diff options
Diffstat (limited to 'arch/s390/kvm/gaccess.c')
| -rw-r--r-- | arch/s390/kvm/gaccess.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index 8e245e7..ba49852 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -8,6 +8,7 @@ #include <linux/vmalloc.h> #include <linux/err.h> #include <asm/pgtable.h> +#include <asm/gmap.h> #include "kvm-s390.h" #include "gaccess.h" #include <asm/switch_to.h> @@ -946,3 +947,170 @@ int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra) return 0; return trans_exc(vcpu, PGM_PROTECTION, gra, 0, GACC_STORE, PROT_TYPE_LA); } + +/** + * 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 + */ +static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, + unsigned long *pgt, int *dat_protection) +{ + struct gmap *parent; + union asce asce; + union vaddress vaddr; + unsigned long ptr; + int rc; + + parent = sg->parent; + vaddr.addr = saddr; + asce.val = sg->orig_asce; + ptr = asce.origin * 4096; + switch (asce.dt) { + case ASCE_TYPE_REGION1: + if (vaddr.rfx01 > asce.tl) + return PGM_REGION_FIRST_TRANS; + break; + case ASCE_TYPE_REGION2: + if (vaddr.rfx) + return PGM_ASCE_TYPE; + if (vaddr.rsx01 > asce.tl) + return PGM_REGION_SECOND_TRANS; + break; + case ASCE_TYPE_REGION3: + if (vaddr.rfx || vaddr.rsx) + return PGM_ASCE_TYPE; + if (vaddr.rtx01 > asce.tl) + return PGM_REGION_THIRD_TRANS; + break; + case ASCE_TYPE_SEGMENT: + if (vaddr.rfx || vaddr.rsx || vaddr.rtx) + return PGM_ASCE_TYPE; + if (vaddr.sx01 > asce.tl) + return PGM_SEGMENT_TRANSLATION; + break; + } + + switch (asce.dt) { + case ASCE_TYPE_REGION1: { + union region1_table_entry rfte; + + rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, &rfte.val); + if (rc) + return rc; + if (rfte.i) + return PGM_REGION_FIRST_TRANS; + if (rfte.tt != TABLE_TYPE_REGION1) + return PGM_TRANSLATION_SPEC; + if (vaddr.rsx01 < rfte.tf || vaddr.rsx01 > rfte.tl) + return PGM_REGION_SECOND_TRANS; + rc = gmap_shadow_r2t(sg, saddr, rfte.val); + if (rc) + return rc; + ptr = rfte.rto * 4096; + /* fallthrough */ + } + case ASCE_TYPE_REGION2: { + union region2_table_entry rste; + + rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, &rste.val); + if (rc) + return rc; + if (rste.i) + return PGM_REGION_SECOND_TRANS; + if (rste.tt != TABLE_TYPE_REGION2) + return PGM_TRANSLATION_SPEC; + if (vaddr.rtx01 < rste.tf || vaddr.rtx01 > rste.tl) + return PGM_REGION_THIRD_TRANS; + rc = gmap_shadow_r3t(sg, saddr, rste.val); + if (rc) + return rc; + ptr = rste.rto * 4096; + /* fallthrough */ + } + case ASCE_TYPE_REGION3: { + union region3_table_entry rtte; + + rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, &rtte.val); + if (rc) + return rc; + if (rtte.i) + return PGM_REGION_THIRD_TRANS; + if (rtte.tt != TABLE_TYPE_REGION3) + return PGM_TRANSLATION_SPEC; + if (vaddr.sx01 < rtte.fc0.tf || vaddr.sx01 > rtte.fc0.tl) + return PGM_SEGMENT_TRANSLATION; + rc = gmap_shadow_sgt(sg, saddr, rtte.val); + if (rc) + return rc; + ptr = rtte.fc0.sto * 4096; + /* fallthrough */ + } + case ASCE_TYPE_SEGMENT: { + union segment_table_entry ste; + + rc = gmap_read_table(parent, ptr + vaddr.sx * 8, &ste.val); + if (rc) + return rc; + if (ste.i) + return PGM_SEGMENT_TRANSLATION; + if (ste.tt != TABLE_TYPE_SEGMENT) + return PGM_TRANSLATION_SPEC; + if (ste.cs && asce.p) + return PGM_TRANSLATION_SPEC; + *dat_protection = ste.fc0.p; + rc = gmap_shadow_pgt(sg, saddr, ste.val); + if (rc) + return rc; + ptr = ste.fc0.pto * 2048; + } + } + /* Return the parent address of the page table */ + *pgt = ptr; + return 0; +} + +/** + * kvm_s390_shadow_fault - handle fault on a shadow page table + * @sg: pointer to the shadow guest address space structure + * @saddr: faulting address in the shadow gmap + * @write: =1 map r/w, =0 map r/o + * + * Returns: - 0 if the shadow fault was successfully resolved + * - > 0 (pgm exception code) on exceptions while faulting + * - -EAGAIN if the caller can retry immediately + * - -EFAULT when accessing invalid guest addresses + * - -ENOMEM if out of memory + */ +int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr, int write) +{ + union vaddress vaddr; + union page_table_entry pte; + unsigned long pgt; + int dat_protection; + int rc; + + rc = gmap_shadow_pgt_lookup(sg, saddr, &pgt, &dat_protection); + if (rc) { + rc = kvm_s390_shadow_tables(sg, saddr, &pgt, &dat_protection); + if (rc) + return rc; + } + + vaddr.addr = saddr; + rc = gmap_read_table(sg->parent, pgt + vaddr.px * 8, &pte.val); + if (rc) + return rc; + if (pte.i) + return PGM_PAGE_TRANSLATION; + if (pte.z || pte.co) + return PGM_TRANSLATION_SPEC; + dat_protection |= pte.p; + if (write && dat_protection) + return PGM_PROTECTION; + rc = gmap_shadow_page(sg, saddr, pte.pfra * 4096, write); + if (rc) + return rc; + return 0; +} |