From patchwork Wed Aug 1 16:19:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Baron X-Patchwork-Id: 174523 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E49122C0CCD for ; Thu, 2 Aug 2012 02:19:52 +1000 (EST) Received: from localhost ([::1]:44409 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwbeH-0004pA-Fw for incoming@patchwork.ozlabs.org; Wed, 01 Aug 2012 12:19:49 -0400 Received: from eggs.gnu.org ([208.118.235.92]:50122) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swbe5-0004oL-Gt for qemu-devel@nongnu.org; Wed, 01 Aug 2012 12:19:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Swbdz-0005o1-FW for qemu-devel@nongnu.org; Wed, 01 Aug 2012 12:19:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14182) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swbdz-0005nq-7n for qemu-devel@nongnu.org; Wed, 01 Aug 2012 12:19:31 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q71GJTBs026450 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 1 Aug 2012 12:19:29 -0400 Received: from redhat.com (dhcp-185-114.bos.redhat.com [10.16.185.114]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q71GJSqg017150; Wed, 1 Aug 2012 12:19:28 -0400 Date: Wed, 1 Aug 2012 12:19:28 -0400 From: Jason Baron Message-Id: <201208011619.q71GJSqg017150@int-mx01.intmail.prod.int.phx2.redhat.com> To: avi@redhat.com, anthony@codemonkey.ws, eblake@redhat.com X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: mtosatti@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH v2] memory: add cmd line option, to omit guest memory from qemu core dump X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Add a new '[,dump_guest_core=on|off]' option to the '-machine' option. When 'dump_guest_core=off' is specified, guest memory is omitted from the core dump. The default behavior continues to be to include guest memory when a core dump is triggered. In my testing, this brought the core dump size down from 384MB to 6MB on a 2GB guest. Changelog: v2: move the option from -m to -machine, rename option dump -> dump_guest_core Signed-off-by: Jason Baron --- exec.c | 13 +++++++++++++ osdep.h | 7 +++++++ qemu-config.c | 4 ++++ qemu-options.hx | 5 ++++- sysemu.h | 1 + vl.c | 4 ++++ 6 files changed, 33 insertions(+), 1 deletions(-) diff --git a/exec.c b/exec.c index feb4795..0764818 100644 --- a/exec.c +++ b/exec.c @@ -35,6 +35,7 @@ #include "qemu-timer.h" #include "memory.h" #include "exec-memory.h" +#include "sysemu.h" #if defined(CONFIG_USER_ONLY) #include #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) @@ -2514,6 +2515,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, MemoryRegion *mr) { RAMBlock *new_block; + int ret; size = TARGET_PAGE_ALIGN(size); new_block = g_malloc0(sizeof(*new_block)); @@ -2555,6 +2557,17 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, last_ram_offset() >> TARGET_PAGE_BITS); cpu_physical_memory_set_dirty_range(new_block->offset, size, 0xff); + + /* Use MADV_DONTDUMP, if user doesn't want the guest memory in the core */ + if (dont_dump_guest_core) { + ret = qemu_madvise(new_block->host, size, QEMU_MADV_DONTDUMP); + if (ret) { + perror("qemu_madvise"); + fprintf(stderr, "madvise doesn't support MADV_DONTDUMP, " + "but dump_guest_core=off specified\n"); + } + } + if (kvm_enabled()) kvm_setup_guest_memory(new_block->host, size); diff --git a/osdep.h b/osdep.h index 1e15a4b..e2d0f57 100644 --- a/osdep.h +++ b/osdep.h @@ -102,6 +102,11 @@ void qemu_vfree(void *ptr); #else #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID #endif +#ifdef MADV_DONTDUMP +#define QEMU_MADV_DONTDUMP MADV_DONTDUMP +#else +#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID +#endif #elif defined(CONFIG_POSIX_MADVISE) @@ -109,6 +114,7 @@ void qemu_vfree(void *ptr); #define QEMU_MADV_DONTNEED POSIX_MADV_DONTNEED #define QEMU_MADV_DONTFORK QEMU_MADV_INVALID #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID +#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID #else /* no-op */ @@ -116,6 +122,7 @@ void qemu_vfree(void *ptr); #define QEMU_MADV_DONTNEED QEMU_MADV_INVALID #define QEMU_MADV_DONTFORK QEMU_MADV_INVALID #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID +#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID #endif diff --git a/qemu-config.c b/qemu-config.c index 5c3296b..5c2c9a9 100644 --- a/qemu-config.c +++ b/qemu-config.c @@ -595,6 +595,10 @@ static QemuOptsList qemu_machine_opts = { .name = "dt_compatible", .type = QEMU_OPT_STRING, .help = "Overrides the \"compatible\" property of the dt root node", + }, { + .name = "dump_guest_core", + .type = QEMU_OPT_BOOL, + .help = "Include guest memory in a core dump", }, { /* End of list */ } }, diff --git a/qemu-options.hx b/qemu-options.hx index dc68e15..e917829 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -33,7 +33,8 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ " property accel=accel1[:accel2[:...]] selects accelerator\n" " supported accelerators are kvm, xen, tcg (default: tcg)\n" " kernel_irqchip=on|off controls accelerated irqchip support\n" - " kvm_shadow_mem=size of KVM shadow MMU\n", + " kvm_shadow_mem=size of KVM shadow MMU\n" + " dump_guest_core=on|off include guest memory in a core dump (default=on)\n", QEMU_ARCH_ALL) STEXI @item -machine [type=]@var{name}[,prop=@var{value}[,...]] @@ -50,6 +51,8 @@ to initialize. Enables in-kernel irqchip support for the chosen accelerator when available. @item kvm_shadow_mem=size Defines the size of the KVM shadow MMU. +@item dump_guest_core=on|off +Include guest memory in a core dump. The default is on. @end table ETEXI diff --git a/sysemu.h b/sysemu.h index 6540c79..caf33ce 100644 --- a/sysemu.h +++ b/sysemu.h @@ -132,6 +132,7 @@ extern uint8_t *boot_splash_filedata; extern int boot_splash_filedata_size; extern uint8_t qemu_extra_params_fw[2]; extern QEMUClock *rtc_clock; +extern int dont_dump_guest_core; #define MAX_NODES 64 extern int nb_numa_nodes; diff --git a/vl.c b/vl.c index c18bb80..accfd28 100644 --- a/vl.c +++ b/vl.c @@ -226,6 +226,7 @@ int boot_menu; uint8_t *boot_splash_filedata; int boot_splash_filedata_size; uint8_t qemu_extra_params_fw[2]; +int dont_dump_guest_core; typedef struct FWBootEntry FWBootEntry; @@ -2976,6 +2977,9 @@ int main(int argc, char **argv, char **envp) if (optarg) { machine = machine_parse(optarg); } + if (!qemu_opt_get_bool(opts, "dump_guest_core", true)) { + dont_dump_guest_core = 1; + } break; case QEMU_OPTION_usb: usb_enabled = 1;