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

[Kai Huang <kai.huang@intel.com>]

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
> > 
> >