Merge tag 'kvm-s390-next-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git...

KVM: s390: Fix and cleanup

- fix sigp sense/start/stop/inconsistency
- cleanups

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index aeeb071..b86c7ed 100644 (file)
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -3701,7 +3701,7 @@ KVM with the currently defined set of flags.
 :Architectures: s390
 :Type: vm ioctl
 :Parameters: struct kvm_s390_skeys
-:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage
+:Returns: 0 on success, KVM_S390_GET_SKEYS_NONE if guest is not using storage
           keys, negative value on error
 
 This ioctl is used to get guest storage key values on the s390
@@ -3720,7 +3720,7 @@ you want to get.
 
 The count field is the number of consecutive frames (starting from start_gfn)
 whose storage keys to get. The count field must be at least 1 and the maximum
-allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
+allowed value is defined as KVM_S390_SKEYS_MAX. Values outside this range
 will cause the ioctl to return -EINVAL.
 
 The skeydata_addr field is the address to a buffer large enough to hold count
@@ -3744,7 +3744,7 @@ you want to set.
 
 The count field is the number of consecutive frames (starting from start_gfn)
 whose storage keys to get. The count field must be at least 1 and the maximum
-allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
+allowed value is defined as KVM_S390_SKEYS_MAX. Values outside this range
 will cause the ioctl to return -EINVAL.
 
 The skeydata_addr field is the address to a buffer containing count bytes of

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 72d3e49..8621838 100644 (file)
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -91,23 +91,23 @@ struct uv_cb_header {
 
 /* Query Ultravisor Information */
 struct uv_cb_qui {
-       struct uv_cb_header header;
-       u64 reserved08;
-       u64 inst_calls_list[4];
-       u64 reserved30[2];
-       u64 uv_base_stor_len;
-       u64 reserved48;
-       u64 conf_base_phys_stor_len;
-       u64 conf_base_virt_stor_len;
-       u64 conf_virt_var_stor_len;
-       u64 cpu_stor_len;
-       u32 reserved70[3];
-       u32 max_num_sec_conf;
-       u64 max_guest_stor_addr;
-       u8  reserved88[158 - 136];
-       u16 max_guest_cpu_id;
-       u64 uv_feature_indications;
-       u8  reserveda0[200 - 168];
+       struct uv_cb_header header;             /* 0x0000 */
+       u64 reserved08;                         /* 0x0008 */
+       u64 inst_calls_list[4];                 /* 0x0010 */
+       u64 reserved30[2];                      /* 0x0030 */
+       u64 uv_base_stor_len;                   /* 0x0040 */
+       u64 reserved48;                         /* 0x0048 */
+       u64 conf_base_phys_stor_len;            /* 0x0050 */
+       u64 conf_base_virt_stor_len;            /* 0x0058 */
+       u64 conf_virt_var_stor_len;             /* 0x0060 */
+       u64 cpu_stor_len;                       /* 0x0068 */
+       u32 reserved70[3];                      /* 0x0070 */
+       u32 max_num_sec_conf;                   /* 0x007c */
+       u64 max_guest_stor_addr;                /* 0x0080 */
+       u8  reserved88[158 - 136];              /* 0x0088 */
+       u16 max_guest_cpu_id;                   /* 0x009e */
+       u64 uv_feature_indications;             /* 0x00a0 */
+       u8  reserveda8[200 - 168];              /* 0x00a8 */
 } __packed __aligned(8);
 
 /* Initialize Ultravisor */

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 6af59c5..4460808 100644 (file)
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -794,46 +794,100 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
        return 1;
 }
 
