[Qemu-devel] [PULL v1 3/4] tpm: CRB: Enforce locality is requested before processing buffer

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

Section 5.5.3.2.2 of the CRB specs states that use of the TPM
through the localty control method must first be requested,
otherwise the command will be dropped.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 hw/tpm/tpm_crb.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
index ee6c87e..a92dd50 100644
--- a/hw/tpm/tpm_crb.c
+++ b/hw/tpm/tpm_crb.c
@@ -76,6 +76,8 @@ enum crb_cancel {
     CRB_CANCEL_INVOKE = BIT(0),
 };
 
+#define TPM_CRB_NO_LOCALITY 0xff
+
 static uint64_t tpm_crb_mmio_read(void *opaque, hwaddr addr,
                                   unsigned size)
 {
@@ -95,10 +97,19 @@ static uint64_t tpm_crb_mmio_read(void *opaque, hwaddr addr,
     return val;
 }
 
+static uint8_t tpm_crb_get_active_locty(CRBState *s)
+{
+    if (!ARRAY_FIELD_EX32(s->regs, CRB_LOC_STATE, locAssigned)) {
+        return TPM_CRB_NO_LOCALITY;
+    }
+    return ARRAY_FIELD_EX32(s->regs, CRB_LOC_STATE, activeLocality);
+}
+
 static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
                                uint64_t val, unsigned size)
 {
     CRBState *s = CRB(opaque);
+    uint8_t locty =  addr >> 12;
 
     trace_tpm_crb_mmio_write(addr, size, val);
 
@@ -123,7 +134,8 @@ static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
         break;
     case A_CRB_CTRL_START:
         if (val == CRB_START_INVOKE &&
-            !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE)) {
+            !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) &&
+            tpm_crb_get_active_locty(s) == locty) {
             void *mem = memory_region_get_ram_ptr(&s->cmdmem);
 
             s->regs[R_CRB_CTRL_START] |= CRB_START_INVOKE;
-- 
2.5.5