From 8d7f958d14fa739c64436d0926bc712eaa63fe14 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>

Date: Wed, 13 Dec 2017 13:38:43 +0100

Subject: [PATCH 12/41] hw/misc: add vmcoreinfo device

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RH-Author: Marc-André Lureau <marcandre.lureau@redhat.com>

Message-id: <20171213133912.26176-13-marcandre.lureau@redhat.com>

Patchwork-id: 78362

O-Subject: [RHEL-7.5 qemu-kvm PATCH v3 12/41] hw/misc: add vmcoreinfo device

Bugzilla: 1411490

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

See docs/specs/vmcoreinfo.txt for details.

"etc/vmcoreinfo" fw_cfg entry is added when using "-device vmcoreinfo".

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

(cherry picked from commit 6e43353f10c6688060af0bc26bdfdd4cf9c96ea2)

RHEL: adapted to qemu 1.5 API.

FWCfgState is not exposed, use object_property_get_bool() instead.

DeviceClass.hotpluggable doesn't exist. Not important since libvirt

shouldn't allow or do 'device_add vmcoreinfo'.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 docs/specs/vmcoreinfo.txt    | 41 +++++++++++++++++++

 hw/misc/Makefile.objs        |  1 +

 hw/misc/vmcoreinfo.c         | 96 ++++++++++++++++++++++++++++++++++++++++++++

 include/hw/misc/vmcoreinfo.h | 46 +++++++++++++++++++++

 4 files changed, 184 insertions(+)

 create mode 100644 docs/specs/vmcoreinfo.txt

 create mode 100644 hw/misc/vmcoreinfo.c

 create mode 100644 include/hw/misc/vmcoreinfo.h

diff --git a/docs/specs/vmcoreinfo.txt b/docs/specs/vmcoreinfo.txt

new file mode 100644

index 0000000..2868a77

--- /dev/null

+++ b/docs/specs/vmcoreinfo.txt

@@ -0,0 +1,41 @@

+=================

+VMCoreInfo device

+=================

+

+The `-device vmcoreinfo` will create a fw_cfg entry for a guest to

+store dump details.

+

+etc/vmcoreinfo

+**************

+

+A guest may use this fw_cfg entry to add information details to qemu

+dumps.

+

+The entry of 16 bytes has the following layout, in little-endian::

+

+#define VMCOREINFO_FORMAT_NONE 0x0

+#define VMCOREINFO_FORMAT_ELF 0x1

+

+    struct FWCfgVMCoreInfo {

+        uint16_t host_format;  /* formats host supports */

+        uint16_t guest_format; /* format guest supplies */

+        uint32_t size;         /* size of vmcoreinfo region */

+        uint64_t paddr;        /* physical address of vmcoreinfo region */

+    };

+

+Only full write (of 16 bytes) are considered valid for further

+processing of entry values.

+

+A write of 0 in guest_format will disable further processing of

+vmcoreinfo entry values & content.

+

+Format & content

+****************

+

+As of qemu 2.11, only VMCOREINFO_FORMAT_ELF is supported.

+

+The entry gives location and size of an ELF note that is appended in

+qemu dumps.

+

+The note format/class must be of the target bitness and the size must

+be less than 1Mb.

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs

index cd3123b..39b6593 100644

--- a/hw/misc/Makefile.objs

+++ b/hw/misc/Makefile.objs

@@ -5,6 +5,7 @@ common-obj-$(CONFIG_ISA_DEBUG) += debugexit.o

 common-obj-$(CONFIG_SGA) += sga.o

 common-obj-$(CONFIG_ISA_TESTDEV) += pc-testdev.o

 common-obj-$(CONFIG_PCI_TESTDEV) += pci-testdev.o

+common-obj-y += vmcoreinfo.o

 obj-$(CONFIG_VMPORT) += vmport.o

diff --git a/hw/misc/vmcoreinfo.c b/hw/misc/vmcoreinfo.c

new file mode 100644

index 0000000..1bf6735

--- /dev/null

+++ b/hw/misc/vmcoreinfo.c

@@ -0,0 +1,96 @@

+/*

+ * Virtual Machine coreinfo device

+ *

+ * Copyright (C) 2017 Red Hat, Inc.

+ *

+ * Authors: Marc-André Lureau <marcandre.lureau@redhat.com>

+ *

+ * This work is licensed under the terms of the GNU GPL, version 2 or later.

+ * See the COPYING file in the top-level directory.

