[kvm-unit-tests PATCH v4 0/7] s390: Add support for large pages

[kvm-unit-tests PATCH v4 0/7] s390: Add support for large pages

[Claudio Imbrenda]

Introduce support for large (1M) and huge (2G) pages.

Add a simple testcase for EDAT1 and EDAT2.

v3->v4
* replace macros in patch 5 with a union representing TEID fields
* clear the teid in expect_pgm_int and clear_pgm_int
* update testcase to use expect_pgm_int, remove expect_dat_fault
* update testcase to use teid union

v2->v3
* Add proper macros for control register bits
* Improved patch titles and descriptions
* Moved definition of TEID bits to library
* Rebased on the lastest upstream branch

v1->v2

* split patch 2 -> new patch 2 and new patch 3
* patch 2: fixes pgtable.h, also fixes wrong usage of REGION_TABLE_LENGTH
  instead of SEGMENT_TABLE_LENGTH
* patch 3: introduces new macros and functions for large pages
* patch 4: remove erroneous double call to pte_alloc in get_pte
* patch 4: added comment in mmu.c to bridge the s390x architecural names
  with the Linux ones used in the kvm-unit-tests
* patch 5: added and fixed lots of comments to explain what's going on
* patch 5: set FC for region 3 after writing the canary, like for segments
* patch 5: use uintptr_t instead of intptr_t for set_prefix
* patch 5: introduce new macro PGD_PAGE_SHIFT instead of using magic value 41
* patch 5: use VIRT(0) instead of mem to make it more clear what we are
  doing, even though VIRT(0) expands to mem

Claudio Imbrenda (7):
  s390x: lib: add and use macros for control register bits
  libcflat: add SZ_1M and SZ_2G
  s390x: lib: fix pgtable.h
  s390x: lib: Add idte and other huge pages functions/macros
  s390x: lib: add teid union and clear teid from lowcore
  s390x: mmu: add support for large pages
  s390x: edat test

 s390x/Makefile            |   1 +
 lib/s390x/asm/arch_def.h  |  12 ++
 lib/s390x/asm/float.h     |   4 +-
 lib/s390x/asm/interrupt.h |  26 +++-
 lib/s390x/asm/pgtable.h   |  44 +++++-
 lib/libcflat.h            |   2 +
 lib/s390x/mmu.h           |  73 +++++++++-
 lib/s390x/interrupt.c     |   2 +
 lib/s390x/mmu.c           | 260 ++++++++++++++++++++++++++++++++----
 lib/s390x/sclp.c          |   4 +-
 s390x/diag288.c           |   2 +-
 s390x/edat.c              | 274 ++++++++++++++++++++++++++++++++++++++
 s390x/gs.c                |   2 +-
 s390x/iep.c               |   4 +-
 s390x/skrf.c              |   2 +-
 s390x/smp.c               |   8 +-
 s390x/vector.c            |   2 +-
 s390x/unittests.cfg       |   3 +
 18 files changed, 676 insertions(+), 49 deletions(-)
 create mode 100644 s390x/edat.c

-- 
2.31.1

[kvm-unit-tests PATCH v4 1/7] s390x: lib: add and use macros for control register bits

[Claudio Imbrenda]

Add CTL0_* and CTL2_* macros for specific control register bits.

Replace all hardcoded values in the library and in the existing testcases so
that they use the new macros.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/asm/arch_def.h  | 12 ++++++++++++
 lib/s390x/asm/float.h     |  4 ++--
 lib/s390x/asm/interrupt.h |  4 ++--
 lib/s390x/sclp.c          |  4 ++--
 s390x/diag288.c           |  2 +-
 s390x/gs.c                |  2 +-
 s390x/iep.c               |  4 ++--
 s390x/skrf.c              |  2 +-
 s390x/smp.c               |  8 ++++----
 s390x/vector.c            |  2 +-
 10 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 7e2c5e62..c3568ab9 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -229,6 +229,18 @@ static inline uint64_t stctg(int cr)
 	return value;
 }
 
+#define CTL0_LOW_ADDR_PROT	(63 - 35)
+#define CTL0_EDAT		(63 - 40)
+#define CTL0_IEP		(63 - 43)
+#define CTL0_AFP		(63 - 45)
+#define CTL0_VECTOR		(63 - 46)
+#define CTL0_EMERGENCY_SIGNAL	(63 - 49)
+#define CTL0_EXTERNAL_CALL	(63 - 50)
+#define CTL0_CLOCK_COMPARATOR	(63 - 52)
+#define CTL0_SERVICE_SIGNAL	(63 - 54)
+
+#define CTL2_GUARDED_STORAGE	(63 - 59)
+
 static inline void ctl_set_bit(int cr, unsigned int bit)
 {
         uint64_t reg;
diff --git a/lib/s390x/asm/float.h b/lib/s390x/asm/float.h
index 13679447..98829918 100644
--- a/lib/s390x/asm/float.h
+++ b/lib/s390x/asm/float.h
@@ -38,12 +38,12 @@ static inline void set_fpc_dxc(uint8_t dxc)
 
 static inline void afp_enable(void)
 {
-	ctl_set_bit(0, 63 - 45);
+	ctl_set_bit(0, CTL0_AFP);
 }
 
 static inline void afp_disable(void)
 {
-	ctl_clear_bit(0, 63 - 45);
+	ctl_clear_bit(0, CTL0_AFP);
 }
 
 #endif
diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
index 31e4766d..bf0eb40d 100644
--- a/lib/s390x/asm/interrupt.h
+++ b/lib/s390x/asm/interrupt.h
@@ -27,13 +27,13 @@ void check_pgm_int_code(uint16_t code);
 /* Activate low-address protection */
 static inline void low_prot_enable(void)
 {
-	ctl_set_bit(0, 63 - 35);
+	ctl_set_bit(0, CTL0_LOW_ADDR_PROT);
 }
 
 /* Disable low-address protection */
 static inline void low_prot_disable(void)
 {
-	ctl_clear_bit(0, 63 - 35);
+	ctl_clear_bit(0, CTL0_LOW_ADDR_PROT);
 }
 
 #endif
diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
index 7a9b2c52..0d0b3d6a 100644
--- a/lib/s390x/sclp.c
+++ b/lib/s390x/sclp.c
@@ -50,7 +50,7 @@ void sclp_setup_int(void)
 {
 	uint64_t mask;
 
-	ctl_set_bit(0, 9);
+	ctl_set_bit(0, CTL0_SERVICE_SIGNAL);
 
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
@@ -59,7 +59,7 @@ void sclp_setup_int(void)
 
 void sclp_handle_ext(void)
 {
-	ctl_clear_bit(0, 9);
+	ctl_clear_bit(0, CTL0_SERVICE_SIGNAL);
 	spin_lock(&sclp_lock);
 	sclp_busy = false;
 	spin_unlock(&sclp_lock);
diff --git a/s390x/diag288.c b/s390x/diag288.c
index e132ff04..82b6ec17 100644
--- a/s390x/diag288.c
+++ b/s390x/diag288.c
@@ -86,7 +86,7 @@ static void test_bite(void)
 	asm volatile("stck %0" : "=Q" (time) : : "cc");
 	time += (uint64_t)(16000 * 1000) << 12;
 	asm volatile("sckc %0" : : "Q" (time));
-	ctl_set_bit(0, 11);
+	ctl_set_bit(0, CTL0_CLOCK_COMPARATOR);
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
 	load_psw_mask(mask);
diff --git a/s390x/gs.c b/s390x/gs.c
index 1376d0e6..a017a97d 100644
--- a/s390x/gs.c
+++ b/s390x/gs.c
@@ -145,7 +145,7 @@ static void test_special(void)
 static void init(void)
 {
 	/* Enable control bit for gs */
-	ctl_set_bit(2, 4);
+	ctl_set_bit(2, CTL2_GUARDED_STORAGE);
 
 	/* Setup gs registers to guard the gs_area */
 	gs_cb.gsd = gs_area | 25;
diff --git a/s390x/iep.c b/s390x/iep.c
index fe167ef0..906c77b3 100644
--- a/s390x/iep.c
+++ b/s390x/iep.c
@@ -22,7 +22,7 @@ static void test_iep(void)
 	void (*fn)(void);
 
 	/* Enable IEP */
-	ctl_set_bit(0, 20);
+	ctl_set_bit(0, CTL0_IEP);
 
 	/* Get and protect a page with the IEP bit */
 	iepbuf = alloc_page();
@@ -40,7 +40,7 @@ static void test_iep(void)
 	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
 	report_prefix_pop();
 	unprotect_page(iepbuf, PAGE_ENTRY_IEP);
-	ctl_clear_bit(0, 20);
+	ctl_clear_bit(0, CTL0_IEP);
 	free_page(iepbuf);
 }
 
diff --git a/s390x/skrf.c b/s390x/skrf.c
index 57524ba8..94e906a6 100644
--- a/s390x/skrf.c
+++ b/s390x/skrf.c
@@ -150,7 +150,7 @@ static void ecall_setup(void)
 	/* Put a skey into the ext new psw */
 	lc->ext_new_psw.mask = 0x00F0000180000000UL;
 	/* Open up ext masks */
-	ctl_set_bit(0, 13);
+	ctl_set_bit(0, CTL0_EXTERNAL_CALL);
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
 	load_psw_mask(mask);
diff --git a/s390x/smp.c b/s390x/smp.c
index b0ece491..f25ec769 100644
--- a/s390x/smp.c
+++ b/s390x/smp.c
@@ -154,7 +154,7 @@ static void ecall(void)
 	struct lowcore *lc = (void *)0x0;
 
 	expect_ext_int();
-	ctl_set_bit(0, 13);
+	ctl_set_bit(0, CTL0_EXTERNAL_CALL);
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
 	load_psw_mask(mask);
@@ -188,7 +188,7 @@ static void emcall(void)
 	struct lowcore *lc = (void *)0x0;
 
 	expect_ext_int();
-	ctl_set_bit(0, 14);
+	ctl_set_bit(0, CTL0_EMERGENCY_SIGNAL);
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
 	load_psw_mask(mask);
@@ -283,8 +283,8 @@ static void test_local_ints(void)
 	unsigned long mask;
 
 	/* Open masks for ecall and emcall */
-	ctl_set_bit(0, 13);
-	ctl_set_bit(0, 14);
+	ctl_set_bit(0, CTL0_EXTERNAL_CALL);
+	ctl_set_bit(0, CTL0_EMERGENCY_SIGNAL);
 	mask = extract_psw_mask();
 	mask |= PSW_MASK_EXT;
 	load_psw_mask(mask);
diff --git a/s390x/vector.c b/s390x/vector.c
index b052de55..fdb0eee2 100644
--- a/s390x/vector.c
+++ b/s390x/vector.c
@@ -106,7 +106,7 @@ static void test_bcd_add(void)
 static void init(void)
 {
 	/* Enable vector instructions */
-	ctl_set_bit(0, 17);
+	ctl_set_bit(0, CTL0_VECTOR);
 
