From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38952) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e9YLP-0001Fq-Ba for qemu-devel@nongnu.org; Tue, 31 Oct 2017 11:20:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e9YLO-0000s2-8d for qemu-devel@nongnu.org; Tue, 31 Oct 2017 11:20:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46364) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e9YLN-0000rY-WE for qemu-devel@nongnu.org; Tue, 31 Oct 2017 11:20:46 -0400 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Tue, 31 Oct 2017 16:19:38 +0100 Message-Id: <20171031151938.14982-6-marcandre.lureau@redhat.com> In-Reply-To: <20171031151938.14982-1-marcandre.lureau@redhat.com> References: <20171031151938.14982-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v4 5/5] fw_cfg: write vmcoreinfo details List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: linux-kernel@vger.kernel.org Cc: somlo@cmu.edu, qemu-devel@nongnu.org, mst@redhat.com, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= 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 --- 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_cf= g.c index 8ce5e49b7c62..ebd9bb134900 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= length, 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 -EBUSY; + } + + 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(0, 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_= file *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.rc0.40.gaefcc5f6f