From ba750c8ed71bc73c79fecefa895192793ef6b7db Mon Sep 17 00:00:00 2001

From: Connor Kuehl <ckuehl@redhat.com>

Date: Wed, 2 Jun 2021 19:39:20 -0400

Subject: [PATCH 05/21] target/i386/sev: add support to query the attestation

 report

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Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

RH-Author: Miroslav Rezanina <mrezanin@redhat.com>

RH-MergeRequest: 8: Synchronize with RHEL-AV 8.5 release 19 to RHEL 9

RH-Commit: [4/8] de6088cb0cd1db779b85a50be87846e967f8c92c (mrezanin/centos-src-qemu-kvm)

RH-Bugzilla: 1957194

RH-Acked-by: Daniel P. Berrangé <berrange@redhat.com>

RH-Acked-by: Greg Kurz <gkurz@redhat.com>

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>

From: Brijesh Singh <brijesh.singh@amd.com>

The SEV FW >= 0.23 added a new command that can be used to query the

attestation report containing the SHA-256 digest of the guest memory

and VMSA encrypted with the LAUNCH_UPDATE and sign it with the PEK.

Note, we already have a command (LAUNCH_MEASURE) that can be used to

query the SHA-256 digest of the guest memory encrypted through the

LAUNCH_UPDATE. The main difference between previous and this command

is that the report is signed with the PEK and unlike the LAUNCH_MEASURE

command the ATTESATION_REPORT command can be called while the guest

is running.

Add a QMP interface "query-sev-attestation-report" that can be used

to get the report encoded in base64.

Cc: James Bottomley <jejb@linux.ibm.com>

Cc: Tom Lendacky <Thomas.Lendacky@amd.com>

Cc: Eric Blake <eblake@redhat.com>

Cc: Paolo Bonzini <pbonzini@redhat.com>

Cc: kvm@vger.kernel.org

Reviewed-by: James Bottomley <jejb@linux.ibm.com>

Tested-by: James Bottomley <jejb@linux.ibm.com>

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>

Reviewed-by: Connor Kuehl <ckuehl@redhat.com>

Message-Id: <20210429170728.24322-1-brijesh.singh@amd.com>

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

(cherry picked from commit 3ea1a80243d5b5ba23d8c2b7d3a86034ea0ade22)

Signed-off-by: Connor Kuehl <ckuehl@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 linux-headers/linux/kvm.h |  8 +++++

 qapi/misc-target.json     | 38 ++++++++++++++++++++++

 target/i386/monitor.c     |  6 ++++

 target/i386/sev-stub.c    |  7 ++++

 target/i386/sev.c         | 67 +++++++++++++++++++++++++++++++++++++++

 target/i386/sev_i386.h    |  2 ++

 target/i386/trace-events  |  1 +

 7 files changed, 129 insertions(+)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h

index 020b62a619..897f831374 100644

--- a/linux-headers/linux/kvm.h

+++ b/linux-headers/linux/kvm.h

@@ -1591,6 +1591,8 @@ enum sev_cmd_id {

 	KVM_SEV_DBG_ENCRYPT,

 	/* Guest certificates commands */

 	KVM_SEV_CERT_EXPORT,

+	/* Attestation report */

+	KVM_SEV_GET_ATTESTATION_REPORT,

 	KVM_SEV_NR_MAX,

 };

@@ -1643,6 +1645,12 @@ struct kvm_sev_dbg {

 	__u32 len;

 };

+struct kvm_sev_attestation_report {

+	__u8 mnonce[16];

+	__u64 uaddr;

+	__u32 len;

+};

+

 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)

 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)

 #define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)

diff --git a/qapi/misc-target.json b/qapi/misc-target.json

index 0c7491cd82..4b62f0ac05 100644

--- a/qapi/misc-target.json

+++ b/qapi/misc-target.json

@@ -285,3 +285,41 @@

 ##

 { 'command': 'query-gic-capabilities', 'returns': ['GICCapability'],

   'if': 'defined(TARGET_ARM)' }

+

+

+##

+# @SevAttestationReport:

+#

+# The struct describes attestation report for a Secure Encrypted Virtualization

+# feature.

+#

+# @data:  guest attestation report (base64 encoded)

+#

+#

+# Since: 6.1

+##

+{ 'struct': 'SevAttestationReport',

+  'data': { 'data': 'str'},

+  'if': 'defined(TARGET_I386)' }

+

+##

+# @query-sev-attestation-report:

+#

+# This command is used to get the SEV attestation report, and is supported on AMD

+# X86 platforms only.

+#

+# @mnonce: a random 16 bytes value encoded in base64 (it will be included in report)

+#

+# Returns: SevAttestationReport objects.

