KVM: s390: gaccess: fix real-space designation asce handling for gmap shadows (addb63c1) · Commits · 戴 / test

For real-space designation asces the asce origin part is only a token. The asce token origin must not be used to generate an effective address for storage references. This however is erroneously done within kvm_s390_shadow_tables(). Furthermore within the same function the wrong parts of virtual addresses are used to generate a corresponding real address (e.g. the region second index is used as region first index). Both of the above can result in incorrect address translations. Only for real space designations with a token origin of zero and addresses below one megabyte the translation was correct. Furthermore replace a "!asce.r" statement with a "!*fake" statement to make it more obvious that a specific condition has nothing to do with the architecture, but with the fake handling of real space designations. Fixes: ("s390/mm: support real-space for gmap shadows") Cc: David Hildenbrand <david@redhat.com> Cc: stable@vger.kernel.org Signed-off-by:

Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by:

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

Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/gaccess.c

+6 −9

Original line number	Diff line number	Diff line
		@@ -977,11 +977,12 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
		ptr = asce.origin * 4096;
		if (asce.r) {
		*fake = 1;
		ptr = 0;
		asce.dt = ASCE_TYPE_REGION1;
		}
		switch (asce.dt) {
		case ASCE_TYPE_REGION1:
		if (vaddr.rfx01 > asce.tl && !asce.r)
		if (vaddr.rfx01 > asce.tl && !*fake)
		return PGM_REGION_FIRST_TRANS;
		break;
		case ASCE_TYPE_REGION2:
		@@ -1009,8 +1010,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
		union region1_table_entry rfte;

		if (*fake) {
		/* offset in 16EB guest memory block */
		ptr = ptr + ((unsigned long) vaddr.rsx << 53UL);
		ptr += (unsigned long) vaddr.rfx << 53;
		rfte.val = ptr;
		goto shadow_r2t;
		}
		@@ -1036,8 +1036,7 @@ shadow_r2t:
		union region2_table_entry rste;

		if (*fake) {
		/* offset in 8PB guest memory block */
		ptr = ptr + ((unsigned long) vaddr.rtx << 42UL);
		ptr += (unsigned long) vaddr.rsx << 42;
		rste.val = ptr;
		goto shadow_r3t;
		}
		@@ -1064,8 +1063,7 @@ shadow_r3t:
		union region3_table_entry rtte;

		if (*fake) {
		/* offset in 4TB guest memory block */
		ptr = ptr + ((unsigned long) vaddr.sx << 31UL);
		ptr += (unsigned long) vaddr.rtx << 31;
		rtte.val = ptr;
		goto shadow_sgt;
		}
		@@ -1101,8 +1099,7 @@ shadow_sgt:
		union segment_table_entry ste;

		if (*fake) {
		/* offset in 2G guest memory block */
		ptr = ptr + ((unsigned long) vaddr.sx << 20UL);
		ptr += (unsigned long) vaddr.sx << 20;
		ste.val = ptr;
		goto shadow_pgt;
		}

Admin message