On Wed, Jan 13, 2021 at 02:09:17PM +1300, Kai Huang wrote:
> On Wed, 13 Jan 2021 01:33:51 +0200 jarkko@xxxxxxxxxx wrote:
> > From: "jarkko@xxxxxxxxxx" <jarkko@xxxxxxxxxx>
> >
> > Encapsulate the snippet in sgx_free_epc_page() concerning EREMOVE to
> > sgx_reset_epc_page(), which is a static helper function for
> > sgx_encl_release(). It's the only function existing, which deals with
> > initialized pages.
> >
> > Signed-off-by: jarkko@xxxxxxxxxx <jarkko@xxxxxxxxxx>
> > ---
> > v2: Fixed a compilation error s/page/epc_page/ change not amended
> > to the patches.
> > arch/x86/kernel/cpu/sgx/encl.c | 15 ++++++++++++++-
> > arch/x86/kernel/cpu/sgx/main.c | 10 ++++------
> > 2 files changed, 18 insertions(+), 7 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> > index fe7256db6e73..511f4bc70699 100644
> > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > @@ -389,6 +389,16 @@ const struct vm_operations_struct sgx_vm_ops = {
> > .access = sgx_vma_access,
> > };
> >
> > +
> > +static void sgx_reset_epc_page(struct sgx_epc_page *epc_page)
> > +{
> > + int ret;
> > +
> > + ret = __eremove(sgx_get_epc_virt_addr(epc_page));
> > + if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
> > + return;
> > +}
> > +
> > /**
> > * sgx_encl_release - Destroy an enclave instance
> > * @kref: address of a kref inside &sgx_encl
> > @@ -412,6 +422,7 @@ void sgx_encl_release(struct kref *ref)
> > if (sgx_unmark_page_reclaimable(entry->epc_page))
> > continue;
> >
> > + sgx_reset_epc_page(entry->epc_page);
> > sgx_free_epc_page(entry->epc_page);
> > encl->secs_child_cnt--;
> > entry->epc_page = NULL;
> > @@ -423,6 +434,7 @@ void sgx_encl_release(struct kref *ref)
> > xa_destroy(&encl->page_array);
> >
> > if (!encl->secs_child_cnt && encl->secs.epc_page) {
> > + sgx_reset_epc_page(encl->secs.epc_page);
> > sgx_free_epc_page(encl->secs.epc_page);
> > encl->secs.epc_page = NULL;
> > }
> > @@ -431,7 +443,8 @@ void sgx_encl_release(struct kref *ref)
> > va_page = list_first_entry(&encl->va_pages, struct sgx_va_page,
> > list);
> > list_del(&va_page->list);
> > - sgx_free_epc_page(va_page->epc_page);
> > + sgx_reset_epc_page(entry->epc_page);
> > + sgx_free_epc_page(entry->epc_page);
>
> Reply so that Sean can see, since he just subscribed to linux-sgx list.
>
> As Sean pointed out in KVM SGX virtualization thread, entry should be va_page.
Thank, noticed, and responded. I'm sending v3. I think it would be best to
then include that version to KVM patch set, as there is no such a rush to
get my patches to upstream. I already dropped them from my bleeding edge
numa branch.
/Jarkko
