KVM: s390: gaccess: introduce access modes

We will need special handling when fetching instructions, so let's
introduce new guest access modes GACC_FETCH and GACC_STORE instead
of a write flag. An additional patch will then introduce GACC_IFETCH.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

5 files changed, 43 insertions, 35 deletions

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index d30db40437dc..c72ad9157414 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -373,7 +373,7 @@ void ipte_unlock(struct kvm_vcpu *vcpu)
 }
 
 static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, ar_t ar,
-                          int write)
+                          enum gacc_mode mode)
 {
         union alet alet;
         struct ale ale;
@@ -454,7 +454,7 @@ static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, ar_t ar,
                 }
         }
 
-        if (ale.fo == 1 && write)
+        if (ale.fo == 1 && mode == GACC_STORE)
                 return PGM_PROTECTION;
 
         asce->val = aste.asce;
@@ -477,7 +477,7 @@ enum {
 };
 
 static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce,
-                         ar_t ar, int write)
+                         ar_t ar, enum gacc_mode mode)
 {
         int rc;
         psw_t *psw = &vcpu->arch.sie_block->gpsw;
@@ -486,7 +486,7 @@ static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce,
 
         memset(pgm, 0, sizeof(*pgm));
         tec_bits = (struct trans_exc_code_bits *)&pgm->trans_exc_code;
-        tec_bits->fsi = write ? FSI_STORE : FSI_FETCH;
+        tec_bits->fsi = mode == GACC_STORE ? FSI_STORE : FSI_FETCH;
         tec_bits->as = psw_bits(*psw).as;
 
         if (!psw_bits(*psw).t) {
@@ -506,7 +506,7 @@ static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce,
                 asce->val = vcpu->arch.sie_block->gcr[13];
                 return 0;
         case PSW_AS_ACCREG:
-                rc = ar_translation(vcpu, asce, ar, write);
+                rc = ar_translation(vcpu, asce, ar, mode);
                 switch (rc) {
                 case PGM_ALEN_TRANSLATION:
                 case PGM_ALE_SEQUENCE:
@@ -538,7 +538,7 @@ static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val)
  * @gva: guest virtual address
  * @gpa: points to where guest physical (absolute) address should be stored
  * @asce: effective asce
- * @write: indicates if access is a write access
+ * @mode: indicates the access mode to be used
  *
  * Translate a guest virtual address into a guest absolute address by means
  * of dynamic address translation as specified by the architecture.
@@ -554,7 +554,7 @@ static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val)
  */
 static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva,
                                      unsigned long *gpa, const union asce asce,
-                                     int write)
+                                     enum gacc_mode mode)
 {
         union vaddress vaddr = {.addr = gva};
         union raddress raddr = {.addr = gva};
@@ -699,7 +699,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva,
 real_address:
         raddr.addr = kvm_s390_real_to_abs(vcpu, raddr.addr);
 absolute_address:
-        if (write && dat_protection)
+        if (mode == GACC_STORE && dat_protection)
                 return PGM_PROTECTION;
         if (kvm_is_error_gpa(vcpu->kvm, raddr.addr))
                 return PGM_ADDRESSING;
@@ -728,7 +728,7 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
 
 static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
                             unsigned long *pages, unsigned long nr_pages,
-                            const union asce asce, int write)
+                            const union asce asce, enum gacc_mode mode)
 {
         struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm;
         psw_t *psw = &vcpu->arch.sie_block->gpsw;
@@ -740,13 +740,13 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
         while (nr_pages) {
                 ga = kvm_s390_logical_to_effective(vcpu, ga);
                 tec_bits->addr = ga >> PAGE_SHIFT;
-                if (write && lap_enabled && is_low_address(ga)) {
+                if (mode == GACC_STORE && lap_enabled && is_low_address(ga)) {
                         pgm->code = PGM_PROTECTION;
                         return pgm->code;
                 }
                 ga &= PAGE_MASK;
                 if (psw_bits(*psw).t) {
-                        rc = guest_translate(vcpu, ga, pages, asce, write);
+                        rc = guest_translate(vcpu, ga, pages, asce, mode);
                         if (rc < 0)
                                 return rc;
                         if (rc == PGM_PROTECTION)
@@ -768,7 +768,7 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
 }
 