-static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
-                           unsigned long *pages, unsigned long nr_pages,
-                           const union asce asce, enum gacc_mode mode)
+/**
+ * guest_range_to_gpas() - Calculate guest physical addresses of page fragments
+ * covering a logical range
+ * @vcpu: virtual cpu
+ * @ga: guest address, start of range
+ * @ar: access register
+ * @gpas: output argument, may be NULL
+ * @len: length of range in bytes
+ * @asce: address-space-control element to use for translation
+ * @mode: access mode
+ *
+ * Translate a logical range to a series of guest absolute addresses,
+ * such that the concatenation of page fragments starting at each gpa make up
+ * the whole range.
+ * The translation is performed as if done by the cpu for the given @asce, @ar,
+ * @mode and state of the @vcpu.
+ * If the translation causes an exception, its program interruption code is
+ * returned and the &struct kvm_s390_pgm_info pgm member of @vcpu is modified
+ * such that a subsequent call to kvm_s390_inject_prog_vcpu() will inject
+ * a correct exception into the guest.
+ * The resulting gpas are stored into @gpas, unless it is NULL.
+ *
+ * Note: All fragments except the first one start at the beginning of a page.
+ *      When deriving the boundaries of a fragment from a gpa, all but the last
+ *      fragment end at the end of the page.
+ *
+ * Return:
+ * * 0         - success
+ * * <0                - translation could not be performed, for example if  guest
+ *               memory could not be accessed
+ * * >0                - an access exception occurred. In this case the returned value
+ *               is the program interruption code and the contents of pgm may
+ *               be used to inject an exception into the guest.
+ */
+static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
+                              unsigned long *gpas, unsigned long len,
+                              const union asce asce, enum gacc_mode mode)
 {
        psw_t *psw = &vcpu->arch.sie_block->gpsw;
+       unsigned int offset = offset_in_page(ga);
+       unsigned int fragment_len;
        int lap_enabled, rc = 0;
        enum prot_type prot;
+       unsigned long gpa;
 
        lap_enabled = low_address_protection_enabled(vcpu, asce);
-       while (nr_pages) {
+       while (min(PAGE_SIZE - offset, len) > 0) {
+               fragment_len = min(PAGE_SIZE - offset, len);
                ga = kvm_s390_logical_to_effective(vcpu, ga);
                if (mode == GACC_STORE && lap_enabled && is_low_address(ga))
                        return trans_exc(vcpu, PGM_PROTECTION, ga, ar, mode,
                                         PROT_TYPE_LA);
-               ga &= PAGE_MASK;
                if (psw_bits(*psw).dat) {
-                       rc = guest_translate(vcpu, ga, pages, asce, mode, &prot);
+                       rc = guest_translate(vcpu, ga, &gpa, asce, mode, &prot);
                        if (rc < 0)
                                return rc;
                } else {
-                       *pages = kvm_s390_real_to_abs(vcpu, ga);
-                       if (kvm_is_error_gpa(vcpu->kvm, *pages))
+                       gpa = kvm_s390_real_to_abs(vcpu, ga);
+                       if (kvm_is_error_gpa(vcpu->kvm, gpa))
                                rc = PGM_ADDRESSING;
                }
                if (rc)
                        return trans_exc(vcpu, rc, ga, ar, mode, prot);
-               ga += PAGE_SIZE;
-               pages++;
-               nr_pages--;
+               if (gpas)
+                       *gpas++ = gpa;
+               offset = 0;
+               ga += fragment_len;
+               len -= fragment_len;
        }
        return 0;
 }
 
