diff mbox series

[RFC,49/62] mm, x86: export several MKTME variables

Message ID 20190508144422.13171-50-kirill.shutemov@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Intel MKTME enabling | expand

Commit Message

Kirill A. Shutemov May 8, 2019, 2:44 p.m. UTC
From: Kai Huang <kai.huang@linux.intel.com>

KVM needs those variables to get/set memory encryption mask.

Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/mktme.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Peter Zijlstra June 14, 2019, 11:56 a.m. UTC | #1
On Wed, May 08, 2019 at 05:44:09PM +0300, Kirill A. Shutemov wrote:
> From: Kai Huang <kai.huang@linux.intel.com>
> 
> KVM needs those variables to get/set memory encryption mask.
> 
> Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> ---
>  arch/x86/mm/mktme.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
> index df70651816a1..12f4266cf7ea 100644
> --- a/arch/x86/mm/mktme.c
> +++ b/arch/x86/mm/mktme.c
> @@ -7,13 +7,16 @@
>  
>  /* Mask to extract KeyID from physical address. */
>  phys_addr_t mktme_keyid_mask;
> +EXPORT_SYMBOL_GPL(mktme_keyid_mask);
>  /*
>   * Number of KeyIDs available for MKTME.
>   * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1.
>   */
>  int mktme_nr_keyids;
> +EXPORT_SYMBOL_GPL(mktme_nr_keyids);
>  /* Shift of KeyID within physical address. */
>  int mktme_keyid_shift;
> +EXPORT_SYMBOL_GPL(mktme_keyid_shift);
>  
>  DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
>  EXPORT_SYMBOL_GPL(mktme_enabled_key);

NAK, don't export variables. Who owns the values, who enforces this?
Kai Huang June 17, 2019, 3:14 a.m. UTC | #2
On Fri, 2019-06-14 at 13:56 +0200, Peter Zijlstra wrote:
> On Wed, May 08, 2019 at 05:44:09PM +0300, Kirill A. Shutemov wrote:
> > From: Kai Huang <kai.huang@linux.intel.com>
> > 
> > KVM needs those variables to get/set memory encryption mask.
> > 
> > Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > ---
> >  arch/x86/mm/mktme.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
> > index df70651816a1..12f4266cf7ea 100644
> > --- a/arch/x86/mm/mktme.c
> > +++ b/arch/x86/mm/mktme.c
> > @@ -7,13 +7,16 @@
> >  
> >  /* Mask to extract KeyID from physical address. */
> >  phys_addr_t mktme_keyid_mask;
> > +EXPORT_SYMBOL_GPL(mktme_keyid_mask);
> >  /*
> >   * Number of KeyIDs available for MKTME.
> >   * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1.
> >   */
> >  int mktme_nr_keyids;
> > +EXPORT_SYMBOL_GPL(mktme_nr_keyids);
> >  /* Shift of KeyID within physical address. */
> >  int mktme_keyid_shift;
> > +EXPORT_SYMBOL_GPL(mktme_keyid_shift);
> >  
> >  DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
> >  EXPORT_SYMBOL_GPL(mktme_enabled_key);
> 
> NAK, don't export variables. Who owns the values, who enforces this?
> 

Both KVM and IOMMU driver need page_keyid() and mktme_keyid_shift to set page's keyID to the right
place in the PTE (of KVM EPT and VT-d DMA page table).

MKTME key type code need to know mktme_nr_keyids in order to alloc/free keyID.

Maybe better to introduce functions instead of exposing variables directly?

Or instead of introducing page_keyid(), we use page_encrypt_mask(), which essentially holds
"page_keyid() << mktme_keyid_shift"?