 	/* Preset vector registers to 0xff */
 	memset(pagebuf, 0xff, PAGE_SIZE);
-- 
2.31.1

[kvm-unit-tests PATCH v4 2/7] libcflat: add SZ_1M and SZ_2G

[Claudio Imbrenda]

Add SZ_1M and SZ_2G to libcflat.h

s390x needs those for large/huge pages

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 lib/libcflat.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/libcflat.h b/lib/libcflat.h
index 460a1234..8dac0621 100644
--- a/lib/libcflat.h
+++ b/lib/libcflat.h
@@ -157,7 +157,9 @@ extern void setup_vm(void);
 #define SZ_8K			(1 << 13)
 #define SZ_16K			(1 << 14)
 #define SZ_64K			(1 << 16)
+#define SZ_1M			(1 << 20)
 #define SZ_2M			(1 << 21)
 #define SZ_1G			(1 << 30)
+#define SZ_2G			(1ul << 31)
 
 #endif
-- 
2.31.1

[kvm-unit-tests PATCH v4 3/7] s390x: lib: fix pgtable.h

[Claudio Imbrenda]

Fix pgtable.h:

* SEGMENT_ENTRY_SFAA had one extra bit set
* pmd entries don't have a length field
* ipte does not need to clear the lower bits
 - clearing the 12 lower bits is technically incorrect, as page tables are
   architecturally aligned to 11 bit addresses (even though the unit tests
   allocate always one full page)
* region table entries should use REGION_ENTRY_TL instead of *_TABLE_LENGTH
 - *_TABLE_LENGTH need to stay, because they should be used for ASCEs

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/asm/pgtable.h | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/lib/s390x/asm/pgtable.h b/lib/s390x/asm/pgtable.h
index 277f3480..1a21f175 100644
--- a/lib/s390x/asm/pgtable.h
+++ b/lib/s390x/asm/pgtable.h
@@ -60,7 +60,7 @@
 #define SEGMENT_SHIFT			20
 
 #define SEGMENT_ENTRY_ORIGIN		0xfffffffffffff800UL
-#define SEGMENT_ENTRY_SFAA		0xfffffffffff80000UL
+#define SEGMENT_ENTRY_SFAA		0xfffffffffff00000UL
 #define SEGMENT_ENTRY_AV		0x0000000000010000UL
 #define SEGMENT_ENTRY_ACC		0x000000000000f000UL
 #define SEGMENT_ENTRY_F			0x0000000000000800UL
@@ -143,7 +143,7 @@ static inline p4d_t *p4d_alloc(pgd_t *pgd, unsigned long addr)
 	if (pgd_none(*pgd)) {
 		p4d_t *p4d = p4d_alloc_one();
 		pgd_val(*pgd) = __pa(p4d) | REGION_ENTRY_TT_REGION1 |
-				REGION_TABLE_LENGTH;
+				REGION_ENTRY_TL;
 	}
 	return p4d_offset(pgd, addr);
 }
@@ -163,7 +163,7 @@ static inline pud_t *pud_alloc(p4d_t *p4d, unsigned long addr)
 	if (p4d_none(*p4d)) {
 		pud_t *pud = pud_alloc_one();
 		p4d_val(*p4d) = __pa(pud) | REGION_ENTRY_TT_REGION2 |
-				REGION_TABLE_LENGTH;
+				REGION_ENTRY_TL;
 	}
 	return pud_offset(p4d, addr);
 }
@@ -183,7 +183,7 @@ static inline pmd_t *pmd_alloc(pud_t *pud, unsigned long addr)
 	if (pud_none(*pud)) {
 		pmd_t *pmd = pmd_alloc_one();
 		pud_val(*pud) = __pa(pmd) | REGION_ENTRY_TT_REGION3 |
-				REGION_TABLE_LENGTH;
+				REGION_ENTRY_TL;
 	}
 	return pmd_offset(pud, addr);
 }
@@ -202,15 +202,14 @@ static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr)
 {
 	if (pmd_none(*pmd)) {
 		pte_t *pte = pte_alloc_one();
-		pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT |
-				SEGMENT_TABLE_LENGTH;
+		pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT;
 	}
 	return pte_offset(pmd, addr);
 }
 
 static inline void ipte(unsigned long vaddr, pteval_t *p_pte)
 {
-	unsigned long table_origin = (unsigned long)p_pte & PAGE_MASK;
+	unsigned long table_origin = (unsigned long)p_pte;
 
 	asm volatile(
 		"	ipte %0,%1\n"
-- 
2.31.1

[kvm-unit-tests PATCH v4 4/7] s390x: lib: Add idte and other huge pages functions/macros

[Claudio Imbrenda]

Improve pgtable.h:

* add macros to check whether a pmd or a pud are large / huge
* add idte functions for pmd, pud, p4d and pgd

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/asm/pgtable.h | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/lib/s390x/asm/pgtable.h b/lib/s390x/asm/pgtable.h
index 1a21f175..f166dcc6 100644
--- a/lib/s390x/asm/pgtable.h
+++ b/lib/s390x/asm/pgtable.h
@@ -100,6 +100,9 @@
 #define pmd_none(entry) (pmd_val(entry) & SEGMENT_ENTRY_I)
 #define pte_none(entry) (pte_val(entry) & PAGE_ENTRY_I)
 
+#define pud_huge(entry)  (pud_val(entry) & REGION3_ENTRY_FC)
+#define pmd_large(entry) (pmd_val(entry) & SEGMENT_ENTRY_FC)
+
 #define pgd_addr(entry) __va(pgd_val(entry) & REGION_ENTRY_ORIGIN)
 #define p4d_addr(entry) __va(p4d_val(entry) & REGION_ENTRY_ORIGIN)
 #define pud_addr(entry) __va(pud_val(entry) & REGION_ENTRY_ORIGIN)
@@ -216,6 +219,34 @@ static inline void ipte(unsigned long vaddr, pteval_t *p_pte)
 		: : "a" (table_origin), "a" (vaddr) : "memory");
 }
 
+static inline void idte(unsigned long table_origin, unsigned long vaddr)
+{
+	vaddr &= SEGMENT_ENTRY_SFAA;
+	asm volatile(
+		"	idte %0,0,%1\n"
+		: : "a" (table_origin), "a" (vaddr) : "memory");
+}
+
+static inline void idte_pmdp(unsigned long vaddr, pmdval_t *pmdp)
+{
+	idte((unsigned long)(pmdp - pmd_index(vaddr)) | ASCE_DT_SEGMENT, vaddr);
+}
+
+static inline void idte_pudp(unsigned long vaddr, pudval_t *pudp)
+{
+	idte((unsigned long)(pudp - pud_index(vaddr)) | ASCE_DT_REGION3, vaddr);
+}
+
+static inline void idte_p4dp(unsigned long vaddr, p4dval_t *p4dp)
+{
+	idte((unsigned long)(p4dp - p4d_index(vaddr)) | ASCE_DT_REGION2, vaddr);
+}
+
+static inline void idte_pgdp(unsigned long vaddr, pgdval_t *pgdp)
+{
+	idte((unsigned long)(pgdp - pgd_index(vaddr)) | ASCE_DT_REGION1, vaddr);
+}
+
 void configure_dat(int enable);
 
 #endif /* _ASMS390X_PGTABLE_H_ */
-- 
2.31.1

[kvm-unit-tests PATCH v4 5/7] s390x: lib: add teid union and clear teid from lowcore

[Claudio Imbrenda]

Add a union to represent Translation-Exception Identification (TEID).

Clear the TEID in expect_pgm_int clear_pgm_int.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/asm/interrupt.h | 22 ++++++++++++++++++++++
 lib/s390x/interrupt.c     |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
index bf0eb40d..b40def65 100644
--- a/lib/s390x/asm/interrupt.h
+++ b/lib/s390x/asm/interrupt.h
@@ -13,6 +13,28 @@
 #define EXT_IRQ_EXTERNAL_CALL	0x1202
 #define EXT_IRQ_SERVICE_SIG	0x2401
 
+#define TEID_ASCE_PRIMARY	0
+#define TEID_ASCE_AR		1
+#define TEID_ASCE_SECONDARY	2
+#define TEID_ASCE_HOME		3
+
+union teid {
+	unsigned long val;
+	struct {
+		unsigned long addr:52;
+		unsigned long fetch:1;
+		unsigned long store:1;
+		unsigned long reserved:6;
+		unsigned long acc_list_prot:1;
+		/* depending on the exception and the installed facilities,
+		 * the m field can indicate severel different things,
+		 * including whether the exception was triggered by a MVPG
+		 * instruction, or whether the addr field is meaningful */
+		unsigned long m:1;
+		unsigned long asce_id:2;
+	};
+};
+
 void register_pgm_cleanup_func(void (*f)(void));
 void handle_pgm_int(struct stack_frame_int *stack);
 void handle_ext_int(struct stack_frame_int *stack);
diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
index ce0003de..b627942f 100644
--- a/lib/s390x/interrupt.c
+++ b/lib/s390x/interrupt.c
@@ -22,6 +22,7 @@ void expect_pgm_int(void)
 {
 	pgm_int_expected = true;
 	lc->pgm_int_code = 0;
+	lc->trans_exc_id = 0;
 	mb();
 }
 
@@ -39,6 +40,7 @@ uint16_t clear_pgm_int(void)
 	mb();
 	code = lc->pgm_int_code;
 	lc->pgm_int_code = 0;
+	lc->trans_exc_id = 0;
 	pgm_int_expected = false;
 	return code;
 }
-- 
2.31.1

[kvm-unit-tests PATCH v4 6/7] s390x: mmu: add support for large pages

[Claudio Imbrenda]

Add support for 1M and 2G pages.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/mmu.h |  73 +++++++++++++-
 lib/s390x/mmu.c | 260 +++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 307 insertions(+), 26 deletions(-)

diff --git a/lib/s390x/mmu.h b/lib/s390x/mmu.h
index 603f289e..93208467 100644
--- a/lib/s390x/mmu.h
+++ b/lib/s390x/mmu.h
@@ -10,9 +10,78 @@
 #ifndef _ASMS390X_MMU_H_
 #define _ASMS390X_MMU_H_
 
