From patchwork Tue Mar 15 21:50:31 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 87125 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 448CAB725B for ; Wed, 16 Mar 2011 10:22:27 +1100 (EST) Received: from localhost ([127.0.0.1]:38438 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PzclM-00053G-By for incoming@patchwork.ozlabs.org; Tue, 15 Mar 2011 18:30:48 -0400 Received: from [140.186.70.92] (port=54947 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PzcCn-0006Im-Mz for qemu-devel@nongnu.org; Tue, 15 Mar 2011 17:57:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PzcB7-0003Qc-0r for qemu-devel@nongnu.org; Tue, 15 Mar 2011 17:55:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34480) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PzcB6-0003Pi-Ju for qemu-devel@nongnu.org; Tue, 15 Mar 2011 17:53:20 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p2FLrJRh016131 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 15 Mar 2011 17:53:19 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p2FLrIeD006189; Tue, 15 Mar 2011 17:53:19 -0400 Received: from amt.cnet (vpn1-5-191.ams2.redhat.com [10.36.5.191]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p2FLrEfI023449; Tue, 15 Mar 2011 17:53:17 -0400 Received: from amt.cnet (amt.cnet [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 9A24E68A068; Tue, 15 Mar 2011 18:52:32 -0300 (BRT) Received: (from marcelo@localhost) by amt.cnet (8.14.4/8.14.4/Submit) id p2FLqSEP002118; Tue, 15 Mar 2011 18:52:28 -0300 From: Marcelo Tosatti To: Anthony Liguori Date: Tue, 15 Mar 2011 18:50:31 -0300 Message-Id: <3c85e74fbf9e5a39d8d13ef91a5f3dd91f0bc8a8.1300225848.git.mtosatti@redhat.com> In-Reply-To: References: X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: Jan Kiszka , Marcelo Tosatti , qemu-devel@nongnu.org, kvm@vger.kernel.org, Huang Ying Subject: [Qemu-devel] [PATCH 17/35] KVM, MCE, unpoison memory address across reboot X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Huang Ying In Linux kernel HWPoison processing implementation, the virtual address in processes mapping the error physical memory page is marked as HWPoison. So that, the further accessing to the virtual address will kill corresponding processes with SIGBUS. If the error physical memory page is used by a KVM guest, the SIGBUS will be sent to QEMU, and QEMU will simulate a MCE to report that memory error to the guest OS. If the guest OS can not recover from the error (for example, the page is accessed by kernel code), guest OS will reboot the system. But because the underlying host virtual address backing the guest physical memory is still poisoned, if the guest system accesses the corresponding guest physical memory even after rebooting, the SIGBUS will still be sent to QEMU and MCE will be simulated. That is, guest system can not recover via rebooting. In fact, across rebooting, the contents of guest physical memory page need not to be kept. We can allocate a new host physical page to back the corresponding guest physical address. This patch fixes this issue in QEMU-KVM via calling qemu_ram_remap() to clear the corresponding page table entry, so that make it possible to allocate a new page to recover the issue. [ Jan: rebasing and tiny cleanups] Signed-off-by: Huang Ying Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- target-i386/kvm.c | 36 ++++++++++++++++++++++++++++++++++++ 1 files changed, 36 insertions(+), 0 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 1574186..f7995bd 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -173,7 +173,40 @@ static int get_para_features(CPUState *env) } #endif /* CONFIG_KVM_PARA */ +typedef struct HWPoisonPage { + ram_addr_t ram_addr; + QLIST_ENTRY(HWPoisonPage) list; +} HWPoisonPage; + +static QLIST_HEAD(, HWPoisonPage) hwpoison_page_list = + QLIST_HEAD_INITIALIZER(hwpoison_page_list); + +static void kvm_unpoison_all(void *param) +{ + HWPoisonPage *page, *next_page; + + QLIST_FOREACH_SAFE(page, &hwpoison_page_list, list, next_page) { + QLIST_REMOVE(page, list); + qemu_ram_remap(page->ram_addr, TARGET_PAGE_SIZE); + qemu_free(page); + } +} + #ifdef KVM_CAP_MCE +static void kvm_hwpoison_page_add(ram_addr_t ram_addr) +{ + HWPoisonPage *page; + + QLIST_FOREACH(page, &hwpoison_page_list, list) { + if (page->ram_addr == ram_addr) { + return; + } + } + page = qemu_malloc(sizeof(HWPoisonPage)); + page->ram_addr = ram_addr; + QLIST_INSERT_HEAD(&hwpoison_page_list, page, list); +} + static int kvm_get_mce_cap_supported(KVMState *s, uint64_t *mce_cap, int *max_banks) { @@ -233,6 +266,7 @@ int kvm_arch_on_sigbus_vcpu(CPUState *env, int code, void *addr) hardware_memory_error(); } } + kvm_hwpoison_page_add(ram_addr); kvm_mce_inject(env, paddr, code); } else #endif /* KVM_CAP_MCE */ @@ -263,6 +297,7 @@ int kvm_arch_on_sigbus(int code, void *addr) "QEMU itself instead of guest system!: %p\n", addr); return 0; } + kvm_hwpoison_page_add(ram_addr); kvm_mce_inject(first_cpu, paddr, code); } else #endif /* KVM_CAP_MCE */ @@ -571,6 +606,7 @@ int kvm_arch_init(KVMState *s) fprintf(stderr, "e820_add_entry() table is full\n"); return ret; } + qemu_register_reset(kvm_unpoison_all, NULL); return 0; }