Messages in this thread | | | Date | Tue, 22 Sep 2020 17:03:23 +0300 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH v38 16/24] x86/sgx: Add a page reclaimer |
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On Tue, Sep 22, 2020 at 12:45:38PM +0200, Borislav Petkov wrote: > > + * %SGX_ENCL_PAGE_VA_OFFSET_MASK: Holds the offset in the Version Array > > + * (VA) page for a swapped page. > > * %SGX_ENCL_PAGE_ADDR_MASK: Holds the virtual address of the page. > > * > > * The page address for SECS is zero and is used by the subsystem to recognize > > ...
So what's wrong over here?
> > @@ -86,24 +123,34 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) > > { > > unsigned long encl_size = secs->size + PAGE_SIZE; > > struct sgx_epc_page *secs_epc; > > + struct sgx_va_page *va_page; > > struct sgx_pageinfo pginfo; > > struct sgx_secinfo secinfo; > > struct file *backing; > > long ret; > > > > + va_page = sgx_encl_grow(encl); > > + if (IS_ERR(va_page)) > > + return PTR_ERR(va_page); > > + else if (va_page) > > Not "else" simply? > > AFAICT, sgx_encl_grow() would either return an ERR_PTR or the actual > page... > > Also, should the growing happen *after* the SECS validation?
Yes, it would make sense. I'll move it.
> Let's add some comment blurb about "Write back/invalidate an EPC page" > to at least start to explain what that "ewb" is.
OK, I'll try to write something understandable.
> > + spin_lock(&sgx_active_page_list_lock); > > + for (i = 0; i < SGX_NR_TO_SCAN; i++) { > > + if (list_empty(&sgx_active_page_list)) > > Isn't it enough to do this once, i.e., not in the loop? You're holding > sgx_active_page_list_lock...
I think that would make sense. Distantly analogous to the EINIT discussion. Too complex code for yet to be known problem workloads I'd say.
> > static void sgx_sanitize_section(struct sgx_epc_section *section) > > ...
Is this about documenting this function?
> -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette
Thanks, this was valuable feedback.
/Jarkko
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