From patchwork Wed Jan 29 17:10:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11356615 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 D46C71398 for ; Wed, 29 Jan 2020 17:12:05 +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 B1A5C206D4 for ; Wed, 29 Jan 2020 17:12:05 +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="KaARy7vT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1A5C206D4 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 1iwqrT-0006Gl-57; Wed, 29 Jan 2020 17:10:43 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iwqrR-0006Ge-O3 for xen-devel@lists.xenproject.org; Wed, 29 Jan 2020 17:10:41 +0000 X-Inumbo-ID: 4713ddca-42ba-11ea-8396-bc764e2007e4 Received: from smtp-fw-6002.amazon.com (unknown [52.95.49.90]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 4713ddca-42ba-11ea-8396-bc764e2007e4; Wed, 29 Jan 2020 17:10:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1580317841; x=1611853841; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=jWP/Kr2Ts6Val7nfm7XrDb112aC13m4+y12u2fDJXsQ=; b=KaARy7vTLYfp5vBk43jmHupeAQ6vwgjwawKNSQJumQ+Zv5fqhW2TC1pC R6sCvrxmXe0tESzSj1KLVH7Ee+ygpkyOtr+8EqgPkRKpLmH6R0QDl2k15 g/z7kCiTI1TCWxPs0i8w+tKLrAJe7lqtgpV1Q1PyJi1XVSlmn382TCTjl I=; IronPort-SDR: XbVbMmymz+1uowdhhbY6U8jhmcQpdc5ySX9IeJrYyl064DrtspWqoDPW8rXtYWyk1KMthrP5fC NdPbChQWiv5g== X-IronPort-AV: E=Sophos;i="5.70,378,1574121600"; d="scan'208";a="13881772" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2c-2225282c.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 29 Jan 2020 17:10:39 +0000 Received: from EX13MTAUEA002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2c-2225282c.us-west-2.amazon.com (Postfix) with ESMTPS id A015AA04F7; Wed, 29 Jan 2020 17:10:38 +0000 (UTC) Received: from EX13D32EUB003.ant.amazon.com (10.43.166.165) by EX13MTAUEA002.ant.amazon.com (10.43.61.77) with Microsoft SMTP Server (TLS) id 15.0.1236.3; Wed, 29 Jan 2020 17:10:38 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13D32EUB003.ant.amazon.com (10.43.166.165) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 29 Jan 2020 17:10:37 +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; Wed, 29 Jan 2020 17:10:34 +0000 From: Paul Durrant To: Date: Wed, 29 Jan 2020 17:10:28 +0000 Message-ID: <20200129171030.1341-2-pdurrant@amazon.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200129171030.1341-1-pdurrant@amazon.com> References: <20200129171030.1341-1-pdurrant@amazon.com> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v7 1/3] x86 / vmx: move teardown from domain_destroy()... 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 , George Dunlap , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" ... to domain_relinquish_resources(). The teardown code frees the APICv page. This does not need to be done late so do it in domain_relinquish_resources() rather than domain_destroy(). Signed-off-by: Paul Durrant Reviewed-by: Kevin Tian --- Cc: Jun Nakajima Cc: Kevin Tian Cc: Jan Beulich Cc: Andrew Cooper Cc: Wei Liu Cc: "Roger Pau Monné" Cc: George Dunlap v4: - New in v4 (disaggregated from v3 patch #3) --- xen/arch/x86/hvm/vmx/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index b262d38a7c..606f3dc2eb 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -419,7 +419,7 @@ static int vmx_domain_initialise(struct domain *d) return 0; } -static void vmx_domain_destroy(struct domain *d) +static void vmx_domain_relinquish_resources(struct domain *d) { if ( !has_vlapic(d) ) return; @@ -2240,7 +2240,7 @@ static struct hvm_function_table __initdata vmx_function_table = { .cpu_up_prepare = vmx_cpu_up_prepare, .cpu_dead = vmx_cpu_dead, .domain_initialise = vmx_domain_initialise, - .domain_destroy = vmx_domain_destroy, + .domain_relinquish_resources = vmx_domain_relinquish_resources, .vcpu_initialise = vmx_vcpu_initialise, .vcpu_destroy = vmx_vcpu_destroy, .save_cpu_ctxt = vmx_save_vmcs_ctxt, From patchwork Wed Jan 29 17:10:29 2020 Content-Type: text/plain; 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Wed, 29 Jan 2020 17:10:37 +0000 From: Paul Durrant To: Date: Wed, 29 Jan 2020 17:10:29 +0000 Message-ID: <20200129171030.1341-3-pdurrant@amazon.