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, 68 insertions, 0 deletions

diff --git a/include/sound/seq_virmidi.h b/include/sound/seq_virmidi.h
new file mode 100644
index 000000000..359cb3633
--- /dev/null
+++ b/include/sound/seq_virmidi.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __SOUND_SEQ_VIRMIDI_H
+#define __SOUND_SEQ_VIRMIDI_H
+
+/*
+ *  Virtual Raw MIDI client on Sequencer
+ *  Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>,
+ *                        Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <sound/rawmidi.h>
+#include <sound/seq_midi_event.h>
+
+/*
+ * device file instance:
+ * This instance is created at each time the midi device file is
+ * opened.  Each instance has its own input buffer and MIDI parser
+ * (buffer), and is associated with the device instance.
+ */
+struct snd_virmidi {
+	struct list_head list;
+	int seq_mode;
+	int client;
+	int port;
+	bool trigger;
+	struct snd_midi_event *parser;
+	struct snd_seq_event event;
+	struct snd_virmidi_dev *rdev;
+	struct snd_rawmidi_substream *substream;
+	struct work_struct output_work;
+};
+
+#define SNDRV_VIRMIDI_SUBSCRIBE		(1<<0)
+#define SNDRV_VIRMIDI_USE		(1<<1)
+
+/*
+ * device record:
+ * Each virtual midi device has one device instance.  It contains
+ * common information and the linked-list of opened files, 
+ */
+struct snd_virmidi_dev {
+	struct snd_card *card;		/* associated card */
+	struct snd_rawmidi *rmidi;		/* rawmidi device */
+	int seq_mode;			/* SNDRV_VIRMIDI_XXX */
+	int device;			/* sequencer device */
+	int client;			/* created/attached client */
+	int port;			/* created/attached port */
+	unsigned int flags;		/* SNDRV_VIRMIDI_* */
+	struct rw_semaphore filelist_sem;
+	struct list_head filelist;
+};
+
+/* sequencer mode:
+ * ATTACH = input/output events from midi device are routed to the
+ *          attached sequencer port.  sequencer port is not created
+ *          by virmidi itself.
+ *          the input to rawmidi must be processed by passing the
+ *          incoming events via snd_virmidi_receive()
+ * DISPATCH = input/output events are routed to subscribers.
+ *            sequencer port is created in virmidi.
+ */
+#define SNDRV_VIRMIDI_SEQ_NONE		0
+#define SNDRV_VIRMIDI_SEQ_ATTACH	1
+#define SNDRV_VIRMIDI_SEQ_DISPATCH	2
+
+int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi);
+
+#endif /* __SOUND_SEQ_VIRMIDI */