diff mbox series

[v7,12/52] i386/tdx: Validate TD attributes

Message ID 20250124132048.3229049-13-xiaoyao.li@intel.com (mailing list archive)
State New
Headers show
Series QEMU TDX support | expand

Commit Message

Xiaoyao Li Jan. 24, 2025, 1:20 p.m. UTC
Validate TD attributes with tdx_caps that only supported bits arer
allowed by KVM.

Besides, sanity check the attribute bits that have not been supported by
QEMU yet. e.g., debug bit, it will be allowed in the future when debug
TD support lands in QEMU.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
Changes in v7:
- Define TDX_SUPPORTED_TD_ATTRS as QEMU supported mask, to validates
  user's request. (Rick)

Changes in v3:
- using error_setg() for error report; (Daniel)
---
 qapi/qom.json         |  16 +++++-
 target/i386/kvm/tdx.c | 118 +++++++++++++++++++++++++++++++++++++++++-
 target/i386/kvm/tdx.h |   3 ++
 3 files changed, 134 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/qapi/qom.json b/qapi/qom.json
index 8740626c4ee6..a53000ca6fb4 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -1060,11 +1060,25 @@ 
 #     pages.  Some guest OS (e.g., Linux TD guest) may require this to
 #     be set, otherwise they refuse to boot.
 #
+# @mrconfigid: ID for non-owner-defined configuration of the guest TD,
+#     e.g., run-time or OS configuration (base64 encoded SHA384 digest).
+#     Defaults to all zeros.
+#
+# @mrowner: ID for the guest TD’s owner (base64 encoded SHA384 digest).
+#     Defaults to all zeros.
+#
+# @mrownerconfig: ID for owner-defined configuration of the guest TD,
+#     e.g., specific to the workload rather than the run-time or OS
+#     (base64 encoded SHA384 digest).  Defaults to all zeros.
+#
 # Since: 10.0
 ##
 { 'struct': 'TdxGuestProperties',
   'data': { '*attributes': 'uint64',
-            '*sept-ve-disable': 'bool' } }
+            '*sept-ve-disable': 'bool',
+            '*mrconfigid': 'str',
+            '*mrowner': 'str',
+            '*mrownerconfig': 'str' } }
 
 ##
 # @ThreadContextProperties:
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 653942d83bcb..ed843af1d0b6 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -11,17 +11,24 @@ 
 
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
+#include "qemu/base64.h"
 #include "qapi/error.h"
 #include "qom/object_interfaces.h"
+#include "crypto/hash.h"
 
 #include "hw/i386/x86.h"
 #include "kvm_i386.h"
 #include "tdx.h"
 
+#define TDX_TD_ATTRIBUTES_DEBUG             BIT_ULL(0)
 #define TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE   BIT_ULL(28)
 #define TDX_TD_ATTRIBUTES_PKS               BIT_ULL(30)
 #define TDX_TD_ATTRIBUTES_PERFMON           BIT_ULL(63)
 
+#define TDX_SUPPORTED_TD_ATTRS  (TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE |\
+                                 TDX_TD_ATTRIBUTES_PKS | \
+                                 TDX_TD_ATTRIBUTES_PERFMON)
+
 static TdxGuest *tdx_guest;
 
 static struct kvm_tdx_capabilities *tdx_caps;
@@ -153,13 +160,33 @@  static int tdx_kvm_type(X86ConfidentialGuest *cg)
     return KVM_X86_TDX_VM;
 }
 
-static void setup_td_guest_attributes(X86CPU *x86cpu)
+static int tdx_validate_attributes(TdxGuest *tdx, Error **errp)
+{
+    if ((tdx->attributes & ~tdx_caps->supported_attrs)) {
+        error_setg(errp, "Invalid attributes 0x%lx for TDX VM "
+                   "(KVM supported: 0x%llx)", tdx->attributes,
+                   tdx_caps->supported_attrs);
+        return -1;
+    }
+
+    if (tdx->attributes & ~TDX_SUPPORTED_TD_ATTRS) {
+        warn_report("Some QEMU unsupported TD attribute bits being requested:"
+                    "requested: 0x%lx QEMU supported: 0x%llx",
+                    tdx->attributes, TDX_SUPPORTED_TD_ATTRS);
+    }
+
+    return 0;
+}
+
+static int setup_td_guest_attributes(X86CPU *x86cpu, Error **errp)
 {
     CPUX86State *env = &x86cpu->env;
 
     tdx_guest->attributes |= (env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_PKS) ?
                              TDX_TD_ATTRIBUTES_PKS : 0;
     tdx_guest->attributes |= x86cpu->enable_pmu ? TDX_TD_ATTRIBUTES_PERFMON : 0;
+
+    return tdx_validate_attributes(tdx_guest, errp);
 }
 
 static int setup_td_xfam(X86CPU *x86cpu, Error **errp)
@@ -214,6 +241,7 @@  int tdx_pre_create_vcpu(CPUState *cpu, Error **errp)
     CPUX86State *env = &x86cpu->env;
     g_autofree struct kvm_tdx_init_vm *init_vm = NULL;
     Error *local_err = NULL;
+    size_t data_len;
     int retry = 10000;
     int r = 0;
 
