RE: [RFC PATCH v3 04/10] x86/sgx: Keep record for SGX VA and Guest page type

Zhang, Cathy
2022-04-06T13:31:12Z

> -----Original Message-----
> From: Jarkko Sakkinen <jarkko@kernel.org>
> Sent: Sunday, April 3, 2022 6:11 PM
> To: Zhang, Cathy <cathy.zhang@intel.com>
> Cc: linux-sgx@vger.kernel.org; x86@kernel.org; Chatre, Reinette
> <reinette.chatre@intel.com>; Hansen, Dave <dave.hansen@intel.com>; Raj,
> Ashok <ashok.raj@intel.com>
> Subject: Re: [RFC PATCH v3 04/10] x86/sgx: Keep record for SGX VA and
> Guest page type
>
> On Fri, Apr 01, 2022 at 10:24:03PM +0800, Cathy Zhang wrote:
> > Regular enclave EPC pages have sgx_encl_page as their owner, but SGX
> > VA page and KVM guest EPC page are maintained by different owner
> > structures.
> >
> > SGX CPUSVN update requires to know the EPC page owner's status and
> > then decide how to handle the page.
> >
> > Keep a record of page type for SGX VA and KVM guest page while the
> > other EPC pages already have their type tracked, so that CPUSVN update
> > can get EPC page's owner by type and handle it then.
> >
> > Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> > ---
> > arch/x86/kernel/cpu/sgx/sgx.h | 4 ++++
> > arch/x86/kernel/cpu/sgx/encl.c | 2 ++ arch/x86/kernel/cpu/sgx/virt.c
> > | 2 ++
> > 3 files changed, 8 insertions(+)
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/sgx.h
> > b/arch/x86/kernel/cpu/sgx/sgx.h index f8ed9deac18b..0b036f19cca1
> > 100644
> > --- a/arch/x86/kernel/cpu/sgx/sgx.h
> > +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> > @@ -28,6 +28,10 @@
> >
> > /* Pages on free list */
> > #define SGX_EPC_PAGE_IS_FREE BIT(1)
> > +/* VA page */
> > +#define SGX_EPC_PAGE_VA BIT(2)
> > +/* Pages allocated for KVM guest */
> > +#define SGX_EPC_PAGE_GUEST BIT(3)
>
> Please rename this as either SGX_EPC_PAGE_KVM_GUEST or
> SGX_EPC_PAGE_KVM.
> Then it is hard to not remember what it is.

Renamed as SGX_EPC_PAGE_KVM_GUEST.

>
> BR, Jarkko