| Message ID | 33710E6CAA200E4583255F4FB666C4E21B11A378@G01JPEXMBYT03 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Oct 30, 2017 at 10:44 AM, Hatayama, Daisuke < d.hatayama@jp.fujitsu.com> wrote: > Resend because the mail address for LKML was wrong in the previous mail... > > Marc-Andre, > > Sorry, I missed your original mails from my local data, so I'm replying > this mail as a new thread... > > > From: Marc-Andre Lureau <marcandre.lureau@redhat.com> > > > > If the "etc/vmcoreinfo" file is present, write the addr/size of the > > vmcoreinfo ELF note. > > > > Signed-off-by: Marc-Andre Lureau <marcandre.lureau@redhat.com> > > --- > > drivers/firmware/qemu_fw_cfg.c | 80 ++++++++++++++++++++++++++++++ > +++++++++++- > > 1 file changed, 79 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_ > cfg.c > > index 19b4b4d31547..54b569da3257 100644 > > --- a/drivers/firmware/qemu_fw_cfg.c > > +++ b/drivers/firmware/qemu_fw_cfg.c > > @@ -34,6 +34,7 @@ > > #include <linux/io.h> > > #include <linux/ioport.h> > > #include <linux/dma-mapping.h> > > +#include <linux/crash_core.h> > > > > MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>"); > > MODULE_DESCRIPTION("QEMU fw_cfg sysfs support"); > > @@ -57,6 +58,8 @@ MODULE_LICENSE("GPL"); > > /* fw_cfg "file name" is up to 56 characters (including terminating > nul) */ > > #define FW_CFG_MAX_FILE_PATH 56 > > > > +#define VMCOREINFO_FORMAT_ELF 0x1 > > + > > /* platform device for dma mapping */ > > static struct device *dev; > > > > @@ -107,7 +110,8 @@ static ssize_t fw_cfg_dma_transfer(void *address, > u32 length, u32 control) > > dma_addr_t dma; > > ssize_t ret = length; > > enum dma_data_direction dir = > > - (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); > > > > if (address && length) { > > dma_addr = dma_map_single(dev, address, length, dir); > > @@ -203,6 +207,46 @@ static ssize_t fw_cfg_read_blob(u16 key, > > return ret; > > } > > > > +/* 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 = -1U; > > + acpi_status status; > > + ssize_t ret = count; > > + > > + /* If we have ACPI, ensure mutual exclusion against any potential > > + * device access by the firmware, e.g. via AML methods: > > + */ > > + status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk); > > + if (ACPI_FAILURE(status) && status != 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 == 0) { > > + ret = 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 = fw_cfg_dma_transfer(0, pos, FW_CFG_DMA_CTL_SKIP); > > + if (ret < 0) > > + goto end; > > + ret = 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; > > +} > > + > > /* clean up fw_cfg device i/o */ > > static void fw_cfg_io_cleanup(void) > > { > > @@ -321,6 +365,35 @@ struct fw_cfg_sysfs_entry { > > struct list_head list; > > }; > > > > +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 = 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 = (struct vmci) { > > + .guest_format = cpu_to_le16(VMCOREINFO_FORMAT_ELF), > > + .size = cpu_to_le32(VMCOREINFO_NOTE_SIZE), > > + .paddr = cpu_to_le64(paddr_vmcoreinfo_note()) > > + }; > > + ret = fw_cfg_write_blob(f->select, data, 0, sizeof(struct vmci)); > > + > > + kfree(data); > > + return ret; > > +} > > + > > /* get fw_cfg_sysfs_entry from kobject member */ > > static inline struct fw_cfg_sysfs_entry *to_entry(struct kobject *kobj) > > { > > @@ -560,6 +633,11 @@ static int fw_cfg_register_file(const struct > fw_cfg_file *f) > > int err; > > struct fw_cfg_sysfs_entry *entry; > > > > + if (strcmp(f->name, "etc/vmcoreinfo") == 0) { > > + if (write_vmcoreinfo(f) < 0) > > + pr_warn("fw_cfg: failed to write vmcoreinfo"); > > + } > > + > > Here, it's necessary to care for guest machine to be running in the > kdump capture kernel. How about the following patch? Without this, > vmcoreinfo device is reinitialized by the kdump capture kernel, but > what we need is the vmcoreinfo in the system kernel. > > diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_ > cfg.c > index e2f2ad1..d51e4bb 100644 > --- a/drivers/firmware/qemu_fw_cfg.c > +++ b/drivers/firmware/qemu_fw_cfg.c > @@ -35,6 +35,7 @@ > #include <linux/ioport.h> > #include <linux/dma-mapping.h> > #include <linux/crash_core.h> > +#include <linux/crash_dump.h> > > MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>"); > MODULE_DESCRIPTION("QEMU fw_cfg sysfs support"); > @@ -653,6 +654,8 @@ static int fw_cfg_register_file(const struct > fw_cfg_file *f) > struct fw_cfg_sysfs_entry *entry; > > if (strcmp(f->name, "etc/vmcoreinfo") == 0) { > + if (is_kdump_kernel()) > + return 0; > if (write_vmcoreinfo(f) < 0) > pr_warn("fw_cfg: failed to write vmcoreinfo"); > } > > > /* allocate new entry */ > > entry = kzalloc(sizeof(*entry), GFP_KERNEL); > > if (!entry) > That makes sense, I added a similar change in my patch. Michael, do you want me to resubmit the series now or do you have more comments regarding preliminary patches 1 and 2 ? thanks
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index e2f2ad1..d51e4bb 100644 --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -35,6 +35,7 @@ #include <linux/ioport.h> #include <linux/dma-mapping.h> #include <linux/crash_core.h> +#include <linux/crash_dump.h> MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>"); MODULE_DESCRIPTION("QEMU fw_cfg sysfs support"); @@ -653,6 +654,8 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f) struct fw_cfg_sysfs_entry *entry; if (strcmp(f->name, "etc/vmcoreinfo") == 0) { + if (is_kdump_kernel()) + return 0; if (write_vmcoreinfo(f) < 0) pr_warn("fw_cfg: failed to write vmcoreinfo"); }