From nobody Sat Nov 1 08:18:04 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1510602726865474.07167908335884; Mon, 13 Nov 2017 11:52:06 -0800 (PST) Received: from localhost ([::1]:56052 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eEKVB-0003bz-Ts for importer@patchew.org; Mon, 13 Nov 2017 14:34:37 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44879) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eEKRl-0000Tv-BK for qemu-devel@nongnu.org; Mon, 13 Nov 2017 14:31:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eEKRk-0002dF-8a for qemu-devel@nongnu.org; Mon, 13 Nov 2017 14:31:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41368) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eEKRk-0002cS-0V for qemu-devel@nongnu.org; Mon, 13 Nov 2017 14:31:04 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 003CFC04D28B; Mon, 13 Nov 2017 19:31:03 +0000 (UTC) Received: from localhost (unknown [10.36.112.13]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3C530857AA; Mon, 13 Nov 2017 19:30:55 +0000 (UTC) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: linux-kernel@vger.kernel.org Date: Mon, 13 Nov 2017 20:29:58 +0100 Message-Id: <20171113192958.22953-6-marcandre.lureau@redhat.com> In-Reply-To: <20171113192958.22953-1-marcandre.lureau@redhat.com> References: <20171113192958.22953-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 13 Nov 2017 19:31:03 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v6 5/5] fw_cfg: write vmcoreinfo details X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , somlo@cmu.edu, qemu-devel@nongnu.org, mst@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" If the "etc/vmcoreinfo" fw_cfg file is present and we are not running the kdump kernel, write the addr/size of the vmcoreinfo ELF note. Signed-off-by: Marc-Andr=C3=A9 Lureau Reviewed-by: Gabriel Somlo --- drivers/firmware/qemu_fw_cfg.c | 87 ++++++++++++++++++++++++++++++++++++++= +++- 1 file changed, 86 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index 2ac4cd869fe6..7a70e7a549f6 100644 --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -35,6 +35,8 @@ #include #include #include +#include +#include =20 MODULE_AUTHOR("Gabriel L. Somlo "); MODULE_DESCRIPTION("QEMU fw_cfg sysfs support"); @@ -59,6 +61,8 @@ MODULE_LICENSE("GPL"); /* fw_cfg "file name" is up to 56 characters (including terminating nul) */ #define FW_CFG_MAX_FILE_PATH 56 =20 +#define VMCOREINFO_FORMAT_ELF 0x1 + /* platform device for dma mapping */ static struct device *dev; =20 @@ -127,7 +131,8 @@ static ssize_t fw_cfg_dma_transfer(void *address, u32 l= ength, u32 control) dma_addr_t dma; ssize_t ret =3D length; enum dma_data_direction dir =3D - (control & FW_CFG_DMA_CTL_READ ? DMA_FROM_DEVICE : 0); + (control & FW_CFG_DMA_CTL_READ ? DMA_FROM_DEVICE : 0) | + (control & FW_CFG_DMA_CTL_WRITE ? DMA_TO_DEVICE : 0); =20 if (address && length) { dma_addr =3D dma_map_single(dev, address, length, dir); @@ -225,6 +230,48 @@ static ssize_t fw_cfg_read_blob(u16 key, return ret; } =20 +#ifdef CONFIG_CRASH_CORE +/* write chunk of given fw_cfg blob (caller responsible for sanity-check) = */ +static ssize_t fw_cfg_write_blob(u16 key, + void *buf, loff_t pos, size_t count) +{ + u32 glk =3D -1U; + acpi_status status; + ssize_t ret =3D count; + + /* If we have ACPI, ensure mutual exclusion against any potential + * device access by the firmware, e.g. via AML methods: + */ + status =3D acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk); + if (ACPI_FAILURE(status) && status !=3D AE_NOT_CONFIGURED) { + /* Should never get here */ + WARN(1, "%s: Failed to lock ACPI!\n", __func__); + memset(buf, 0, count); + return -EINVAL; + } + + mutex_lock(&fw_cfg_dev_lock); + if (pos =3D=3D 0) { + ret =3D fw_cfg_dma_transfer(buf, count, key << 16 + | FW_CFG_DMA_CTL_SELECT + | FW_CFG_DMA_CTL_WRITE); + } else { + iowrite16(fw_cfg_sel_endianness(key), fw_cfg_reg_ctrl); + ret =3D fw_cfg_dma_transfer(NULL, pos, FW_CFG_DMA_CTL_SKIP); + if (ret < 0) + goto end; + ret =3D fw_cfg_dma_transfer(buf, count, FW_CFG_DMA_CTL_WRITE); + } + +end: + mutex_unlock(&fw_cfg_dev_lock); + + acpi_release_global_lock(glk); + + return ret; +} +#endif /* CONFIG_CRASH_CORE */ + /* clean up fw_cfg device i/o */ static void fw_cfg_io_cleanup(void) { @@ -343,6 +390,37 @@ struct fw_cfg_sysfs_entry { struct list_head list; }; =20 +#ifdef CONFIG_CRASH_CORE +static ssize_t write_vmcoreinfo(const struct fw_cfg_file *f) +{ + struct vmci { + __le16 host_format; + __le16 guest_format; + __le32 size; + __le64 paddr; + } __packed; + struct vmci *data; + ssize_t ret; + + data =3D kmalloc(sizeof(struct vmci), GFP_KERNEL | GFP_DMA); + if (!data) + return -ENOMEM; + + /* spare ourself reading host format support for now since we + * don't know what else to format - host may ignore ours + */ + *data =3D (struct vmci) { + .guest_format =3D cpu_to_le16(VMCOREINFO_FORMAT_ELF), + .size =3D cpu_to_le32(VMCOREINFO_NOTE_SIZE), + .paddr =3D cpu_to_le64(paddr_vmcoreinfo_note()) + }; + ret =3D fw_cfg_write_blob(f->select, data, 0, sizeof(struct vmci)); + + kfree(data); + return ret; +} +#endif /* CONFIG_CRASH_CORE */ + /* get fw_cfg_sysfs_entry from kobject member */ static inline struct fw_cfg_sysfs_entry *to_entry(struct kobject *kobj) { @@ -582,6 +660,13 @@ static int fw_cfg_register_file(const struct fw_cfg_fi= le *f) int err; struct fw_cfg_sysfs_entry *entry; =20 +#ifdef CONFIG_CRASH_CORE + if (strcmp(f->name, "etc/vmcoreinfo") =3D=3D 0 && !is_kdump_kernel()) { + if (write_vmcoreinfo(f) < 0) + pr_warn("fw_cfg: failed to write vmcoreinfo"); + } +#endif + /* allocate new entry */ entry =3D kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) --=20 2.15.0.125.g8f49766d64