-void protect_page(void *vaddr, unsigned long prot);
+/*
+ * Splits the pagetables down to the given DAT tables level.
+ * Returns a pointer to the DAT table entry of the given level.
+ * @pgtable root of the page table tree
+ * @vaddr address whose page tables are to split
+ * @level 3 (for 2GB pud), 4 (for 1 MB pmd) or 5 (for 4KB pages)
+ */
+void *split_page(pgd_t *pgtable, void *vaddr, unsigned int level);
+
+/*
+ * Applies the given protection bits to the given DAT tables level,
+ * splitting if necessary.
+ * @pgtable root of the page table tree
+ * @vaddr address whose protection bits are to be changed
+ * @prot the protection bits to set
+ * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4KB pages)
+ */
+void protect_dat_entry(void *vaddr, unsigned long prot, unsigned int level);
+/*
+ * Clears the given protection bits from the given DAT tables level,
+ * splitting if necessary.
+ * @pgtable root of the page table tree
+ * @vaddr address whose protection bits are to be changed
+ * @prot the protection bits to clear
+ * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4kB pages)
+ */
+void unprotect_dat_entry(void *vaddr, unsigned long prot, unsigned int level);
+
+/*
+ * Applies the given protection bits to the given 4kB pages range,
+ * splitting if necessary.
+ * @start starting address whose protection bits are to be changed
+ * @len size in bytes
+ * @prot the protection bits to set
+ */
 void protect_range(void *start, unsigned long len, unsigned long prot);
-void unprotect_page(void *vaddr, unsigned long prot);
+/*
+ * Clears the given protection bits from the given 4kB pages range,
+ * splitting if necessary.
+ * @start starting address whose protection bits are to be changed
+ * @len size in bytes
+ * @prot the protection bits to set
+ */
 void unprotect_range(void *start, unsigned long len, unsigned long prot);
 
+/* Similar to install_page, maps the virtual address to the physical address
+ * for the given page tables, using 1MB large pages.
+ * Returns a pointer to the DAT table entry.
+ * @pgtable root of the page table tree
+ * @phys physical address to map, must be 1MB aligned!
+ * @vaddr virtual address to map, must be 1MB aligned!
+ */
+pmdval_t *install_large_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr);
+
+/* Similar to install_page, maps the virtual address to the physical address
+ * for the given page tables, using 2GB huge pages.
+ * Returns a pointer to the DAT table entry.
+ * @pgtable root of the page table tree
+ * @phys physical address to map, must be 2GB aligned!
+ * @vaddr virtual address to map, must be 2GB aligned!
+ */
+pudval_t *install_huge_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr);
+
+static inline void protect_page(void *vaddr, unsigned long prot)
+{
+	protect_dat_entry(vaddr, prot, 5);
+}
+
+static inline void unprotect_page(void *vaddr, unsigned long prot)
+{
+	unprotect_dat_entry(vaddr, prot, 5);
+}
+void *get_dat_entry(pgd_t *pgtable, void *vaddr, unsigned int level);
+
 #endif /* _ASMS390X_MMU_H_ */
diff --git a/lib/s390x/mmu.c b/lib/s390x/mmu.c
index 5c517366..def91334 100644
--- a/lib/s390x/mmu.c
+++ b/lib/s390x/mmu.c
@@ -15,6 +15,18 @@
 #include <vmalloc.h>
 #include "mmu.h"
 
+/*
+ * The naming convention used here is the same as used in the Linux kernel,
+ * and this is the corrispondence between the s390x architectural names and
+ * the Linux ones:
+ *
+ * pgd - region 1 table entry
+ * p4d - region 2 table entry
+ * pud - region 3 table entry
+ * pmd - segment table entry
+ * pte - page table entry
+ */
+
 static pgd_t *table_root;
 
 void configure_dat(int enable)
@@ -46,54 +58,254 @@ static void mmu_enable(pgd_t *pgtable)
 	lc->pgm_new_psw.mask |= PSW_MASK_DAT;
 }
 
-static pteval_t *get_pte(pgd_t *pgtable, uintptr_t vaddr)
+/*
+ * Get the pud (region 3) DAT table entry for the given address and root,
+ * allocating it if necessary
+ */
+static inline pud_t *get_pud(pgd_t *pgtable, uintptr_t vaddr)
 {
 	pgd_t *pgd = pgd_offset(pgtable, vaddr);
 	p4d_t *p4d = p4d_alloc(pgd, vaddr);
 	pud_t *pud = pud_alloc(p4d, vaddr);
-	pmd_t *pmd = pmd_alloc(pud, vaddr);
-	pte_t *pte = pte_alloc(pmd, vaddr);
 
-	return &pte_val(*pte);
+	return pud;
+}
+
+/*
+ * Get the pmd (segment) DAT table entry for the given address and pud,
+ * allocating it if necessary.
+ * The pud must not be huge.
+ */
+static inline pmd_t *get_pmd(pud_t *pud, uintptr_t vaddr)
+{
+	pmd_t *pmd;
+
+	assert(!pud_huge(*pud));
+	pmd = pmd_alloc(pud, vaddr);
+	return pmd;
+}
+
+/*
+ * Get the pte (page) DAT table entry for the given address and pmd,
+ * allocating it if necessary.
+ * The pmd must not be large.
+ */
+static inline pte_t *get_pte(pmd_t *pmd, uintptr_t vaddr)
+{
+	pte_t *pte;
+
+	assert(!pmd_large(*pmd));
+	pte = pte_alloc(pmd, vaddr);
+	return pte;
+}
+
+/*
+ * Splits a large pmd (segment) DAT table entry into equivalent 4kB small
+ * pages.
+ * @pmd The pmd to split, it must be large.
+ * @va the virtual address corresponding to this pmd.
+ */
+static void split_pmd(pmd_t *pmd, uintptr_t va)
+{
+	phys_addr_t pa = pmd_val(*pmd) & SEGMENT_ENTRY_SFAA;
+	unsigned long i;
+	pte_t *pte;
+
+	assert(pmd_large(*pmd));
+	pte = alloc_pages(PAGE_TABLE_ORDER);
+	for (i = 0; i < PAGE_TABLE_ENTRIES; i++)
+		pte_val(pte[i]) =  pa | PAGE_SIZE * i;
+	idte_pmdp(va, &pmd_val(*pmd));
+	pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT;
+
+}
+
+/*
+ * Splits a huge pud (region 3) DAT table entry into equivalent 1MB large
+ * pages.
+ * @pud The pud to split, it must be huge.
+ * @va the virtual address corresponding to this pud.
+ */
+static void split_pud(pud_t *pud, uintptr_t va)
+{
+	phys_addr_t pa = pud_val(*pud) & REGION3_ENTRY_RFAA;
+	unsigned long i;
+	pmd_t *pmd;
+
+	assert(pud_huge(*pud));
+	pmd = alloc_pages(SEGMENT_TABLE_ORDER);
+	for (i = 0; i < SEGMENT_TABLE_ENTRIES; i++)
+		pmd_val(pmd[i]) =  pa | SZ_1M * i | SEGMENT_ENTRY_FC | SEGMENT_ENTRY_TT_SEGMENT;
+	idte_pudp(va, &pud_val(*pud));
+	pud_val(*pud) = __pa(pmd) | REGION_ENTRY_TT_REGION3 | REGION_TABLE_LENGTH;
+}
+
+void *get_dat_entry(pgd_t *pgtable, void *vaddr, unsigned int level)
+{
+	uintptr_t va = (uintptr_t)vaddr;
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	assert(level && (level <= 5));
+	pgd = pgd_offset(pgtable, va);
+	if (level == 1)
+		return pgd;
+	p4d = p4d_alloc(pgd, va);
+	if (level == 2)
+		return p4d;
+	pud = pud_alloc(p4d, va);
+
+	if (level == 3)
+		return pud;
+	if (!pud_none(*pud) && pud_huge(*pud))
+		split_pud(pud, va);
+	pmd = get_pmd(pud, va);
+	if (level == 4)
+		return pmd;
+	if (!pmd_none(*pmd) && pmd_large(*pmd))
+		split_pmd(pmd, va);
+	return get_pte(pmd, va);
+}
+
+void *split_page(pgd_t *pgtable, void *vaddr, unsigned int level)
+{
+	assert((level >= 3) && (level <= 5));
+	return get_dat_entry(pgtable ? pgtable : table_root, vaddr, level);
 }
 
 phys_addr_t virt_to_pte_phys(pgd_t *pgtable, void *vaddr)
 {
-	return (*get_pte(pgtable, (uintptr_t)vaddr) & PAGE_MASK) +
-	       ((unsigned long)vaddr & ~PAGE_MASK);
+	uintptr_t va = (uintptr_t)vaddr;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	pud = get_pud(pgtable, va);
+	if (pud_huge(*pud))
+		return (pud_val(*pud) & REGION3_ENTRY_RFAA) | (va & ~REGION3_ENTRY_RFAA);
+	pmd = get_pmd(pud, va);
+	if (pmd_large(*pmd))
+		return (pmd_val(*pmd) & SEGMENT_ENTRY_SFAA) | (va & ~SEGMENT_ENTRY_SFAA);
+	pte = get_pte(pmd, va);
+	return (pte_val(*pte) & PAGE_MASK) | (va & ~PAGE_MASK);
+}
+
+/*
+ * Get the DAT table entry of the given level for the given address,
+ * splitting if necessary. If the entry was not invalid, invalidate it, and
+ * return the pointer to the entry and, if requested, its old value.
+ * @pgtable root of the page tables
+ * @vaddr virtual address
+ * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4kB pages)
+ * @old if not NULL, will be written with the old value of the DAT table
+ * entry before invalidation
+ */
+static void *dat_get_and_invalidate(pgd_t *pgtable, void *vaddr, unsigned int level, unsigned long *old)
+{
+	unsigned long va = (unsigned long)vaddr;
+	void *ptr;
+
+	ptr = get_dat_entry(pgtable, vaddr, level);
+	if (old)
+		*old = *(unsigned long *)ptr;
+	if ((level == 1) && !pgd_none(*(pgd_t *)ptr))
+		idte_pgdp(va, ptr);
+	else if ((level == 2) && !p4d_none(*(p4d_t *)ptr))
+		idte_p4dp(va, ptr);
+	else if ((level == 3) && !pud_none(*(pud_t *)ptr))
+		idte_pudp(va, ptr);
+	else if ((level == 4) && !pmd_none(*(pmd_t *)ptr))
+		idte_pmdp(va, ptr);
+	else if (!pte_none(*(pte_t *)ptr))
+		ipte(va, ptr);
+	return ptr;
 }
 
-static pteval_t *set_pte(pgd_t *pgtable, pteval_t val, void *vaddr)
+static void cleanup_pmd(pmd_t *pmd)
 {
-	pteval_t *p_pte = get_pte(pgtable, (uintptr_t)vaddr);
+	/* was invalid or large, nothing to do */
+	if (pmd_none(*pmd) || pmd_large(*pmd))
+		return;
+	/* was not large, free the corresponding page table */
+	free_pages((void *)(pmd_val(*pmd) & PAGE_MASK));
+}
 
-	/* first flush the old entry (if we're replacing anything) */
-	if (!(*p_pte & PAGE_ENTRY_I))
-		ipte((uintptr_t)vaddr, p_pte);
+static void cleanup_pud(pud_t *pud)
+{
+	unsigned long i;
+	pmd_t *pmd;
 
