KVM: s390: vsie: use common code functions for pinning

We will not see -ENOMEM (gfn_to_hva() will return KVM_ERR_PTR_BAD_PAGE
for all errors). So we can also get rid of special handling in the
callers of pin_guest_page() and always assume that it is a g2 error.

As also kvm_s390_inject_program_int() should never fail, we can
simplify pin_scb(), too.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170901151143.22714-1-david@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index b18b5652e5c59b84f64f24a89fb2a14033e65e36..a311938b63b3b4eea0dd57e80bd02c4708dfcd92 100644 (file)
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -443,22 +443,14 @@ static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
  *
  * Returns: - 0 on success
  *          - -EINVAL if the gpa is not valid guest storage
- *          - -ENOMEM if out of memory
  */
 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
 {
        struct page *page;
-       hva_t hva;
-       int rc;
 
-       hva = gfn_to_hva(kvm, gpa_to_gfn(gpa));
-       if (kvm_is_error_hva(hva))
+       page = gfn_to_page(kvm, gpa_to_gfn(gpa));
+       if (is_error_page(page))
                return -EINVAL;
-       rc = get_user_pages_fast(hva, 1, 1, &page);
-       if (rc < 0)
-               return rc;
-       else if (rc != 1)
-               return -ENOMEM;
        *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK);
        return 0;
 }
@@ -466,11 +458,7 @@ static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
 {
-       struct page *page;
-
-       page = virt_to_page(hpa);
-       set_page_dirty_lock(page);
-       put_page(page);
+       kvm_release_pfn_dirty(hpa >> PAGE_SHIFT);
        /* mark the page always as dirty for migration */
        mark_page_dirty(kvm, gpa_to_gfn(gpa));
 }
@@ -557,7 +545,7 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
                        rc = set_validity_icpt(scb_s, 0x003bU);
                if (!rc) {
                        rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
-                       if (rc == -EINVAL)
+                       if (rc)
                                rc = set_validity_icpt(scb_s, 0x0034U);
                }
                if (rc)
@@ -574,10 +562,10 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
                }
                /* 256 bytes cannot cross page boundaries */
                rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
-               if (rc == -EINVAL)
+               if (rc) {
                        rc = set_validity_icpt(scb_s, 0x0080U);
-               if (rc)
                        goto unpin;
+               }
                scb_s->itdba = hpa;
        }
 
@@ -592,10 +580,10 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
                 * if this block gets bigger, we have to shadow it.
                 */
                rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
-               if (rc == -EINVAL)
+               if (rc) {
                        rc = set_validity_icpt(scb_s, 0x1310U);
-               if (rc)
                        goto unpin;
+               }
                scb_s->gvrd = hpa;
        }
 
@@ -607,11 +595,11 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
                }
                /* 64 bytes cannot cross page boundaries */
                rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
-               if (rc == -EINVAL)
+               if (rc) {
                        rc = set_validity_icpt(scb_s, 0x0043U);
-               /* Validity 0x0044 will be checked by SIE */
-               if (rc)
                        goto unpin;
+               }
+               /* Validity 0x0044 will be checked by SIE */
                scb_s->riccbd = hpa;
        }
        if ((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
@@ -635,10 +623,10 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
                 * cross page boundaries
                 */
                rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
-               if (rc == -EINVAL)
+               if (rc) {
                        rc = set_validity_icpt(scb_s, 0x10b0U);
-               if (rc)
                        goto unpin;
+               }
                scb_s->sdnxo = hpa | sdnxc;
        }
        return 0;
@@ -663,7 +651,6 @@ static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
  *
  * Returns: - 0 if the scb was pinned.
  *          - > 0 if control has to be given to guest 2
- *          - -ENOMEM if out of memory
  */
 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
                   gpa_t gpa)
@@ -672,14 +659,13 @@ static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
        int rc;
 
        rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
-       if (rc == -EINVAL) {
+       if (rc) {
                rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
-               if (!rc)
-                       rc = 1;
+               WARN_ON_ONCE(rc);
+               return 1;
        }
-       if (!rc)
-               vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
-       return rc;
+       vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
+       return 0;
 }
 
 /*

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6882538eda329fb4a59c4bb1b2957003f6fdb9e9..2e754b7c282c8324778b60e7ea57940d9f72c22d 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -667,6 +667,7 @@ kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
                               bool *writable);
 
 void kvm_release_pfn_clean(kvm_pfn_t pfn);
+void kvm_release_pfn_dirty(kvm_pfn_t pfn);
 void kvm_set_pfn_dirty(kvm_pfn_t pfn);
 void kvm_set_pfn_accessed(kvm_pfn_t pfn);
 void kvm_get_pfn(kvm_pfn_t pfn);

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9deb5a245b83032ffaa960d42cd6f01ecb614b1b..37731f661be57f9523c7ac229b0497b3288d5254 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -122,7 +122,6 @@ static void hardware_disable_all(void);
 
 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
 
-static void kvm_release_pfn_dirty(kvm_pfn_t pfn);
 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot, gfn_t gfn);
 
 __visible bool kvm_rebooting;
@@ -1679,11 +1678,12 @@ void kvm_release_page_dirty(struct page *page)
 }
 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
 
-static void kvm_release_pfn_dirty(kvm_pfn_t pfn)
+void kvm_release_pfn_dirty(kvm_pfn_t pfn)
 {
        kvm_set_pfn_dirty(pfn);
        kvm_release_pfn_clean(pfn);
 }
+EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
 
 void kvm_set_pfn_dirty(kvm_pfn_t pfn)
 {