Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging
* fix vss-win32 compilation with clang++
* update Coverity model
* add measurement calculation to amd-memory-encryption docs
# gpg: Signature made Tue 05 Apr 2022 09:42:59 BST
# gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg: issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83
* tag 'for-upstream' of https://gitlab.com/bonzini/qemu:
docs/system/i386: Add measurement calculation details to amd-memory-encryption
qga/vss-win32: fix compilation with clang++
coverity: update model for latest tools
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/docs/system/i386/amd-memory-encryption.rst b/docs/system/i386/amd-memory-encryption.rst
index 215946f..dcf4add 100644
--- a/docs/system/i386/amd-memory-encryption.rst
+++ b/docs/system/i386/amd-memory-encryption.rst
@@ -47,7 +47,7 @@
but should not modify it (any modification of the policy bits will result
in bad measurement). The guest policy is a 4-byte data structure containing
several flags that restricts what can be done on a running SEV guest.
-See KM Spec section 3 and 6.2 for more details.
+See SEV API Spec ([SEVAPI]_) section 3 and 6.2 for more details.
The guest policy can be provided via the ``policy`` property::
@@ -92,7 +92,7 @@
``LAUNCH_FINISH`` finalizes the guest launch and destroys the cryptographic
context.
-See SEV KM API Spec ([SEVKM]_) 'Launching a guest' usage flow (Appendix A) for the
+See SEV API Spec ([SEVAPI]_) 'Launching a guest' usage flow (Appendix A) for the
complete flow chart.
To launch a SEV guest::
@@ -118,6 +118,49 @@
- Requires in-kernel irqchip - the burden is placed on the hypervisor to
manage booting APs.
+Calculating expected guest launch measurement
+---------------------------------------------
+
+In order to verify the guest launch measurement, The Guest Owner must compute
+it in the exact same way as it is calculated by the AMD-SP. SEV API Spec
+([SEVAPI]_) section 6.5.1 describes the AMD-SP operations:
+
+ GCTX.LD is finalized, producing the hash digest of all plaintext data
+ imported into the guest.
+
+ The launch measurement is calculated as:
+
+ HMAC(0x04 || API_MAJOR || API_MINOR || BUILD || GCTX.POLICY || GCTX.LD || MNONCE; GCTX.TIK)
+
+ where "||" represents concatenation.
+
+The values of API_MAJOR, API_MINOR, BUILD, and GCTX.POLICY can be obtained
+from the ``query-sev`` qmp command.
+
+The value of MNONCE is part of the response of ``query-sev-launch-measure``: it
+is the last 16 bytes of the base64-decoded data field (see SEV API Spec
+([SEVAPI]_) section 6.5.2 Table 52: LAUNCH_MEASURE Measurement Buffer).
+
+The value of GCTX.LD is
+``SHA256(firmware_blob || kernel_hashes_blob || vmsas_blob)``, where:
+
+* ``firmware_blob`` is the content of the entire firmware flash file (for
+ example, ``OVMF.fd``). Note that you must build a stateless firmware file
+ which doesn't use an NVRAM store, because the NVRAM area is not measured, and
+ therefore it is not secure to use a firmware which uses state from an NVRAM
+ store.
+* if kernel is used, and ``kernel-hashes=on``, then ``kernel_hashes_blob`` is
+ the content of PaddedSevHashTable (including the zero padding), which itself
+ includes the hashes of kernel, initrd, and cmdline that are passed to the
+ guest. The PaddedSevHashTable struct is defined in ``target/i386/sev.c``.
+* if SEV-ES is enabled (``policy & 0x4 != 0``), ``vmsas_blob`` is the
+ concatenation of all VMSAs of the guest vcpus. Each VMSA is 4096 bytes long;
+ its content is defined inside Linux kernel code as ``struct vmcb_save_area``,
+ or in AMD APM Volume 2 ([APMVOL2]_) Table B-2: VMCB Layout, State Save Area.
+
+If kernel hashes are not used, or SEV-ES is disabled, use empty blobs for
+``kernel_hashes_blob`` and ``vmsas_blob`` as needed.
+
Debugging
---------
@@ -142,8 +185,11 @@
`AMD Memory Encryption whitepaper
<https://developer.amd.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf>`_
-.. [SEVKM] `Secure Encrypted Virtualization Key Management
- <http://developer.amd.com/wordpress/media/2017/11/55766_SEV-KM-API_Specification.pdf>`_
+.. [SEVAPI] `Secure Encrypted Virtualization API
+ <https://www.amd.com/system/files/TechDocs/55766_SEV-KM_API_Specification.pdf>`_
+
+.. [APMVOL2] `AMD64 Architecture Programmer's Manual Volume 2: System Programming
+ <https://www.amd.com/system/files/TechDocs/24593.pdf>`_
KVM Forum slides:
diff --git a/qga/vss-win32/install.cpp b/qga/vss-win32/install.cpp
index 8076efe..b57508f 100644
--- a/qga/vss-win32/install.cpp
+++ b/qga/vss-win32/install.cpp
@@ -46,7 +46,8 @@
* If text doesn't contains '(', negative precision is given, which is
* treated as though it were missing.
*/
- char *msg = NULL, *nul = strchr(text, '(');
+ char *msg = NULL;
+ const char *nul = strchr(text, '(');
int len = nul ? nul - text : -1;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
diff --git a/scripts/coverity-scan/model.c b/scripts/coverity-scan/model.c
index 9d4fba5..686d1a3 100644
--- a/scripts/coverity-scan/model.c
+++ b/scripts/coverity-scan/model.c
@@ -356,7 +356,8 @@
typedef struct _GIOChannel GIOChannel;
GIOChannel *g_io_channel_unix_new(int fd)
{
- GIOChannel *c = g_malloc0(sizeof(GIOChannel));
+ /* cannot use incomplete type, the actual struct is roughly this size. */
+ GIOChannel *c = g_malloc0(20 * sizeof(void *));
__coverity_escape__(fd);
return c;
}