+#

+# Since: 6.1

+#

+# Example:

+#

+# -> { "execute" : "query-sev-attestation-report", "arguments": { "mnonce": "aaaaaaa" } }

+# <- { "return" : { "data": "aaaaaaaabbbddddd"} }

+#

+##

+{ 'command': 'query-sev-attestation-report', 'data': { 'mnonce': 'str' },

+  'returns': 'SevAttestationReport',

+  'if': 'defined(TARGET_I386)' }

diff --git a/target/i386/monitor.c b/target/i386/monitor.c

index 5994408bee..119211f0b0 100644

--- a/target/i386/monitor.c

+++ b/target/i386/monitor.c

@@ -757,3 +757,9 @@ void qmp_sev_inject_launch_secret(const char *packet_hdr,

     sev_inject_launch_secret(packet_hdr, secret, gpa, errp);

 }

+

+SevAttestationReport *

+qmp_query_sev_attestation_report(const char *mnonce, Error **errp)

+{

+    return sev_get_attestation_report(mnonce, errp);

+}

diff --git a/target/i386/sev-stub.c b/target/i386/sev-stub.c

index 0207f1c5aa..0227cb5177 100644

--- a/target/i386/sev-stub.c

+++ b/target/i386/sev-stub.c

@@ -74,3 +74,10 @@ int sev_es_save_reset_vector(void *flash_ptr, uint64_t flash_size)

 {

     abort();

 }

+

+SevAttestationReport *

+sev_get_attestation_report(const char *mnonce, Error **errp)

+{

+    error_setg(errp, "SEV is not available in this QEMU");

+    return NULL;

+}

diff --git a/target/i386/sev.c b/target/i386/sev.c

index 72b9e2ab40..740548f213 100644

--- a/target/i386/sev.c

+++ b/target/i386/sev.c

@@ -491,6 +491,73 @@ out:

     return cap;

 }

+SevAttestationReport *

+sev_get_attestation_report(const char *mnonce, Error **errp)

+{

+    struct kvm_sev_attestation_report input = {};

+    SevAttestationReport *report = NULL;

+    SevGuestState *sev = sev_guest;

+    guchar *data;

+    guchar *buf;

+    gsize len;

+    int err = 0, ret;

+

+    if (!sev_enabled()) {

+        error_setg(errp, "SEV is not enabled");

+        return NULL;

+    }

+

+    /* lets decode the mnonce string */

+    buf = g_base64_decode(mnonce, &len;;

+    if (!buf) {

+        error_setg(errp, "SEV: failed to decode mnonce input");

+        return NULL;

+    }

+

+    /* verify the input mnonce length */

+    if (len != sizeof(input.mnonce)) {

+        error_setg(errp, "SEV: mnonce must be %zu bytes (got %" G_GSIZE_FORMAT ")",

+                sizeof(input.mnonce), len);

+        g_free(buf);

+        return NULL;

+    }

+

+    /* Query the report length */

+    ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT,

+            &input, &err;;

+    if (ret < 0) {

+        if (err != SEV_RET_INVALID_LEN) {

+            error_setg(errp, "failed to query the attestation report length "

+                    "ret=%d fw_err=%d (%s)", ret, err, fw_error_to_str(err));

+            g_free(buf);

+            return NULL;

+        }

+    }

+

+    data = g_malloc(input.len);

+    input.uaddr = (unsigned long)data;

+    memcpy(input.mnonce, buf, sizeof(input.mnonce));

+

+    /* Query the report */

+    ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT,

+            &input, &err;;

+    if (ret) {

+        error_setg_errno(errp, errno, "Failed to get attestation report"

+                " ret=%d fw_err=%d (%s)", ret, err, fw_error_to_str(err));

+        goto e_free_data;

+    }

+

+    report = g_new0(SevAttestationReport, 1);

+    report->data = g_base64_encode(data, input.len);

+

+    trace_kvm_sev_attestation_report(mnonce, report->data);

+

+e_free_data:

+    g_free(data);

+    g_free(buf);

+    return report;

+}

+

 static int

 sev_read_file_base64(const char *filename, guchar **data, gsize *len)

 {

diff --git a/target/i386/sev_i386.h b/target/i386/sev_i386.h

index ae221d4c72..ae6d840478 100644

--- a/target/i386/sev_i386.h

+++ b/target/i386/sev_i386.h

@@ -35,5 +35,7 @@ extern uint32_t sev_get_cbit_position(void);

 extern uint32_t sev_get_reduced_phys_bits(void);

 extern char *sev_get_launch_measurement(void);

 extern SevCapability *sev_get_capabilities(Error **errp);

+extern SevAttestationReport *

+sev_get_attestation_report(const char *mnonce, Error **errp);

 #endif

diff --git a/target/i386/trace-events b/target/i386/trace-events

index a22ab24e21..8d6437404d 100644

--- a/target/i386/trace-events

+++ b/target/i386/trace-events

@@ -10,3 +10,4 @@ kvm_sev_launch_update_data(void *addr, uint64_t len) "addr %p len 0x%" PRIx64

 kvm_sev_launch_measurement(const char *value) "data %s"

 kvm_sev_launch_finish(void) ""

 kvm_sev_launch_secret(uint64_t hpa, uint64_t hva, uint64_t secret, int len) "hpa 0x%" PRIx64 " hva 0x%" PRIx64 " data 0x%" PRIx64 " len %d"

+kvm_sev_attestation_report(const char *mnonce, const char *data) "mnonce %s data %s"

-- 

2.27.0