xen/hvm: Fix handling of obsolete HVM_PARAMs

The local xc_hvm_param_deprecated_check() in libxc tries to guess Xen's
behaviour for the MEMORY_EVENT params, but is wrong for the get side, where
Xen would return 0 (which is also a bug).  Delete the helper.

In Xen, perform the checks in hvm_allow_set_param(), rather than
hvm_set_param(), and actually implement checks on the get side so the
hypercall doesn't return successfully with 0 as an answer.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>

diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
index e544218d2e6a09093db2ac1782592fb8d56f9fc0..71829c2bce3e6b80a7cacee57bc3722f9b3f50a0 100644 (file)
--- a/tools/libxc/xc_domain.c
+++ b/tools/libxc/xc_domain.c
@@ -1441,31 +1441,10 @@ int xc_domain_send_trigger(xc_interface *xch,
     return do_domctl(xch, &domctl);
 }
 
-static inline int xc_hvm_param_deprecated_check(uint32_t param)
-{
-    switch ( param )
-    {
-        case HVM_PARAM_MEMORY_EVENT_CR0:
-        case HVM_PARAM_MEMORY_EVENT_CR3:
-        case HVM_PARAM_MEMORY_EVENT_CR4:
-        case HVM_PARAM_MEMORY_EVENT_INT3:
-        case HVM_PARAM_MEMORY_EVENT_SINGLE_STEP:
-        case HVM_PARAM_MEMORY_EVENT_MSR:
-            return -EOPNOTSUPP;
-        default:
-            break;
-    };
-
-    return 0;
-}
-
 int xc_hvm_param_set(xc_interface *handle, uint32_t dom, uint32_t param, uint64_t value)
 {
     DECLARE_HYPERCALL_BUFFER(xen_hvm_param_t, arg);
-    int rc = xc_hvm_param_deprecated_check(param);
-
-    if ( rc )
-        return rc;
+    int rc;
 
     arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
     if ( arg == NULL )
@@ -1484,10 +1463,7 @@ int xc_hvm_param_set(xc_interface *handle, uint32_t dom, uint32_t param, uint64_
 int xc_hvm_param_get(xc_interface *handle, uint32_t dom, uint32_t param, uint64_t *value)
 {
     DECLARE_HYPERCALL_BUFFER(xen_hvm_param_t, arg);
-    int rc = xc_hvm_param_deprecated_check(param);
-
-    if ( rc )
-        return rc;
+    int rc;
 
     arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
     if ( arg == NULL )

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 00a9e70b7c6f79132b4d5d9b04cd3968277b126e..93795dab928fb482e90ef1abddf43b39adf33d63 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4105,8 +4105,14 @@ static int hvm_allow_set_param(struct domain *d,
         break;
     /* The following parameters are deprecated. */
     case HVM_PARAM_DM_DOMAIN:
+    case HVM_PARAM_MEMORY_EVENT_CR0:
+    case HVM_PARAM_MEMORY_EVENT_CR3:
+    case HVM_PARAM_MEMORY_EVENT_CR4:
+    case HVM_PARAM_MEMORY_EVENT_INT3:
+    case HVM_PARAM_MEMORY_EVENT_SINGLE_STEP:
     case HVM_PARAM_BUFIOREQ_EVTCHN:
-        rc = -EPERM;
+    case HVM_PARAM_MEMORY_EVENT_MSR:
+        rc = -EINVAL;
         break;
     /*
      * The following parameters must not be set by the guest
@@ -4221,15 +4227,6 @@ static int hvm_set_param(struct domain *d, uint32_t index, uint64_t value)
     case HVM_PARAM_ACPI_IOPORTS_LOCATION:
         rc = pmtimer_change_ioport(d, value);
         break;
-    case HVM_PARAM_MEMORY_EVENT_CR0:
-    case HVM_PARAM_MEMORY_EVENT_CR3:
-    case HVM_PARAM_MEMORY_EVENT_CR4:
-    case HVM_PARAM_MEMORY_EVENT_INT3:
-    case HVM_PARAM_MEMORY_EVENT_SINGLE_STEP:
-    case HVM_PARAM_MEMORY_EVENT_MSR:
-        /* Deprecated */
-        rc = -EOPNOTSUPP;
-        break;
     case HVM_PARAM_NESTEDHVM:
         rc = xsm_hvm_param_nested(XSM_PRIV, d);
         if ( rc )
@@ -4411,8 +4408,14 @@ static int hvm_allow_get_param(struct domain *d,
         break;
     /* The following parameters are deprecated. */
     case HVM_PARAM_DM_DOMAIN:
+    case HVM_PARAM_MEMORY_EVENT_CR0:
+    case HVM_PARAM_MEMORY_EVENT_CR3:
+    case HVM_PARAM_MEMORY_EVENT_CR4:
+    case HVM_PARAM_MEMORY_EVENT_INT3:
+    case HVM_PARAM_MEMORY_EVENT_SINGLE_STEP:
     case HVM_PARAM_BUFIOREQ_EVTCHN:
-        rc = -ENODATA;
+    case HVM_PARAM_MEMORY_EVENT_MSR:
+        rc = -EINVAL;
         break;
     /* The remaining parameters should not be read by the guest. */
     default:

diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h
index 36832e4b9438f0d06bccee0bac7b573c48e9fbe7..68293e314e1a2c0988c449086b88893df4a8c687 100644 (file)
--- a/xen/include/public/hvm/params.h
+++ b/xen/include/public/hvm/params.h
@@ -28,8 +28,14 @@
 /* These parameters are deprecated and their meaning is undefined. */
 #if defined(__XEN__) || defined(__XEN_TOOLS__)
 
-#define HVM_PARAM_DM_DOMAIN 13
-#define HVM_PARAM_BUFIOREQ_EVTCHN 26
+#define HVM_PARAM_DM_DOMAIN                 13
+#define HVM_PARAM_MEMORY_EVENT_CR0          20
+#define HVM_PARAM_MEMORY_EVENT_CR3          21
+#define HVM_PARAM_MEMORY_EVENT_CR4          22
+#define HVM_PARAM_MEMORY_EVENT_INT3         23
+#define HVM_PARAM_MEMORY_EVENT_SINGLE_STEP  25
+#define HVM_PARAM_BUFIOREQ_EVTCHN           26
+#define HVM_PARAM_MEMORY_EVENT_MSR          30
 
 #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
 
@@ -227,14 +233,6 @@
  */
 #define HVM_PARAM_ACPI_IOPORTS_LOCATION 19
 
-/* Deprecated */
-#define HVM_PARAM_MEMORY_EVENT_CR0          20
-#define HVM_PARAM_MEMORY_EVENT_CR3          21
-#define HVM_PARAM_MEMORY_EVENT_CR4          22
-#define HVM_PARAM_MEMORY_EVENT_INT3         23
-#define HVM_PARAM_MEMORY_EVENT_SINGLE_STEP  25
-#define HVM_PARAM_MEMORY_EVENT_MSR          30
-
 /* Boolean: Enable nestedhvm (hvm only) */
 #define HVM_PARAM_NESTEDHVM    24