From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __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 Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- drivers/of/empty_root.dts | 13 +++++++++++++ 1 file changed, 13 insertions(+) create mode 100644 drivers/of/empty_root.dts (limited to 'drivers/of/empty_root.dts') diff --git a/drivers/of/empty_root.dts b/drivers/of/empty_root.dts new file mode 100644 index 000000000..cbe169ba3 --- /dev/null +++ b/drivers/of/empty_root.dts @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0-only +/dts-v1/; + +/ { + /* + * #address-cells/#size-cells are required properties at root node. + * Use 2 cells for both address cells and size cells in order to fully + * support 64-bit addresses and sizes on systems using this empty root + * node. + */ + #address-cells = <0x02>; + #size-cells = <0x02>; +}; -- cgit v1.3.1