-	*p_pte = val;
-	return p_pte;
+	/* was invalid or large, nothing to do */
+	if (pud_none(*pud) || pud_huge(*pud))
+		return;
+	/* recursively clean up all pmds if needed */
+	pmd = (pmd_t *)(pud_val(*pud) & PAGE_MASK);
+	for (i = 0; i < SEGMENT_TABLE_ENTRIES; i++)
+		cleanup_pmd(pmd + i);
+	/* free the corresponding segment table */
+	free_pages(pmd);
+}
+
+/*
+ * Set the DAT entry for the given level of the given virtual address. If a
+ * mapping already existed, it is overwritten. If an existing mapping with
+ * smaller pages existed, all the lower tables are freed.
+ * Returns the pointer to the DAT table entry.
+ * @pgtable root of the page tables
+ * @val the new value for the DAT table entry
+ * @vaddr the virtual address
+ * @level 3 for pud (region 3), 4 for pmd (segment) and 5 for pte (pages)
+ */
+static void *set_dat_entry(pgd_t *pgtable, unsigned long val, void *vaddr, unsigned int level)
+{
+	unsigned long old, *res;
+
+	res = dat_get_and_invalidate(pgtable, vaddr, level, &old);
+	if (level == 4)
+		cleanup_pmd((pmd_t *)&old);
+	if (level == 3)
+		cleanup_pud((pud_t *)&old);
+	*res = val;
+	return res;
 }
 
 pteval_t *install_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr)
 {
-	return set_pte(pgtable, __pa(phys), vaddr);
+	assert(IS_ALIGNED(phys, PAGE_SIZE));
+	assert(IS_ALIGNED((uintptr_t)vaddr, PAGE_SIZE));
+	return set_dat_entry(pgtable, phys, vaddr, 5);
+}
+
+pmdval_t *install_large_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr)
+{
+	assert(IS_ALIGNED(phys, SZ_1M));
+	assert(IS_ALIGNED((uintptr_t)vaddr, SZ_1M));
+	return set_dat_entry(pgtable, phys | SEGMENT_ENTRY_FC, vaddr, 4);
+}
+
+pudval_t *install_huge_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr)
+{
+	assert(IS_ALIGNED(phys, SZ_2G));
+	assert(IS_ALIGNED((uintptr_t)vaddr, SZ_2G));
+	return set_dat_entry(pgtable, phys | REGION3_ENTRY_FC | REGION_ENTRY_TT_REGION3, vaddr, 3);
 }
 
-void protect_page(void *vaddr, unsigned long prot)
+void protect_dat_entry(void *vaddr, unsigned long prot, unsigned int level)
 {
-	pteval_t *p_pte = get_pte(table_root, (uintptr_t)vaddr);
-	pteval_t n_pte = *p_pte | prot;
+	unsigned long old, *ptr;
 
-	set_pte(table_root, n_pte, vaddr);
+	ptr = dat_get_and_invalidate(table_root, vaddr, level, &old);
+	*ptr = old | prot;
 }
 
-void unprotect_page(void *vaddr, unsigned long prot)
+void unprotect_dat_entry(void *vaddr, unsigned long prot, unsigned int level)
 {
-	pteval_t *p_pte = get_pte(table_root, (uintptr_t)vaddr);
-	pteval_t n_pte = *p_pte & ~prot;
+	unsigned long old, *ptr;
 
-	set_pte(table_root, n_pte, vaddr);
+	ptr = dat_get_and_invalidate(table_root, vaddr, level, &old);
+	*ptr = old & ~prot;
 }
 
 void protect_range(void *start, unsigned long len, unsigned long prot)
@@ -102,7 +314,7 @@ void protect_range(void *start, unsigned long len, unsigned long prot)
 
 	len &= PAGE_MASK;
 	for (; len; len -= PAGE_SIZE, curr += PAGE_SIZE)
-		protect_page((void *)curr, prot);
+		protect_dat_entry((void *)curr, prot, 5);
 }
 
 void unprotect_range(void *start, unsigned long len, unsigned long prot)
@@ -111,7 +323,7 @@ void unprotect_range(void *start, unsigned long len, unsigned long prot)
 
 	len &= PAGE_MASK;
 	for (; len; len -= PAGE_SIZE, curr += PAGE_SIZE)
-		unprotect_page((void *)curr, prot);
+		unprotect_dat_entry((void *)curr, prot, 5);
 }
 
 static void setup_identity(pgd_t *pgtable, phys_addr_t start_addr,
-- 
2.31.1

[kvm-unit-tests PATCH v4 7/7] s390x: edat test

[Claudio Imbrenda]

Simple EDAT test.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/Makefile      |   1 +
 s390x/edat.c        | 274 ++++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg |   3 +
 3 files changed, 278 insertions(+)
 create mode 100644 s390x/edat.c

diff --git a/s390x/Makefile b/s390x/Makefile
index b92de9c5..26bb1684 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -21,6 +21,7 @@ tests += $(TEST_DIR)/css.elf
 tests += $(TEST_DIR)/uv-guest.elf
 tests += $(TEST_DIR)/sie.elf
 tests += $(TEST_DIR)/mvpg.elf
+tests += $(TEST_DIR)/edat.elf
 
 tests_binary = $(patsubst %.elf,%.bin,$(tests))
 ifneq ($(HOST_KEY_DOCUMENT),)
diff --git a/s390x/edat.c b/s390x/edat.c
new file mode 100644
index 00000000..0d56ed78
--- /dev/null
+++ b/s390x/edat.c
@@ -0,0 +1,274 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * EDAT test.
+ *
+ * Copyright (c) 2021 IBM Corp
+ *
+ * Authors:
+ *	Claudio Imbrenda <imbrenda@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <vmalloc.h>
+#include <asm/facility.h>
+#include <asm/interrupt.h>
+#include <mmu.h>
+#include <asm/pgtable.h>
+#include <asm-generic/barrier.h>
+
+#define PGD_PAGE_SHIFT (REGION1_SHIFT - PAGE_SHIFT)
+
+#define LC_SIZE	(2 * PAGE_SIZE)
+#define VIRT(x)	((void *)((unsigned long)(x) + (unsigned long)mem))
+
+static uint8_t prefix_buf[LC_SIZE] __attribute__((aligned(LC_SIZE)));
+static unsigned int tmp[1024] __attribute__((aligned(PAGE_SIZE)));
+static void *root, *mem, *m;
+static struct lowcore *lc;
+volatile unsigned int *p;
+
+/*
+ * Check if a non-access-list protection exception happened for the given
+ * address, in the primary address space.
+ */
+static bool check_pgm_prot(void *ptr)
+{
+	union teid teid;
+
+	if (lc->pgm_int_code != PGM_INT_CODE_PROTECTION)
+		return false;
+
+	teid.val = lc->trans_exc_id;
+
+	/*
+	 * depending on the presence of the ESOP feature, the rest of the
+	 * field might or might not be meaningful when the m field is 0.
+	 */
+	if (!teid.m)
+		return true;
+	return (!teid.acc_list_prot && !teid.asce_id &&
+		(teid.addr == ((unsigned long)ptr >> PAGE_SHIFT)));
+}
+
+static void test_dat(void)
+{
+	report_prefix_push("edat off");
+	/* disable EDAT */
+	ctl_clear_bit(0, CTL0_EDAT);
+
+	/* Check some basics */
+	p[0] = 42;
+	report(p[0] == 42, "pte, r/w");
+	p[0] = 0;
+
+	/* Write protect the page and try to write, expect a fault */
+	protect_page(m, PAGE_ENTRY_P);
+	expect_pgm_int();
+	p[0] = 42;
+	unprotect_page(m, PAGE_ENTRY_P);
+	report(!p[0] && check_pgm_prot(m), "pte, ro");
+
+	/*
+	 * The FC bit (for large pages) should be ignored because EDAT is
+	 * off. We set a value and then we try to read it back again after
+	 * setting the FC bit. This way we can check if large pages were
+	 * erroneously enabled despite EDAT being off.
+	 */
+	p[0] = 42;
+	protect_dat_entry(m, SEGMENT_ENTRY_FC, 4);
+	report(p[0] == 42, "pmd, fc=1, r/w");
+	unprotect_dat_entry(m, SEGMENT_ENTRY_FC, 4);
+	p[0] = 0;
+
+	/*
+	 * Segment protection should work even with EDAT off, try to write
+	 * anyway and expect a fault
+	 */
+	protect_dat_entry(m, SEGMENT_ENTRY_P, 4);
+	expect_pgm_int();
+	p[0] = 42;
+	report(!p[0] && check_pgm_prot(m), "pmd, ro");
+	unprotect_dat_entry(m, SEGMENT_ENTRY_P, 4);
+
+	/* The FC bit should be ignored because EDAT is off, like above */
+	p[0] = 42;
+	protect_dat_entry(m, REGION3_ENTRY_FC, 3);
+	report(p[0] == 42, "pud, fc=1, r/w");
+	unprotect_dat_entry(m, REGION3_ENTRY_FC, 3);
+	p[0] = 0;
+
+	/*
+	 * Region1/2/3 protection should not work, because EDAT is off.
+	 * Protect the various region1/2/3 entries and write, expect the
+	 * write to be successful.
+	 */
+	protect_dat_entry(m, REGION_ENTRY_P, 3);
+	p[0] = 42;
+	report(p[0] == 42, "pud, ro");
+	unprotect_dat_entry(m, REGION_ENTRY_P, 3);
+	p[0] = 0;
+
+	protect_dat_entry(m, REGION_ENTRY_P, 2);
+	p[0] = 42;
+	report(p[0] == 42, "p4d, ro");
+	unprotect_dat_entry(m, REGION_ENTRY_P, 2);
+	p[0] = 0;
+
+	protect_dat_entry(m, REGION_ENTRY_P, 1);
+	p[0] = 42;
+	report(p[0] == 42, "pgd, ro");
+	unprotect_dat_entry(m, REGION_ENTRY_P, 1);
+	p[0] = 0;
+
+	report_prefix_pop();
+}
+
+static void test_edat1(void)
+{
+	report_prefix_push("edat1");
+	/* Enable EDAT */
+	ctl_set_bit(0, CTL0_EDAT);
+	p[0] = 0;
+
+	/*
+	 * Segment protection should work normally, try to write and expect
+	 * a fault.
+	 */
+	expect_pgm_int();
+	protect_dat_entry(m, SEGMENT_ENTRY_P, 4);
+	p[0] = 42;
+	report(!p[0] && check_pgm_prot(m), "pmd, ro");
+	unprotect_dat_entry(m, SEGMENT_ENTRY_P, 4);
+
+	/*
+	 * Region1/2/3 protection should work now, because EDAT is on. Try
+	 * to write anyway and expect a fault.
+	 */
+	expect_pgm_int();
+	protect_dat_entry(m, REGION_ENTRY_P, 3);
+	p[0] = 42;
+	report(!p[0] && check_pgm_prot(m), "pud, ro");
+	unprotect_dat_entry(m, REGION_ENTRY_P, 3);
+
+	expect_pgm_int();
+	protect_dat_entry(m, REGION_ENTRY_P, 2);
+	p[0] = 42;
+	report(!p[0] && check_pgm_prot(m), "p4d, ro");
+	unprotect_dat_entry(m, REGION_ENTRY_P, 2);
+
+	expect_pgm_int();
+	protect_dat_entry(m, REGION_ENTRY_P, 1);
+	p[0] = 42;
+	report(!p[0] && check_pgm_prot(m), "pgd, ro");
+	unprotect_dat_entry(m, REGION_ENTRY_P, 1);
+
+	/* Large pages should work */
+	p[0] = 42;
+	install_large_page(root, 0, mem);
+	report(p[0] == 42, "pmd, large");
+
+	/*
+	 * Prefixing should not work with large pages. Since the lower
+	 * addresses are mapped with small pages, which are subject to
+	 * prefixing, and the pages mapped with large pages are not subject
+	 * to prefixing, this is the resulting scenario:
+	 *
+	 * virtual 0 = real 0 -> absolute prefix_buf
+	 * virtual prefix_buf = real prefix_buf -> absolute 0
+	 * VIRT(0) -> absolute 0
+	 * VIRT(prefix_buf) -> absolute prefix_buf
+	 *
+	 * The testcase checks if the memory at virtual 0 has the same
+	 * content as the memory at VIRT(prefix_buf) and the memory at
+	 * VIRT(0) has the same content as the memory at virtual prefix_buf.
+	 * If prefixing is erroneously applied for large pages, the testcase
+	 * will therefore fail.
+	 */
+	report(!memcmp(0, VIRT(prefix_buf), LC_SIZE) &&
+		!memcmp(prefix_buf, VIRT(0), LC_SIZE),
+		"pmd, large, prefixing");
+
+	report_prefix_pop();
+}
+
+static void test_edat2(void)
+{
+	report_prefix_push("edat2");
+	p[0] = 42;
+
+	/* Huge pages should work */
+	install_huge_page(root, 0, mem);
+	report(p[0] == 42, "pud, huge");
+
+	/* Prefixing should not work with huge pages, just like large pages */
+	report(!memcmp(0, VIRT(prefix_buf), LC_SIZE) &&
+		!memcmp(prefix_buf, VIRT(0), LC_SIZE),
+		"pmd, large, prefixing");
+
+	report_prefix_pop();
+}
+
+static unsigned int setup(void)
+{
+	bool has_edat1 = test_facility(8);
+	bool has_edat2 = test_facility(78);
+	unsigned long pa, va;
+
+	if (has_edat2 && !has_edat1)
+		report_abort("EDAT2 available, but EDAT1 not available");
+
+	/* Setup DAT 1:1 mapping and memory management */
+	setup_vm();
+	root = (void *)(stctg(1) & PAGE_MASK);
+
+	/*
+	 * Get a pgd worth of virtual memory, so we can test things later
+	 * without interfering with the test code or the interrupt handler
+	 */
+	mem = alloc_vpages_aligned(BIT_ULL(PGD_PAGE_SHIFT), PGD_PAGE_SHIFT);
+	assert(mem);
+	va = (unsigned long)mem;
+
+	/* Map the first 1GB of real memory */
+	for (pa = 0; pa < SZ_1G; pa += PAGE_SIZE, va += PAGE_SIZE)
+		install_page(root, pa, (void *)va);
+
+	/*
+	 * Move the lowcore to a known non-zero location. This is needed
+	 * later to check whether prefixing is working with large pages.
+	 */
+	assert((unsigned long)&prefix_buf < SZ_2G);
+	memcpy(prefix_buf, 0, LC_SIZE);
+	set_prefix((uint32_t)(uintptr_t)prefix_buf);
+	/* Clear the old copy */
+	memset(prefix_buf, 0, LC_SIZE);
+
+	/* m will point to tmp through the new virtual mapping */
+	m = VIRT(&tmp);
+	/* p is the same as m but volatile */
+	p = (volatile unsigned int *)m;
+
+	return has_edat1 + has_edat2;
+}
+
+int main(void)
+{
+	unsigned int edat;
+
+	report_prefix_push("edat");
+	edat = setup();
+
+	test_dat();
+
+	if (edat)
+		test_edat1();
+	else
+		report_skip("EDAT not available");
+
+	if (edat >= 2)
+		test_edat2();
+	else
+		report_skip("EDAT2 not available");
+
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 9f81a608..a0ec8864 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -103,3 +103,6 @@ file = sie.elf
 [mvpg]
 file = mvpg.elf
 timeout = 10
+
+[edat]
+file = edat.elf
-- 
2.31.1