 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
-                 unsigned long len, int write)
+                 unsigned long len, enum gacc_mode mode)
 {
         psw_t *psw = &vcpu->arch.sie_block->gpsw;
         unsigned long _len, nr_pages, gpa, idx;
@@ -780,7 +780,7 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
 
         if (!len)
                 return 0;
-        rc = get_vcpu_asce(vcpu, &asce, ar, write);
+        rc = get_vcpu_asce(vcpu, &asce, ar, mode);
         if (rc)
                 return rc;
         nr_pages = (((ga & ~PAGE_MASK) + len - 1) >> PAGE_SHIFT) + 1;
@@ -792,11 +792,11 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
         need_ipte_lock = psw_bits(*psw).t && !asce.r;
         if (need_ipte_lock)
                 ipte_lock(vcpu);
-        rc = guest_page_range(vcpu, ga, pages, nr_pages, asce, write);
+        rc = guest_page_range(vcpu, ga, pages, nr_pages, asce, mode);
         for (idx = 0; idx < nr_pages && !rc; idx++) {
                 gpa = *(pages + idx) + (ga & ~PAGE_MASK);
                 _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);
-                if (write)
+                if (mode == GACC_STORE)
                         rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);
                 else
                         rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);
@@ -812,7 +812,7 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
 }
 
 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
-                      void *data, unsigned long len, int write)
+                      void *data, unsigned long len, enum gacc_mode mode)
 {
         unsigned long _len, gpa;
         int rc = 0;
@@ -820,7 +820,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
         while (len && !rc) {
                 gpa = kvm_s390_real_to_abs(vcpu, gra);
                 _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);
-                if (write)
+                if (mode)
                         rc = write_guest_abs(vcpu, gpa, data, _len);
                 else
                         rc = read_guest_abs(vcpu, gpa, data, _len);
@@ -841,7 +841,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
  * has to take care of this.
  */
 int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
-                            unsigned long *gpa, int write)
+                            unsigned long *gpa, enum gacc_mode mode)
 {
         struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm;
         psw_t *psw = &vcpu->arch.sie_block->gpsw;
@@ -851,19 +851,19 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
 
         gva = kvm_s390_logical_to_effective(vcpu, gva);
         tec = (struct trans_exc_code_bits *)&pgm->trans_exc_code;
-        rc = get_vcpu_asce(vcpu, &asce, ar, write);
+        rc = get_vcpu_asce(vcpu, &asce, ar, mode);
         tec->addr = gva >> PAGE_SHIFT;
         if (rc)
                 return rc;
         if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) {
-                if (write) {
+                if (mode == GACC_STORE) {
                         rc = pgm->code = PGM_PROTECTION;
                         return rc;
                 }
         }
 
         if (psw_bits(*psw).t && !asce.r) {      /* Use DAT? */
-                rc = guest_translate(vcpu, gva, gpa, asce, write);
+                rc = guest_translate(vcpu, gva, gpa, asce, mode);
                 if (rc > 0) {
                         if (rc == PGM_PROTECTION)
                                 tec->b61 = 1;
@@ -883,7 +883,7 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
  * check_gva_range - test a range of guest virtual addresses for accessibility
  */
 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
-                    unsigned long length, int is_write)
+                    unsigned long length, enum gacc_mode mode)
 {
         unsigned long gpa;
         unsigned long currlen;
@@ -892,7 +892,7 @@ int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
         ipte_lock(vcpu);
         while (length > 0 && !rc) {
                 currlen = min(length, PAGE_SIZE - (gva % PAGE_SIZE));
-                rc = guest_translate_address(vcpu, gva, ar, &gpa, is_write);
+                rc = guest_translate_address(vcpu, gva, ar, &gpa, mode);
                 gva += currlen;
                 length -= currlen;
         }
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index ef03726cc661..2a6f8bfd22f8 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -155,16 +155,21 @@ int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
         return kvm_read_guest(vcpu->kvm, gpa, data, len);
 }
 
