Commit 2c46e974 authored by Janosch Frank's avatar Janosch Frank
Browse files

s390/mm: Abstract gmap notify bit setting 



Currently we use the software PGSTE bits PGSTE_IN_BIT and
PGSTE_VSIE_BIT to notify before an invalidation occurs on a prefix
page or a VSIE page respectively. Both bits are pgste specific, but
are used when protecting a memory range.

Let's introduce abstract GMAP_NOTIFY_* bits that will be realized into
the respective bits when gmap DAT table entries are protected.

Signed-off-by: default avatarJanosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
parent 5a045bb9

arch/s390/include/asm/gmap.h

+4 −0
Original line number Diff line number Diff line
@@ -9,6 +9,10 @@ 
#ifndef _ASM_S390_GMAP_H

#define _ASM_S390_GMAP_H



/* Generic bits for GMAP notification on DAT table entry changes. */

#define GMAP_NOTIFY_SHADOW	0x2

#define GMAP_NOTIFY_MPROT	0x1



/**

 * struct gmap_struct - guest address space

 * @list: list head for the mm->context gmap list

arch/s390/mm/gmap.c

+7 −4
Original line number Diff line number Diff line
@@ -912,7 +912,7 @@ static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp) 
 * @gaddr: virtual address in the guest address space

 * @pmdp: pointer to the pmd associated with the pte

 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE

 * @bits: pgste notification bits to set

 * @bits: notification bits to set

 *

 * Returns 0 if successfully protected, -ENOMEM if out of memory and

 * -EAGAIN if a fixup is needed.
@@ -925,6 +925,7 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, 
	int rc;

	pte_t *ptep;

	spinlock_t *ptl = NULL;

	unsigned long pbits = 0;



	if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)

		return -EAGAIN;
@@ -933,8 +934,10 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, 
	if (!ptep)

		return -ENOMEM;



	pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;

	pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;

	/* Protect and unlock. */

	rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits);

	rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);

	gmap_pte_op_end(ptl);

	return rc;

}
@@ -1008,7 +1011,7 @@ int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr, 
	if (!MACHINE_HAS_ESOP && prot == PROT_READ)

		return -EINVAL;

	down_read(&gmap->mm->mmap_sem);

	rc = gmap_protect_range(gmap, gaddr, len, prot, PGSTE_IN_BIT);

	rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);

	up_read(&gmap->mm->mmap_sem);

	return rc;

}
@@ -1599,7 +1602,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce, 
	down_read(&parent->mm->mmap_sem);

	rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,

				((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,

				PROT_READ, PGSTE_VSIE_BIT);

				PROT_READ, GMAP_NOTIFY_SHADOW);

	up_read(&parent->mm->mmap_sem);

	spin_lock(&parent->shadow_lock);

	new->initialized = true;

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