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 --- lib/test_debug_virtual.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 lib/test_debug_virtual.c (limited to 'lib/test_debug_virtual.c') diff --git a/lib/test_debug_virtual.c b/lib/test_debug_virtual.c new file mode 100644 index 000000000..518ee8d21 --- /dev/null +++ b/lib/test_debug_virtual.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#ifdef CONFIG_MIPS +#include +#endif + +struct foo { + unsigned int bar; +}; + +static struct foo *foo; + +static int __init test_debug_virtual_init(void) +{ + phys_addr_t pa; + void *va; + + va = (void *)VMALLOC_START; + pa = virt_to_phys(va); + + pr_info("PA: %pa for VA: 0x%lx\n", &pa, (unsigned long)va); + + foo = kzalloc_obj(*foo); + if (!foo) + return -ENOMEM; + + pa = virt_to_phys(foo); + va = foo; + pr_info("PA: %pa for VA: 0x%lx\n", &pa, (unsigned long)va); + + return 0; +} +module_init(test_debug_virtual_init); + +static void __exit test_debug_virtual_exit(void) +{ + kfree(foo); +} +module_exit(test_debug_virtual_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Test module for CONFIG_DEBUG_VIRTUAL"); -- cgit v1.3.1