Re: [kvm-unit-tests PATCH v4 3/7] s390x: lib: fix pgtable.h

[Janosch Frank]

On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> Fix pgtable.h:
> 
> * SEGMENT_ENTRY_SFAA had one extra bit set
> * pmd entries don't have a length field
> * ipte does not need to clear the lower bits
>  - clearing the 12 lower bits is technically incorrect, as page tables are
>    architecturally aligned to 11 bit addresses (even though the unit tests
>    allocate always one full page)
> * region table entries should use REGION_ENTRY_TL instead of *_TABLE_LENGTH
>  - *_TABLE_LENGTH need to stay, because they should be used for ASCEs
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

> ---
>  lib/s390x/asm/pgtable.h | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/s390x/asm/pgtable.h b/lib/s390x/asm/pgtable.h
> index 277f3480..1a21f175 100644
> --- a/lib/s390x/asm/pgtable.h
> +++ b/lib/s390x/asm/pgtable.h
> @@ -60,7 +60,7 @@
>  #define SEGMENT_SHIFT			20
>  
>  #define SEGMENT_ENTRY_ORIGIN		0xfffffffffffff800UL
> -#define SEGMENT_ENTRY_SFAA		0xfffffffffff80000UL
> +#define SEGMENT_ENTRY_SFAA		0xfffffffffff00000UL
>  #define SEGMENT_ENTRY_AV		0x0000000000010000UL
>  #define SEGMENT_ENTRY_ACC		0x000000000000f000UL
>  #define SEGMENT_ENTRY_F			0x0000000000000800UL
> @@ -143,7 +143,7 @@ static inline p4d_t *p4d_alloc(pgd_t *pgd, unsigned long addr)
>  	if (pgd_none(*pgd)) {
>  		p4d_t *p4d = p4d_alloc_one();
>  		pgd_val(*pgd) = __pa(p4d) | REGION_ENTRY_TT_REGION1 |
> -				REGION_TABLE_LENGTH;
> +				REGION_ENTRY_TL;
>  	}
>  	return p4d_offset(pgd, addr);
>  }
> @@ -163,7 +163,7 @@ static inline pud_t *pud_alloc(p4d_t *p4d, unsigned long addr)
>  	if (p4d_none(*p4d)) {
>  		pud_t *pud = pud_alloc_one();
>  		p4d_val(*p4d) = __pa(pud) | REGION_ENTRY_TT_REGION2 |
> -				REGION_TABLE_LENGTH;
> +				REGION_ENTRY_TL;
>  	}
>  	return pud_offset(p4d, addr);
>  }
> @@ -183,7 +183,7 @@ static inline pmd_t *pmd_alloc(pud_t *pud, unsigned long addr)
>  	if (pud_none(*pud)) {
>  		pmd_t *pmd = pmd_alloc_one();
>  		pud_val(*pud) = __pa(pmd) | REGION_ENTRY_TT_REGION3 |
> -				REGION_TABLE_LENGTH;
> +				REGION_ENTRY_TL;
>  	}
>  	return pmd_offset(pud, addr);
>  }
> @@ -202,15 +202,14 @@ static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr)
>  {
>  	if (pmd_none(*pmd)) {
>  		pte_t *pte = pte_alloc_one();
> -		pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT |
> -				SEGMENT_TABLE_LENGTH;
> +		pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT;
>  	}
>  	return pte_offset(pmd, addr);
>  }
>  
>  static inline void ipte(unsigned long vaddr, pteval_t *p_pte)
>  {
> -	unsigned long table_origin = (unsigned long)p_pte & PAGE_MASK;
> +	unsigned long table_origin = (unsigned long)p_pte;
>  
>  	asm volatile(
>  		"	ipte %0,%1\n"
> 

Re: [kvm-unit-tests PATCH v4 5/7] s390x: lib: add teid union and clear teid from lowcore

[Janosch Frank]

On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> Add a union to represent Translation-Exception Identification (TEID).
> 
> Clear the TEID in expect_pgm_int clear_pgm_int.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

> ---
>  lib/s390x/asm/interrupt.h | 22 ++++++++++++++++++++++
>  lib/s390x/interrupt.c     |  2 ++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
> index bf0eb40d..b40def65 100644
> --- a/lib/s390x/asm/interrupt.h
> +++ b/lib/s390x/asm/interrupt.h
> @@ -13,6 +13,28 @@
>  #define EXT_IRQ_EXTERNAL_CALL	0x1202
>  #define EXT_IRQ_SERVICE_SIG	0x2401
>  
> +#define TEID_ASCE_PRIMARY	0
> +#define TEID_ASCE_AR		1
> +#define TEID_ASCE_SECONDARY	2
> +#define TEID_ASCE_HOME		3
> +
> +union teid {
> +	unsigned long val;
> +	struct {
> +		unsigned long addr:52;
> +		unsigned long fetch:1;
> +		unsigned long store:1;
> +		unsigned long reserved:6;
> +		unsigned long acc_list_prot:1;
> +		/* depending on the exception and the installed facilities,
> +		 * the m field can indicate severel different things,

several

> +		 * including whether the exception was triggered by a MVPG
> +		 * instruction, or whether the addr field is meaningful */

Could you please convert the comment style to this?

