Re: [RFC PATCH v3 13/27] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs

Kai Huang
2021-02-01T01:20:47Z

On Sat, 30 Jan 2021 16:49:20 +0200 Jarkko Sakkinen wrote:
> On Tue, Jan 26, 2021 at 10:31:05PM +1300, Kai Huang wrote:
> > Add a helper to update SGX_LEPUBKEYHASHn MSRs. SGX virtualization also
> > needs to update those MSRs based on guest's "virtual" SGX_LEPUBKEYHASHn
> > before EINIT from guest.
> >
> > Signed-off-by: Kai Huang <kai.huang@intel.com>
>
>
> Acked-by: Jarkko Sakkinen <jarkko@kernel.org>

Thanks Jarkko.

Hi Dave,

This patch originally had your Acked-by, but since I added a comment, I removed
it. May I still have your Acked-by?

>
> /Jarkko
>
> > ---
> > v2->v3:
> >
> > - Added comment for sgx_update_lepubkeyhash(), per Jarkko and Dave.
> >
> > ---
> > arch/x86/kernel/cpu/sgx/ioctl.c | 5 ++---
> > arch/x86/kernel/cpu/sgx/main.c | 15 +++++++++++++++
> > arch/x86/kernel/cpu/sgx/sgx.h | 2 ++
> > 3 files changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
> > index e5977752c7be..1bae754268d1 100644
> > --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> > @@ -495,7 +495,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
> > void *token)
> > {
> > u64 mrsigner[4];
> > - int i, j, k;
> > + int i, j;
> > void *addr;
> > int ret;
> >
> > @@ -544,8 +544,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
> >
> > preempt_disable();
> >
> > - for (k = 0; k < 4; k++)
> > - wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + k, mrsigner[k]);
> > + sgx_update_lepubkeyhash(mrsigner);
> >
> > ret = __einit(sigstruct, token, addr);
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> > index 93d249f7bff3..b456899a9532 100644
> > --- a/arch/x86/kernel/cpu/sgx/main.c
> > +++ b/arch/x86/kernel/cpu/sgx/main.c
> > @@ -697,6 +697,21 @@ static bool __init sgx_page_cache_init(void)
> > return true;
> > }
> >
> > +
> > +/*
> > + * Update the SGX_LEPUBKEYHASH MSRs to the values specified by caller.
> > + * Bare-metal driver requires to update them to hash of enclave's signer
> > + * before EINIT. KVM needs to update them to guest's virtual MSR values
> > + * before doing EINIT from guest.
> > + */
> > +void sgx_update_lepubkeyhash(u64 *lepubkeyhash)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < 4; i++)
> > + wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]);
> > +}
> > +
> > static int __init sgx_init(void)
> > {
> > int ret;
> > diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
> > index 509f2af33e1d..ccd4f145c464 100644
> > --- a/arch/x86/kernel/cpu/sgx/sgx.h
> > +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> > @@ -83,4 +83,6 @@ void sgx_mark_page_reclaimable(struct sgx_epc_page *page);
> > int sgx_unmark_page_reclaimable(struct sgx_epc_page *page);
> > struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim);
> >
> > +void sgx_update_lepubkeyhash(u64 *lepubkeyhash);
> > +
> > #endif /* _X86_SGX_H */
> > --
> > 2.29.2
> >
> >