[Xen-devel] [V8 0/4] add xsaves/xrstors support

[Shuai Ruan <shuai.ruan@xxxxxxxxxxxxxxx>]

From: Shuai Ruan <shuai.ruan@xxxxxxxxx>

Changes in v8:
* Address comments form Jan/Andrew:
* Add optimisation in set_msr_xss in patch1.
* Change from black listing feature to white listing in pv_cpuid in patch2.
* Add MSR_IA32_XSS save/restore support in patch2.
* Fix some code errors and coding style errors.

Changes in v7:
* Address comments form Jan/Andrew:
* Move macro XSTATE_FIXUP into patch3.
* Change lazy write to xss_msr in patch1.
* Drop inner set of brackets and stray cast in patch2.
* Move the condition and memcpy() wouldn't into the new called functions in 
patch2.
* Rebase patch4 base on Andrew's"tools/libxc: Improve efficiency of 
xc_cpuid_apply_policy()".
* For no XSS features are currently supported.For leaf 2...63,ecx remain zero 
at 
  the moment in patch4.

Changes in v6:
* Address comments from Jan.
* Rebase the code based on Andrew'patch "xen/x86: Record xsave features in 
c->x86_capabilities".
* Re-split the patch to avoid building errors. Move some func definitions from 
patch1 to patch2.
* Change func name load/save_xsave_states to compress/expand_xsave_states in 
patch2.  
* Add macro to handle redundancy in xrstor.
* Fix some code errors and coding style errors.
* Add some descriptions in commit message.

Changes in v5:
* Address comments from Andrew/Jan,mainly:
* Add lazy writes of the xss_msr.
* Add xsave_area check when save/restore guest.
* Add xsavec support.
* Use word 2 in xen/include/asm-x86/cpufeature.h.
* Fix some code errors.

Changes in v4:
* Address comments from Andrew, mainly:
* No xsaves suporting for pv guest.
* Using xstate_sizes instead of domain_cpuid in hvm_cupid in patch 3.
* Add support for format translation when perform pv guest migration in patch 
2. 
* Fix some code errors.

Changes in v3:
* Address comments from Jan/Konrad
* Change the bits of eax/ebx/ecx/edx passed to guest in patch 4.
* Add code to verify whether host supports xsaves or not in patch 1.

Changes in v2:
* Address comments from Andrew/chao/Jan, mainly:
* Add details information of xsaves/xrstors feature.
* Test migration between xsaves-support machine and none-xsaves-support machine 
* Remove XGETBV1/XSAVEC/XSAVEOPT out of 'else' in patch 3.
* Change macro name XGETBV to XGETBV1 in patch 4.

This patchset enable xsaves/xrstors feature which will be available on 
Intel Skylake and later platform. Like xsave/xrstor, xsaves/xrstors 
feature will save and load processor state from a region of memory called 
XSAVE area. While unlike xsave/xrstor, xsaves/xrstors:

a) use the compacted format only for the extended region 
   of the XSAVE area which saves memory for you;
b) can operate on supervisor state components so the feature
   is prerequisite to support new supervisor state components;
c) execute only if CPL=0. 

Detail hardware spec can be found in chapter 13 (section 13.11 13.12) of the 
Intel SDM [1].

patch1: add basic definition/function to support xsaves
patch2: add xsaves/xrstors support for xen
patch3-4: add xsaves/xrstors support for hvm guest


[1] Intel SDM 
(http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-manual-325462.pdf)

Shuai Ruan (4):
  x86/xsaves: add basic definitions/helpers to support xsaves
  x86/xsaves: enable xsaves/xrstors/xsavec in xen
  x86/xsaves: enable xsaves/xrstors for hvm guest
  libxc: expose xsaves/xgetbv1/xsavec to hvm guest

 tools/libxc/xc_cpuid_x86.c             |  10 +-
 xen/arch/x86/domain.c                  |   7 +
 xen/arch/x86/domctl.c                  |  31 +++-
 xen/arch/x86/hvm/hvm.c                 |  51 ++++++-
 xen/arch/x86/hvm/vmx/vmcs.c            |   5 +-
 xen/arch/x86/hvm/vmx/vmx.c             |  20 +++
 xen/arch/x86/i387.c                    |   4 +
 xen/arch/x86/traps.c                   |   7 +-
 xen/arch/x86/xstate.c                  | 267 +++++++++++++++++++++++++++++----
 xen/include/asm-x86/hvm/vcpu.h         |   1 +
 xen/include/asm-x86/hvm/vmx/vmcs.h     |   4 +
 xen/include/asm-x86/hvm/vmx/vmx.h      |   2 +
 xen/include/asm-x86/msr-index.h        |   2 +
 xen/include/asm-x86/xstate.h           |  15 +-
 xen/include/public/arch-x86/hvm/save.h |   1 +
 15 files changed, 377 insertions(+), 50 deletions(-)

-- 
1.9.1


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