/*
 * Text
 */

> +		unsigned long m:1;
> +		unsigned long asce_id:2;
> +	};
> +};
> +
>  void register_pgm_cleanup_func(void (*f)(void));
>  void handle_pgm_int(struct stack_frame_int *stack);
>  void handle_ext_int(struct stack_frame_int *stack);
> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
> index ce0003de..b627942f 100644
> --- a/lib/s390x/interrupt.c
> +++ b/lib/s390x/interrupt.c
> @@ -22,6 +22,7 @@ void expect_pgm_int(void)
>  {
>  	pgm_int_expected = true;
>  	lc->pgm_int_code = 0;
> +	lc->trans_exc_id = 0;
>  	mb();
>  }
>  
> @@ -39,6 +40,7 @@ uint16_t clear_pgm_int(void)
>  	mb();
>  	code = lc->pgm_int_code;
>  	lc->pgm_int_code = 0;
> +	lc->trans_exc_id = 0;
>  	pgm_int_expected = false;
>  	return code;
>  }
> 

Re: [kvm-unit-tests PATCH v4 5/7] s390x: lib: add teid union and clear teid from lowcore

[Claudio Imbrenda]

On Thu, 27 May 2021 16:52:48 +0200
Janosch Frank <frankja@linux.ibm.com> wrote:

> On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> > Add a union to represent Translation-Exception Identification
> > (TEID).
> > 
> > Clear the TEID in expect_pgm_int clear_pgm_int.
> > 
> > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>  
> 
> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
> 
> > ---
> >  lib/s390x/asm/interrupt.h | 22 ++++++++++++++++++++++
> >  lib/s390x/interrupt.c     |  2 ++
> >  2 files changed, 24 insertions(+)
> > 
> > diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
> > index bf0eb40d..b40def65 100644
> > --- a/lib/s390x/asm/interrupt.h
> > +++ b/lib/s390x/asm/interrupt.h
> > @@ -13,6 +13,28 @@
> >  #define EXT_IRQ_EXTERNAL_CALL	0x1202
> >  #define EXT_IRQ_SERVICE_SIG	0x2401
> >  
> > +#define TEID_ASCE_PRIMARY	0
> > +#define TEID_ASCE_AR		1
> > +#define TEID_ASCE_SECONDARY	2
> > +#define TEID_ASCE_HOME		3
> > +
> > +union teid {
> > +	unsigned long val;
> > +	struct {
> > +		unsigned long addr:52;
> > +		unsigned long fetch:1;
> > +		unsigned long store:1;
> > +		unsigned long reserved:6;
> > +		unsigned long acc_list_prot:1;
> > +		/* depending on the exception and the installed
> > facilities,
> > +		 * the m field can indicate severel different
> > things,  
> 
> several

fixed

> > +		 * including whether the exception was triggered
> > by a MVPG
> > +		 * instruction, or whether the addr field is
> > meaningful */  
> 
> Could you please convert the comment style to this?
> 
> /*
>  * Text
>  */

and fixed

> > +		unsigned long m:1;
> > +		unsigned long asce_id:2;
> > +	};
> > +};
> > +
> >  void register_pgm_cleanup_func(void (*f)(void));
> >  void handle_pgm_int(struct stack_frame_int *stack);
> >  void handle_ext_int(struct stack_frame_int *stack);
> > diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
> > index ce0003de..b627942f 100644
> > --- a/lib/s390x/interrupt.c
> > +++ b/lib/s390x/interrupt.c
> > @@ -22,6 +22,7 @@ void expect_pgm_int(void)
> >  {
> >  	pgm_int_expected = true;
> >  	lc->pgm_int_code = 0;
> > +	lc->trans_exc_id = 0;
> >  	mb();
> >  }
> >  
> > @@ -39,6 +40,7 @@ uint16_t clear_pgm_int(void)
> >  	mb();
> >  	code = lc->pgm_int_code;
> >  	lc->pgm_int_code = 0;
> > +	lc->trans_exc_id = 0;
> >  	pgm_int_expected = false;
> >  	return code;
> >  }
> >   
> 

Re: [kvm-unit-tests PATCH v4 6/7] s390x: mmu: add support for large pages

[Janosch Frank]

On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> Add support for 1M and 2G pages.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
>  lib/s390x/mmu.h |  73 +++++++++++++-
>  lib/s390x/mmu.c | 260 +++++++++++++++++++++++++++++++++++++++++++-----
>  2 files changed, 307 insertions(+), 26 deletions(-)
> 
> diff --git a/lib/s390x/mmu.h b/lib/s390x/mmu.h
> index 603f289e..93208467 100644
> --- a/lib/s390x/mmu.h
> +++ b/lib/s390x/mmu.h
> @@ -10,9 +10,78 @@
>  #ifndef _ASMS390X_MMU_H_
>  #define _ASMS390X_MMU_H_
>  
> -void protect_page(void *vaddr, unsigned long prot);
> +/*
> + * Splits the pagetables down to the given DAT tables level.
> + * Returns a pointer to the DAT table entry of the given level.
> + * @pgtable root of the page table tree
> + * @vaddr address whose page tables are to split
> + * @level 3 (for 2GB pud), 4 (for 1 MB pmd) or 5 (for 4KB pages)
> + */
> +void *split_page(pgd_t *pgtable, void *vaddr, unsigned int level);
> +
> +/*
> + * Applies the given protection bits to the given DAT tables level,
> + * splitting if necessary.
> + * @pgtable root of the page table tree
> + * @vaddr address whose protection bits are to be changed
> + * @prot the protection bits to set
> + * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4KB pages)
> + */
> +void protect_dat_entry(void *vaddr, unsigned long prot, unsigned int level);
> +/*
> + * Clears the given protection bits from the given DAT tables level,
> + * splitting if necessary.
> + * @pgtable root of the page table tree
> + * @vaddr address whose protection bits are to be changed
> + * @prot the protection bits to clear
> + * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4kB pages)
> + */
> +void unprotect_dat_entry(void *vaddr, unsigned long prot, unsigned int level);
> +
> +/*
> + * Applies the given protection bits to the given 4kB pages range,
> + * splitting if necessary.
> + * @start starting address whose protection bits are to be changed
> + * @len size in bytes
> + * @prot the protection bits to set
> + */
>  void protect_range(void *start, unsigned long len, unsigned long prot);
> -void unprotect_page(void *vaddr, unsigned long prot);
> +/*
> + * Clears the given protection bits from the given 4kB pages range,
> + * splitting if necessary.
> + * @start starting address whose protection bits are to be changed
> + * @len size in bytes
> + * @prot the protection bits to set
> + */
>  void unprotect_range(void *start, unsigned long len, unsigned long prot);
>  
> +/* Similar to install_page, maps the virtual address to the physical address
> + * for the given page tables, using 1MB large pages.
> + * Returns a pointer to the DAT table entry.
> + * @pgtable root of the page table tree
> + * @phys physical address to map, must be 1MB aligned!
> + * @vaddr virtual address to map, must be 1MB aligned!
> + */
> +pmdval_t *install_large_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr);
> +
> +/* Similar to install_page, maps the virtual address to the physical address
> + * for the given page tables, using 2GB huge pages.
> + * Returns a pointer to the DAT table entry.
> + * @pgtable root of the page table tree
> + * @phys physical address to map, must be 2GB aligned!
> + * @vaddr virtual address to map, must be 2GB aligned!
> + */
> +pudval_t *install_huge_page(pgd_t *pgtable, phys_addr_t phys, void *vaddr);
> +
> +static inline void protect_page(void *vaddr, unsigned long prot)
> +{
> +	protect_dat_entry(vaddr, prot, 5);
> +}
> +
> +static inline void unprotect_page(void *vaddr, unsigned long prot)
> +{
> +	unprotect_dat_entry(vaddr, prot, 5);
> +}

\n

> +void *get_dat_entry(pgd_t *pgtable, void *vaddr, unsigned int level);
> +
>  #endif /* _ASMS390X_MMU_H_ */
> diff --git a/lib/s390x/mmu.c b/lib/s390x/mmu.c
> index 5c517366..def91334 100644
> --- a/lib/s390x/mmu.c
> +++ b/lib/s390x/mmu.c
> @@ -15,6 +15,18 @@
>  #include <vmalloc.h>
>  #include "mmu.h"
>  
> +/*
> + * The naming convention used here is the same as used in the Linux kernel,
> + * and this is the corrispondence between the s390x architectural names and

corresponds

> + * the Linux ones:
> + *
> + * pgd - region 1 table entry
> + * p4d - region 2 table entry
> + * pud - region 3 table entry
> + * pmd - segment table entry
> + * pte - page table entry
> + */
> +
>  static pgd_t *table_root;
>  
>  void configure_dat(int enable)
> @@ -46,54 +58,254 @@ static void mmu_enable(pgd_t *pgtable)
>  	lc->pgm_new_psw.mask |= PSW_MASK_DAT;
>  }
>  
> -static pteval_t *get_pte(pgd_t *pgtable, uintptr_t vaddr)
> +/*
> + * Get the pud (region 3) DAT table entry for the given address and root,
> + * allocating it if necessary
> + */
> +static inline pud_t *get_pud(pgd_t *pgtable, uintptr_t vaddr)
>  {
>  	pgd_t *pgd = pgd_offset(pgtable, vaddr);
>  	p4d_t *p4d = p4d_alloc(pgd, vaddr);
>  	pud_t *pud = pud_alloc(p4d, vaddr);
> -	pmd_t *pmd = pmd_alloc(pud, vaddr);
> -	pte_t *pte = pte_alloc(pmd, vaddr);
>  
> -	return &pte_val(*pte);
> +	return pud;
> +}
> +
> +/*
> + * Get the pmd (segment) DAT table entry for the given address and pud,
> + * allocating it if necessary.
> + * The pud must not be huge.
> + */
> +static inline pmd_t *get_pmd(pud_t *pud, uintptr_t vaddr)
> +{
> +	pmd_t *pmd;
> +
> +	assert(!pud_huge(*pud));
> +	pmd = pmd_alloc(pud, vaddr);

Don't we have the *_alloc_map() functions in the kernel whic either map
or allocate? I'd prefer that naming over *_alloc() if you also map if
already allocated.

> +	return pmd;
> +}
> +
> +/*
> + * Get the pte (page) DAT table entry for the given address and pmd,
> + * allocating it if necessary.
> + * The pmd must not be large.
> + */
> +static inline pte_t *get_pte(pmd_t *pmd, uintptr_t vaddr)
> +{
> +	pte_t *pte;
> +
> +	assert(!pmd_large(*pmd));
> +	pte = pte_alloc(pmd, vaddr);
> +	return pte;
> +}
> +
> +/*
> + * Splits a large pmd (segment) DAT table entry into equivalent 4kB small
> + * pages.
> + * @pmd The pmd to split, it must be large.
> + * @va the virtual address corresponding to this pmd.
> + */
> +static void split_pmd(pmd_t *pmd, uintptr_t va)
> +{
> +	phys_addr_t pa = pmd_val(*pmd) & SEGMENT_ENTRY_SFAA;
> +	unsigned long i;
> +	pte_t *pte;
> +
> +	assert(pmd_large(*pmd));
> +	pte = alloc_pages(PAGE_TABLE_ORDER);
> +	for (i = 0; i < PAGE_TABLE_ENTRIES; i++)
> +		pte_val(pte[i]) =  pa | PAGE_SIZE * i;
> +	idte_pmdp(va, &pmd_val(*pmd));
> +	pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT;

Equivalent would mean we carry over protection, no?