@@ -225,7 +253,40 @@  int tdx_pre_create_vcpu(CPUState *cpu, Error **errp)
     init_vm = g_malloc0(sizeof(struct kvm_tdx_init_vm) +
                         sizeof(struct kvm_cpuid_entry2) * KVM_MAX_CPUID_ENTRIES);
 
-    setup_td_guest_attributes(x86cpu);
+    if (tdx_guest->mrconfigid) {
+        g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrconfigid,
+                              strlen(tdx_guest->mrconfigid), &data_len, errp);
+        if (!data || data_len != QCRYPTO_HASH_DIGEST_LEN_SHA384) {
+            error_setg(errp, "TDX: failed to decode mrconfigid");
+            return -1;
+        }
+        memcpy(init_vm->mrconfigid, data, data_len);
+    }
+
+    if (tdx_guest->mrowner) {
+        g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrowner,
+                              strlen(tdx_guest->mrowner), &data_len, errp);
+        if (!data || data_len != QCRYPTO_HASH_DIGEST_LEN_SHA384) {
+            error_setg(errp, "TDX: failed to decode mrowner");
+            return -1;
+        }
+        memcpy(init_vm->mrowner, data, data_len);
+    }
+
+    if (tdx_guest->mrownerconfig) {
+        g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrownerconfig,
+                            strlen(tdx_guest->mrownerconfig), &data_len, errp);
+        if (!data || data_len != QCRYPTO_HASH_DIGEST_LEN_SHA384) {
+            error_setg(errp, "TDX: failed to decode mrownerconfig");
+            return -1;
+        }
+        memcpy(init_vm->mrownerconfig, data, data_len);
+    }
+
+    r = setup_td_guest_attributes(x86cpu, errp);
+    if (r) {
+        return r;
+    }
 
     r = setup_td_xfam(x86cpu, errp);
     if (r) {
@@ -283,6 +344,51 @@  static void tdx_guest_set_sept_ve_disable(Object *obj, bool value, Error **errp)
     }
 }
 
+static char *tdx_guest_get_mrconfigid(Object *obj, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    return g_strdup(tdx->mrconfigid);
+}
+
+static void tdx_guest_set_mrconfigid(Object *obj, const char *value, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    g_free(tdx->mrconfigid);
+    tdx->mrconfigid = g_strdup(value);
+}
+
+static char *tdx_guest_get_mrowner(Object *obj, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    return g_strdup(tdx->mrowner);
+}
+
+static void tdx_guest_set_mrowner(Object *obj, const char *value, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    g_free(tdx->mrowner);
+    tdx->mrowner = g_strdup(value);
+}
+
+static char *tdx_guest_get_mrownerconfig(Object *obj, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    return g_strdup(tdx->mrownerconfig);
+}
+
+static void tdx_guest_set_mrownerconfig(Object *obj, const char *value, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    g_free(tdx->mrownerconfig);
+    tdx->mrownerconfig = g_strdup(value);
+}
+
 /* tdx guest */
 OBJECT_DEFINE_TYPE_WITH_INTERFACES(TdxGuest,
                                    tdx_guest,
@@ -306,6 +412,14 @@  static void tdx_guest_init(Object *obj)
     object_property_add_bool(obj, "sept-ve-disable",
                              tdx_guest_get_sept_ve_disable,
                              tdx_guest_set_sept_ve_disable);
+    object_property_add_str(obj, "mrconfigid",
+                            tdx_guest_get_mrconfigid,
+                            tdx_guest_set_mrconfigid);
+    object_property_add_str(obj, "mrowner",
+                            tdx_guest_get_mrowner, tdx_guest_set_mrowner);
+    object_property_add_str(obj, "mrownerconfig",
+                            tdx_guest_get_mrownerconfig,
+                            tdx_guest_set_mrownerconfig);
 }
 
 static void tdx_guest_finalize(Object *obj)
diff --git a/target/i386/kvm/tdx.h b/target/i386/kvm/tdx.h
index 4e2b5c61ff5b..e472b11fb0dd 100644
--- a/target/i386/kvm/tdx.h
+++ b/target/i386/kvm/tdx.h
@@ -24,6 +24,9 @@  typedef struct TdxGuest {
     bool initialized;
     uint64_t attributes;    /* TD attributes */
     uint64_t xfam;
+    char *mrconfigid;       /* base64 encoded sha348 digest */
+    char *mrowner;          /* base64 encoded sha348 digest */
+    char *mrownerconfig;    /* base64 encoded sha348 digest */
 } TdxGuest;
 
 #ifdef CONFIG_TDX