+enum gacc_mode {
+        GACC_FETCH,
+        GACC_STORE,
+};
+
 int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
-                            ar_t ar, unsigned long *gpa, int write);
+                            ar_t ar, unsigned long *gpa, enum gacc_mode mode);
 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
-                    unsigned long length, int is_write);
+                    unsigned long length, enum gacc_mode mode);
 
 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
-                 unsigned long len, int write);
+                 unsigned long len, enum gacc_mode mode);
 
 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
-                      void *data, unsigned long len, int write);
+                      void *data, unsigned long len, enum gacc_mode mode);
 
 /**
  * write_guest - copy data from kernel space to guest space
@@ -215,7 +220,7 @@ static inline __must_check
 int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
                 unsigned long len)
 {
-        return access_guest(vcpu, ga, ar, data, len, 1);
+        return access_guest(vcpu, ga, ar, data, len, GACC_STORE);
 }
 
 /**
@@ -235,7 +240,7 @@ static inline __must_check
 int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
                unsigned long len)
 {
-        return access_guest(vcpu, ga, ar, data, len, 0);
+        return access_guest(vcpu, ga, ar, data, len, GACC_FETCH);
 }
 
 /**
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 7f992e02124a..44bb923a6482 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -317,7 +317,7 @@ static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 
         /* Make sure that the source is paged-in */
         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
-                                     reg2, &srcaddr, 0);
+                                     reg2, &srcaddr, GACC_FETCH);
         if (rc)
                 return kvm_s390_inject_prog_cond(vcpu, rc);
         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
@@ -326,7 +326,7 @@ static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 
         /* Make sure that the destination is paged-in */
         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
-                                     reg1, &dstaddr, 1);
+                                     reg1, &dstaddr, GACC_STORE);
         if (rc)
                 return kvm_s390_inject_prog_cond(vcpu, rc);
         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index cd84a3eeb214..85e169b8e90d 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2610,7 +2610,8 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
         switch (mop->op) {
         case KVM_S390_MEMOP_LOGICAL_READ:
                 if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
-                        r = check_gva_range(vcpu, mop->gaddr, mop->ar, mop->size, false);
+                        r = check_gva_range(vcpu, mop->gaddr, mop->ar,
+                                            mop->size, GACC_FETCH);
                         break;
                 }
                 r = read_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
@@ -2621,7 +2622,8 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
                 break;
         case KVM_S390_MEMOP_LOGICAL_WRITE:
                 if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
-                        r = check_gva_range(vcpu, mop->gaddr, mop->ar, mop->size, true);
+                        r = check_gva_range(vcpu, mop->gaddr, mop->ar,
+                                            mop->size, GACC_STORE);
                         break;
                 }
                 if (copy_from_user(tmpbuf, uaddr, mop->size)) {
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index d58cbe9813db..add990945986 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -981,11 +981,12 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
                 return -EOPNOTSUPP;
         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
                 ipte_lock(vcpu);
-        ret = guest_translate_address(vcpu, address1, ar, &gpa, 1);
+        ret = guest_translate_address(vcpu, address1, ar, &gpa, GACC_STORE);
         if (ret == PGM_PROTECTION) {
                 /* Write protected? Try again with read-only... */
                 cc = 1;
-                ret = guest_translate_address(vcpu, address1, ar, &gpa, 0);
+                ret = guest_translate_address(vcpu, address1, ar, &gpa,
+                                              GACC_FETCH);
         }
         if (ret) {
                 if (ret == PGM_ADDRESSING || ret == PGM_TRANSLATION_SPEC) {