Thanks,
-Kai
Peter Zijlstra June 17, 2019, 7:46 a.m. UTC | #3
On Mon, Jun 17, 2019 at 03:14:29PM +1200, Kai Huang wrote:
> On Fri, 2019-06-14 at 13:56 +0200, Peter Zijlstra wrote:
> > On Wed, May 08, 2019 at 05:44:09PM +0300, Kirill A. Shutemov wrote:
> > > From: Kai Huang <kai.huang@linux.intel.com>
> > > 
> > > KVM needs those variables to get/set memory encryption mask.
> > > 
> > > Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
> > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > > ---
> > >  arch/x86/mm/mktme.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
> > > index df70651816a1..12f4266cf7ea 100644
> > > --- a/arch/x86/mm/mktme.c
> > > +++ b/arch/x86/mm/mktme.c
> > > @@ -7,13 +7,16 @@
> > >  
> > >  /* Mask to extract KeyID from physical address. */
> > >  phys_addr_t mktme_keyid_mask;
> > > +EXPORT_SYMBOL_GPL(mktme_keyid_mask);
> > >  /*
> > >   * Number of KeyIDs available for MKTME.
> > >   * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1.
> > >   */
> > >  int mktme_nr_keyids;
> > > +EXPORT_SYMBOL_GPL(mktme_nr_keyids);
> > >  /* Shift of KeyID within physical address. */
> > >  int mktme_keyid_shift;
> > > +EXPORT_SYMBOL_GPL(mktme_keyid_shift);
> > >  
> > >  DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
> > >  EXPORT_SYMBOL_GPL(mktme_enabled_key);
> > 
> > NAK, don't export variables. Who owns the values, who enforces this?
> > 
> 
> Both KVM and IOMMU driver need page_keyid() and mktme_keyid_shift to set page's keyID to the right
> place in the PTE (of KVM EPT and VT-d DMA page table).
> 
> MKTME key type code need to know mktme_nr_keyids in order to alloc/free keyID.
> 
> Maybe better to introduce functions instead of exposing variables directly?
> 
> Or instead of introducing page_keyid(), we use page_encrypt_mask(), which essentially holds
> "page_keyid() << mktme_keyid_shift"?

Yes, that's much better, because that strictly limits the access to R/O.
Kai Huang June 17, 2019, 8:39 a.m. UTC | #4
On Mon, 2019-06-17 at 09:46 +0200, Peter Zijlstra wrote:
> On Mon, Jun 17, 2019 at 03:14:29PM +1200, Kai Huang wrote:
> > On Fri, 2019-06-14 at 13:56 +0200, Peter Zijlstra wrote:
> > > On Wed, May 08, 2019 at 05:44:09PM +0300, Kirill A. Shutemov wrote:
> > > > From: Kai Huang <kai.huang@linux.intel.com>
> > > > 
> > > > KVM needs those variables to get/set memory encryption mask.
> > > > 
> > > > Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
> > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > > > ---
> > > >  arch/x86/mm/mktme.c | 3 +++
> > > >  1 file changed, 3 insertions(+)
> > > > 
> > > > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
> > > > index df70651816a1..12f4266cf7ea 100644
> > > > --- a/arch/x86/mm/mktme.c
> > > > +++ b/arch/x86/mm/mktme.c
> > > > @@ -7,13 +7,16 @@
> > > >  
> > > >  /* Mask to extract KeyID from physical address. */
> > > >  phys_addr_t mktme_keyid_mask;
> > > > +EXPORT_SYMBOL_GPL(mktme_keyid_mask);
> > > >  /*
> > > >   * Number of KeyIDs available for MKTME.
> > > >   * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1.
> > > >   */
> > > >  int mktme_nr_keyids;
> > > > +EXPORT_SYMBOL_GPL(mktme_nr_keyids);
> > > >  /* Shift of KeyID within physical address. */
> > > >  int mktme_keyid_shift;
> > > > +EXPORT_SYMBOL_GPL(mktme_keyid_shift);
> > > >  
> > > >  DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
> > > >  EXPORT_SYMBOL_GPL(mktme_enabled_key);
> > > 
> > > NAK, don't export variables. Who owns the values, who enforces this?
> > > 
> > 
> > Both KVM and IOMMU driver need page_keyid() and mktme_keyid_shift to set page's keyID to the
> > right
> > place in the PTE (of KVM EPT and VT-d DMA page table).
> > 
> > MKTME key type code need to know mktme_nr_keyids in order to alloc/free keyID.
> > 
> > Maybe better to introduce functions instead of exposing variables directly?
> > 
> > Or instead of introducing page_keyid(), we use page_encrypt_mask(), which essentially holds
> > "page_keyid() << mktme_keyid_shift"?
> 
> Yes, that's much better, because that strictly limits the access to R/O.
> 

Thanks. I think Kirill will be the one to handle your suggestion. :)

Kirill?

