| From 5ac14bac08ae827b619f21bcceaaac3b8c497e31 Mon Sep 17 00:00:00 2001 |
| From: Claudio Imbrenda <imbrenda@linux.ibm.com> |
| Date: Mon, 1 Feb 2021 17:26:54 +0100 |
| Subject: KVM: s390: extend kvm_s390_shadow_fault to return entry pointer |
| |
| From: Claudio Imbrenda <imbrenda@linux.ibm.com> |
| |
| commit 5ac14bac08ae827b619f21bcceaaac3b8c497e31 upstream. |
| |
| 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: |
| PEI_DAT_PROT: indicates that DAT protection applies because of the |
| protection bit in the segment (or, if EDAT, region) tables. |
| PEI_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> |
| Reviewed-by: David Hildenbrand <david@redhat.com> |
| Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> |
| Link: https://lore.kernel.org/r/20210302174443.514363-3-imbrenda@linux.ibm.com |
| [borntraeger@de.ibm.com: fold in a fix from Claudio] |
| Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| arch/s390/kvm/gaccess.c | 30 +++++++++++++++++++++++++----- |
| arch/s390/kvm/gaccess.h | 6 +++++- |
| arch/s390/kvm/vsie.c | 8 ++++---- |
| 3 files changed, 34 insertions(+), 10 deletions(-) |
| |
| --- a/arch/s390/kvm/gaccess.c |
| +++ b/arch/s390/kvm/gaccess.c |
| @@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(st |
| * 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 |
| rfte.val = ptr; |
| goto shadow_r2t; |
| } |
| + *pgt = ptr + vaddr.rfx * 8; |
| rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, &rfte.val); |
| if (rc) |
| return rc; |
| @@ -1060,6 +1063,7 @@ shadow_r2t: |
| rste.val = ptr; |
| goto shadow_r3t; |
| } |
| + *pgt = ptr + vaddr.rsx * 8; |
| rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, &rste.val); |
| if (rc) |
| return rc; |
| @@ -1087,6 +1091,7 @@ shadow_r3t: |
| rtte.val = ptr; |
| goto shadow_sgt; |
| } |
| + *pgt = ptr + vaddr.rtx * 8; |
| rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, &rtte.val); |
| if (rc) |
| return rc; |
| @@ -1123,6 +1128,7 @@ shadow_sgt: |
| ste.val = ptr; |
| goto shadow_pgt; |
| } |
| + *pgt = ptr + vaddr.sx * 8; |
| rc = gmap_read_table(parent, ptr + vaddr.sx * 8, &ste.val); |
| if (rc) |
| return rc; |
| @@ -1157,6 +1163,8 @@ shadow_pgt: |
| * @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 @@ shadow_pgt: |
| * - -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_vcp |
| 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 |= PEI_NOT_PTE; |
| + break; |
| + case 0: |
| + pgt += vaddr.px * 8; |
| + rc = gmap_read_table(sg->parent, pgt, &pte.val); |
| + } |
| + if (datptr) |
| + *datptr = pgt | dat_protection * PEI_DAT_PROT; |
| if (!rc && pte.i) |
| rc = PGM_PAGE_TRANSLATION; |
| if (!rc && pte.z) |
| --- a/arch/s390/kvm/gaccess.h |
| +++ b/arch/s390/kvm/gaccess.h |
| @@ -387,7 +387,11 @@ 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); |
| |
| +/* MVPG PEI indication bits */ |
| +#define PEI_DAT_PROT 2 |
| +#define PEI_NOT_PTE 4 |
| + |
| 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 */ |
| --- a/arch/s390/kvm/vsie.c |
| +++ b/arch/s390/kvm/vsie.c |
| @@ -614,10 +614,10 @@ static int map_prefix(struct kvm_vcpu *v |
| /* 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. |
| @@ -908,7 +908,7 @@ static int handle_fault(struct kvm_vcpu |
| current->thread.gmap_addr, 1); |
| |
| rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, |
| - current->thread.gmap_addr); |
| + current->thread.gmap_addr, NULL); |
| if (rc > 0) { |
| rc = inject_fault(vcpu, rc, |
| current->thread.gmap_addr, |
| @@ -930,7 +930,7 @@ static void handle_last_fault(struct kvm |
| { |
| if (vsie_page->fault_addr) |
| kvm_s390_shadow_fault(vcpu, vsie_page->gmap, |
| - vsie_page->fault_addr); |
| + vsie_page->fault_addr, NULL); |
| vsie_page->fault_addr = 0; |
| } |
| |