[PATCH v2 12/15] KVM: s390: move gmap_shadow_pgt_lookup() into kvm

Claudio Imbrenda
2025-01-16T11:34:09Z

Move gmap_shadow_pgt_lookup() from mm/gmap.c into kvm/gaccess.c .

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
arch/s390/include/asm/gmap.h | 3 +--
arch/s390/kvm/gaccess.c | 40 +++++++++++++++++++++++++++++++
arch/s390/kvm/gmap.h | 2 ++
arch/s390/mm/gmap.c | 46 ++----------------------------------
4 files changed, 45 insertions(+), 46 deletions(-)

diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index 99ded56c914b..ec07f99fcc7d 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -127,8 +127,6 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
int fake);
int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
int fake);
-int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
- unsigned long *pgt, int *dat_protection, int *fake);
int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);

void gmap_register_pte_notifier(struct gmap_notifier *);
@@ -143,6 +141,7 @@ int s390_replace_asce(struct gmap *gmap);
void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
unsigned long end, bool interruptible);
+unsigned long *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level);

/**
* s390_uv_destroy_range - Destroy a range of pages in the given mm.
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 9816b0060fbe..560b5677929b 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -16,6 +16,7 @@
#include <asm/gmap.h>
#include <asm/dat-bits.h>
#include "kvm-s390.h"
+#include "gmap.h"
#include "gaccess.h"

/*
@@ -1392,6 +1393,42 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
return 0;
}

+/**
+ * gmap_shadow_pgt_lookup - find a shadow page table
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: the address in the shadow aguest address space
+ * @pgt: parent gmap address of the page table to get shadowed
+ * @dat_protection: if the pgtable is marked as protected by dat
+ * @fake: pgt references contiguous guest memory block, not a pgtable
+ *
+ * Returns 0 if the shadow page table was found and -EAGAIN if the page
+ * table was not found.
+ *
+ * Called with sg->mm->mmap_lock in read.
+ */
+static int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr, unsigned long *pgt,
+ int *dat_protection, int *fake)
+{
+ unsigned long *table;
+ struct page *page;
+ int rc;
+
+ spin_lock(&sg->guest_table_lock);
+ table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
+ if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
+ /* Shadow page tables are full pages (pte+pgste) */
+ page = pfn_to_page(*table >> PAGE_SHIFT);
+ *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
+ *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
+ *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
+ rc = 0;
+ } else {
+ rc = -EAGAIN;
+ }
+ spin_unlock(&sg->guest_table_lock);
+ return rc;
+}
+
/**
* kvm_s390_shadow_fault - handle fault on a shadow page table
* @vcpu: virtual cpu
@@ -1415,6 +1452,9 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
int dat_protection, fake;
int rc;

+ if (KVM_BUG_ON(!gmap_is_shadow(sg), vcpu->kvm))
+ return -EFAULT;
+
mmap_read_lock(sg->mm);
/*
* We don't want any guest-2 tables to change - so the parent
diff --git a/arch/s390/kvm/gmap.h b/arch/s390/kvm/gmap.h
index 978f541059f0..c8f031c9ea5f 100644
--- a/arch/s390/kvm/gmap.h
+++ b/arch/s390/kvm/gmap.h
@@ -10,6 +10,8 @@
#ifndef ARCH_KVM_S390_GMAP_H
#define ARCH_KVM_S390_GMAP_H

+#define GMAP_SHADOW_FAKE_TABLE 1ULL
+
int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index a5c3ae18bc6f..9d4a62628e51 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -27,8 +27,6 @@
#define GADDR_VALID(gaddr) ((gaddr) & 1)
#define GMAP_SHADOW_FAKE_TABLE 1ULL

-static inline unsigned long *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level);
-
static struct page *gmap_alloc_crst(void)
{
struct page *page;
@@ -729,8 +727,7 @@ static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
*
* Note: Can also be called for shadow gmaps.
*/
-static inline unsigned long *gmap_table_walk(struct gmap *gmap,
- unsigned long gaddr, int level)
+unsigned long *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level)
{
const int asce_type = gmap->asce & _ASCE_TYPE_MASK;
unsigned long *table = gmap->table;
@@ -781,6 +778,7 @@ static inline unsigned long *gmap_table_walk(struct gmap *gmap,
}
return table;
}
+EXPORT_SYMBOL(gmap_table_walk);

/**
* gmap_pte_op_walk - walk the gmap page table, get the page table lock
@@ -1731,46 +1729,6 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
}
EXPORT_SYMBOL_GPL(gmap_shadow_sgt);

-/**
- * gmap_shadow_pgt_lookup - find a shadow page table
- * @sg: pointer to the shadow guest address space structure
- * @saddr: the address in the shadow aguest address space
- * @pgt: parent gmap address of the page table to get shadowed
- * @dat_protection: if the pgtable is marked as protected by dat
- * @fake: pgt references contiguous guest memory block, not a pgtable
- *
- * Returns 0 if the shadow page table was found and -EAGAIN if the page
- * table was not found.
- *
- * Called with sg->mm->mmap_lock in read.
- */
-int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
- unsigned long *pgt, int *dat_protection,
- int *fake)
-{
- unsigned long *table;
- struct page *page;
- int rc;
-
- BUG_ON(!gmap_is_shadow(sg));
- spin_lock(&sg->guest_table_lock);
- table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
- if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
- /* Shadow page tables are full pages (pte+pgste) */
- page = pfn_to_page(*table >> PAGE_SHIFT);
- *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
- *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
- *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
- rc = 0;
- } else {
- rc = -EAGAIN;
- }
- spin_unlock(&sg->guest_table_lock);
- return rc;
-
-}
-EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
-
/**
* gmap_shadow_pgt - instantiate a shadow page table
* @sg: pointer to the shadow guest address space structure
--
2.47.1