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, 34 insertions, 0 deletions

diff --git a/drivers/gpib/common/ibsys.h b/drivers/gpib/common/ibsys.h
new file mode 100644
index 000000000..e5a148f51
--- /dev/null
+++ b/drivers/gpib/common/ibsys.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include "gpibP.h"
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/major.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/timer.h>
+
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <asm/irq.h>
+#include <asm/dma.h>
+
+#define MAX_GPIB_PRIMARY_ADDRESS 30
+#define MAX_GPIB_SECONDARY_ADDRESS 31
+
+int gpib_allocate_board(struct gpib_board *board);
+void gpib_deallocate_board(struct gpib_board *board);
+
+unsigned int num_status_bytes(const struct gpib_status_queue *dev);
+int push_status_byte(struct gpib_board *board, struct gpib_status_queue *device,
+		     u8 poll_byte);
+int pop_status_byte(struct gpib_board *board, struct gpib_status_queue *device,
+		    u8 *poll_byte);
+struct gpib_status_queue *get_gpib_status_queue(struct gpib_board *board,
+						unsigned int pad, int sad);
+int get_serial_poll_byte(struct gpib_board *board, unsigned int pad, int sad,
+			 unsigned int usec_timeout, u8 *poll_byte);
+int autopoll_all_devices(struct gpib_board *board);