From patchwork Wed Oct 31 13:26:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Orr X-Patchwork-Id: 10662683 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 33EC113BF for ; Wed, 31 Oct 2018 13:26:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 24298284BD for ; Wed, 31 Oct 2018 13:26:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 17FAF28AA4; Wed, 31 Oct 2018 13:26:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 923CB284BD for ; Wed, 31 Oct 2018 13:26:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729266AbeJaWYu (ORCPT ); Wed, 31 Oct 2018 18:24:50 -0400 Received: from mail-pg1-f201.google.com ([209.85.215.201]:46974 "EHLO mail-pg1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729118AbeJaWYu (ORCPT ); Wed, 31 Oct 2018 18:24:50 -0400 Received: by mail-pg1-f201.google.com with SMTP id 75-v6so11467663pgc.13 for ; Wed, 31 Oct 2018 06:26:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=unPH4bSgTFjVNwKk6oCcUeWwQ3wTeQ6A3j9CRmR6rxE=; b=cTbNiZHLLqiCsYSAZzQUyUDFYhvrkAWgtf3cj0Miwz59hKR9ktOnzwuowCNk10ND2T XeC/gRxIHywBmmJIRBm202aMLKcmxqyqY5Jtg5SqkFm4X2H6ffysMCn7ybtrWYT+PaaG M0udFkpE2MJmeBW3yYirc9TQFPR+lwIX/UJkCkjvvv5cDEEMWsZV5vM7mQLnxMTRsD3j ifkQ6gYckIfuYPQVcq+Uen7rBOmcmYiU5wMG6yroNThexULCmjpdl7EG7m7JYQpb5ct4 65Rcfut8b2u83RbIRPgKl12fBTrwroL2+60iS17EuEts6hEnbbtCZ/zelxNB/5rTu84f W3AA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=unPH4bSgTFjVNwKk6oCcUeWwQ3wTeQ6A3j9CRmR6rxE=; b=PQknEiU/89mcytkCBw/FhIEuyMEZBSikZSPLt365hmC6OHXEQ4EtYPtFeJ60o3mS++ PStyaLkPgCKw09b8/nQh6O0O7oPJQKb3JCGkWdLvIl2fE5/5ntC5go+Xq3NDh64GNtY9 xTpDlH4sVPZtJ54adhnyn3KltHYSTnzGjFTXZRtVBzRP3PyGxxtbS36IS5lI1kKdMU+X +gFsed308T/Fwv9mVNHLYHna2p+KuDCfbmq4lMXctSR41TgmDh/OBAwAbLsxI/WbikIr 4zonGIM5u0tcZ8is8ZbVffYt1wkhFwoMAuf8QQU7MZT9n3QE5wdu8NvuPlaudp9NPzwp JWEQ== X-Gm-Message-State: AGRZ1gL1YTollcTVKJAG0EgbyUytcTmmJVloihFADdVoWiPbzTgsrLPw awA/938iCNtket692nVfBTQOJjsvobNWb5iXfrH5nO1u5CTkv2wXZUX8Sn1mjGpZMycD/3ulTvX E5S57xWeyDwaf1d98U7Tpl8ENmK5WRI4gJWBBPnLS3CEmL49LQwDUdfDm4AiA X-Google-Smtp-Source: AJdET5fwqKY/nofJYGiflINsQ/c34vPpLl2kZUVixIhMBX5Oty0tx4FrTX1q4lr7MlcFLh3fR7e1oRtlW1FC X-Received: by 2002:a17:902:20e8:: with SMTP id v37-v6mr1039308plg.42.1540992408341; Wed, 31 Oct 2018 06:26:48 -0700 (PDT) Date: Wed, 31 Oct 2018 06:26:34 -0700 In-Reply-To: <20181031132634.50440-1-marcorr@google.com> Message-Id: <20181031132634.50440-5-marcorr@google.com> Mime-Version: 1.0 References: <20181031132634.50440-1-marcorr@google.com> X-Mailer: git-send-email 2.19.1.568.g152ad8e336-goog Subject: [kvm PATCH v5 4/4] kvm: vmx: use vmalloc() to allocate vcpus From: Marc Orr To: kvm@vger.kernel.org, jmattson@google.com, rientjes@google.com, konrad.wilk@oracle.com, linux-mm@kvack.org, akpm@linux-foundation.org, pbonzini@redhat.com, rkrcmar@redhat.com, willy@infradead.org, sean.j.christopherson@intel.com, dave.hansen@linux.intel.com, kernellwp@gmail.com Cc: Marc Orr Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Previously, vcpus were allocated through the kmem_cache_zalloc() API, which requires the underlying physical memory to be contiguous. Because the x86 vcpu struct, struct vcpu_vmx, is relatively large (e.g., currently 47680 bytes on my setup), it can become hard to find contiguous memory. At the same time, the comments in the code indicate that the primary reason for using the kmem_cache_zalloc() API is to align the memory rather than to provide physical contiguity. Thus, this patch updates the vcpu allocation logic for vmx to use the vmalloc() API. Signed-off-by: Marc Orr --- arch/x86/kvm/vmx.c | 37 ++++++++++++++++++++++++++++++------- virt/kvm/kvm_main.c | 28 ++++++++++++++++------------ 2 files changed, 46 insertions(+), 19 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 315cf4b5f262..af651540ee45 