+static int access_guest_page(struct kvm *kvm, enum gacc_mode mode, gpa_t gpa,
+                            void *data, unsigned int len)
+{
+       const unsigned int offset = offset_in_page(gpa);
+       const gfn_t gfn = gpa_to_gfn(gpa);
+       int rc;
+
+       if (mode == GACC_STORE)
+               rc = kvm_write_guest_page(kvm, gfn, data, offset, len);
+       else
+               rc = kvm_read_guest_page(kvm, gfn, data, offset, len);
+       return rc;
+}
+
 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
                 unsigned long len, enum gacc_mode mode)
 {
        psw_t *psw = &vcpu->arch.sie_block->gpsw;
-       unsigned long _len, nr_pages, gpa, idx;
-       unsigned long pages_array[2];
-       unsigned long *pages;
+       unsigned long nr_pages, idx;
+       unsigned long gpa_array[2];
+       unsigned int fragment_len;
+       unsigned long *gpas;
        int need_ipte_lock;
        union asce asce;
        int rc;
@@ -845,49 +899,42 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
        if (rc)
                return rc;
        nr_pages = (((ga & ~PAGE_MASK) + len - 1) >> PAGE_SHIFT) + 1;
-       pages = pages_array;
-       if (nr_pages > ARRAY_SIZE(pages_array))
-               pages = vmalloc(array_size(nr_pages, sizeof(unsigned long)));
-       if (!pages)
+       gpas = gpa_array;
+       if (nr_pages > ARRAY_SIZE(gpa_array))
+               gpas = vmalloc(array_size(nr_pages, sizeof(unsigned long)));
+       if (!gpas)
                return -ENOMEM;
        need_ipte_lock = psw_bits(*psw).dat && !asce.r;
        if (need_ipte_lock)
                ipte_lock(vcpu);
-       rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode);
+       rc = guest_range_to_gpas(vcpu, ga, ar, gpas, len, 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 (mode == GACC_STORE)
-                       rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);
-               else
-                       rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);
-               len -= _len;
-               ga += _len;
-               data += _len;
+               fragment_len = min(PAGE_SIZE - offset_in_page(gpas[idx]), len);
+               rc = access_guest_page(vcpu->kvm, mode, gpas[idx], data, fragment_len);
+               len -= fragment_len;
+               data += fragment_len;
        }
        if (need_ipte_lock)
                ipte_unlock(vcpu);
-       if (nr_pages > ARRAY_SIZE(pages_array))
-               vfree(pages);
+       if (nr_pages > ARRAY_SIZE(gpa_array))
+               vfree(gpas);
        return rc;
 }
 
 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
                      void *data, unsigned long len, enum gacc_mode mode)
 {
-       unsigned long _len, gpa;
+       unsigned int fragment_len;
+       unsigned long gpa;
        int rc = 0;
 
        while (len && !rc) {
                gpa = kvm_s390_real_to_abs(vcpu, gra);
-               _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);
-               if (mode)
-                       rc = write_guest_abs(vcpu, gpa, data, _len);
-               else
-                       rc = read_guest_abs(vcpu, gpa, data, _len);
-               len -= _len;
-               gra += _len;
-               data += _len;
+               fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
+               rc = access_guest_page(vcpu->kvm, mode, gpa, data, fragment_len);
+               len -= fragment_len;
+               gra += fragment_len;
+               data += fragment_len;
        }
        return rc;
 }
@@ -909,8 +956,6 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
 int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
                            unsigned long *gpa, enum gacc_mode mode)
 {
-       psw_t *psw = &vcpu->arch.sie_block->gpsw;
-       enum prot_type prot;
        union asce asce;
        int rc;
 
@@ -918,23 +963,7 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
        rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode);
        if (rc)
                return rc;
-       if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) {
-               if (mode == GACC_STORE)
-                       return trans_exc(vcpu, PGM_PROTECTION, gva, 0,
-                                        mode, PROT_TYPE_LA);
-       }
-
-       if (psw_bits(*psw).dat && !asce.r) {    /* Use DAT? */
-               rc = guest_translate(vcpu, gva, gpa, asce, mode, &prot);
-               if (rc > 0)
-                       return trans_exc(vcpu, rc, gva, 0, mode, prot);
-       } else {
-               *gpa = kvm_s390_real_to_abs(vcpu, gva);
-               if (kvm_is_error_gpa(vcpu->kvm, *gpa))
-                       return trans_exc(vcpu, rc, gva, PGM_ADDRESSING, mode, 0);
-       }
-
-       return rc;
+       return guest_range_to_gpas(vcpu, gva, ar, gpa, 1, asce, mode);
 }
 
 /**
@@ -948,17 +977,14 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
                    unsigned long length, enum gacc_mode mode)
 {
-       unsigned long gpa;
-       unsigned long currlen;
+       union asce asce;
        int rc = 0;
 
