Re: [Qemu-devel] [PATCH v8 0/5] fw_cfg: add DMA operations & etc/vmcoreinfo support

[Michael S. Tsirkin]

On Thu, Nov 23, 2017 at 03:02:01PM +0100, Marc-André Lureau wrote:
> Hi,
> 
> This series adds DMA operations support to the qemu fw_cfg kernel
> module and populates "etc/vmcoreinfo" with vmcoreinfo location
> details.
> 
> Note: the support for this entry handling has been merged for upcoming
> qemu release (2.11).

I parked this on vhost branch, part of linux-next.

> v8:
> - fix ltp again: bring back kmalloc() for DMA memory (see "What memory
>   is DMA'able?" limitations in Documentation/DMA-API-HOWTO.txt)
>   Interestingly, it didn't fail when the module was linked in..
> 
> v7:
> - add a patch to fix driver remove()
> - remove DMA operatiom timeout (qemu finishes sync today)
> - synchronize the DMA transfer before reading from CPU
> - removed kmalloc() use static allocation instead
> - drop some r-b tags
> 
> v6:
> - change acpi_acquire_global_lock() error to return EINVAL
>   (instead of EBUSY)
> - replace 0 as pointer argument for NULL
> - add Gabriel r-b/a-b tags
> 
> v5:
> - resent to CC kdump people on the paddr_vmcoreinfo_note() export patch
> 
> v4:
> - export paddr_vmcoreinfo_note() to fix fw_cfg.ko build
> - fix build with !CONFIG_CRASH_CORE
> - replace the unbounded yield() loop with a usleep_range() loop and a
>   200ms timeout
> - do not write vmcoreinfo entry when running the kdump kernel (D. Hatayama)
> - drop the experimental sysfs write support patch from this series
> 
> v3: (thanks kbuild)
> - add "fw_cfg: fix the command line module name" patch
> - fix build of "fw_cfg: add DMA register" with CONFIG_FW_CFG_SYSFS_CMDLINE=y
> - fix 'Wshift-count-overflow'
> 
> v2:
> - use platform device for dma mapping
> - add etc/vmcoreinfo patch
> - some code cleanups
> 
> Marc-André Lureau (5):
>   fw_cfg: fix driver remove
>   fw_cfg: add DMA register
>   fw_cfg: do DMA read operation
>   crash: export paddr_vmcoreinfo_note()
>   fw_cfg: write vmcoreinfo details
> 
>  drivers/firmware/qemu_fw_cfg.c | 283 
> ++++++++++++++++++++++++++++++++++++-----
>  kernel/crash_core.c            |   1 +
>  2 files changed, 254 insertions(+), 30 deletions(-)
> 
> -- 
> 2.15.0.277.ga3d2ad2c43