KVM: s390: fix task size check (ee6ee55b) · Commits · 戴 / test

The gmap_map_segment function uses PGDIR_SIZE in the check for the maximum address in the tasks address space. This incorrectly limits the amount of memory usable for a kvm guest to 4TB. The correct limit is (1UL << 53). As the TASK_SIZE has different values (4TB vs 8PB) dependent on the existance of the fourth page table level, create a new define 'TASK_MAX_SIZE' for (1UL << 53). Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:

Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/s390/include/asm/processor.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@ extern void execve_tail(void);
		#ifndef CONFIG_64BIT

		#define TASK_SIZE (1UL << 31)
		#define TASK_MAX_SIZE (1UL << 31)
		#define TASK_UNMAPPED_BASE (1UL << 30)

		#else /* CONFIG_64BIT */
		@@ -51,6 +52,7 @@ extern void execve_tail(void);
		#define TASK_UNMAPPED_BASE (test_thread_flag(TIF_31BIT) ? \
		(1UL << 30) : (1UL << 41))
		#define TASK_SIZE TASK_SIZE_OF(current)
		#define TASK_MAX_SIZE (1UL << 53)

		#endif /* CONFIG_64BIT */

arch/s390/mm/pgtable.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -335,7 +335,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,

		if ((from \| to \| len) & (PMD_SIZE - 1))
		return -EINVAL;
		if (len == 0 \|\| from + len > PGDIR_SIZE \|\|
		if (len == 0 \|\| from + len > TASK_MAX_SIZE \|\|
		from + len < from \|\| to + len < to)
		return -EINVAL;

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