[CRIU] [PATCH] x86/crtools: do not error when YMM is missing

[Cyrill Gorcunov]

On Tue, Apr 16, 2019 at 03:45:05PM +0800, ning.a.zhang at intel.com wrote:
> From: Zhang Ning <ning.a.zhang at intel.com>
> 
> for Intel Apollo Lake SOC, its cpuinfo and fpu features:
> cpu: x86_family 6 x86_vendor_id GenuineIntel x86_model_id Intel(R) Celeron(R) CPU J3455 @ 1.50GHz
> cpu: fpu: xfeatures_mask 0x11 xsave_size 1088 xsave_size_max 1088 xsaves_size 704
> cpu: fpu: x87 floating point registers     xstate_offsets      0 / 0      xstate_sizes    160 / 160
> 
> this CPU doesn't have AVX registers, YMM feature.
> 
> when CRIU runs on this CPU, it will report dump error:
> Dumping GP/FPU registers for 4888
> Error (criu/arch/x86/crtools.c:362): x86: Corruption in XFEATURE_YMM area (expected 64 but 0 obtained)
> Error (criu/cr-dump.c:1278): Can't infect (pid: 4888) with parasite
> 
> that's because x86/crtools.c will still valid YMM xsave frame, thus fail to dump.
> 
> bypass unsupported feature, to make CRIU runs this kinds of CPUs.
> 
> Cc: Chen Hu <hu1.chen at intel.com>
> Signed-off-by: Zhang Ning <ning.a.zhang at intel.com>

Well, to be honest we never tested celeron series, neither lack of avx support.
Patch looks ok to me though. But requires more testing. Does it passes all
tests on your machine?