diff mbox series

[v17,07/23] x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit

Message ID 20181116010412.23967-8-jarkko.sakkinen@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series [v17,01/23] x86/sgx: Update MAINTAINERS | expand

Commit Message

Jarkko Sakkinen Nov. 16, 2018, 1:01 a.m. UTC 
From: Sean Christopherson <sean.j.christopherson@intel.com>

The SGX bit is set in the #PF error code if and only if the fault is
detected by the Enclave Page Cache Map (EPCM), a hardware-managed
table that enforces the paging permissions defined by the enclave,
e.g. to prevent the kernel from changing the permissions of an
enclave's page(s).

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/include/asm/traps.h | 1 +
 1 file changed, 1 insertion(+)

Comments

Dave Hansen Nov. 16, 2018, 11:33 p.m. UTC | #1 
On 11/15/18 5:01 PM, Jarkko Sakkinen wrote:
> The SGX bit is set in the #PF error code if and only if the fault is
> detected by the Enclave Page Cache Map (EPCM), a hardware-managed
> table that enforces the paging permissions defined by the enclave,
> e.g. to prevent the kernel from changing the permissions of an
> enclave's page(s).

This should probably also mention that, despite being a page fault,
X86_PF_SGX has nothing to do with paging itself.
Jarkko Sakkinen Nov. 18, 2018, 8:38 a.m. UTC | #2 
On Fri, Nov 16, 2018 at 03:33:35PM -0800, Dave Hansen wrote:
> On 11/15/18 5:01 PM, Jarkko Sakkinen wrote:
> > The SGX bit is set in the #PF error code if and only if the fault is
> > detected by the Enclave Page Cache Map (EPCM), a hardware-managed
> > table that enforces the paging permissions defined by the enclave,
> > e.g. to prevent the kernel from changing the permissions of an
> > enclave's page(s).
> 
> This should probably also mention that, despite being a page fault,
> X86_PF_SGX has nothing to do with paging itself.

A valid point.

/Jarkko
diff mbox series

Patch

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 3de69330e6c5..165c93dd700e 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -162,5 +162,6 @@  enum x86_pf_error_code {
 	X86_PF_RSVD	=		1 << 3,
 	X86_PF_INSTR	=		1 << 4,
 	X86_PF_PK	=		1 << 5,
+	X86_PF_SGX	=		1 << 15,
 };
 #endif /* _ASM_X86_TRAPS_H */