From patchwork Tue Feb 15 08:23:37 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 83215 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 696BCB6F12 for ; Tue, 15 Feb 2011 19:46:00 +1100 (EST) Received: from localhost ([127.0.0.1]:46813 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PpGXl-00051s-G1 for incoming@patchwork.ozlabs.org; Tue, 15 Feb 2011 03:45:57 -0500 Received: from [140.186.70.92] (port=44510 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PpGD2-00066y-Cy for qemu-devel@nongnu.org; Tue, 15 Feb 2011 03:25:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PpGCF-0004F8-9X for qemu-devel@nongnu.org; Tue, 15 Feb 2011 03:23:44 -0500 Received: from goliath.siemens.de ([192.35.17.28]:21267) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PpGCE-0004Ed-Uo for qemu-devel@nongnu.org; Tue, 15 Feb 2011 03:23:43 -0500 Received: from mail1.siemens.de (localhost [127.0.0.1]) by goliath.siemens.de (8.13.6/8.13.6) with ESMTP id p1F8NdJv011897; Tue, 15 Feb 2011 09:23:39 +0100 Received: from mchn199C.mchp.siemens.de ([139.25.246.60]) by mail1.siemens.de (8.13.6/8.13.6) with ESMTP id p1F8Nb0x027686; Tue, 15 Feb 2011 09:23:39 +0100 From: Jan Kiszka To: Avi Kivity , Marcelo Tosatti Date: Tue, 15 Feb 2011 09:23:37 +0100 Message-Id: <9edbfeecbb577d7db970e0a21d7e5444e331184f.1297758211.git.jan.kiszka@siemens.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: References: In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 192.35.17.28 Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, Huang Ying Subject: [Qemu-devel] [PATCH 13/13] 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 --- 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 8eda78b..45e366a 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 *hvaddr) hardware_memory_error(); } } + kvm_hwpoison_page_add(ram_addr); kvm_mce_inject(env, gpaddr, code); } else #endif /* KVM_CAP_MCE */ @@ -263,6 +297,7 @@ int kvm_arch_on_sigbus(int code, void *hvaddr) "QEMU itself instead of guest system!: %p\n", hvaddr); return 0; } + kvm_hwpoison_page_add(ram_addr); kvm_mce_inject(first_cpu, gpaddr, code); } else #endif /* KVM_CAP_MCE */ @@ -577,6 +612,7 @@ 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; }