Re: [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()

[Sean Christopherson]

On Thu, Mar 11, 2021, Kai Huang wrote:
> From: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> 
> EREMOVE takes a page and removes any association between that page and
> an enclave.  It must be run on a page before it can be added into
> another enclave.  Currently, EREMOVE is run as part of pages being freed
> into the SGX page allocator.  It is not expected to fail.
> 
> KVM does not track how guest pages are used, which means that SGX
> virtualization use of EREMOVE might fail.
> 
> Break out the EREMOVE call from the SGX page allocator.  This will allow
> the SGX virtualization code to use the allocator directly.  (SGX/KVM
> will also introduce a more permissive EREMOVE helper).
> 
> Implement original sgx_free_epc_page() as sgx_encl_free_epc_page() to be
> more specific that it is used to free EPC page assigned to one enclave.
> Print an error message when EREMOVE fails to explicitly call out EPC
> page is leaked, and requires machine reboot to get leaked pages back.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Co-developed-by: Kai Huang <kai.huang@xxxxxxxxx>
> Acked-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
> ---
> v2->v3:
> 
>  - Fixed bug during copy/paste which results in SECS page and va pages are not
>    correctly freed in sgx_encl_release() (sorry for the mistake).
>  - Added Jarkko's Acked-by.

That Acked-by should either be dropped or moved above Co-developed-by to make
checkpatch happy.

Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>