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 imbrenda@linux.ibm.com Cc: stable@vger.kernel.org
Reviewed-by: Janosch Frank frankja@de.ibm.com
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;@@ -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;@@ -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;@@ -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;@@ -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, &pte.val);
- 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, &pte.val);- }
- if (*datptr)
*datptr = pgt | dat_protection * DAT_PROT;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 ipte_unlock(struct kvm_vcpu *vcpu); int ipte_lock_held(struct kvm_vcpu *vcpu); int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra); +#define DAT_PROT 2 +#define NOT_PTE 4
I'd like to have a PEI prefix and a short comment where this comes from, something like: "MVPG PEI indication bits"
int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow,
unsigned long saddr);
unsigned long saddr, unsigned long *datptr);#endif /* __KVM_S390_GACCESS_H */ diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index c5d0a58b2c29..7db022141db3 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -619,10 +619,10 @@ static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) /* with mso/msl, the prefix lies at offset *mso* */ prefix += scb_s->mso;
- rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
- rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL); if (!rc && (scb_s->ecb & ECB_TE)) rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
prefix + PAGE_SIZE);
prefix + PAGE_SIZE, NULL);
- We don't have to mprotect, we will be called for all unshadows.
- SIE will detect if protection applies and trigger a validity.
@@ -913,7 +913,7 @@ static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) current->thread.gmap_addr, 1); rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
current->thread.gmap_addr);
current->thread.gmap_addr, NULL);@@ -935,7 +935,7 @@ static void handle_last_fault(struct kvm_vcpu *vcpu, { if (vsie_page->fault_addr) kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
vsie_page->fault_addr);
vsie_page->fault_addr, NULL);}