Re: [PATCH 16/50] ppc/xive: Fix pulling pool and phys contexts

[Mike Kowal]

On 5/11/2025 10:10 PM, Nicholas Piggin wrote:

This improves the implementation of pulling pool and phys contexts in
XIVE1, by following closer the OS pulling code.

In particular, the old ring data is returned rather than the modified,
and irq signals are reset on pull.

Reviewed-by: Michael Kowal <ko...@linux.ibm.com>

Thanks MAK

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
  hw/intc/xive.c | 66 ++++++++++++++++++++++++++++++++++++++++++++------
  1 file changed, 58 insertions(+), 8 deletions(-)

diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index c2da23f9ea..1a94642c62 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -241,25 +241,75 @@ static uint64_t xive_tm_ack_hv_reg(XivePresenter *xptr, 
XiveTCTX *tctx,
      return xive_tctx_accept(tctx, TM_QW3_HV_PHYS);
  }

+static void xive_pool_cam_decode(uint32_t cam, uint8_t *nvt_blk,

+                                 uint32_t *nvt_idx, bool *vp)
+{
+    if (nvt_blk) {
+        *nvt_blk = xive_nvt_blk(cam);
+    }
+    if (nvt_idx) {
+        *nvt_idx = xive_nvt_idx(cam);
+    }
+    if (vp) {
+        *vp = !!(cam & TM_QW2W2_VP);
+    }
+}
+
+static uint32_t xive_tctx_get_pool_cam(XiveTCTX *tctx, uint8_t *nvt_blk,
+                                       uint32_t *nvt_idx, bool *vp)
+{
+    uint32_t qw2w2 = xive_tctx_word2(&tctx->regs[TM_QW2_HV_POOL]);
+    uint32_t cam = be32_to_cpu(qw2w2);
+
+    xive_pool_cam_decode(cam, nvt_blk, nvt_idx, vp);
+    return qw2w2;
+}
+
+static void xive_tctx_set_pool_cam(XiveTCTX *tctx, uint32_t qw2w2)
+{
+    memcpy(&tctx->regs[TM_QW2_HV_POOL + TM_WORD2], &qw2w2, 4);
+}
+
  static uint64_t xive_tm_pull_pool_ctx(XivePresenter *xptr, XiveTCTX *tctx,
                                        hwaddr offset, unsigned size)
  {
-    uint32_t qw2w2_prev = xive_tctx_word2(&tctx->regs[TM_QW2_HV_POOL]);
      uint32_t qw2w2;
+    uint32_t qw2w2_new;
+    uint8_t nvt_blk;
+    uint32_t nvt_idx;
+    bool vp;

- qw2w2 = xive_set_field32(TM_QW2W2_VP, qw2w2_prev, 0);

-    memcpy(&tctx->regs[TM_QW2_HV_POOL + TM_WORD2], &qw2w2, 4);
+    qw2w2 = xive_tctx_get_pool_cam(tctx, &nvt_blk, &nvt_idx, &vp);
+
+    if (!vp) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: pull invalid POOL NVT %x/%x 
!?\n",
+                      nvt_blk, nvt_idx);
+    }
+
+    /* Invalidate CAM line */
+    qw2w2_new = xive_set_field32(TM_QW2W2_VP, qw2w2, 0);
+    xive_tctx_set_pool_cam(tctx, qw2w2_new);
+
+    xive_tctx_reset_signal(tctx, TM_QW1_OS);
+    xive_tctx_reset_signal(tctx, TM_QW2_HV_POOL);
      return qw2w2;
  }

static uint64_t xive_tm_pull_phys_ctx(XivePresenter *xptr, XiveTCTX *tctx,

                                        hwaddr offset, unsigned size)
  {
-    uint8_t qw3b8_prev = tctx->regs[TM_QW3_HV_PHYS + TM_WORD2];
-    uint8_t qw3b8;
+    uint8_t qw3b8 = tctx->regs[TM_QW3_HV_PHYS + TM_WORD2];
+    uint8_t qw3b8_new;
+
+    qw3b8 = tctx->regs[TM_QW3_HV_PHYS + TM_WORD2];
+    if (!(qw3b8 & TM_QW3B8_VT)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: pulling invalid PHYS 
thread!?\n");
+    }
+    qw3b8_new = qw3b8 & ~TM_QW3B8_VT;
+    tctx->regs[TM_QW3_HV_PHYS + TM_WORD2] = qw3b8_new;

- qw3b8 = qw3b8_prev & ~TM_QW3B8_VT;

-    tctx->regs[TM_QW3_HV_PHYS + TM_WORD2] = qw3b8;
+    xive_tctx_reset_signal(tctx, TM_QW1_OS);
+    xive_tctx_reset_signal(tctx, TM_QW3_HV_PHYS);
      return qw3b8;
  }

@@ -489,7 +539,7 @@ static uint64_t xive_tm_pull_os_ctx(XivePresenter *xptr, XiveTCTX *tctx,

      qw1w2 = xive_tctx_get_os_cam(tctx, &nvt_blk, &nvt_idx, &vo);

if (!vo) {

-        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: pulling invalid NVT %x/%x !?\n",
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: pull invalid OS NVT %x/%x !?\n",
                        nvt_blk, nvt_idx);
      }