> +
> +}
> +
> +/*
> + * Splits a huge pud (region 3) DAT table entry into equivalent 1MB large
> + * pages.
> + * @pud The pud to split, it must be huge.
> + * @va the virtual address corresponding to this pud.
> + */
> +static void split_pud(pud_t *pud, uintptr_t va)
> +{
> +	phys_addr_t pa = pud_val(*pud) & REGION3_ENTRY_RFAA;
> +	unsigned long i;
> +	pmd_t *pmd;
> +
> +	assert(pud_huge(*pud));
> +	pmd = alloc_pages(SEGMENT_TABLE_ORDER);
> +	for (i = 0; i < SEGMENT_TABLE_ENTRIES; i++)
> +		pmd_val(pmd[i]) =  pa | SZ_1M * i | SEGMENT_ENTRY_FC | SEGMENT_ENTRY_TT_SEGMENT;
> +	idte_pudp(va, &pud_val(*pud));
> +	pud_val(*pud) = __pa(pmd) | REGION_ENTRY_TT_REGION3 | REGION_TABLE_LENGTH;
> +}

Re: [kvm-unit-tests PATCH v4 6/7] s390x: mmu: add support for large pages

[Claudio Imbrenda]

On Fri, 28 May 2021 10:44:32 +0200
Janosch Frank <frankja@linux.ibm.com> wrote:

> On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> > Add support for 1M and 2G pages.
> > 
> > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> > ---
> >  lib/s390x/mmu.h |  73 +++++++++++++-
> >  lib/s390x/mmu.c | 260
> > +++++++++++++++++++++++++++++++++++++++++++----- 2 files changed,
> > 307 insertions(+), 26 deletions(-)
> > 
> > diff --git a/lib/s390x/mmu.h b/lib/s390x/mmu.h
> > index 603f289e..93208467 100644
> > --- a/lib/s390x/mmu.h
> > +++ b/lib/s390x/mmu.h
> > @@ -10,9 +10,78 @@
> >  #ifndef _ASMS390X_MMU_H_
> >  #define _ASMS390X_MMU_H_
> >  
> > -void protect_page(void *vaddr, unsigned long prot);
> > +/*
> > + * Splits the pagetables down to the given DAT tables level.
> > + * Returns a pointer to the DAT table entry of the given level.
> > + * @pgtable root of the page table tree
> > + * @vaddr address whose page tables are to split
> > + * @level 3 (for 2GB pud), 4 (for 1 MB pmd) or 5 (for 4KB pages)
> > + */
> > +void *split_page(pgd_t *pgtable, void *vaddr, unsigned int level);
> > +
> > +/*
> > + * Applies the given protection bits to the given DAT tables level,
> > + * splitting if necessary.
> > + * @pgtable root of the page table tree
> > + * @vaddr address whose protection bits are to be changed
> > + * @prot the protection bits to set
> > + * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4KB pages)
> > + */
> > +void protect_dat_entry(void *vaddr, unsigned long prot, unsigned
> > int level); +/*
> > + * Clears the given protection bits from the given DAT tables
> > level,
> > + * splitting if necessary.
> > + * @pgtable root of the page table tree
> > + * @vaddr address whose protection bits are to be changed
> > + * @prot the protection bits to clear
> > + * @level 3 (for 2GB pud), 4 (for 1MB pmd) or 5 (for 4kB pages)
> > + */
> > +void unprotect_dat_entry(void *vaddr, unsigned long prot, unsigned
> > int level); +
> > +/*
> > + * Applies the given protection bits to the given 4kB pages range,
> > + * splitting if necessary.
> > + * @start starting address whose protection bits are to be changed
> > + * @len size in bytes
> > + * @prot the protection bits to set
> > + */
> >  void protect_range(void *start, unsigned long len, unsigned long
> > prot); -void unprotect_page(void *vaddr, unsigned long prot);
> > +/*
> > + * Clears the given protection bits from the given 4kB pages range,
> > + * splitting if necessary.
> > + * @start starting address whose protection bits are to be changed
> > + * @len size in bytes
> > + * @prot the protection bits to set
> > + */
> >  void unprotect_range(void *start, unsigned long len, unsigned long
> > prot); 
> > +/* Similar to install_page, maps the virtual address to the
> > physical address
> > + * for the given page tables, using 1MB large pages.
> > + * Returns a pointer to the DAT table entry.
> > + * @pgtable root of the page table tree
> > + * @phys physical address to map, must be 1MB aligned!
> > + * @vaddr virtual address to map, must be 1MB aligned!
> > + */
> > +pmdval_t *install_large_page(pgd_t *pgtable, phys_addr_t phys,
> > void *vaddr); +
> > +/* Similar to install_page, maps the virtual address to the
> > physical address
> > + * for the given page tables, using 2GB huge pages.
> > + * Returns a pointer to the DAT table entry.
> > + * @pgtable root of the page table tree
> > + * @phys physical address to map, must be 2GB aligned!
> > + * @vaddr virtual address to map, must be 2GB aligned!
> > + */
> > +pudval_t *install_huge_page(pgd_t *pgtable, phys_addr_t phys, void
> > *vaddr); +
> > +static inline void protect_page(void *vaddr, unsigned long prot)
> > +{
> > +	protect_dat_entry(vaddr, prot, 5);
> > +}
> > +
> > +static inline void unprotect_page(void *vaddr, unsigned long prot)
> > +{
> > +	unprotect_dat_entry(vaddr, prot, 5);
> > +}  
> 
> \n
> 
> > +void *get_dat_entry(pgd_t *pgtable, void *vaddr, unsigned int
> > level); +
> >  #endif /* _ASMS390X_MMU_H_ */
> > diff --git a/lib/s390x/mmu.c b/lib/s390x/mmu.c
> > index 5c517366..def91334 100644
> > --- a/lib/s390x/mmu.c
> > +++ b/lib/s390x/mmu.c
> > @@ -15,6 +15,18 @@
> >  #include <vmalloc.h>
> >  #include "mmu.h"
> >  
> > +/*
> > + * The naming convention used here is the same as used in the
> > Linux kernel,
> > + * and this is the corrispondence between the s390x architectural
> > names and  
> 
> corresponds

oops

> > + * the Linux ones:
> > + *
> > + * pgd - region 1 table entry
> > + * p4d - region 2 table entry
> > + * pud - region 3 table entry
> > + * pmd - segment table entry
> > + * pte - page table entry
> > + */
> > +
> >  static pgd_t *table_root;
> >  
> >  void configure_dat(int enable)
> > @@ -46,54 +58,254 @@ static void mmu_enable(pgd_t *pgtable)
> >  	lc->pgm_new_psw.mask |= PSW_MASK_DAT;
> >  }
> >  
> > -static pteval_t *get_pte(pgd_t *pgtable, uintptr_t vaddr)
> > +/*
> > + * Get the pud (region 3) DAT table entry for the given address
> > and root,
> > + * allocating it if necessary
> > + */
> > +static inline pud_t *get_pud(pgd_t *pgtable, uintptr_t vaddr)
> >  {
> >  	pgd_t *pgd = pgd_offset(pgtable, vaddr);
> >  	p4d_t *p4d = p4d_alloc(pgd, vaddr);
> >  	pud_t *pud = pud_alloc(p4d, vaddr);
> > -	pmd_t *pmd = pmd_alloc(pud, vaddr);
> > -	pte_t *pte = pte_alloc(pmd, vaddr);
> >  
> > -	return &pte_val(*pte);
> > +	return pud;
> > +}
> > +
> > +/*
> > + * Get the pmd (segment) DAT table entry for the given address and
> > pud,
> > + * allocating it if necessary.
> > + * The pud must not be huge.
> > + */
> > +static inline pmd_t *get_pmd(pud_t *pud, uintptr_t vaddr)
> > +{
> > +	pmd_t *pmd;
> > +
> > +	assert(!pud_huge(*pud));
> > +	pmd = pmd_alloc(pud, vaddr);  
> 
> Don't we have the *_alloc_map() functions in the kernel whic either
> map or allocate? I'd prefer that naming over *_alloc() if you also
> map if already allocated.

the functions existed already, I'm only reusing them.

> > +	return pmd;
> > +}
> > +
> > +/*
> > + * Get the pte (page) DAT table entry for the given address and
> > pmd,
> > + * allocating it if necessary.
> > + * The pmd must not be large.
> > + */
> > +static inline pte_t *get_pte(pmd_t *pmd, uintptr_t vaddr)
> > +{
> > +	pte_t *pte;
> > +
> > +	assert(!pmd_large(*pmd));
> > +	pte = pte_alloc(pmd, vaddr);
> > +	return pte;
> > +}
> > +
> > +/*
> > + * Splits a large pmd (segment) DAT table entry into equivalent
> > 4kB small
> > + * pages.
> > + * @pmd The pmd to split, it must be large.
> > + * @va the virtual address corresponding to this pmd.
> > + */
> > +static void split_pmd(pmd_t *pmd, uintptr_t va)
> > +{
> > +	phys_addr_t pa = pmd_val(*pmd) & SEGMENT_ENTRY_SFAA;
> > +	unsigned long i;
> > +	pte_t *pte;
> > +
> > +	assert(pmd_large(*pmd));
> > +	pte = alloc_pages(PAGE_TABLE_ORDER);
> > +	for (i = 0; i < PAGE_TABLE_ENTRIES; i++)
> > +		pte_val(pte[i]) =  pa | PAGE_SIZE * i;
> > +	idte_pmdp(va, &pmd_val(*pmd));
> > +	pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT;  
> 
> Equivalent would mean we carry over protection, no?

that is a good point... I will need to fix it

> > +
> > +}
> > +
> > +/*
> > + * Splits a huge pud (region 3) DAT table entry into equivalent
> > 1MB large
> > + * pages.
> > + * @pud The pud to split, it must be huge.
> > + * @va the virtual address corresponding to this pud.
> > + */
> > +static void split_pud(pud_t *pud, uintptr_t va)
> > +{
> > +	phys_addr_t pa = pud_val(*pud) & REGION3_ENTRY_RFAA;
> > +	unsigned long i;
> > +	pmd_t *pmd;
> > +
> > +	assert(pud_huge(*pud));
> > +	pmd = alloc_pages(SEGMENT_TABLE_ORDER);
> > +	for (i = 0; i < SEGMENT_TABLE_ENTRIES; i++)
> > +		pmd_val(pmd[i]) =  pa | SZ_1M * i |
> > SEGMENT_ENTRY_FC | SEGMENT_ENTRY_TT_SEGMENT;
> > +	idte_pudp(va, &pud_val(*pud));
> > +	pud_val(*pud) = __pa(pmd) | REGION_ENTRY_TT_REGION3 |
> > REGION_TABLE_LENGTH; +}  

Re: [kvm-unit-tests PATCH v4 7/7] s390x: edat test

[Janosch Frank]

On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> Simple EDAT test.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Some nits below.
Acked-by Janosch Frank <frankja@linux.ibm.com>

