[PATCH v4 15/15] spapr: nested: Set the PCR when logical PVR is set

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

From: Amit Machhiwal <amachhiw@linux.vnet.ibm.com>

In APIv1, KVM L0 sets the PCR, while in the nested papr APIv2, this
doesn't work as the PCR can't be set via the guest state buffer; the
logical PVR is set via the GSB though.

This change sets the PCR whenever the logical PVR is set via the GSB.
Also, unlike the other registers, the value 1 in a defined bit in the
PCR makes the affected resources unavailable and the value 0 makes
them available. Hence, the PCR is set accordingly.

Signed-off-by: Amit Machhiwal <amachhiw@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
---
 include/hw/ppc/spapr_nested.h |  9 +++++++++
 hw/ppc/spapr_nested.c         | 24 ++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h
index da918d2dd0..f67c721f53 100644
--- a/include/hw/ppc/spapr_nested.h
+++ b/include/hw/ppc/spapr_nested.h
@@ -229,6 +229,15 @@ typedef struct SpaprMachineStateNestedGuest {
 #define GUEST_STATE_REQUEST_GUEST_WIDE       0x1
 #define GUEST_STATE_REQUEST_SET              0x2
 
+/* As per ISA v3.1B, following bits are reserved:
+ *      0:2
+ *      4:57  (ISA mentions bit 58 as well but it should be used for P10)
+ *      61:63 (hence, haven't included PCR bits for v2.06 and v2.05
+ *             in LOW BITS)
+ */
+#define PCR_LOW_BITS   (PCR_COMPAT_3_10 | PCR_COMPAT_3_00)
+#define HVMASK_PCR     ~PCR_LOW_BITS
+
 #define GUEST_STATE_ELEMENT(i, sz, s, f, ptr, c) { \
     .id = (i),                                     \
     .size = (sz),                                  \
diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c
index 6e6a90616e..af8a482337 100644
--- a/hw/ppc/spapr_nested.c
+++ b/hw/ppc/spapr_nested.c
@@ -740,9 +740,11 @@ static void out_buf_min_size(void *a, void *b, bool set)
 
 static void copy_logical_pvr(void *a, void *b, bool set)
 {
+    SpaprMachineStateNestedGuest *guest;
     uint32_t *buf; /* 1 word */
     uint32_t *pvr_logical_ptr;
     uint32_t pvr_logical;
+    target_ulong pcr = 0;
 
     pvr_logical_ptr = a;
     buf = b;
@@ -755,6 +757,28 @@ static void copy_logical_pvr(void *a, void *b, bool set)
     pvr_logical = be32_to_cpu(buf[0]);
 
     *pvr_logical_ptr = pvr_logical;
+
+    if (*pvr_logical_ptr) {
+        switch (*pvr_logical_ptr) {
+            case CPU_POWERPC_LOGICAL_3_10:
+                pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00;
+                break;
+            case CPU_POWERPC_LOGICAL_3_00:
+                pcr = PCR_COMPAT_3_00;
+                break;
+            default:
+                qemu_log_mask(LOG_GUEST_ERROR,
+                    "Could not set PCR for LPVR=0x%08x\n", *pvr_logical_ptr);
+                return;
+        }
+    }
+
+    guest = container_of(pvr_logical_ptr,
+                         struct SpaprMachineStateNestedGuest,
+                         pvr_logical);
+    for (int i = 0; i < guest->vcpus; i++) {
+        guest->vcpu[i].state.pcr = ~pcr | HVMASK_PCR;
+    }
 }
 
 static void copy_tb_offset(void *a, void *b, bool set)
-- 
2.39.3