[kvm-unit-tests PATCH v2 3/3] s390x: mvpg-sie: fix virtual-physical address confusion

[Nico Boehr <nrb@linux.ibm.com>]

The addresses reported for the partial execution of mvpg instruction are
physical addresses. Now that MSO is a virtual address, we can't simply
compare the PEI fields in the sie block with MSO, but need to do an
additional translation step.

Add the necessary virtual-physical translations and expose the
virt_to_pte_phys() function in mmu.h which is useful for this kind of
translation.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 lib/s390x/mmu.h  |  2 ++
 s390x/mvpg-sie.c | 15 +++++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/lib/s390x/mmu.h b/lib/s390x/mmu.h
index dadc2e600f9a..e9e837236603 100644
--- a/lib/s390x/mmu.h
+++ b/lib/s390x/mmu.h
@@ -95,4 +95,6 @@ static inline void unprotect_page(void *vaddr, unsigned long prot)
 
 void *get_dat_entry(pgd_t *pgtable, void *vaddr, enum pgt_level level);
 
+phys_addr_t virt_to_pte_phys(pgd_t *pgtable, void *vaddr);
+
 #endif /* _ASMS390X_MMU_H_ */
diff --git a/s390x/mvpg-sie.c b/s390x/mvpg-sie.c
index 99f4859bc2df..effb5eab2c0e 100644
--- a/s390x/mvpg-sie.c
+++ b/s390x/mvpg-sie.c
@@ -23,7 +23,9 @@
 static struct vm vm;
 
 static uint8_t *src;
+static phys_addr_t src_phys;
 static uint8_t *dst;
+static phys_addr_t dst_phys;
 static uint8_t *cmp;
 
 static void test_mvpg_pei(void)
@@ -38,8 +40,8 @@ static void test_mvpg_pei(void)
 	protect_page(src, PAGE_ENTRY_I);
 	sie(&vm);
 	report(vm.sblk->icptcode == ICPT_PARTEXEC, "Partial execution");
-	report((uintptr_t)**pei_src == (uintptr_t)src + PAGE_ENTRY_I, "PEI_SRC correct");
-	report((uintptr_t)**pei_dst == (uintptr_t)dst, "PEI_DST correct");
+	report((uintptr_t)**pei_src == (uintptr_t)src_phys + PAGE_ENTRY_I, "PEI_SRC correct");
+	report((uintptr_t)**pei_dst == (uintptr_t)dst_phys, "PEI_DST correct");
 	unprotect_page(src, PAGE_ENTRY_I);
 	report(!memcmp(cmp, dst, PAGE_SIZE), "Destination intact");
 	/*
@@ -60,8 +62,8 @@ static void test_mvpg_pei(void)
 	protect_page(dst, PAGE_ENTRY_I);
 	sie(&vm);
 	report(vm.sblk->icptcode == ICPT_PARTEXEC, "Partial execution");
-	report((uintptr_t)**pei_src == (uintptr_t)src, "PEI_SRC correct");
-	report((uintptr_t)**pei_dst == (uintptr_t)dst + PAGE_ENTRY_I, "PEI_DST correct");
+	report((uintptr_t)**pei_src == (uintptr_t)src_phys, "PEI_SRC correct");
+	report((uintptr_t)**pei_dst == (uintptr_t)dst_phys + PAGE_ENTRY_I, "PEI_DST correct");
 	/* Needed for the memcmp and general cleanup */
 	unprotect_page(dst, PAGE_ENTRY_I);
 	report(!memcmp(cmp, dst, PAGE_SIZE), "Destination intact");
@@ -82,8 +84,10 @@ static void setup_guest(void)
 {
 	extern const char SNIPPET_NAME_START(c, mvpg_snippet)[];
 	extern const char SNIPPET_NAME_END(c, mvpg_snippet)[];
+	pgd_t *root;
 
 	setup_vm();
+	root = (pgd_t *)(stctg(1) & PAGE_MASK);
 
 	snippet_setup_guest(&vm, false);
 	snippet_init(&vm, SNIPPET_NAME_START(c, mvpg_snippet),
@@ -94,6 +98,9 @@ static void setup_guest(void)
 
 	src = (uint8_t *) vm.sblk->mso + PAGE_SIZE * 6;
 	dst = (uint8_t *) vm.sblk->mso + PAGE_SIZE * 5;
+	src_phys = virt_to_pte_phys(root, src);
+	dst_phys = virt_to_pte_phys(root, dst);
+
 	cmp = alloc_page();
 	memset(cmp, 0, PAGE_SIZE);
 }
-- 
2.41.0