL, gpa, pte, false); + /* + * We can always call stage2_set_pte with logging_active == false, + * because MMU notifiers will have unmapped a huge PMD before calling + * ->change_pte() (which in turn calls kvm_set_spte_hva()) and therefore + * stage2_set_pte() never needs to clear out a huge PMD through this + * calling path. + */ + + stage2_set_pte(kvm, NULL, gpa, pte, 0); }