Re: [PATCH v3 1/2] s390/kvm: extend kvm_s390_shadow_fault to return entry pointer
On 11.02.21 13:57, Claudio Imbrenda wrote:
On Thu, 11 Feb 2021 10:18:56 +0100
David Hildenbrand wrote:
On 09.02.21 16:43, Claudio Imbrenda wrote:
Extend kvm_s390_shadow_fault to return the pointer to the valid leaf
DAT table entry, or to the invalid entry.
Also return some flags in the lower bits of the address:
DAT_PROT: indicates that DAT protection applies because of the
protection bit in the segment (or, if EDAT, region)
tables NOT_PTE: indicates that the address of the DAT table entry
returned does not refer to a PTE, but to a segment or region table.
I've been thinking about one possible issue, but I think it's not
actually an issue. Just sharing so others can verify:
In case our guest uses huge pages / gigantic pages / ASCE R, we
create fake page tables (GMAP_SHADOW_FAKE_TABLE).
So, it could be that kvm_s390_shadow_fault()->gmap_shadow_pgt_lookup()
succeeds, however, we have a fake PTE in our hands. We lost the
actual guest STE/RTE address. (I think it could be recovered somehow
via page->index, thought)
But I guess, if there is a fake PTE, then there is not acutally
something that could go wrong in gmap_shadow_page() anymore that could
lead us in responding something wrong to the guest. We can only really
fail with -EINVAL, -ENOMEM or -EFAULT.
this was also my reasoning
So if the guest changed anything in the meantime (e.g., zap a
segment), we would have unshadowed the whole fake page table
hierarchy and would simply retry.
Signed-off-by: Claudio Imbrenda
Cc: sta...@vger.kernel.org
---
arch/s390/kvm/gaccess.c | 30 +-
arch/s390/kvm/gaccess.h | 5 -
arch/s390/kvm/vsie.c| 8
3 files changed, 33 insertions(+), 10 deletions(-)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 6d6b57059493..e0ab83f051d2 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(struct
kvm_vcpu *vcpu, unsigned long gra)
* kvm_s390_shadow_tables - walk the guest page table and create
shadow tables
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
- * @pgt: pointer to the page table address result
+ * @pgt: pointer to the beginning of the page table for the given
address if
+ * successful (return value 0), or to the first invalid DAT
entry in
+ * case of exceptions (return value > 0)
* @fake: pgt references contiguous guest memory block, not a
pgtable */
static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long
saddr, @@ -1034,6 +1036,7 @@ static int
kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
rfte.val = ptr; goto shadow_r2t;
}
+ *pgt = ptr + vaddr.rfx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rfx * 8,
);
Using
gmap_read_table(parent, *pgt, );
or similar with a local variable might then be even clearer. But no
strong opinion.
that's also something I had thought about, in the end this minimizes
the number of lines / variables while still being readable
if (rc)
return rc;
@@ -1060,6 +1063,7 @@ static int kvm_s390_shadow_tables(struct gmap
*sg, unsigned long saddr, rste.val = ptr;
goto shadow_r3t;
}
+ *pgt = ptr + vaddr.rsx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rsx * 8,
); if (rc)
return rc;
@@ -1087,6 +1091,7 @@ static int kvm_s390_shadow_tables(struct gmap
*sg, unsigned long saddr, rtte.val = ptr;
goto shadow_sgt;
}
+ *pgt = ptr + vaddr.rtx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rtx * 8,
); if (rc)
return rc;
@@ -1123,6 +1128,7 @@ static int kvm_s390_shadow_tables(struct gmap
*sg, unsigned long saddr, ste.val = ptr;
goto shadow_pgt;
}
+ *pgt = ptr + vaddr.sx * 8;
rc = gmap_read_table(parent, ptr + vaddr.sx * 8,
); if (rc)
return rc;
@@ -1157,6 +1163,8 @@ static int kvm_s390_shadow_tables(struct gmap
*sg, unsigned long saddr,
* @vcpu: virtual cpu
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
+ * @datptr: will contain the address of the faulting DAT table
entry, or of
+ * the valid leaf, plus some flags
*
* Returns: - 0 if the shadow fault was successfully resolved
* - > 0 (pgm exception code) on exceptions while
faulting @@ -1165,11 +1173,11 @@ static int
kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
* - -ENOMEM if out of memory
*/
int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
- unsigned long saddr)
+ unsigned long saddr, unsigned long
*datptr) {
union
Re: [PATCH v3 1/2] s390/kvm: extend kvm_s390_shadow_fault to return entry pointer
