Re: [V9 0/3] Refactor ioreq server for better performance.

["Yu, Zhang" <yu.c.zhang@linux.intel.com>]

Shuai, thank you very much for helping me push these patches!
And sorry for the delay due to my illness.
Now I'm back and will pick this up. :)

B.R.
Yu

On 12/15/2015 10:05 AM, Shuai Ruan wrote:
> From: Yu Zhang <yu.c.zhang@linux.intel.com>ng the
>
> XenGT leverages ioreq server to track and forward the accesses to
> GPU I/O resources, e.g. the PPGTT(per-process graphic translation
> tables). Currently, ioreq server uses rangeset to track the BDF/
> PIO/MMIO ranges to be emulated. To select an ioreq server, the
> rangeset is searched to see if the I/O range is recorded. However,
> traversing the link list inside rangeset could be time consuming
> when number of ranges is too high. On HSW platform, number of PPGTTs
> for each vGPU could be several hundred. On BDW, this value could
> be several thousand.  This patch series refactored rangeset to base
> it on red-back tree, so that the searching would be more efficient.
>
> Besides, this patchset also splits the tracking of MMIO and guest
> ram ranges into different rangesets. And to accommodate more ranges,
> limitation of the number of ranges in an ioreq server, MAX_NR_IO_RANGES
> is changed - future patches might be provided to tune this with other
> approaches.
>
> Changes in v9:
> 1> Change order of patch 2 and patch3.
> 2> Intruduce a const static array before hvm_ioreq_server_alloc_rangesets().
> 3> Coding style changes.
>
> Changes in v8:
> Use a clearer API name to map/unmap the write-protected memory in
> ioreq server.
>
> Changes in v7:
> 1> Coding style changes;
> 2> Fix a typo in hvm_select_ioreq_server().
>
> Changes in v6:
> Break the identical relationship between ioreq type and rangeset
> index inside ioreq server.
>
> Changes in v5:
> 1> Use gpfn, instead of gpa to track guest write-protected pages;
> 2> Remove redundant conditional statement in routine find_range().
>
> Changes in v4:
> Keep the name HVMOP_IO_RANGE_MEMORY for MMIO resources, and add
> a new one, HVMOP_IO_RANGE_WP_MEM, for write-protected memory.
>
> Changes in v3:
> 1> Use a seperate rangeset for guest ram pages in ioreq server;
> 2> Refactor rangeset, instead of introduce a new data structure.
>
> Changes in v2:
> 1> Split the original patch into 2;
> 2> Take Paul Durrant's comments:
>    a> Add a name member in the struct rb_rangeset, and use the 'q'
> debug key to dump the ranges in ioreq server;
>    b> Keep original routine names for hvm ioreq server;
>    c> Commit message changes - mention that a future patch to change
> the maximum ranges inside ioreq server.
>
>
> Yu Zhang (3):
>    Remove identical relationship between ioreq type and rangeset type.
>    Refactor rangeset structure for better performance.
>    Differentiate IO/mem resources tracked by ioreq server
>
>   tools/libxc/include/xenctrl.h    | 31 +++++++++++++++
>   tools/libxc/xc_domain.c          | 61 ++++++++++++++++++++++++++++++
>   xen/arch/x86/hvm/hvm.c           | 43 ++++++++++++++-------
>   xen/common/rangeset.c            | 82 +++++++++++++++++++++++++++++-----------
>   xen/include/asm-x86/hvm/domain.h |  4 +-
>   xen/include/public/hvm/hvm_op.h  |  1 +
>   6 files changed, 185 insertions(+), 37 deletions(-)
>