From d222b01e516bba73ef9fefee4146734a5f260fa1 Mon Sep 17 00:00:00 2001

From: Lianbo Jiang <lijiang@redhat.com>

Date: Wed, 30 Jan 2019 10:48:53 +0800

Subject: [PATCH] [PATCH] x86_64: Add support for AMD Secure Memory Encryption

On AMD machine with Secure Memory Encryption (SME) feature, if SME is

enabled, page tables contain a specific attribute bit (C-bit) in their

entries to indicate whether a page is encrypted or unencrypted.

So get NUMBER(sme_mask) from vmcoreinfo, which stores the value of

the C-bit position, and drop it to obtain the true physical address.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>

---

 arch/x86_64.c  | 30 +++++++++++++++++++-----------

 makedumpfile.c |  4 ++++

 makedumpfile.h |  1 +

 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/arch/x86_64.c b/arch/x86_64.c

index 9db1f8139f28..46e93366f0be 100644

--- a/makedumpfile-1.6.5/arch/x86_64.c

+++ b/makedumpfile-1.6.5/arch/x86_64.c

@@ -297,6 +297,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 	unsigned long page_dir, pgd, pud_paddr, pud_pte, pmd_paddr, pmd_pte;

 	unsigned long pte_paddr, pte;

 	unsigned long p4d_paddr, p4d_pte;

+	unsigned long entry_mask = ENTRY_MASK;

 	/*

 	 * Get PGD.

@@ -308,6 +309,9 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 			return NOT_PADDR;

 	}

+	if (NUMBER(sme_mask) != NOT_FOUND_NUMBER)

+		entry_mask &= ~(NUMBER(sme_mask));

+

 	if (check_5level_paging()) {

 		page_dir += pgd5_index(vaddr) * sizeof(unsigned long);

 		if (!readmem(PADDR, page_dir, &pgd, sizeof pgd)) {

@@ -324,7 +328,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 		/*

 		 * Get P4D.

 		 */

-		p4d_paddr  = pgd & ENTRY_MASK;

+		p4d_paddr = pgd & entry_mask;

 		p4d_paddr += p4d_index(vaddr) * sizeof(unsigned long);

 		if (!readmem(PADDR, p4d_paddr, &p4d_pte, sizeof p4d_pte)) {

 			ERRMSG("Can't get p4d_pte (p4d_paddr:%lx).\n", p4d_paddr);

@@ -337,7 +341,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 			ERRMSG("Can't get a valid p4d_pte.\n");

 			return NOT_PADDR;

 		}

-		pud_paddr  = p4d_pte & ENTRY_MASK;

+		pud_paddr = p4d_pte & entry_mask;

 	}else {

 		page_dir += pgd_index(vaddr) * sizeof(unsigned long);

 		if (!readmem(PADDR, page_dir, &pgd, sizeof pgd)) {

@@ -351,7 +355,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 			ERRMSG("Can't get a valid pgd.\n");

 			return NOT_PADDR;

 		}

-		pud_paddr  = pgd & ENTRY_MASK;

+		pud_paddr = pgd & entry_mask;

 	}

 	/*

@@ -370,13 +374,13 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 		return NOT_PADDR;

 	}

 	if (pud_pte & _PAGE_PSE)	/* 1GB pages */

-		return (pud_pte & ENTRY_MASK & PUD_MASK) +

+		return (pud_pte & entry_mask & PUD_MASK) +

 			(vaddr & ~PUD_MASK);

 	/*

 	 * Get PMD.

 	 */

-	pmd_paddr  = pud_pte & ENTRY_MASK;

+	pmd_paddr = pud_pte & entry_mask;

 	pmd_paddr += pmd_index(vaddr) * sizeof(unsigned long);

 	if (!readmem(PADDR, pmd_paddr, &pmd_pte, sizeof pmd_pte)) {

 		ERRMSG("Can't get pmd_pte (pmd_paddr:%lx).\n", pmd_paddr);

@@ -390,13 +394,13 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 		return NOT_PADDR;

 	}

 	if (pmd_pte & _PAGE_PSE)	/* 2MB pages */

-		return (pmd_pte & ENTRY_MASK & PMD_MASK) +

+		return (pmd_pte & entry_mask & PMD_MASK) +

 			(vaddr & ~PMD_MASK);

 	/*

 	 * Get PTE.

