On 11/10/13 15:11, 李德新 wrote:
Hi,
      page->tlbflush_timestamp is used to filter and flush the TLB whenever type change of page happens. But why does xen flush TLB upon the type change? And we already know that guest kernel will flush the TLB in order to make the page table modifications take effect.
     
      Thanks!

Best regards,
Sam

The comment beside the code you reference explains why this is required for safety.

On a more pragmatic view however, there is no Xen can trust that guest kernels are operating correctly.

~Andrew