s390x: Introduce PV query interface

Introduce an interface over which we can get information about UV data.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20221017083822.43118-8-frankja@linux.ibm.com>

hw/s390x/pv.c

@@ -20,6 +20,11 @@
 #include "exec/confidential-guest-support.h"
 #include "hw/s390x/ipl.h"
 #include "hw/s390x/pv.h"
+#include "target/s390x/kvm/kvm_s390x.h"
+
+static bool info_valid;
+static struct kvm_s390_pv_info_vm info_vm;
+static struct kvm_s390_pv_info_dump info_dump;
 
 static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data)
 {
@@ -56,6 +61,42 @@ static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data)
     }                                  \
 }
 
+int s390_pv_query_info(void)
+{
+    struct kvm_s390_pv_info info = {
+        .header.id = KVM_PV_INFO_VM,
+        .header.len_max = sizeof(info.header) + sizeof(info.vm),
+    };
+    int rc;
+
+    /* Info API's first user is dump so they are bundled */
+    if (!kvm_s390_get_protected_dump()) {
+        return 0;
+    }
+
+    rc = s390_pv_cmd(KVM_PV_INFO, &info);
+    if (rc) {
+        error_report("KVM PV INFO cmd %x failed: %s",
+                     info.header.id, strerror(-rc));
+        return rc;
+    }
+    memcpy(&info_vm, &info.vm, sizeof(info.vm));
+
+    info.header.id = KVM_PV_INFO_DUMP;
+    info.header.len_max = sizeof(info.header) + sizeof(info.dump);
+    rc = s390_pv_cmd(KVM_PV_INFO, &info);
+    if (rc) {
+        error_report("KVM PV INFO cmd %x failed: %s",
+                     info.header.id, strerror(-rc));
+        return rc;
+    }
+
+    memcpy(&info_dump, &info.dump, sizeof(info.dump));
+    info_valid = true;
+
+    return rc;
+}
+
 int s390_pv_vm_enable(void)
 {
     return s390_pv_cmd(KVM_PV_ENABLE, NULL);
@@ -114,6 +155,26 @@ void s390_pv_inject_reset_error(CPUState *cs)
     env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV;
 }
 
+uint64_t kvm_s390_pv_dmp_get_size_cpu(void)
+{
+    return info_dump.dump_cpu_buffer_len;
+}
+
+uint64_t kvm_s390_pv_dmp_get_size_completion_data(void)
+{
+    return info_dump.dump_config_finalize_len;
+}
+
+uint64_t kvm_s390_pv_dmp_get_size_mem_state(void)
+{
+    return info_dump.dump_config_mem_buffer_per_1m;
+}
+
+bool kvm_s390_pv_info_basic_valid(void)
+{
+    return info_valid;
+}
+
 #define TYPE_S390_PV_GUEST "s390-pv-guest"
 OBJECT_DECLARE_SIMPLE_TYPE(S390PVGuest, S390_PV_GUEST)
 

hw/s390x/s390-virtio-ccw.c

@@ -366,6 +366,12 @@ static int s390_machine_protect(S390CcwMachineState *ms)
 
     ms->pv = true;
 
+    /* Will return 0 if API is not available since it's not vital */
+    rc = s390_pv_query_info();
+    if (rc) {
+        goto out_err;
+    }
+
     /* Set SE header and unpack */
     rc = s390_ipl_prepare_pv_header();
     if (rc) {

include/hw/s390x/pv.h

@@ -38,6 +38,7 @@ static inline bool s390_is_pv(void)
     return ccw->pv;
 }
 
+int s390_pv_query_info(void);
 int s390_pv_vm_enable(void);
 void s390_pv_vm_disable(void);
 int s390_pv_set_sec_parms(uint64_t origin, uint64_t length);
@@ -46,8 +47,13 @@ void s390_pv_prep_reset(void);
 int s390_pv_verify(void);
 void s390_pv_unshare(void);
 void s390_pv_inject_reset_error(CPUState *cs);
+uint64_t kvm_s390_pv_dmp_get_size_cpu(void);
+uint64_t kvm_s390_pv_dmp_get_size_mem_state(void);
+uint64_t kvm_s390_pv_dmp_get_size_completion_data(void);
+bool kvm_s390_pv_info_basic_valid(void);
 #else /* CONFIG_KVM */
 static inline bool s390_is_pv(void) { return false; }
+static inline int s390_pv_query_info(void) { return 0; }
 static inline int s390_pv_vm_enable(void) { return 0; }
 static inline void s390_pv_vm_disable(void) {}
 static inline int s390_pv_set_sec_parms(uint64_t origin, uint64_t length) { return 0; }
@@ -56,6 +62,10 @@ static inline void s390_pv_prep_reset(void) {}
 static inline int s390_pv_verify(void) { return 0; }
 static inline void s390_pv_unshare(void) {}
 static inline void s390_pv_inject_reset_error(CPUState *cs) {};
+static inline uint64_t kvm_s390_pv_dmp_get_size_cpu(void) { return 0; }
+static inline uint64_t kvm_s390_pv_dmp_get_size_mem_state(void) { return 0; }
+static inline uint64_t kvm_s390_pv_dmp_get_size_completion_data(void) { return 0; }
+static inline bool kvm_s390_pv_info_basic_valid(void) { return false; }
 #endif /* CONFIG_KVM */
 
 int s390_pv_kvm_init(ConfidentialGuestSupport *cgs, Error **errp);