[PATCH v2 01/14] ppc/xive2: Update NVP save/restore for group attributes

[Michael Kowal <kowal@linux.ibm.com>]

From: Frederic Barrat <fbarrat@linux.ibm.com>

If the 'H' attribute is set on the NVP structure, the hardware
automatically saves and restores some attributes from the TIMA in the
NVP structure.
The group-specific attributes LSMFB, LGS and T have an extra flag to
individually control what is saved/restored.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Kowal <kowal@linux.ibm.com>
---
 include/hw/ppc/xive2_regs.h | 10 +++++++---
 hw/intc/xive2.c             | 23 ++++++++++++++++++-----
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/include/hw/ppc/xive2_regs.h b/include/hw/ppc/xive2_regs.h
index 1d00c8df64..e88d6eab1e 100644
--- a/include/hw/ppc/xive2_regs.h
+++ b/include/hw/ppc/xive2_regs.h
@@ -1,10 +1,9 @@
 /*
  * QEMU PowerPC XIVE2 internal structure definitions (POWER10)
  *
- * Copyright (c) 2019-2022, IBM Corporation.
+ * Copyright (c) 2019-2024, IBM Corporation.
  *
- * This code is licensed under the GPL version 2 or later. See the
- * COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef PPC_XIVE2_REGS_H
@@ -152,6 +151,9 @@ typedef struct Xive2Nvp {
         uint32_t       w0;
 #define NVP2_W0_VALID              PPC_BIT32(0)
 #define NVP2_W0_HW                 PPC_BIT32(7)
+#define NVP2_W0_L                  PPC_BIT32(8)
+#define NVP2_W0_G                  PPC_BIT32(9)
+#define NVP2_W0_T                  PPC_BIT32(10)
 #define NVP2_W0_ESC_END            PPC_BIT32(25) /* 'N' bit 0:ESB  1:END */
 #define NVP2_W0_PGOFIRST           PPC_BITMASK32(26, 31)
         uint32_t       w1;
@@ -163,6 +165,8 @@ typedef struct Xive2Nvp {
 #define NVP2_W2_CPPR               PPC_BITMASK32(0, 7)
 #define NVP2_W2_IPB                PPC_BITMASK32(8, 15)
 #define NVP2_W2_LSMFB              PPC_BITMASK32(16, 23)
+#define NVP2_W2_T                  PPC_BIT32(27)
+#define NVP2_W2_LGS                PPC_BITMASK32(28, 31)
         uint32_t       w3;
         uint32_t       w4;
 #define NVP2_W4_ESC_ESB_BLOCK      PPC_BITMASK32(0, 3)  /* N:0 */
diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index d1df35e9b3..24e504fce1 100644
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -1,10 +1,9 @@
 /*
  * QEMU PowerPC XIVE2 interrupt controller model (POWER10)
  *
- * Copyright (c) 2019-2022, IBM Corporation..
+ * Copyright (c) 2019-2024, IBM Corporation..
  *
- * This code is licensed under the GPL version 2 or later. See the
- * COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "qemu/osdep.h"
@@ -313,7 +312,19 @@ static void xive2_tctx_save_ctx(Xive2Router *xrtr, XiveTCTX *tctx,
 
     nvp.w2 = xive_set_field32(NVP2_W2_IPB, nvp.w2, regs[TM_IPB]);
     nvp.w2 = xive_set_field32(NVP2_W2_CPPR, nvp.w2, regs[TM_CPPR]);
-    nvp.w2 = xive_set_field32(NVP2_W2_LSMFB, nvp.w2, regs[TM_LSMFB]);
+    if (nvp.w0 & NVP2_W0_L) {
+        /*
+         * Typically not used. If LSMFB is restored with 0, it will
+         * force a backlog rescan
+         */
+        nvp.w2 = xive_set_field32(NVP2_W2_LSMFB, nvp.w2, regs[TM_LSMFB]);
+    }
+    if (nvp.w0 & NVP2_W0_G) {
+        nvp.w2 = xive_set_field32(NVP2_W2_LGS, nvp.w2, regs[TM_LGS]);
+    }
+    if (nvp.w0 & NVP2_W0_T) {
+        nvp.w2 = xive_set_field32(NVP2_W2_T, nvp.w2, regs[TM_T]);
+    }
     xive2_router_write_nvp(xrtr, nvp_blk, nvp_idx, &nvp, 2);
 
     nvp.w1 = xive_set_field32(NVP2_W1_CO, nvp.w1, 0);
@@ -527,7 +538,9 @@ static uint8_t xive2_tctx_restore_os_ctx(Xive2Router *xrtr, XiveTCTX *tctx,
     xive2_router_write_nvp(xrtr, nvp_blk, nvp_idx, nvp, 2);
 
     tctx->regs[TM_QW1_OS + TM_CPPR] = cppr;
-    /* we don't model LSMFB */
+    tctx->regs[TM_QW1_OS + TM_LSMFB] = xive_get_field32(NVP2_W2_LSMFB, nvp->w2);
+    tctx->regs[TM_QW1_OS + TM_LGS] = xive_get_field32(NVP2_W2_LGS, nvp->w2);
+    tctx->regs[TM_QW1_OS + TM_T] = xive_get_field32(NVP2_W2_T, nvp->w2);
 
     nvp->w1 = xive_set_field32(NVP2_W1_CO, nvp->w1, 1);
     nvp->w1 = xive_set_field32(NVP2_W1_CO_THRID_VALID, nvp->w1, 1);
-- 
2.43.0