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -898,7 +898,14 @@ struct nested_vmx { #define POSTED_INTR_ON 0 #define POSTED_INTR_SN 1 -/* Posted-Interrupt Descriptor */ +/* + * Posted-Interrupt Descriptor + * + * Note, the physical address of this structure is used by VMX. Furthermore, the + * translation code assumes that the entire pi_desc struct resides within a + * single page, which will be true because the struct is 64 bytes and 64-byte + * aligned. + */ struct pi_desc { u32 pir[8]; /* Posted interrupt requested */ union { @@ -6633,6 +6640,14 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) } if (kvm_vcpu_apicv_active(&vmx->vcpu)) { + /* + * Note, pi_desc is contained within a single + * page because the struct is 64 bytes and 64-byte aligned. + */ + phys_addr_t pi_desc_phys = + page_to_phys(vmalloc_to_page(&vmx->pi_desc)) + + (u64)&vmx->pi_desc % PAGE_SIZE; + vmcs_write64(EOI_EXIT_BITMAP0, 0); vmcs_write64(EOI_EXIT_BITMAP1, 0); vmcs_write64(EOI_EXIT_BITMAP2, 0); @@ -6641,7 +6656,7 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) vmcs_write16(GUEST_INTR_STATUS, 0); vmcs_write16(POSTED_INTR_NV, POSTED_INTR_VECTOR); - vmcs_write64(POSTED_INTR_DESC_ADDR, __pa((&vmx->pi_desc))); + vmcs_write64(POSTED_INTR_DESC_ADDR, pi_desc_phys); } if (!kvm_pause_in_guest(vmx->vcpu.kvm)) { @@ -11494,13 +11509,18 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) kfree(vmx->guest_msrs); kvm_vcpu_uninit(vcpu); kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu); - kmem_cache_free(kvm_vcpu_cache, vmx); + kmem_cache_free(vmx_msr_entry_cache, vmx->msr_autoload.guest.val); + kmem_cache_free(vmx_msr_entry_cache, vmx->msr_autoload.host.val); + vfree(vmx); } static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) { int err; - struct vcpu_vmx *vmx = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL); + struct vcpu_vmx *vmx = + __vmalloc(sizeof(struct vcpu_vmx), + GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT, + PAGE_KERNEL); unsigned long *msr_bitmap; int cpu; @@ -11620,7 +11640,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) free_fpu: kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu); free_partial_vcpu: - kmem_cache_free(kvm_vcpu_cache, vmx); + vfree(vmx); return ERR_PTR(err); } @@ -15231,8 +15251,11 @@ static int __init vmx_init(void) } #endif - r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx), - __alignof__(struct vcpu_vmx), THIS_MODULE); + /* + * Disable kmem cache; vmalloc will be used instead + * to avoid OOM'ing when memory is available but not contiguous. + */ + r = kvm_init(&vmx_x86_ops, 0, 0, THIS_MODULE); if (r) return r; /* diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 786ade1843a2..8b979e7c3ecd 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4038,18 +4038,22 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, goto out_free_2; register_reboot_notifier(&kvm_reboot_notifier); - /* A kmem cache lets us meet the alignment requirements of fx_save. */ - if (!vcpu_align) - vcpu_align = __alignof__(struct kvm_vcpu); - kvm_vcpu_cache = - kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align, - SLAB_ACCOUNT, - offsetof(struct kvm_vcpu, arch), - sizeof_field(struct kvm_vcpu, arch), - NULL); - if (!kvm_vcpu_cache) { - r = -ENOMEM; - goto out_free_3; + /* + * When vcpu_size is zero, + * architecture-specific code manages its own vcpu allocation. + */ + kvm_vcpu_cache = NULL; + if (vcpu_size) { + if (!vcpu_align) + vcpu_align = __alignof__(struct kvm_vcpu); + kvm_vcpu_cache = kmem_cache_create_usercopy( + "kvm_vcpu", vcpu_size, vcpu_align, SLAB_ACCOUNT, + offsetof(struct kvm_vcpu, arch), + sizeof_field(struct kvm_vcpu, arch), NULL); + if (!kvm_vcpu_cache) { + r = -ENOMEM; + goto out_free_3; + } } r = kvm_async_pf_init();