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200129171030.1341-1-pdurrant@amazon.com> References: <20200129171030.1341-1-pdurrant@amazon.com> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v7 2/3] mm: make pages allocated with MEMF_no_refcount safe to assign 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: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Paul Durrant , Ian Jackson , Volodymyr Babchuk , =?utf-8?q?Roger_Pau_Monn?= =?utf-8?q?=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Currently it is unsafe to assign a domheap page allocated with MEMF_no_refcount to a domain because the domain't 'tot_pages' will not be incremented, but will be decrement when the page is freed (since free_domheap_pages() has no way of telling that the increment was skipped). This patch allocates a new 'count_info' bit for a PGC_extra flag which is then used to mark pages when alloc_domheap_pages() is called with MEMF_no_refcount. The MEMF_no_refcount is *not* passed through to assign_pages() because it still needs to call domain_adjust_tot_pages() to make sure the domain is appropriately referenced. assign_pages() is accordingly modified to account pages marked with PGC_extra to an 'extra_pages' counter, which is then subtracted from 'tot_pages' before it is checked against 'max_pages', thus avoiding over-allocation errors. NOTE: steal_page() is also modified to decrement extra_pages in the case of a PGC_extra page being stolen from a domain. Also, whilst adding the extra_pages counter into struct domain, make some cosmetic fixes to comments for neighbouring fields. Signed-off-by: Paul Durrant --- Cc: Andrew Cooper Cc: George Dunlap Cc: Ian Jackson Cc: Jan Beulich Cc: Julien Grall Cc: Konrad Rzeszutek Wilk Cc: Stefano Stabellini Cc: Wei Liu Cc: Volodymyr Babchuk Cc: "Roger Pau Monné" v7: - s/PGC_no_refcount/PGC_extra/g - Re-work allocation to account for 'extra' pages, also making it safe to assign PGC_extra pages post-allocation v6: - Add an extra ASSERT into assign_pages() that PGC_no_refcount is not set if MEMF_no_refcount is clear - ASSERT that count_info is 0 in alloc_domheap_pages() and set to PGC_no_refcount rather than ORing v5: - Make sure PGC_no_refcount is set before assign_pages() is called - Don't bother to clear PGC_no_refcount in free_domheap_pages() and drop ASSERT in free_heap_pages() - Don't latch count_info in free_heap_pages() v4: - New in v4 --- xen/arch/x86/mm.c | 5 ++++ xen/common/page_alloc.c | 49 +++++++++++++++++++++++++++++----------- xen/include/asm-arm/mm.h | 5 +++- xen/include/asm-x86/mm.h | 7 ++++-- xen/include/xen/sched.h | 18 ++++++++------- 5 files changed, 60 insertions(+), 24 deletions(-) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index f50c065af3..5b04db8c21 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -4266,6 +4266,11 @@ int steal_page( page_list_del(page, &d->page_list); /* Unlink from original owner. */ + if ( page->count_info & PGC_extra ) + { + ASSERT(d->extra_pages); + d->extra_pages--; + } if ( !(memflags & MEMF_no_refcount) && !domain_adjust_tot_pages(d, -1) ) drop_dom_ref = true; diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 919a270587..a2d69f222a 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -2256,6 +2256,7 @@ int assign_pages( { int rc = 0; unsigned long i; + unsigned int extra_pages = 0; spin_lock(&d->page_alloc_lock); @@ -2267,13 +2268,19 @@ int assign_pages( goto out; } + for ( i = 0; i < (1 << order); i++ ) + if ( pg[i].count_info & PGC_extra ) + extra_pages++; + if ( !(memflags & MEMF_no_refcount) ) { - if ( unlikely((d->tot_pages + (1 << order)) > d->max_pages) ) + unsigned int max_pages = d->max_pages - d->extra_pages - extra_pages; + + if ( unlikely((d->tot_pages + (1 << order)) > max_pages) ) { gprintk(XENLOG_INFO, "Over-allocation for domain %u: " "%u > %u\n", d->domain_id, - d->tot_pages + (1 << order), d->max_pages); + d->tot_pages + (1 << order), max_pages); rc = -E2BIG; goto out; } @@ -2282,13 +2289,17 @@ int assign_pages( get_knownalive_domain(d); } + d->extra_pages += extra_pages; for ( i = 0; i < (1 << order); i++ ) { + unsigned long count_info = pg[i].count_info; + ASSERT(page_get_owner(&pg[i]) == NULL); - ASSERT(!pg[i].count_info); + ASSERT(!