+ *

+ */

+#include "qemu/osdep.h"

+#include "qapi/error.h"

+#include "hw/nvram/fw_cfg.h"

+#include "hw/misc/vmcoreinfo.h"

+

+static void fw_cfg_vmci_write(void *dev, off_t offset, size_t len)

+{

+    VMCoreInfoState *s = VMCOREINFO(dev);

+

+    s->has_vmcoreinfo = offset == 0 && len == sizeof(s->vmcoreinfo)

+        && s->vmcoreinfo.guest_format != VMCOREINFO_FORMAT_NONE;

+}

+

+static void vmcoreinfo_reset(void *dev)

+{

+    VMCoreInfoState *s = VMCOREINFO(dev);

+

+    s->has_vmcoreinfo = false;

+    memset(&s->vmcoreinfo, 0, sizeof(s->vmcoreinfo));

+    s->vmcoreinfo.host_format = cpu_to_le16(VMCOREINFO_FORMAT_ELF);

+}

+

+static void vmcoreinfo_realize(DeviceState *dev, Error **errp)

+{

+    VMCoreInfoState *s = VMCOREINFO(dev);

+    FWCfgState *fw_cfg = fw_cfg_find();

+

+    /* Given that this function is executing, there is at least one VMCOREINFO

+     * device. Check if there are several.

+     */

+    if (!vmcoreinfo_find()) {

+        error_setg(errp, "at most one %s device is permitted",

+                   VMCOREINFO_DEVICE);

+        return;

+    }

+

+    if (!fw_cfg || !object_property_get_bool(OBJECT(fw_cfg), "dma_enabled", NULL)) {

+        error_setg(errp, "%s device requires fw_cfg with DMA",

+                   VMCOREINFO_DEVICE);

+        return;

+    }

+

+    fw_cfg_add_file_callback(fw_cfg, "etc/vmcoreinfo",

+                             NULL, fw_cfg_vmci_write, s,

+                             &s->vmcoreinfo, sizeof(s->vmcoreinfo),

+                             false);

+

+    qemu_register_reset(vmcoreinfo_reset, dev);

+}

+

+static const VMStateDescription vmstate_vmcoreinfo = {

+    .name = "vmcoreinfo",

+    .version_id = 1,

+    .minimum_version_id = 1,

+    .fields = (VMStateField[]) {

+        VMSTATE_BOOL(has_vmcoreinfo, VMCoreInfoState),

+        VMSTATE_UINT16(vmcoreinfo.host_format, VMCoreInfoState),

+        VMSTATE_UINT16(vmcoreinfo.guest_format, VMCoreInfoState),

+        VMSTATE_UINT32(vmcoreinfo.size, VMCoreInfoState),

+        VMSTATE_UINT64(vmcoreinfo.paddr, VMCoreInfoState),

+        VMSTATE_END_OF_LIST()

+    },

+};

+

+static void vmcoreinfo_device_class_init(ObjectClass *klass, void *data)

+{

+    DeviceClass *dc = DEVICE_CLASS(klass);

+

+    dc->vmsd = &vmstate_vmcoreinfo;

+    dc->realize = vmcoreinfo_realize;

+}

+

+static const TypeInfo vmcoreinfo_device_info = {

+    .name          = VMCOREINFO_DEVICE,

+    .parent        = TYPE_DEVICE,

+    .instance_size = sizeof(VMCoreInfoState),

+    .class_init    = vmcoreinfo_device_class_init,

+};

+

+static void vmcoreinfo_register_types(void)

+{

+    type_register_static(&vmcoreinfo_device_info);

+}

+

+type_init(vmcoreinfo_register_types)

diff --git a/include/hw/misc/vmcoreinfo.h b/include/hw/misc/vmcoreinfo.h

new file mode 100644

index 0000000..c3aa856

--- /dev/null

+++ b/include/hw/misc/vmcoreinfo.h

@@ -0,0 +1,46 @@

+/*

+ * Virtual Machine coreinfo device

+ *

+ * Copyright (C) 2017 Red Hat, Inc.

+ *

+ * Authors: Marc-André Lureau <marcandre.lureau@redhat.com>

+ *

+ * This work is licensed under the terms of the GNU GPL, version 2 or later.

+ * See the COPYING file in the top-level directory.

+ *

+ */

+#ifndef VMCOREINFO_H

+#define VMCOREINFO_H

+

+#include "hw/qdev.h"

+

+#define VMCOREINFO_DEVICE "vmcoreinfo"

+#define VMCOREINFO(obj) OBJECT_CHECK(VMCoreInfoState, (obj), VMCOREINFO_DEVICE)

+

+#define VMCOREINFO_FORMAT_NONE 0x0

+#define VMCOREINFO_FORMAT_ELF 0x1

+

+/* all fields are little-endian */

+typedef struct FWCfgVMCoreInfo {

+    uint16_t host_format; /* set on reset */

+    uint16_t guest_format;

+    uint32_t size;

+    uint64_t paddr;

+} QEMU_PACKED FWCfgVMCoreInfo;

+

+typedef struct VMCoreInfoState {

+    DeviceClass parent_obj;

+

+    bool has_vmcoreinfo;

+    FWCfgVMCoreInfo vmcoreinfo;

+} VMCoreInfoState;

+

+/* returns NULL unless there is exactly one device */

+static inline VMCoreInfoState *vmcoreinfo_find(void)

+{

+    Object *o = object_resolve_path_type("", VMCOREINFO_DEVICE, NULL);

+

+    return o ? VMCOREINFO(o) : NULL;

+}

+

+#endif

-- 

1.8.3.1