+       rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode);
+       if (rc)
+               return rc;
        ipte_lock(vcpu);
-       while (length > 0 && !rc) {
-               currlen = min(length, PAGE_SIZE - (gva % PAGE_SIZE));
-               rc = guest_translate_address(vcpu, gva, ar, &gpa, mode);
-               gva += currlen;
-               length -= currlen;
-       }
+       rc = guest_range_to_gpas(vcpu, gva, ar, NULL, length, asce, mode);
        ipte_unlock(vcpu);
 
        return rc;

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index dbabd6f..db933c2 100644 (file)
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2116,6 +2116,13 @@ int kvm_s390_is_stop_irq_pending(struct kvm_vcpu *vcpu)
        return test_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs);
 }
 
+int kvm_s390_is_restart_irq_pending(struct kvm_vcpu *vcpu)
+{
+       struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
+
+       return test_bit(IRQ_PEND_RESTART, &li->pending_irqs);
+}
+
 void kvm_s390_clear_stop_irq(struct kvm_vcpu *vcpu)
 {
        struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index dd099d3..9c6d45d 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4599,10 +4599,15 @@ int kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu)
                }
        }
 
-       /* SIGP STOP and SIGP STOP AND STORE STATUS has been fully processed */
+       /*
+        * Set the VCPU to STOPPED and THEN clear the interrupt flag,
+        * now that the SIGP STOP and SIGP STOP AND STORE STATUS orders
+        * have been fully processed. This will ensure that the VCPU
+        * is kept BUSY if another VCPU is inquiring with SIGP SENSE.
+        */
+       kvm_s390_set_cpuflags(vcpu, CPUSTAT_STOPPED);
        kvm_s390_clear_stop_irq(vcpu);
 
-       kvm_s390_set_cpuflags(vcpu, CPUSTAT_STOPPED);
        __disable_ibs_on_vcpu(vcpu);
 
        for (i = 0; i < online_vcpus; i++) {

diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 60f0eff..098831e 100644 (file)
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -441,6 +441,7 @@ void kvm_s390_destroy_adapters(struct kvm *kvm);
 int kvm_s390_ext_call_pending(struct kvm_vcpu *vcpu);
 extern struct kvm_device_ops kvm_flic_ops;
 int kvm_s390_is_stop_irq_pending(struct kvm_vcpu *vcpu);
+int kvm_s390_is_restart_irq_pending(struct kvm_vcpu *vcpu);
 void kvm_s390_clear_stop_irq(struct kvm_vcpu *vcpu);
 int kvm_s390_set_irq_state(struct kvm_vcpu *vcpu,
                           void __user *buf, int len);

diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index cf4de80..8aaee28 100644 (file)
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -276,6 +276,34 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
        if (!dst_vcpu)
                return SIGP_CC_NOT_OPERATIONAL;
 
+       /*
+        * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
+        * are processed asynchronously. Until the affected VCPU finishes
+        * its work and calls back into KVM to clear the (RESTART or STOP)
+        * interrupt, we need to return any new non-reset orders "busy".
+        *
+        * This is important because a single VCPU could issue:
+        *  1) SIGP STOP $DESTINATION
+        *  2) SIGP SENSE $DESTINATION
+        *
+        * If the SIGP SENSE would not be rejected as "busy", it could
+        * return an incorrect answer as to whether the VCPU is STOPPED
+        * or OPERATING.
+        */
+       if (order_code != SIGP_INITIAL_CPU_RESET &&
+           order_code != SIGP_CPU_RESET) {
+               /*
+                * Lockless check. Both SIGP STOP and SIGP (RE)START
+                * properly synchronize everything while processing
+                * their orders, while the guest cannot observe a
+                * difference when issuing other orders from two
+                * different VCPUs.
+                */
+               if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
+                   kvm_s390_is_restart_irq_pending(dst_vcpu))
+                       return SIGP_CC_BUSY;
+       }
+
        switch (order_code) {
        case SIGP_SENSE:
                vcpu->stat.instruction_sigp_sense++;