Thanks,
-Kai
Kirill A. Shutemov June 17, 2019, 11:25 a.m. UTC | #5
On Mon, Jun 17, 2019 at 08:39:43PM +1200, Kai Huang wrote:
> On Mon, 2019-06-17 at 09:46 +0200, Peter Zijlstra wrote:
> > On Mon, Jun 17, 2019 at 03:14:29PM +1200, Kai Huang wrote:
> > > On Fri, 2019-06-14 at 13:56 +0200, Peter Zijlstra wrote:
> > > > On Wed, May 08, 2019 at 05:44:09PM +0300, Kirill A. Shutemov wrote:
> > > > > From: Kai Huang <kai.huang@linux.intel.com>
> > > > > 
> > > > > KVM needs those variables to get/set memory encryption mask.
> > > > > 
> > > > > Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
> > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > > > > ---
> > > > >  arch/x86/mm/mktme.c | 3 +++
> > > > >  1 file changed, 3 insertions(+)
> > > > > 
> > > > > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
> > > > > index df70651816a1..12f4266cf7ea 100644
> > > > > --- a/arch/x86/mm/mktme.c
> > > > > +++ b/arch/x86/mm/mktme.c
> > > > > @@ -7,13 +7,16 @@
> > > > >  
> > > > >  /* Mask to extract KeyID from physical address. */
> > > > >  phys_addr_t mktme_keyid_mask;
> > > > > +EXPORT_SYMBOL_GPL(mktme_keyid_mask);
> > > > >  /*
> > > > >   * Number of KeyIDs available for MKTME.
> > > > >   * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1.
> > > > >   */
> > > > >  int mktme_nr_keyids;
> > > > > +EXPORT_SYMBOL_GPL(mktme_nr_keyids);
> > > > >  /* Shift of KeyID within physical address. */
> > > > >  int mktme_keyid_shift;
> > > > > +EXPORT_SYMBOL_GPL(mktme_keyid_shift);
> > > > >  
> > > > >  DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
> > > > >  EXPORT_SYMBOL_GPL(mktme_enabled_key);
> > > > 
> > > > NAK, don't export variables. Who owns the values, who enforces this?
> > > > 
> > > 
> > > Both KVM and IOMMU driver need page_keyid() and mktme_keyid_shift to set page's keyID to the
> > > right
> > > place in the PTE (of KVM EPT and VT-d DMA page table).
> > > 
> > > MKTME key type code need to know mktme_nr_keyids in order to alloc/free keyID.
> > > 
> > > Maybe better to introduce functions instead of exposing variables directly?
> > > 
> > > Or instead of introducing page_keyid(), we use page_encrypt_mask(), which essentially holds
> > > "page_keyid() << mktme_keyid_shift"?
> > 
> > Yes, that's much better, because that strictly limits the access to R/O.
> > 
> 
> Thanks. I think Kirill will be the one to handle your suggestion. :)
> 
> Kirill?

Will do.
diff mbox series

Patch

diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
index df70651816a1..12f4266cf7ea 100644
--- a/arch/x86/mm/mktme.c
+++ b/arch/x86/mm/mktme.c
@@ -7,13 +7,16 @@ 
 
 /* Mask to extract KeyID from physical address. */
 phys_addr_t mktme_keyid_mask;
+EXPORT_SYMBOL_GPL(mktme_keyid_mask);
 /*
  * Number of KeyIDs available for MKTME.
  * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1.
  */
 int mktme_nr_keyids;
+EXPORT_SYMBOL_GPL(mktme_nr_keyids);
 /* Shift of KeyID within physical address. */
 int mktme_keyid_shift;
+EXPORT_SYMBOL_GPL(mktme_keyid_shift);
 
 DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
 EXPORT_SYMBOL_GPL(mktme_enabled_key);