From patchwork Wed Feb 9 03:00:31 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Ying" X-Patchwork-Id: 82426 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 AB3ABB7123 for ; Wed, 9 Feb 2011 14:02:41 +1100 (EST) Received: from localhost ([127.0.0.1]:49340 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pn0KE-0006RA-OM for incoming@patchwork.ozlabs.org; Tue, 08 Feb 2011 22:02:38 -0500 Received: from [140.186.70.92] (port=50238 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pn0II-0005hw-SS for qemu-devel@nongnu.org; Tue, 08 Feb 2011 22:00:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Pn0IH-0006KN-Ku for qemu-devel@nongnu.org; Tue, 08 Feb 2011 22:00:38 -0500 Received: from mga11.intel.com ([192.55.52.93]:13732) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Pn0IH-0006KF-B9 for qemu-devel@nongnu.org; Tue, 08 Feb 2011 22:00:37 -0500 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP; 08 Feb 2011 19:00:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.60,445,1291622400"; d="scan'208";a="885703242" Received: from yhuang-dev.sh.intel.com (HELO [10.239.13.107]) ([10.239.13.107]) by fmsmga001.fm.intel.com with ESMTP; 08 Feb 2011 19:00:34 -0800 From: Huang Ying To: Avi Kivity , Marcelo Tosatti , Anthony Liguori Date: Wed, 09 Feb 2011 11:00:31 +0800 Message-ID: <1297220431.5180.15.camel@yhuang-dev> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 Cc: Dean Nelson , Andi Kleen , Jan Kiszka , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" Subject: [Qemu-devel] [PATCH uq/master -v2 2/2] 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 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. Signed-off-by: Huang Ying --- target-i386/kvm.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -508,6 +508,42 @@ static int kvm_get_supported_msrs(KVMSta return ret; } +struct HWPoisonPage; +typedef struct HWPoisonPage HWPoisonPage; +struct HWPoisonPage +{ + ram_addr_t ram_addr; + QLIST_ENTRY(HWPoisonPage) list; +}; + +static QLIST_HEAD(hwpoison_page_list, 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); + } +} + +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); +} + int kvm_arch_init(KVMState *s) { uint64_t identity_base = 0xfffbc000; @@ -556,6 +592,7 @@ 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; } @@ -1882,6 +1919,7 @@ int kvm_arch_on_sigbus_vcpu(CPUState *en hardware_memory_error(); } } + kvm_hwpoison_page_add(ram_addr); if (code == BUS_MCEERR_AR) { /* Fake an Intel architectural Data Load SRAR UCR */ @@ -1926,6 +1964,7 @@ int kvm_arch_on_sigbus(int code, void *a "QEMU itself instead of guest system!: %p\n", addr); return 0; } + kvm_hwpoison_page_add(ram_addr); kvm_mce_inj_srao_memscrub2(first_cpu, paddr); } else #endif