On Thu, 11 Feb 2021 10:18:56 +0100 David Hildenbrand wrote: > On 09.02.21 16:43, Claudio Imbrenda wrote: > > Extend kvm_s390_shadow_fault to return the pointer to the valid leaf > > DAT table entry, or to the invalid entry. > > > > Also return some flags in the lower bits of the address: > > DAT_PROT: indicates that DAT protection applies because of the > >protection bit in the segment (or, if EDAT, region) > > tables NOT_PTE: indicates that the address of the DAT table entry > > returned does not refer to a PTE, but to a segment or region table. > > > > I've been thinking about one possible issue, but I think it's not > actually an issue. Just sharing so others can verify: > > In case our guest uses huge pages / gigantic pages / ASCE R, we > create fake page tables (GMAP_SHADOW_FAKE_TABLE). > > So, it could be that kvm_s390_shadow_fault()->gmap_shadow_pgt_lookup() > succeeds, however, we have a fake PTE in our hands. We lost the > actual guest STE/RTE address. (I think it could be recovered somehow > via page->index, thought) > > But I guess, if there is a fake PTE, then there is not acutally > something that could go wrong in gmap_shadow_page() anymore that could > lead us in responding something wrong to the guest. We can only really > fail with -EINVAL, -ENOMEM or -EFAULT. this was also my reasoning > So if the guest changed anything in the meantime (e.g., zap a > segment), we would have unshadowed the whole fake page table > hierarchy and would simply retry. > > > Signed-off-by: Claudio Imbrenda > > Cc: sta...@vger.kernel.org > > --- > > arch/s390/kvm/gaccess.c | 30 +- > > arch/s390/kvm/gaccess.h | 5 - > > arch/s390/kvm/vsie.c| 8 > > 3 files changed, 33 insertions(+), 10 deletions(-) > > > > diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c > > index 6d6b57059493..e0ab83f051d2 100644 > > --- a/arch/s390/kvm/gaccess.c > > +++ b/arch/s390/kvm/gaccess.c > > @@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(struct > > kvm_vcpu *vcpu, unsigned long gra) > >* kvm_s390_shadow_tables - walk the guest page table and create > > shadow tables > >* @sg: pointer to the shadow guest address space structure > >* @saddr: faulting address in the shadow gmap > > - * @pgt: pointer to the page table address result > > + * @pgt: pointer to the beginning of the page table for the given > > address if > > + * successful (return value 0), or to the first invalid DAT > > entry in > > + * case of exceptions (return value > 0) > >* @fake: pgt references contiguous guest memory block, not a > > pgtable */ > > static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long > > saddr, @@ -1034,6 +1036,7 @@ static int > > kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, > > rfte.val = ptr; goto shadow_r2t; > > } > > + *pgt = ptr + vaddr.rfx * 8; > > rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, > > ); > > Using > > gmap_read_table(parent, *pgt, ); > > or similar with a local variable might then be even clearer. But no > strong opinion. that's also something I had thought about, in the end this minimizes the number of lines / variables while still being readable > > if (rc) > > return rc; > > @@ -1060,6 +1063,7 @@ static int kvm_s390_shadow_tables(struct gmap > > *sg, unsigned long saddr, rste.val = ptr; > > goto shadow_r3t; > > } > > + *pgt = ptr + vaddr.rsx * 8; > > rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, > > ); if (rc) > > return rc; > > @@ -1087,6 +1091,7 @@ static int kvm_s390_shadow_tables(struct gmap > > *sg, unsigned long saddr, rtte.val = ptr; > > goto shadow_sgt; > > } > > + *pgt = ptr + vaddr.rtx * 8; > > rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, > > ); if (rc) > > return rc; > > @@ -1123,6 +1128,7 @@ static int kvm_s390_shadow_tables(struct gmap > > *sg, unsigned long saddr, ste.val = ptr; > > goto shadow_pgt; > > } > > + *pgt = ptr + vaddr.sx * 8; > > rc = gmap_read_table(parent, ptr + vaddr.sx * 8, > > ); if (rc) > > return rc; > > @@ -1157,6 +1163,8 @@ static int kvm_s390_shadow_tables(struct gmap > > *sg, unsigned long saddr, > >* @vcpu: virtual cpu > >* @sg: pointer to the shadow guest address space structure > >* @saddr: faulting address in the shadow gmap > > + * @datptr: will contain the address of the faulting DAT table > > entry, or of > > + * the valid leaf, plus some flags > >* > >* Returns: - 0 if the shadow fault was successfully resolved > >*- > 0 (pgm exception code) on exceptions while > > faulting @@ -1165,11 +1173,11 @@ static int > > kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, > >
Re: [PATCH v3 1/2] s390/kvm: extend kvm_s390_shadow_fault to return entry pointer
On 09.02.21 16:43, Claudio Imbrenda wrote:
Extend kvm_s390_shadow_fault to return the pointer to the valid leaf
DAT table entry, or to the invalid entry.
