On 4/2/2025 7:51 PM, Daniel P. Berrangé wrote:
On Tue, Apr 01, 2025 at 09:01:23AM -0400, Xiaoyao Li wrote:
From: Isaku Yamahata <isaku.yamah...@intel.com>
Three sha384 hash values, mrconfigid, mrowner and mrownerconfig, of a TD
can be provided for TDX attestation. Detailed meaning of them can be
found:
https://lore.kernel.org/qemu-devel/31d6dbc1-f453-4cef-ab08-4813f4e0f...@intel.com/
Allow user to specify those values via property mrconfigid, mrowner and
mrownerconfig. They are all in base64 format.
example
-object tdx-guest, \
mrconfigid=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v,\
mrowner=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v,\
mrownerconfig=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v
Signed-off-by: Isaku Yamahata <isaku.yamah...@intel.com>
Co-developed-by: Xiaoyao Li <xiaoyao...@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com>
---
Changes in v8:
- it gets squashed into previous patch in v7. So split it out in v8;
Changes in v6:
- refine the doc comment of QAPI properties;
Changes in v5:
- refine the description of QAPI properties and add description of
default value when not specified;
Changes in v4:
- describe more of there fields in qom.json
- free the old value before set new value to avoid memory leak in
_setter(); (Daniel)
Changes in v3:
- use base64 encoding instread of hex-string;
---
qapi/qom.json | 16 +++++++-
target/i386/kvm/tdx.c | 86 +++++++++++++++++++++++++++++++++++++++++++
target/i386/kvm/tdx.h | 3 ++
3 files changed, 104 insertions(+), 1 deletion(-)
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index aa043acb1a88..77ddb2655c53 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -11,8 +11,10 @@
#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"
@@ -239,6 +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;
@@ -250,6 +253,36 @@ 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);
+ 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;
+ }
When '!data', qbase64_decode will have already filled 'errp' with
details, so we must immediately 'return -1', as a repeated error_setg
call is an programming error.
The error_setg call should only be done in response to failing
the 'data_len' check and the message should specify the lengths
eg more like this
if (!data) {
return -1;
}
if (data_len != QCRYPTO_HASH_DIGEST_LEN_SHA384) {
error_setg(errp, "TDX mrconfigid len %d must match SHA384 digest len %d",
data_len, QCRYPTO_HASH_DIGEST_LEN_SHA384)
return -1;
}
Nice catch!
+ 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;
With regards,
Daniel
