Re: [PATCH] [kvm-unit-tests PATCH] x86/access: Fix intermittent test failure

[Paolo Bonzini <pbonzini@redhat.com>]

On 09/04/21 09:55, Yang Weijiang wrote:
> During kvm-unit-test, below failure pattern is observed, this is due to testing thread
> migration + cache "lazy" flush during test, so forcely flush the cache to avoid the issue.
> Pin the test app to certain physical CPU can fix the issue as well. The error report is
> misleading, pke is the victim of the issue.
> 
> test user cr4.pke: FAIL: error code 5 expected 4
> Dump mapping: address: 0x123400000000
> ------L4: 21ea007
> ------L3: 21eb007
> ------L2: 21ec000
> ------L1: 2000000
> 
> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
> ---
>   x86/access.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/x86/access.c b/x86/access.c
> index 7dc9eb6..379d533 100644
> --- a/x86/access.c
> +++ b/x86/access.c
> @@ -211,6 +211,8 @@ static unsigned set_cr4_smep(int smep)
>           ptl2[2] |= PT_USER_MASK;
>       if (!r)
>           shadow_cr4 = cr4;
> +
> +    invlpg((void *)(ptl2[2] & ~PAGE_SIZE));
>       return r;
>   }
>   
> 

Applied, thanks.

Paolo