[PULL 2/3] sev: add sev-inject-launch-secret

[Eduardo Habkost]

From: Tobin Feldman-Fitzthum <tobin@ibm.com>

AMD SEV allows a guest owner to inject a secret blob
into the memory of a virtual machine. The secret is
encrypted with the SEV Transport Encryption Key and
integrity is guaranteed with the Transport Integrity
Key. Although QEMU facilitates the injection of the
launch secret, it cannot access the secret.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@linux.ibm.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Message-Id: <20201027170303.47550-1-tobin@linux.ibm.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 qapi/misc-target.json     | 18 +++++++++++
 include/monitor/monitor.h |  3 ++
 include/sysemu/sev.h      |  2 ++
 monitor/misc.c            | 17 +++++++---
 target/i386/monitor.c     |  7 +++++
 target/i386/sev-stub.c    |  5 +++
 target/i386/sev.c         | 65 +++++++++++++++++++++++++++++++++++++++
 target/i386/trace-events  |  1 +
 8 files changed, 114 insertions(+), 4 deletions(-)

diff --git a/qapi/misc-target.json b/qapi/misc-target.json
index cbe5135264..06ef8757f0 100644
--- a/qapi/misc-target.json
+++ b/qapi/misc-target.json
@@ -201,6 +201,24 @@
 { 'command': 'query-sev-capabilities', 'returns': 'SevCapability',
   'if': 'defined(TARGET_I386)' }
 
+##
+# @sev-inject-launch-secret:
+#
+# This command injects a secret blob into memory of SEV guest.
+#
+# @packet-header: the launch secret packet header encoded in base64
+#
+# @secret: the launch secret data to be injected encoded in base64
+#
+# @gpa: the guest physical address where secret will be injected.
+#
+# Since: 6.0
+#
+##
+{ 'command': 'sev-inject-launch-secret',
+  'data': { 'packet-header': 'str', 'secret': 'str', 'gpa': 'uint64' },
+  'if': 'defined(TARGET_I386)' }
+
 ##
 # @dump-skeys:
 #
diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
index 348bfad3d5..af3887bb71 100644
--- a/include/monitor/monitor.h
+++ b/include/monitor/monitor.h
@@ -4,6 +4,7 @@
 #include "block/block.h"
 #include "qapi/qapi-types-misc.h"
 #include "qemu/readline.h"
+#include "include/exec/hwaddr.h"
 
 typedef struct MonitorHMP MonitorHMP;
 typedef struct MonitorOptions MonitorOptions;
@@ -37,6 +38,8 @@ void monitor_flush(Monitor *mon);
 int monitor_set_cpu(Monitor *mon, int cpu_index);
 int monitor_get_cpu_index(Monitor *mon);
 
+void *gpa2hva(MemoryRegion **p_mr, hwaddr addr, uint64_t size, Error **errp);
+
 void monitor_read_command(MonitorHMP *mon, int show_prompt);
 int monitor_read_password(MonitorHMP *mon, ReadLineFunc *readline_func,
                           void *opaque);
diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index 98c1ec8d38..7ab6e3e31d 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -18,4 +18,6 @@
 
 void *sev_guest_init(const char *id);
 int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len);
+int sev_inject_launch_secret(const char *hdr, const char *secret,
+                             uint64_t gpa, Error **errp);
 #endif
diff --git a/monitor/misc.c b/monitor/misc.c
index 7ffe6f7a84..fde6e36a0b 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -667,10 +667,11 @@ static void hmp_physical_memory_dump(Monitor *mon, const 
QDict *qdict)
     memory_dump(mon, count, format, size, addr, 1);
 }
 
-static void *gpa2hva(MemoryRegion **p_mr, hwaddr addr, Error **errp)
+void *gpa2hva(MemoryRegion **p_mr, hwaddr addr, uint64_t size, Error **errp)
 {
+    Int128 gpa_region_size;
     MemoryRegionSection mrs = memory_region_find(get_system_memory(),
-                                                 addr, 1);
+                                                 addr, size);
 
     if (!mrs.mr) {
         error_setg(errp, "No memory is mapped at address 0x%" HWADDR_PRIx, 
addr);
@@ -683,6 +684,14 @@ static void *gpa2hva(MemoryRegion **p_mr, hwaddr addr, 
Error **errp)
         return NULL;
     }
 
+    gpa_region_size = int128_make64(size);
+    if (int128_lt(mrs.size, gpa_region_size)) {
+        error_setg(errp, "Size of memory region at 0x%" HWADDR_PRIx
+                   " exceeded.", addr);
+        memory_region_unref(mrs.mr);
+        return NULL;
+    }
+
     *p_mr = mrs.mr;
     return qemu_map_ram_ptr(mrs.mr->ram_block, mrs.offset_within_region);
 }
@@ -694,7 +703,7 @@ static void hmp_gpa2hva(Monitor *mon, const QDict *qdict)
     MemoryRegion *mr = NULL;
     void *ptr;
 