Also return some flags in the lower bits of the address:
DAT_PROT: indicates that DAT protection applies because of the
protection bit in the segment (or, if EDAT, region) tables
NOT_PTE: indicates that the address of the DAT table entry returned
does not refer to a PTE, but to a segment or region table.
I've been thinking about one possible issue, but I think it's not
actually an issue. Just sharing so others can verify:
In case our guest uses huge pages / gigantic pages / ASCE R, we create
fake page tables (GMAP_SHADOW_FAKE_TABLE).
So, it could be that kvm_s390_shadow_fault()->gmap_shadow_pgt_lookup()
succeeds, however, we have a fake PTE in our hands. We lost the
actual guest STE/RTE address. (I think it could be recovered somehow via
page->index, thought)
But I guess, if there is a fake PTE, then there is not acutally
something that could go wrong in gmap_shadow_page() anymore that could
lead us in responding something wrong to the guest. We can only really
fail with -EINVAL, -ENOMEM or -EFAULT.
So if the guest changed anything in the meantime (e.g., zap a segment),
we would have unshadowed the whole fake page table hierarchy and would
simply retry.
Signed-off-by: Claudio Imbrenda
Cc: sta...@vger.kernel.org
---
arch/s390/kvm/gaccess.c | 30 +-
arch/s390/kvm/gaccess.h | 5 -
arch/s390/kvm/vsie.c| 8
3 files changed, 33 insertions(+), 10 deletions(-)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 6d6b57059493..e0ab83f051d2 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu
*vcpu, unsigned long gra)
* kvm_s390_shadow_tables - walk the guest page table and create shadow tables
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
- * @pgt: pointer to the page table address result
+ * @pgt: pointer to the beginning of the page table for the given address if
+ * successful (return value 0), or to the first invalid DAT entry in
+ * case of exceptions (return value > 0)
* @fake: pgt references contiguous guest memory block, not a pgtable
*/
static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
@@ -1034,6 +1036,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
rfte.val = ptr;
goto shadow_r2t;
}
+ *pgt = ptr + vaddr.rfx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, );
Using
gmap_read_table(parent, *pgt, );
or similar with a local variable might then be even clearer. But no
strong opinion.
if (rc)
return rc;
@@ -1060,6 +1063,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
rste.val = ptr;
goto shadow_r3t;
}
+ *pgt = ptr + vaddr.rsx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, );
if (rc)
return rc;
@@ -1087,6 +1091,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
rtte.val = ptr;
goto shadow_sgt;
}
+ *pgt = ptr + vaddr.rtx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, );
if (rc)
return rc;
@@ -1123,6 +1128,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
ste.val = ptr;
goto shadow_pgt;
}
+ *pgt = ptr + vaddr.sx * 8;
rc = gmap_read_table(parent, ptr + vaddr.sx * 8, );
if (rc)
return rc;
@@ -1157,6 +1163,8 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
* @vcpu: virtual cpu
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
+ * @datptr: will contain the address of the faulting DAT table entry, or of
+ * the valid leaf, plus some flags
*
* Returns: - 0 if the shadow fault was successfully resolved
*- > 0 (pgm exception code) on exceptions while faulting
@@ -1165,11 +1173,11 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
*- -ENOMEM if out of memory
*/
int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
- unsigned long saddr)
+ unsigned long saddr, unsigned long *datptr)
{
union vaddress vaddr;
union page_table_entry pte;
- unsigned long pgt;
+
Re: [PATCH v3 1/2] s390/kvm: extend kvm_s390_shadow_fault to return entry pointer
On 2/9/21 4:43 PM, Claudio Imbrenda wrote:
> Extend kvm_s390_shadow_fault to return the pointer to the valid leaf
> DAT table entry, or to the invalid entry.
