Commit 2da68a77 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_sgx_for_6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 sgx updates from Dave Hansen:
 "The biggest deal in this series is support for a new hardware feature
  that allows enclaves to detect and mitigate single-stepping attacks.

  There's also a minor performance tweak and a little piece of the
  kmap_atomic() -> kmap_local() transition.

  Summary:

   - Introduce a new SGX feature (Asynchrounous Exit Notification) for
     bare-metal enclaves and KVM guests to mitigate single-step attacks

   - Increase batching to speed up enclave release

   - Replace kmap/kunmap_atomic() calls"

* tag 'x86_sgx_for_6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Replace kmap/kunmap_atomic() calls
  KVM/VMX: Allow exposing EDECCSSA user leaf function to KVM guest
  x86/sgx: Allow enclaves to use Asynchrounous Exit Notification
  x86/sgx: Reduce delay and interference of enclave release
parents c1f0fcd8 89e927bb

arch/x86/include/asm/cpufeatures.h

+1 −0
Original line number Diff line number Diff line
@@ -304,6 +304,7 @@ 
#define X86_FEATURE_UNRET		(11*32+15) /* "" AMD BTB untrain return */

#define X86_FEATURE_USE_IBPB_FW		(11*32+16) /* "" Use IBPB during runtime firmware calls */

#define X86_FEATURE_RSB_VMEXIT_LITE	(11*32+17) /* "" Fill RSB on VM exit when EIBRS is enabled */

#define X86_FEATURE_SGX_EDECCSSA	(11*32+18) /* "" SGX EDECCSSA user leaf function */





#define X86_FEATURE_MSR_TSX_CTRL	(11*32+20) /* "" MSR IA32_TSX_CTRL (Intel) implemented */

arch/x86/include/asm/sgx.h

+26 −7
Original line number Diff line number Diff line
@@ -115,17 +115,36 @@ enum sgx_miscselect { 
 * %SGX_ATTR_EINITTOKENKEY:	Allow to use token signing key that is used to

 *				sign cryptographic tokens that can be passed to

 *				EINIT as an authorization to run an enclave.

 * %SGX_ATTR_ASYNC_EXIT_NOTIFY:	Allow enclaves to be notified after an

 *				asynchronous exit has occurred.

 */

enum sgx_attribute {

	SGX_ATTR_INIT		   = BIT(0),

	SGX_ATTR_DEBUG		   = BIT(1),

	SGX_ATTR_MODE64BIT	   = BIT(2),

				  /* BIT(3) is reserved */

	SGX_ATTR_PROVISIONKEY	   = BIT(4),

	SGX_ATTR_EINITTOKENKEY	   = BIT(5),

				  /* BIT(6) is for CET */

	SGX_ATTR_KSS		   = BIT(7),

				  /* BIT(8) is reserved */

				  /* BIT(9) is reserved */

	SGX_ATTR_ASYNC_EXIT_NOTIFY = BIT(10),

};



#define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | BIT_ULL(6) | GENMASK_ULL(63, 8))

#define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | \

				 BIT_ULL(6) | \

				 BIT_ULL(8) | \

				 BIT_ULL(9) | \

				 GENMASK_ULL(63, 11))



#define SGX_ATTR_UNPRIV_MASK	(SGX_ATTR_DEBUG	    | \

				 SGX_ATTR_MODE64BIT | \

				 SGX_ATTR_KSS	    | \

				 SGX_ATTR_ASYNC_EXIT_NOTIFY)



#define SGX_ATTR_PRIV_MASK	(SGX_ATTR_PROVISIONKEY	| \

				 SGX_ATTR_EINITTOKENKEY)



/**

 * struct sgx_secs - SGX Enclave Control Structure (SECS)

arch/x86/kernel/cpu/cpuid-deps.c

+1 −0
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ static const struct cpuid_dep cpuid_deps[] = { 
	{ X86_FEATURE_SGX_LC,			X86_FEATURE_SGX	      },