-    ptr = gpa2hva(&mr, addr, &local_err);
+    ptr = gpa2hva(&mr, addr, 1, &local_err);
     if (local_err) {
         error_report_err(local_err);
         return;
@@ -770,7 +779,7 @@ static void hmp_gpa2hpa(Monitor *mon, const QDict *qdict)
     void *ptr;
     uint64_t physaddr;
 
-    ptr = gpa2hva(&mr, addr, &local_err);
+    ptr = gpa2hva(&mr, addr, 1, &local_err);
     if (local_err) {
         error_report_err(local_err);
         return;
diff --git a/target/i386/monitor.c b/target/i386/monitor.c
index 9f9e1c42f4..1bc91442b1 100644
--- a/target/i386/monitor.c
+++ b/target/i386/monitor.c
@@ -729,3 +729,10 @@ SevCapability *qmp_query_sev_capabilities(Error **errp)
 {
     return sev_get_capabilities(errp);
 }
+
+void qmp_sev_inject_launch_secret(const char *packet_hdr,
+                                  const char *secret, uint64_t gpa,
+                                  Error **errp)
+{
+    sev_inject_launch_secret(packet_hdr, secret, gpa, errp);
+}
diff --git a/target/i386/sev-stub.c b/target/i386/sev-stub.c
index 88e3f39a1e..c1fecc2101 100644
--- a/target/i386/sev-stub.c
+++ b/target/i386/sev-stub.c
@@ -49,3 +49,8 @@ SevCapability *sev_get_capabilities(Error **errp)
     error_setg(errp, "SEV is not available in this QEMU");
     return NULL;
 }
+int sev_inject_launch_secret(const char *hdr, const char *secret,
+                             uint64_t gpa, Error **errp)
+{
+    return 1;
+}
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 93c4d60b82..1546606811 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -29,6 +29,8 @@
 #include "trace.h"
 #include "migration/blocker.h"
 #include "qom/object.h"
+#include "exec/address-spaces.h"
+#include "monitor/monitor.h"
 
 #define TYPE_SEV_GUEST "sev-guest"
 OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST)
@@ -785,6 +787,69 @@ sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len)
     return 0;
 }
 
+int sev_inject_launch_secret(const char *packet_hdr, const char *secret,
+                             uint64_t gpa, Error **errp)
+{
+    struct kvm_sev_launch_secret input;
+    g_autofree guchar *data = NULL, *hdr = NULL;
+    int error, ret = 1;
+    void *hva;
+    gsize hdr_sz = 0, data_sz = 0;
+    MemoryRegion *mr = NULL;
+
+    if (!sev_guest) {
+        error_setg(errp, "SEV: SEV not enabled.");
+        return 1;
+    }
+
+    /* secret can be injected only in this state */
+    if (!sev_check_state(sev_guest, SEV_STATE_LAUNCH_SECRET)) {
+        error_setg(errp, "SEV: Not in correct state. (LSECRET) %x",
+                     sev_guest->state);
+        return 1;
+    }
+
+    hdr = g_base64_decode(packet_hdr, &hdr_sz);
+    if (!hdr || !hdr_sz) {
+        error_setg(errp, "SEV: Failed to decode sequence header");
+        return 1;
+    }
+
+    data = g_base64_decode(secret, &data_sz);
+    if (!data || !data_sz) {
+        error_setg(errp, "SEV: Failed to decode data");
+        return 1;
+    }
+
+    hva = gpa2hva(&mr, gpa, data_sz, errp);
+    if (!hva) {
+        error_prepend(errp, "SEV: Failed to calculate guest address: ");
+        return 1;
+    }
+
+    input.hdr_uaddr = (uint64_t)(unsigned long)hdr;
+    input.hdr_len = hdr_sz;
+
+    input.trans_uaddr = (uint64_t)(unsigned long)data;
+    input.trans_len = data_sz;
+
+    input.guest_uaddr = (uint64_t)(unsigned long)hva;
+    input.guest_len = data_sz;
+
+    trace_kvm_sev_launch_secret(gpa, input.guest_uaddr,
+                                input.trans_uaddr, input.trans_len);
+
+    ret = sev_ioctl(sev_guest->sev_fd, KVM_SEV_LAUNCH_SECRET,
+                    &input, &error);
+    if (ret) {
+        error_setg(errp, "SEV: failed to inject secret ret=%d fw_error=%d 
'%s'",
+                     ret, error, fw_error_to_str(error));
+        return ret;
+    }
+
+    return 0;
+}
+
 static void
 sev_register_types(void)
 {
diff --git a/target/i386/trace-events b/target/i386/trace-events
index 789c700d4a..9f299e94a2 100644
--- a/target/i386/trace-events
+++ b/target/i386/trace-events
@@ -15,3 +15,4 @@ kvm_sev_launch_start(int policy, void *session, void *pdh) 
"policy 0x%x session
 kvm_sev_launch_update_data(void *addr, uint64_t len) "addr %p len 0x%" PRIu64
 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"
-- 
2.28.0