>
> Also return some flags in the lower bits of the address:
> DAT_PROT: indicates that DAT protection applies because of the
> protection bit in the segment (or, if EDAT, region) tables
> NOT_PTE: indicates that the address of the DAT table entry returned
> does not refer to a PTE, but to a segment or region table.
>
> Signed-off-by: Claudio Imbrenda
> Cc: sta...@vger.kernel.org
Reviewed-by: Janosch Frank
Small nit below.
> ---
> arch/s390/kvm/gaccess.c | 30 +-
> arch/s390/kvm/gaccess.h | 5 -
> arch/s390/kvm/vsie.c| 8
> 3 files changed, 33 insertions(+), 10 deletions(-)
>
> diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
> index 6d6b57059493..e0ab83f051d2 100644
> --- a/arch/s390/kvm/gaccess.c
> +++ b/arch/s390/kvm/gaccess.c
> @@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu
> *vcpu, unsigned long gra)
> * kvm_s390_shadow_tables - walk the guest page table and create shadow
> tables
> * @sg: pointer to the shadow guest address space structure
> * @saddr: faulting address in the shadow gmap
> - * @pgt: pointer to the page table address result
> + * @pgt: pointer to the beginning of the page table for the given address if
> + * successful (return value 0), or to the first invalid DAT entry in
> + * case of exceptions (return value > 0)
> * @fake: pgt references contiguous guest memory block, not a pgtable
> */
> static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
> @@ -1034,6 +1036,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
> unsigned long saddr,
> rfte.val = ptr;
> goto shadow_r2t;
> }
> + *pgt = ptr + vaddr.rfx * 8;
> rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, );
> if (rc)
> return rc;
> @@ -1060,6 +1063,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
> unsigned long saddr,
> rste.val = ptr;
> goto shadow_r3t;
> }
> + *pgt = ptr + vaddr.rsx * 8;
> rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, );
> if (rc)
> return rc;
> @@ -1087,6 +1091,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
> unsigned long saddr,
> rtte.val = ptr;
> goto shadow_sgt;
> }
> + *pgt = ptr + vaddr.rtx * 8;
> rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, );
> if (rc)
> return rc;
> @@ -1123,6 +1128,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
> unsigned long saddr,
> ste.val = ptr;
> goto shadow_pgt;
> }
> + *pgt = ptr + vaddr.sx * 8;
> rc = gmap_read_table(parent, ptr + vaddr.sx * 8, );
> if (rc)
> return rc;
> @@ -1157,6 +1163,8 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
> unsigned long saddr,
> * @vcpu: virtual cpu
> * @sg: pointer to the shadow guest address space structure
> * @saddr: faulting address in the shadow gmap
> + * @datptr: will contain the address of the faulting DAT table entry, or of
> + * the valid leaf, plus some flags
> *
> * Returns: - 0 if the shadow fault was successfully resolved
> * - > 0 (pgm exception code) on exceptions while faulting
> @@ -1165,11 +1173,11 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
> unsigned long saddr,
> * - -ENOMEM if out of memory
> */
> int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
> - unsigned long saddr)
> + unsigned long saddr, unsigned long *datptr)
> {
> union vaddress vaddr;
> union page_table_entry pte;
> - unsigned long pgt;
> + unsigned long pgt = 0;
> int dat_protection, fake;
> int rc;
>
> @@ -1191,8 +1199,20 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu,
> struct gmap *sg,
> pte.val = pgt + vaddr.px * PAGE_SIZE;
> goto shadow_page;
> }
> - if (!rc)
> - rc = gmap_read_table(sg->parent, pgt + vaddr.px * 8, );
> +
> + switch (rc) {
> + case PGM_SEGMENT_TRANSLATION:
> + case PGM_REGION_THIRD_TRANS:
> + case PGM_REGION_SECOND_TRANS:
> + case PGM_REGION_FIRST_TRANS:
> + pgt |= NOT_PTE;
> + break;
> + case 0:
> + pgt += vaddr.px * 8;
> + rc = gmap_read_table(sg->parent, pgt, );
> + }
> + if (*datptr)
> + *datptr = pgt | dat_protection * DAT_PROT;
> if (!rc && pte.i)
> rc = PGM_PAGE_TRANSLATION;
> if (!rc
[PATCH v3 1/2] s390/kvm: extend kvm_s390_shadow_fault to return entry pointer
Extend kvm_s390_shadow_fault to return the pointer to the valid leaf
DAT table entry, or to the invalid entry.