(count_info & ~PGC_extra)); page_set_owner(&pg[i], d); smp_wmb(); /* Domain pointer must be visible before updating refcnt. */ - pg[i].count_info = PGC_allocated | 1; + count_info &= PGC_extra; + pg[i].count_info = count_info | PGC_allocated | 1; page_list_add_tail(&pg[i], &d->page_list); } @@ -2314,11 +2325,6 @@ struct page_info *alloc_domheap_pages( if ( memflags & MEMF_no_owner ) memflags |= MEMF_no_refcount; - else if ( (memflags & MEMF_no_refcount) && d ) - { - ASSERT(!(memflags & MEMF_no_refcount)); - return NULL; - } if ( !dma_bitsize ) memflags &= ~MEMF_no_dma; @@ -2331,11 +2337,23 @@ struct page_info *alloc_domheap_pages( memflags, d)) == NULL)) ) return NULL; - if ( d && !(memflags & MEMF_no_owner) && - assign_pages(d, pg, order, memflags) ) + if ( d && !(memflags & MEMF_no_owner) ) { - free_heap_pages(pg, order, memflags & MEMF_no_scrub); - return NULL; + if ( memflags & MEMF_no_refcount ) + { + unsigned long i; + + for ( i = 0; i < (1ul << order); i++ ) + { + ASSERT(!pg[i].count_info); + pg[i].count_info = PGC_extra; + } + } + if ( assign_pages(d, pg, order, memflags & ~MEMF_no_refcount) ) + { + free_heap_pages(pg, order, memflags & MEMF_no_scrub); + return NULL; + } } return pg; @@ -2383,6 +2401,11 @@ void free_domheap_pages(struct page_info *pg, unsigned int order) BUG(); } arch_free_heap_page(d, &pg[i]); + if ( pg[i].count_info & PGC_extra ) + { + ASSERT(d->extra_pages); + d->extra_pages--; + } } drop_dom_ref = !domain_adjust_tot_pages(d, -(1 << order)); diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h index 333efd3a60..7df91280bc 100644 --- a/xen/include/asm-arm/mm.h +++ b/xen/include/asm-arm/mm.h @@ -119,9 +119,12 @@ struct page_info #define PGC_state_offlined PG_mask(2, 9) #define PGC_state_free PG_mask(3, 9) #define page_state_is(pg, st) (((pg)->count_info&PGC_state) == PGC_state_##st) +/* Page is not reference counted */ +#define _PGC_extra PG_shift(10) +#define PGC_extra PG_mask(1, 10) /* Count of references to this frame. */ -#define PGC_count_width PG_shift(9) +#define PGC_count_width PG_shift(10) #define PGC_count_mask ((1UL<count_info&PGC_state) == PGC_state_##st) +/* Page is not reference counted */ +#define _PGC_extra PG_shift(10) +#define PGC_extra PG_mask(1, 10) - /* Count of references to this frame. */ -#define PGC_count_width PG_shift(9) +/* Count of references to this frame. */ +#define PGC_count_width PG_shift(10) #define PGC_count_mask ((1UL< X-Patchwork-Id: 11356613 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 4CE7D13A4 for ; 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29 Jan 2020 17:10:58 +0000 Received: from EX13MTAUEA002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-859fe132.us-west-2.amazon.com (Postfix) with ESMTPS id 6BC24221CF5; Wed, 29 Jan 2020 17:10:57 +0000 (UTC) Received: from EX13D32EUC001.ant.amazon.com (10.43.164.159) by EX13MTAUEA002.ant.amazon.com (10.43.61.77) with Microsoft SMTP Server (TLS) id 15.0.1236.3; Wed, 29 Jan 2020 17:10:45 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13D32EUC001.ant.amazon.com (10.43.164.159) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 29 Jan 2020 17:10:44 +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; Wed, 29 Jan 2020 17:10:41 +0000 From: Paul Durrant To: Date: Wed, 29 Jan 2020 17:10:30 +0000 Message-ID: <20200129171030.1341-4-pdurrant@amazon.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200129171030.1341-1-pdurrant@amazon.com> References: <20200129171030.1341-1-pdurrant@amazon.com> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v7 3/3] 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 , Wei Liu , Andrew Cooper , Paul Durrant , Jun Nakajima , =?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: 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 5b04db8c21..8b290ab3a2 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 06d64d494d..fafb3af46d 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;