	{ X86_FEATURE_SGX1,			X86_FEATURE_SGX       },

	{ X86_FEATURE_SGX2,			X86_FEATURE_SGX1      },

	{ X86_FEATURE_SGX_EDECCSSA,		X86_FEATURE_SGX1      },

	{ X86_FEATURE_XFD,			X86_FEATURE_XSAVES    },

	{ X86_FEATURE_XFD,			X86_FEATURE_XGETBV1   },

	{ X86_FEATURE_AMX_TILE,			X86_FEATURE_XFD       },

arch/x86/kernel/cpu/scattered.c

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ static const struct cpuid_bit cpuid_bits[] = { 
	{ X86_FEATURE_PER_THREAD_MBA,	CPUID_ECX,  0, 0x00000010, 3 },

	{ X86_FEATURE_SGX1,		CPUID_EAX,  0, 0x00000012, 0 },

	{ X86_FEATURE_SGX2,		CPUID_EAX,  1, 0x00000012, 0 },

	{ X86_FEATURE_SGX_EDECCSSA,	CPUID_EAX, 11, 0x00000012, 0 },

	{ X86_FEATURE_HW_PSTATE,	CPUID_EDX,  7, 0x80000007, 0 },

	{ X86_FEATURE_CPB,		CPUID_EDX,  9, 0x80000007, 0 },

	{ X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },

arch/x86/kernel/cpu/sgx/encl.c

+25 −10
Original line number Diff line number Diff line
@@ -160,8 +160,8 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page, 
		return ret;



	pginfo.addr = encl_page->desc & PAGE_MASK;

	pginfo.contents = (unsigned long)kmap_atomic(b.contents);

	pcmd_page = kmap_atomic(b.pcmd);

	pginfo.contents = (unsigned long)kmap_local_page(b.contents);

	pcmd_page = kmap_local_page(b.pcmd);

	pginfo.metadata = (unsigned long)pcmd_page + b.pcmd_offset;



	if (secs_page)
@@ -187,8 +187,8 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page, 
	 */

	pcmd_page_empty = !memchr_inv(pcmd_page, 0, PAGE_SIZE);



	kunmap_atomic(pcmd_page);

	kunmap_atomic((void *)(unsigned long)pginfo.contents);

	kunmap_local(pcmd_page);

	kunmap_local((void *)(unsigned long)pginfo.contents);



	get_page(b.pcmd);

	sgx_encl_put_backing(&b);
@@ -197,10 +197,10 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page, 


	if (pcmd_page_empty && !reclaimer_writing_to_pcmd(encl, pcmd_first_page)) {

		sgx_encl_truncate_backing_page(encl, PFN_DOWN(page_pcmd_off));

		pcmd_page = kmap_atomic(b.pcmd);

		pcmd_page = kmap_local_page(b.pcmd);

		if (memchr_inv(pcmd_page, 0, PAGE_SIZE))

			pr_warn("PCMD page not empty after truncate.\n");

		kunmap_atomic(pcmd_page);

		kunmap_local(pcmd_page);

	}



	put_page(b.pcmd);
@@ -680,11 +680,15 @@ const struct vm_operations_struct sgx_vm_ops = { 
void sgx_encl_release(struct kref *ref)

{

	struct sgx_encl *encl = container_of(ref, struct sgx_encl, refcount);

	unsigned long max_page_index = PFN_DOWN(encl->base + encl->size - 1);

	struct sgx_va_page *va_page;

	struct sgx_encl_page *entry;

	unsigned long index;

	unsigned long count = 0;



	XA_STATE(xas, &encl->page_array, PFN_DOWN(encl->base));



	xa_for_each(&encl->page_array, index, entry) {

	xas_lock(&xas);

	xas_for_each(&xas, entry, max_page_index) {

		if (entry->epc_page) {

			/*

			 * The page and its radix tree entry cannot be freed
@@ -699,9 +703,20 @@ void sgx_encl_release(struct kref *ref) 
		}



		kfree(entry);

		/* Invoke scheduler to prevent soft lockups. */

		/*

		 * Invoke scheduler on every XA_CHECK_SCHED iteration

		 * to prevent soft lockups.

		 */

		if (!(++count % XA_CHECK_SCHED)) {

			xas_pause(&xas);

			xas_unlock(&xas);



			cond_resched();



			xas_lock(&xas);

		}

	}

	xas_unlock(&xas);



	xa_destroy(&encl->page_array);