Re: [PATCH 1/2] x86: sgx_vepc: extract sgx_vepc_remove_page

Jarkko Sakkinen
2021-09-13T20:34:01Z

On Mon, 2021-09-13 at 09:11 -0400, Paolo Bonzini wrote:
> Windows expects all pages to be in uninitialized state on startup.
> In order to implement this, we will need a ioctl that performs
> EREMOVE on all pages mapped by a /dev/sgx_vepc file descriptor:
> other possibilities, such as closing and reopening the device,
> are racy.

So what makes it racy, and what do mean by racy in this case?

I.e. you have to do open() and mmap(), and munmap() + close()
for removal. Depending on situation that is racy or not...

And is "Windows" more precisely a "Windows guest running in
Linux QEMU host"? It's ambiguous..

/Jarkko