Commit 03b122da authored by Tony Luck's avatar Tony Luck Committed by Dave Hansen
Browse files

x86/sgx: Hook arch_memory_failure() into mainline code 



Add a call inside memory_failure() to call the arch specific code
to check if the address is an SGX EPC page and handle it.

Note the SGX EPC pages do not have a "struct page" entry, so the hook
goes in at the same point as the device mapping hook.

Pull the call to acquire the mutex earlier so the SGX errors are also
protected.

Make set_mce_nospec() skip SGX pages when trying to adjust
the 1:1 map.

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: default avatarNaoya Horiguchi <naoya.horiguchi@nec.com>
Tested-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/20211026220050.697075-6-tony.luck@intel.com
parent a495cbdf

arch/x86/include/asm/processor.h

+8 −0
Original line number Diff line number Diff line
@@ -855,4 +855,12 @@ enum mds_mitigations { 
	MDS_MITIGATION_VMWERV,

};



#ifdef CONFIG_X86_SGX

int arch_memory_failure(unsigned long pfn, int flags);

#define arch_memory_failure arch_memory_failure



bool arch_is_platform_page(u64 paddr);

#define arch_is_platform_page arch_is_platform_page

#endif



#endif /* _ASM_X86_PROCESSOR_H */

arch/x86/include/asm/set_memory.h

+4 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#ifndef _ASM_X86_SET_MEMORY_H

#define _ASM_X86_SET_MEMORY_H



#include <linux/mm.h>

#include <asm/page.h>

#include <asm-generic/set_memory.h>
@@ -99,6 +100,9 @@ static inline int set_mce_nospec(unsigned long pfn, bool unmap) 
	unsigned long decoy_addr;

	int rc;



	/* SGX pages are not in the 1:1 map */

	if (arch_is_platform_page(pfn << PAGE_SHIFT))

		return 0;

	/*

	 * We would like to just call:

	 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);

include/linux/mm.h

+13 −0
Original line number Diff line number Diff line
@@ -3231,6 +3231,19 @@ extern void shake_page(struct page *p); 
extern atomic_long_t num_poisoned_pages __read_mostly;

extern int soft_offline_page(unsigned long pfn, int flags);



#ifndef arch_memory_failure

static inline int arch_memory_failure(unsigned long pfn, int flags)

{

	return -ENXIO;

}

#endif



#ifndef arch_is_platform_page

static inline bool arch_is_platform_page(u64 paddr)

{

	return false;

}

#endif



/*

 * Error handlers for various types of pages.

mm/memory-failure.c

+13 −6
Original line number Diff line number Diff line
@@ -1651,21 +1651,28 @@ int memory_failure(unsigned long pfn, int flags) 
	if (!sysctl_memory_failure_recovery)

		panic("Memory failure on page %lx", pfn);



	mutex_lock(&mf_mutex);



	p = pfn_to_online_page(pfn);

	if (!p) {

		res = arch_memory_failure(pfn, flags);

		if (res == 0)

			goto unlock_mutex;



		if (pfn_valid(pfn)) {

			pgmap = get_dev_pagemap(pfn, NULL);

			if (pgmap)

				return memory_failure_dev_pagemap(pfn, flags,

			if (pgmap) {

				res = memory_failure_dev_pagemap(pfn, flags,

								 pgmap);

				goto unlock_mutex;

			}

		}

		pr_err("Memory failure: %#lx: memory outside kernel control\n",

			pfn);

		return -ENXIO;

		res = -ENXIO;

		goto unlock_mutex;

	}



	mutex_lock(&mf_mutex);



try_again:

	if (PageHuge(p)) {

		res = memory_failure_hugetlb(pfn, flags);