From patchwork Fri Jan 24 15:31:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11350599 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D169924 for ; Fri, 24 Jan 2020 15:33:34 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 79A6320838 for ; Fri, 24 Jan 2020 15:33:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="P81SGzqv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79A6320838 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iv0w4-0006yy-99; Fri, 24 Jan 2020 15:31:52 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iv0w3-0006yi-Nm for xen-devel@lists.xenproject.org; Fri, 24 Jan 2020 15:31:51 +0000 X-Inumbo-ID: 9fb133a6-3ebe-11ea-aecd-bc764e2007e4 Received: from smtp-fw-6001.amazon.com (unknown [52.95.48.154]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 9fb133a6-3ebe-11ea-aecd-bc764e2007e4; Fri, 24 Jan 2020 15:31:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1579879903; x=1611415903; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=oMAppv56KAfQ4kG90bZsQ7GWRcBbT/ckuNqYoVVoRUo=; b=P81SGzqvHUvmMPRxtvUrK4AHgJh4fKhEwVSoOFc/9O7iva1q/rrqiPQV C/PYRKk6Ckxog6JbSYTYe7dQgxUXa4yFhsjQipZUp7C4rzaFgrtvCUGAT d2maKFKUnPzUz8dxV3q/hRRLNRng/wwJnvAs7LYGpvGJUYhMzQxRzK4gR o=; IronPort-SDR: aY36YlnjNi0Jjuto+xQ+UYxvQSo8r/WRRZxXs8VSNuIC3VBYUqNKtH4MfMsCSayOLqtHUIq8bd HmNOXy8ebUag== X-IronPort-AV: E=Sophos;i="5.70,358,1574121600"; d="scan'208";a="14564178" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2a-53356bf6.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6001.iad6.amazon.com with ESMTP; 24 Jan 2020 15:31:41 +0000 Received: from EX13MTAUEA002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2a-53356bf6.us-west-2.amazon.com (Postfix) with ESMTPS id E029FA2316; Fri, 24 Jan 2020 15:31:40 +0000 (UTC) Received: from EX13D32EUC003.ant.amazon.com (10.43.164.24) by EX13MTAUEA002.ant.amazon.com (10.43.61.77) with Microsoft SMTP Server (TLS) id 15.0.1236.3; Fri, 24 Jan 2020 15:31:28 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13D32EUC003.ant.amazon.com (10.43.164.24) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Fri, 24 Jan 2020 15:31:26 +0000 Received: from u2f063a87eabd5f.cbg10.amazon.com (10.125.106.135) by mail-relay.amazon.com (10.43.161.249) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Fri, 24 Jan 2020 15:31:24 +0000 From: Paul Durrant To: Date: Fri, 24 Jan 2020 15:31:02 +0000 Message-ID: <20200124153103.18321-7-pdurrant@amazon.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200124153103.18321-1-pdurrant@amazon.com> References: <20200124153103.18321-1-pdurrant@amazon.com> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v4 6/7] x86 / vmx: use a MEMF_no_refcount domheap page for APIC_DEFAULT_PHYS_BASE X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Kevin Tian , Jun Nakajima , Wei Liu , Andrew Cooper , Paul Durrant , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" vmx_alloc_vlapic_mapping() currently contains some very odd looking code that allocates a MEMF_no_owner domheap page and then shares with the guest as if it were a xenheap page. This then requires vmx_free_vlapic_mapping() to call a special function in the mm code: free_shared_domheap_page(). By using a MEMF_no_refcount domheap page instead, the odd looking code in vmx_alloc_vlapic_mapping() can simply use get_page_and_type() to set up a writable mapping before insertion in the P2M and vmx_free_vlapic_mapping() can simply release the page using put_page_alloc_ref() followed by put_page_and_type(). This then allows free_shared_domheap_page() to be purged. Signed-off-by: Paul Durrant Reviewed-by: Jan Beulich --- Cc: Jun Nakajima Cc: Kevin Tian Cc: Jan Beulich Cc: Andrew Cooper Cc: Wei Liu Cc: "Roger Pau Monné" v4: - Use a MEMF_no_refcount page rather than a 'normal' page v2: - Set an initial value for max_pages rather than avoiding the check in assign_pages() - Make domain_destroy() optional --- xen/arch/x86/hvm/vmx/vmx.c | 21 ++++++++++++++++++--- xen/arch/x86/mm.c | 10 ---------- xen/include/asm-x86/mm.h | 2 -- 3 files changed, 18 insertions(+), 15 deletions(-) diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 606f3dc2eb..7423d2421b 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -3028,12 +3028,22 @@ static int vmx_alloc_vlapic_mapping(struct domain *d) if ( !cpu_has_vmx_virtualize_apic_accesses ) return 0; - pg = alloc_domheap_page(d, MEMF_no_owner); + pg = alloc_domheap_page(d, MEMF_no_refcount); if ( !pg ) return -ENOMEM; + + if ( !get_page_and_type(pg, d, PGT_writable_page) ) + { + /* + * The domain can't possibly know about this page yet, so failure + * here is a clear indication of something fishy going on. + */ + domain_crash(d); + return -ENODATA; + } + mfn = page_to_mfn(pg); clear_domain_page(mfn); - share_xen_page_with_guest(pg, d, SHARE_rw); d->arch.hvm.vmx.apic_access_mfn = mfn; return set_mmio_p2m_entry(d, paddr_to_pfn(APIC_DEFAULT_PHYS_BASE), mfn, @@ -3047,7 +3057,12 @@ static void vmx_free_vlapic_mapping(struct domain *d) d->arch.hvm.vmx.apic_access_mfn = _mfn(0); if ( !mfn_eq(mfn, _mfn(0)) ) - free_shared_domheap_page(mfn_to_page(mfn)); + { + struct page_info *pg = mfn_to_page(mfn); + + put_page_alloc_ref(pg); + put_page_and_type(pg); + } } static void vmx_install_vlapic_mapping(struct vcpu *v) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 654190e9e9..2a6d2e8af9 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -496,16 +496,6 @@ void share_xen_page_with_guest(struct page_info *page, struct domain *d, spin_unlock(&d->page_alloc_lock); } -void free_shared_domheap_page(struct page_info *page) -{ - put_page_alloc_ref(page); - if ( !test_and_clear_bit(_PGC_xen_heap, &page->count_info) ) - ASSERT_UNREACHABLE(); - page->u.inuse.type_info = 0; - page_set_owner(page, NULL); - free_domheap_page(page); -} - void make_cr3(struct vcpu *v, mfn_t mfn) { struct domain *d = v->domain; diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h index e75feea15e..036d7ac22f 100644 --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -320,8 +320,6 @@ struct page_info #define maddr_get_owner(ma) (page_get_owner(maddr_to_page((ma)))) -extern void free_shared_domheap_page(struct page_info *page); - #define frame_table ((struct page_info *)FRAMETABLE_VIRT_START) extern unsigned long max_page; extern unsigned long total_pages;