> ---
>  s390x/Makefile      |   1 +
>  s390x/edat.c        | 274 ++++++++++++++++++++++++++++++++++++++++++++
>  s390x/unittests.cfg |   3 +
>  3 files changed, 278 insertions(+)
>  create mode 100644 s390x/edat.c
> 
> diff --git a/s390x/Makefile b/s390x/Makefile
> index b92de9c5..26bb1684 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -21,6 +21,7 @@ tests += $(TEST_DIR)/css.elf
>  tests += $(TEST_DIR)/uv-guest.elf
>  tests += $(TEST_DIR)/sie.elf
>  tests += $(TEST_DIR)/mvpg.elf
> +tests += $(TEST_DIR)/edat.elf
>  
>  tests_binary = $(patsubst %.elf,%.bin,$(tests))
>  ifneq ($(HOST_KEY_DOCUMENT),)
> diff --git a/s390x/edat.c b/s390x/edat.c
> new file mode 100644
> index 00000000..0d56ed78
> --- /dev/null
> +++ b/s390x/edat.c
> @@ -0,0 +1,274 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * EDAT test.
> + *
> + * Copyright (c) 2021 IBM Corp
> + *
> + * Authors:
> + *	Claudio Imbrenda <imbrenda@linux.ibm.com>
> + */
> +#include <libcflat.h>
> +#include <vmalloc.h>
> +#include <asm/facility.h>
> +#include <asm/interrupt.h>
> +#include <mmu.h>
> +#include <asm/pgtable.h>
> +#include <asm-generic/barrier.h>
> +
> +#define PGD_PAGE_SHIFT (REGION1_SHIFT - PAGE_SHIFT)
> +
> +#define LC_SIZE	(2 * PAGE_SIZE)
> +#define VIRT(x)	((void *)((unsigned long)(x) + (unsigned long)mem))
> +
> +static uint8_t prefix_buf[LC_SIZE] __attribute__((aligned(LC_SIZE)));
> +static unsigned int tmp[1024] __attribute__((aligned(PAGE_SIZE)));
> +static void *root, *mem, *m;
> +static struct lowcore *lc;
> +volatile unsigned int *p;
> +
> +/*
> + * Check if a non-access-list protection exception happened for the given
> + * address, in the primary address space.
> + */
> +static bool check_pgm_prot(void *ptr)
> +{
> +	union teid teid;
> +
> +	if (lc->pgm_int_code != PGM_INT_CODE_PROTECTION)
> +		return false;
> +
> +	teid.val = lc->trans_exc_id;
> +
> +	/*
> +	 * depending on the presence of the ESOP feature, the rest of the
> +	 * field might or might not be meaningful when the m field is 0.
> +	 */
> +	if (!teid.m)
> +		return true;
> +	return (!teid.acc_list_prot && !teid.asce_id &&
> +		(teid.addr == ((unsigned long)ptr >> PAGE_SHIFT)));
> +}
> +
> +static void test_dat(void)
> +{
> +	report_prefix_push("edat off");
> +	/* disable EDAT */
> +	ctl_clear_bit(0, CTL0_EDAT);
> +
> +	/* Check some basics */
> +	p[0] = 42;
> +	report(p[0] == 42, "pte, r/w");
> +	p[0] = 0;
> +
> +	/* Write protect the page and try to write, expect a fault */
> +	protect_page(m, PAGE_ENTRY_P);
> +	expect_pgm_int();
> +	p[0] = 42;
> +	unprotect_page(m, PAGE_ENTRY_P);
> +	report(!p[0] && check_pgm_prot(m), "pte, ro");
> +
> +	/*
> +	 * The FC bit (for large pages) should be ignored because EDAT is
> +	 * off. We set a value and then we try to read it back again after
> +	 * setting the FC bit. This way we can check if large pages were
> +	 * erroneously enabled despite EDAT being off.
> +	 */
> +	p[0] = 42;
> +	protect_dat_entry(m, SEGMENT_ENTRY_FC, 4);
> +	report(p[0] == 42, "pmd, fc=1, r/w");
> +	unprotect_dat_entry(m, SEGMENT_ENTRY_FC, 4);
> +	p[0] = 0;

Could we pack that into a function and re-use it for the checks below?

> +
> +	/*
> +	 * Segment protection should work even with EDAT off, try to write
> +	 * anyway and expect a fault
> +	 */
> +	protect_dat_entry(m, SEGMENT_ENTRY_P, 4);

These page table level magic constants give me a headache.
PGTABLE_LEVEL_PMD ?

> +	expect_pgm_int();
> +	p[0] = 42;
> +	report(!p[0] && check_pgm_prot(m), "pmd, ro");
> +	unprotect_dat_entry(m, SEGMENT_ENTRY_P, 4);
> +
> +	/* The FC bit should be ignored because EDAT is off, like above */
> +	p[0] = 42;
> +	protect_dat_entry(m, REGION3_ENTRY_FC, 3);
> +	report(p[0] == 42, "pud, fc=1, r/w");
> +	unprotect_dat_entry(m, REGION3_ENTRY_FC, 3);
> +	p[0] = 0;
> +
> +	/*
> +	 * Region1/2/3 protection should not work, because EDAT is off.
> +	 * Protect the various region1/2/3 entries and write, expect the
> +	 * write to be successful.
> +	 */
> +	protect_dat_entry(m, REGION_ENTRY_P, 3);
> +	p[0] = 42;
> +	report(p[0] == 42, "pud, ro");
> +	unprotect_dat_entry(m, REGION_ENTRY_P, 3);
> +	p[0] = 0;
> +
> +	protect_dat_entry(m, REGION_ENTRY_P, 2);
> +	p[0] = 42;
> +	report(p[0] == 42, "p4d, ro");
> +	unprotect_dat_entry(m, REGION_ENTRY_P, 2);
> +	p[0] = 0;
> +
> +	protect_dat_entry(m, REGION_ENTRY_P, 1);
> +	p[0] = 42;
> +	report(p[0] == 42, "pgd, ro");
> +	unprotect_dat_entry(m, REGION_ENTRY_P, 1);
> +	p[0] = 0;
> +
> +	report_prefix_pop();
> +}
> +
> +static void test_edat1(void)
> +{
> +	report_prefix_push("edat1");
> +	/* Enable EDAT */
> +	ctl_set_bit(0, CTL0_EDAT);
> +	p[0] = 0;
> +
> +	/*
> +	 * Segment protection should work normally, try to write and expect
> +	 * a fault.
> +	 */
> +	expect_pgm_int();
> +	protect_dat_entry(m, SEGMENT_ENTRY_P, 4);
> +	p[0] = 42;
> +	report(!p[0] && check_pgm_prot(m), "pmd, ro");
> +	unprotect_dat_entry(m, SEGMENT_ENTRY_P, 4);
> +
> +	/*
> +	 * Region1/2/3 protection should work now, because EDAT is on. Try
> +	 * to write anyway and expect a fault.
> +	 */
> +	expect_pgm_int();
> +	protect_dat_entry(m, REGION_ENTRY_P, 3);
> +	p[0] = 42;
> +	report(!p[0] && check_pgm_prot(m), "pud, ro");
> +	unprotect_dat_entry(m, REGION_ENTRY_P, 3);
> +
> +	expect_pgm_int();
> +	protect_dat_entry(m, REGION_ENTRY_P, 2);
> +	p[0] = 42;
> +	report(!p[0] && check_pgm_prot(m), "p4d, ro");
> +	unprotect_dat_entry(m, REGION_ENTRY_P, 2);
> +
> +	expect_pgm_int();
> +	protect_dat_entry(m, REGION_ENTRY_P, 1);
> +	p[0] = 42;
> +	report(!p[0] && check_pgm_prot(m), "pgd, ro");
> +	unprotect_dat_entry(m, REGION_ENTRY_P, 1);
> +
> +	/* Large pages should work */
> +	p[0] = 42;
> +	install_large_page(root, 0, mem);
> +	report(p[0] == 42, "pmd, large");
> +
> +	/*
> +	 * Prefixing should not work with large pages. Since the lower
> +	 * addresses are mapped with small pages, which are subject to
> +	 * prefixing, and the pages mapped with large pages are not subject
> +	 * to prefixing, this is the resulting scenario:
> +	 *
> +	 * virtual 0 = real 0 -> absolute prefix_buf
> +	 * virtual prefix_buf = real prefix_buf -> absolute 0
> +	 * VIRT(0) -> absolute 0
> +	 * VIRT(prefix_buf) -> absolute prefix_buf
> +	 *
> +	 * The testcase checks if the memory at virtual 0 has the same
> +	 * content as the memory at VIRT(prefix_buf) and the memory at
> +	 * VIRT(0) has the same content as the memory at virtual prefix_buf.
> +	 * If prefixing is erroneously applied for large pages, the testcase
> +	 * will therefore fail.
> +	 */
> +	report(!memcmp(0, VIRT(prefix_buf), LC_SIZE) &&
> +		!memcmp(prefix_buf, VIRT(0), LC_SIZE),
> +		"pmd, large, prefixing");
> +
> +	report_prefix_pop();
> +}
> +
> +static void test_edat2(void)
> +{
> +	report_prefix_push("edat2");
> +	p[0] = 42;
> +
> +	/* Huge pages should work */
> +	install_huge_page(root, 0, mem);
> +	report(p[0] == 42, "pud, huge");
> +
> +	/* Prefixing should not work with huge pages, just like large pages */
> +	report(!memcmp(0, VIRT(prefix_buf), LC_SIZE) &&
> +		!memcmp(prefix_buf, VIRT(0), LC_SIZE),
> +		"pmd, large, prefixing");
> +
> +	report_prefix_pop();
> +}
> +
> +static unsigned int setup(void)
> +{
> +	bool has_edat1 = test_facility(8);
> +	bool has_edat2 = test_facility(78);
> +	unsigned long pa, va;
> +
> +	if (has_edat2 && !has_edat1)
> +		report_abort("EDAT2 available, but EDAT1 not available");
> +
> +	/* Setup DAT 1:1 mapping and memory management */
> +	setup_vm();
> +	root = (void *)(stctg(1) & PAGE_MASK);
> +
> +	/*
> +	 * Get a pgd worth of virtual memory, so we can test things later
> +	 * without interfering with the test code or the interrupt handler
> +	 */
> +	mem = alloc_vpages_aligned(BIT_ULL(PGD_PAGE_SHIFT), PGD_PAGE_SHIFT);
> +	assert(mem);
> +	va = (unsigned long)mem;
> +
> +	/* Map the first 1GB of real memory */
> +	for (pa = 0; pa < SZ_1G; pa += PAGE_SIZE, va += PAGE_SIZE)
> +		install_page(root, pa, (void *)va);
> +
> +	/*
> +	 * Move the lowcore to a known non-zero location. This is needed
> +	 * later to check whether prefixing is working with large pages.
> +	 */
> +	assert((unsigned long)&prefix_buf < SZ_2G);
> +	memcpy(prefix_buf, 0, LC_SIZE);
> +	set_prefix((uint32_t)(uintptr_t)prefix_buf);
> +	/* Clear the old copy */
> +	memset(prefix_buf, 0, LC_SIZE);
> +
> +	/* m will point to tmp through the new virtual mapping */
> +	m = VIRT(&tmp);
> +	/* p is the same as m but volatile */
> +	p = (volatile unsigned int *)m;
> +
> +	return has_edat1 + has_edat2;
> +}
> +
> +int main(void)
> +{
> +	unsigned int edat;
> +
> +	report_prefix_push("edat");
> +	edat = setup();
> +
> +	test_dat();
> +
> +	if (edat)
> +		test_edat1();
> +	else
> +		report_skip("EDAT not available");
> +
> +	if (edat >= 2)
> +		test_edat2();
> +	else
> +		report_skip("EDAT2 not available");
> +
> +	report_prefix_pop();
> +	return report_summary();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index 9f81a608..a0ec8864 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -103,3 +103,6 @@ file = sie.elf
>  [mvpg]
>  file = mvpg.elf
>  timeout = 10
> +
> +[edat]
> +file = edat.elf
>