Also return some flags in the lower bits of the address:
DAT_PROT: indicates that DAT protection applies because of the
protection bit in the segment (or, if EDAT, region) tables
NOT_PTE: indicates that the address of the DAT table entry returned
does not refer to a PTE, but to a segment or region table.
Signed-off-by: Claudio Imbrenda
Cc: sta...@vger.kernel.org
---
arch/s390/kvm/gaccess.c | 30 +-
arch/s390/kvm/gaccess.h | 5 -
arch/s390/kvm/vsie.c| 8
3 files changed, 33 insertions(+), 10 deletions(-)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 6d6b57059493..e0ab83f051d2 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu
*vcpu, unsigned long gra)
* kvm_s390_shadow_tables - walk the guest page table and create shadow tables
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
- * @pgt: pointer to the page table address result
+ * @pgt: pointer to the beginning of the page table for the given address if
+ * successful (return value 0), or to the first invalid DAT entry in
+ * case of exceptions (return value > 0)
* @fake: pgt references contiguous guest memory block, not a pgtable
*/
static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
@@ -1034,6 +1036,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
rfte.val = ptr;
goto shadow_r2t;
}
+ *pgt = ptr + vaddr.rfx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, );
if (rc)
return rc;
@@ -1060,6 +1063,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
rste.val = ptr;
goto shadow_r3t;
}
+ *pgt = ptr + vaddr.rsx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, );
if (rc)
return rc;
@@ -1087,6 +1091,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
rtte.val = ptr;
goto shadow_sgt;
}
+ *pgt = ptr + vaddr.rtx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, );
if (rc)
return rc;
@@ -1123,6 +1128,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
ste.val = ptr;
goto shadow_pgt;
}
+ *pgt = ptr + vaddr.sx * 8;
rc = gmap_read_table(parent, ptr + vaddr.sx * 8, );
if (rc)
return rc;
@@ -1157,6 +1163,8 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
* @vcpu: virtual cpu
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
+ * @datptr: will contain the address of the faulting DAT table entry, or of
+ * the valid leaf, plus some flags
*
* Returns: - 0 if the shadow fault was successfully resolved
* - > 0 (pgm exception code) on exceptions while faulting
@@ -1165,11 +1173,11 @@ static int kvm_s390_shadow_tables(struct gmap *sg,
unsigned long saddr,
* - -ENOMEM if out of memory
*/
int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
- unsigned long saddr)
+ unsigned long saddr, unsigned long *datptr)
{
union vaddress vaddr;
union page_table_entry pte;
- unsigned long pgt;
+ unsigned long pgt = 0;
int dat_protection, fake;
int rc;
@@ -1191,8 +1199,20 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct
gmap *sg,
pte.val = pgt + vaddr.px * PAGE_SIZE;
goto shadow_page;
}
- if (!rc)
- rc = gmap_read_table(sg->parent, pgt + vaddr.px * 8, );
+
+ switch (rc) {
+ case PGM_SEGMENT_TRANSLATION:
+ case PGM_REGION_THIRD_TRANS:
+ case PGM_REGION_SECOND_TRANS:
+ case PGM_REGION_FIRST_TRANS:
+ pgt |= NOT_PTE;
+ break;
+ case 0:
+ pgt += vaddr.px * 8;
+ rc = gmap_read_table(sg->parent, pgt, );
+ }
+ if (*datptr)
+ *datptr = pgt | dat_protection * DAT_PROT;
if (!rc && pte.i)
rc = PGM_PAGE_TRANSLATION;
if (!rc && pte.z)
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index f4c51756c462..fec26bbb17ba 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -359,7 +359,10 @@ void
