arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/include/rdma/frmr_pools.h b/include/rdma/frmr_pools.h
new file mode 100644
index 000000000..aed4d69d3
--- /dev/null
+++ b/include/rdma/frmr_pools.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+ *
+ * Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ */
+
+#ifndef FRMR_POOLS_H
+#define FRMR_POOLS_H
+
+#include <linux/types.h>
+#include <asm/page.h>
+
+struct ib_device;
+struct ib_mr;
+
+struct ib_frmr_key {
+	u64 vendor_key;
+	/* A pool with non-zero kernel_vendor_key is a kernel-only pool. */
+	u64 kernel_vendor_key;
+	size_t num_dma_blocks;
+	int access_flags;
+	u8 ats:1;
+};
+
+struct ib_frmr_pool_ops {
+	int (*create_frmrs)(struct ib_device *device, struct ib_frmr_key *key,
+			    u32 *handles, u32 count);
+	void (*destroy_frmrs)(struct ib_device *device, u32 *handles,
+			      u32 count);
+	int (*build_key)(struct ib_device *device, const struct ib_frmr_key *in,
+			 struct ib_frmr_key *out);
+};
+
+int ib_frmr_pools_init(struct ib_device *device,
+		       const struct ib_frmr_pool_ops *pool_ops);
+void ib_frmr_pools_cleanup(struct ib_device *device);
+int ib_frmr_pool_pop(struct ib_device *device, struct ib_mr *mr);
+void ib_frmr_pool_push(struct ib_device *device, struct ib_mr *mr);
+void ib_frmr_pool_drop(struct ib_mr *mr);
+
+#endif /* FRMR_POOLS_H */