 	 */

-	pte_paddr  = pmd_pte & ENTRY_MASK;

+	pte_paddr = pmd_pte & entry_mask;

 	pte_paddr += pte_index(vaddr) * sizeof(unsigned long);

 	if (!readmem(PADDR, pte_paddr, &pte, sizeof pte)) {

 		ERRMSG("Can't get pte (pte_paddr:%lx).\n", pte_paddr);

@@ -409,7 +413,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)

 		ERRMSG("Can't get a valid pte.\n");

 		return NOT_PADDR;

 	}

-	return (pte & ENTRY_MASK) + PAGEOFFSET(vaddr);

+	return (pte & entry_mask) + PAGEOFFSET(vaddr);

 }

 unsigned long long

@@ -642,6 +646,7 @@ find_vmemmap_x86_64()

 	unsigned long pmd, tpfn;

 	unsigned long pvaddr = 0;

 	unsigned long data_addr = 0, last_data_addr = 0, start_data_addr = 0;

+	unsigned long pmask = PMASK;

 	/*

 	 * data_addr is the paddr of the page holding the page structs.

 	 * We keep lists of contiguous pages and the pfn's that their

@@ -662,6 +667,9 @@ find_vmemmap_x86_64()

 		return FAILED;

 	}

+	if (NUMBER(sme_mask) != NOT_FOUND_NUMBER)

+		pmask &= ~(NUMBER(sme_mask));

+

 	pagestructsize = size_table.page;

 	hugepagesize = PTRS_PER_PMD * info->page_size;

 	vaddr_base = info->vmemmap_start;

@@ -692,7 +700,7 @@ find_vmemmap_x86_64()

 		}

 		/* mask the pgd entry for the address of the pud page */

-		pud_addr &= PMASK;

+		pud_addr &= pmask;

 		if (pud_addr == 0)

 			  continue;

 		/* read the entire pud page */

@@ -705,7 +713,7 @@ find_vmemmap_x86_64()

 		/* pudp points to an entry in the pud page */

 		for (pudp = (unsigned long *)pud_page, pudindex = 0;

 					pudindex < PTRS_PER_PUD; pudindex++, pudp++) {

-			pmd_addr = *pudp & PMASK;

+			pmd_addr = *pudp & pmask;

 			/* read the entire pmd page */

 			if (pmd_addr == 0)

 				continue;

@@ -747,7 +755,7 @@ find_vmemmap_x86_64()

 				 * - we discontiguous page is a string of valids

 				 */

 				if (pmd) {

-					data_addr = (pmd & PMASK);

+					data_addr = (pmd & pmask);

 					if (start_range) {

 						/* first-time kludge */

 						start_data_addr = data_addr;

diff --git a/makedumpfile.c b/makedumpfile.c

index 7dfe70fb8792..590f759c84f1 100644

--- a/makedumpfile-1.6.5/makedumpfile.c

+++ b/makedumpfile-1.6.5/makedumpfile.c

@@ -993,6 +993,8 @@ next_page:

 	read_size = MIN(info->page_size - PAGEOFFSET(paddr), size);

 	pgaddr = PAGEBASE(paddr);

+	if (NUMBER(sme_mask) != NOT_FOUND_NUMBER)

+		pgaddr = pgaddr & ~(NUMBER(sme_mask));

 	pgbuf = cache_search(pgaddr, read_size);

 	if (!pgbuf) {

 		++cache_miss;

@@ -2292,6 +2294,7 @@ write_vmcoreinfo_data(void)

 	WRITE_NUMBER("NR_FREE_PAGES", NR_FREE_PAGES);

 	WRITE_NUMBER("N_ONLINE", N_ONLINE);

 	WRITE_NUMBER("pgtable_l5_enabled", pgtable_l5_enabled);

+	WRITE_NUMBER("sme_mask", sme_mask);

 	WRITE_NUMBER("PG_lru", PG_lru);

 	WRITE_NUMBER("PG_private", PG_private);

@@ -2695,6 +2698,7 @@ read_vmcoreinfo(void)

 	READ_NUMBER("NR_FREE_PAGES", NR_FREE_PAGES);

 	READ_NUMBER("N_ONLINE", N_ONLINE);

 	READ_NUMBER("pgtable_l5_enabled", pgtable_l5_enabled);

+	READ_NUMBER("sme_mask", sme_mask);

 	READ_NUMBER("PG_lru", PG_lru);

 	READ_NUMBER("PG_private", PG_private);

diff --git a/makedumpfile.h b/makedumpfile.h

index 2e73beca48c5..5ad38e9ae40c 100644

--- a/makedumpfile-1.6.5/makedumpfile.h

+++ b/makedumpfile-1.6.5/makedumpfile.h

@@ -1913,6 +1913,7 @@ struct number_table {

 	long	NR_FREE_PAGES;

 	long	N_ONLINE;

 	long	pgtable_l5_enabled;

+	long	sme_mask;

 	/*

  	* Page flags

-- 

2.17.1