KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 266 insertions, 0 deletions

diff --git a/sound/firewire/fireface/ff.c b/sound/firewire/fireface/ff.c
new file mode 100644
index 000000000..13472822d
--- /dev/null
+++ b/sound/firewire/fireface/ff.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ff.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ */
+
+#include "ff.h"
+
+#define OUI_RME	0x000a35
+
+MODULE_DESCRIPTION("RME Fireface series Driver");
+MODULE_AUTHOR("Takashi Sakamoto <o-takashi@sakamocchi.jp>");
+MODULE_LICENSE("GPL");
+
+static void name_card(struct snd_ff *ff)
+{
+	struct fw_device *fw_dev = fw_parent_device(ff->unit);
+	static const char *const names[] = {
+		[SND_FF_UNIT_VERSION_FF800]	= "Fireface800",
+		[SND_FF_UNIT_VERSION_FF400]	= "Fireface400",
+		[SND_FF_UNIT_VERSION_UFX]	= "FirefaceUFX",
+		[SND_FF_UNIT_VERSION_UCX]	= "FirefaceUCX",
+		[SND_FF_UNIT_VERSION_802]	= "Fireface802",
+	};
+	const char *name;
+
+	name = names[ff->unit_version];
+
+	strscpy(ff->card->driver, "Fireface");
+	strscpy(ff->card->shortname, name);
+	strscpy(ff->card->mixername, name);
+	snprintf(ff->card->longname, sizeof(ff->card->longname),
+		 "RME %s, GUID %08x%08x at %s, S%d", name,
+		 fw_dev->config_rom[3], fw_dev->config_rom[4],
+		 dev_name(&ff->unit->device), 100 << fw_dev->max_speed);
+}
+
+static void ff_card_free(struct snd_card *card)
+{
+	struct snd_ff *ff = card->private_data;
+
+	snd_ff_stream_destroy_duplex(ff);
+	snd_ff_transaction_unregister(ff);
+
+	kfree(ff->msg_parser);
+
+	mutex_destroy(&ff->mutex);
+	fw_unit_put(ff->unit);
+}
+
+static int snd_ff_probe(struct fw_unit *unit, const struct ieee1394_device_id *entry)
+{
+	struct snd_card *card;
+	struct snd_ff *ff;
+	int err;
+
+	err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE, sizeof(*ff), &card);
+	if (err < 0)
+		return err;
+	card->private_free = ff_card_free;
+
+	ff = card->private_data;
+	ff->unit = fw_unit_get(unit);
+	dev_set_drvdata(&unit->device, ff);
+	ff->card = card;
+
+	mutex_init(&ff->mutex);
+	spin_lock_init(&ff->lock);
+	init_waitqueue_head(&ff->hwdep_wait);
+
+	ff->unit_version = entry->version;
+	ff->spec = entry->driver_data_ptr;
+
+	err = snd_ff_transaction_register(ff);
+	if (err < 0)
+		goto error;
+
+	name_card(ff);
+
+	err = snd_ff_stream_init_duplex(ff);
+	if (err < 0)
+		goto error;
+
+	snd_ff_proc_init(ff);
+
+	err = snd_ff_create_midi_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_ff_create_pcm_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_ff_create_hwdep_devices(ff);
+	if (err < 0)
+		goto error;
+
+	if (ff->spec->protocol->msg_parser_size > 0) {
+		ff->msg_parser = kzalloc(ff->spec->protocol->msg_parser_size, GFP_KERNEL);
+		if (!ff->msg_parser) {
+			err = -ENOMEM;
+			goto error;
+		}
+	}
+
+	err = snd_card_register(card);
+	if (err < 0)
+		goto error;
+
+	return 0;
+error:
+	snd_card_free(card);
+	return err;
+}
+
+static void snd_ff_update(struct fw_unit *unit)
+{
+	struct snd_ff *ff = dev_get_drvdata(&unit->device);
+
+	snd_ff_transaction_reregister(ff);
+
+	snd_ff_stream_update_duplex(ff);
+}
+
+static void snd_ff_remove(struct fw_unit *unit)
+{
+	struct snd_ff *ff = dev_get_drvdata(&unit->device);
+
+	// Block till all of ALSA character devices are released.
+	snd_card_free(ff->card);
+}
+
+static const struct snd_ff_spec spec_ff800 = {
+	.pcm_capture_channels = {28, 20, 12},
+	.pcm_playback_channels = {28, 20, 12},
+	.midi_in_ports = 1,
+	.midi_out_ports = 1,
+	.protocol = &snd_ff_protocol_ff800,
+	.midi_high_addr = 0x000200000320ull,
+	.midi_addr_range = 12,
+	.midi_rx_addrs = {0x000080180000ull, 0},
+};
+
+static const struct snd_ff_spec spec_ff400 = {
+	.pcm_capture_channels = {18, 14, 10},
+	.pcm_playback_channels = {18, 14, 10},
+	.midi_in_ports = 2,
+	.midi_out_ports = 2,
+	.protocol = &snd_ff_protocol_ff400,
+	.midi_high_addr = 0x0000801003f4ull,
+	.midi_addr_range = SND_FF_MAXIMIM_MIDI_QUADS * 4,
+	.midi_rx_addrs = {0x000080180000ull, 0x000080190000ull},
+};
+
+static const struct snd_ff_spec spec_ucx = {
+	.pcm_capture_channels = {18, 14, 12},
+	.pcm_playback_channels = {18, 14, 12},
+	.midi_in_ports = 2,
+	.midi_out_ports = 2,
+	.protocol = &snd_ff_protocol_latter,
+	.midi_high_addr = 0xffff00000034ull,
+	.midi_addr_range = 0x80,
+	.midi_rx_addrs = {0xffff00000030ull, 0xffff00000030ull},
+};
+
+static const struct snd_ff_spec spec_ufx_802 = {
+	.pcm_capture_channels = {30, 22, 14},
+	.pcm_playback_channels = {30, 22, 14},
+	.midi_in_ports = 1,
+	.midi_out_ports = 1,
+	.protocol = &snd_ff_protocol_latter,
+	.midi_high_addr = 0xffff00000034ull,
+	.midi_addr_range = 0x80,
+	.midi_rx_addrs = {0xffff00000030ull, 0xffff00000030ull},
+};
+
+static const struct ieee1394_device_id snd_ff_id_table[] = {
+	/* Fireface 800 */
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_FF800,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ff800,
+	},
+	/* Fireface 400 */
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_FF400,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ff400,
+	},
+	// Fireface UFX.
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_UFX,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ufx_802,
+	},
+	// Fireface UCX.
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_UCX,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ucx,
+	},
+	// Fireface 802.
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_802,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ufx_802,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(ieee1394, snd_ff_id_table);
+
+static struct fw_driver ff_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= KBUILD_MODNAME,
+		.bus	= &fw_bus_type,
+	},
+	.probe    = snd_ff_probe,
+	.update   = snd_ff_update,
+	.remove   = snd_ff_remove,
+	.id_table = snd_ff_id_table,
+};
+
+static int __init snd_ff_init(void)
+{
+	return driver_register(&ff_driver.driver);
+}
+
+static void __exit snd_ff_exit(void)
+{
+	driver_unregister(&ff_driver.driver);
+}
+
+module_init(snd_ff_init);
+module_exit(snd_ff_exit);