KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 559 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt700-sdw.c b/sound/soc/codecs/rt700-sdw.c
new file mode 100644
index 000000000..3ba0cc37a
--- /dev/null
+++ b/sound/soc/codecs/rt700-sdw.c
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// rt700-sdw.c -- rt700 ALSA SoC audio driver
+//
+// Copyright(c) 2019 Realtek Semiconductor Corp.
+//
+//
+
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+#include <linux/soundwire/sdw_registers.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <sound/soc.h>
+#include "rt700.h"
+#include "rt700-sdw.h"
+
+static bool rt700_readable_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case 0x00e0:
+	case 0x00f0:
+	case 0x2000 ... 0x200e:
+	case 0x2012 ... 0x2016:
+	case 0x201a ... 0x2027:
+	case 0x2029 ... 0x202a:
+	case 0x202d ... 0x2034:
+	case 0x2200 ... 0x2204:
+	case 0x2206 ... 0x2212:
+	case 0x2220 ... 0x2223:
+	case 0x2230 ... 0x2231:
+	case 0x3000 ... 0x3fff:
+	case 0x7000 ... 0x7fff:
+	case 0x8300 ... 0x83ff:
+	case 0x9c00 ... 0x9cff:
+	case 0xb900 ... 0xb9ff:
+	case 0x75201a:
+	case 0x752045:
+	case 0x752046:
+	case 0x752048:
+	case 0x75204a:
+	case 0x75206b:
+	case 0x752080:
+	case 0x752081:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rt700_volatile_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case 0x2009:
+	case 0x2016:
+	case 0x201b:
+	case 0x201c:
+	case 0x201d:
+	case 0x201f:
+	case 0x2021:
+	case 0x2023:
+	case 0x2230:
+	case 0x200b ... 0x200e: /* i2c read */
+	case 0x2012 ... 0x2015: /* HD-A read */
+	case 0x202d ... 0x202f: /* BRA */
+	case 0x2201 ... 0x2212: /* i2c debug */
+	case 0x2220 ... 0x2223: /* decoded HD-A */
+	case 0x9c00 ... 0x9cff:
+	case 0xb900 ... 0xb9ff:
+	case 0xff01:
+	case 0x75201a:
+	case 0x752046:
+	case 0x752080:
+	case 0x752081:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static int rt700_sdw_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct device *dev = context;
+	struct rt700_priv *rt700 = dev_get_drvdata(dev);
+	unsigned int sdw_data_3, sdw_data_2, sdw_data_1, sdw_data_0;
+	unsigned int reg2 = 0, reg3 = 0, reg4 = 0, mask, nid, val2;
+	unsigned int is_hda_reg = 1, is_index_reg = 0;
+	int ret;
+
+	if (reg > 0xffff)
+		is_index_reg = 1;
+
+	mask = reg & 0xf000;
+
+	if (is_index_reg) { /* index registers */
+		val2 = reg & 0xff;
+		reg = reg >> 8;
+		nid = reg & 0xff;
+		ret = regmap_write(rt700->sdw_regmap, reg, 0);
+		if (ret < 0)
+			return ret;
+		reg2 = reg + 0x1000;
+		reg2 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg2, val2);
+		if (ret < 0)
+			return ret;
+
+		reg3 = RT700_PRIV_DATA_R_H | nid;
+		ret = regmap_write(rt700->sdw_regmap,
+			reg3, ((*val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		reg4 = reg3 + 0x1000;
+		reg4 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg4, (*val & 0xff));
+		if (ret < 0)
+			return ret;
+	} else if (mask   == 0x3000) {
+		reg += 0x8000;
+		ret = regmap_write(rt700->sdw_regmap, reg, *val);
+		if (ret < 0)
+			return ret;
+	} else if (mask == 0x7000) {
+		reg += 0x2000;
+		reg |= 0x800;
+		ret = regmap_write(rt700->sdw_regmap,
+			reg, ((*val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		reg2 = reg + 0x1000;
+		reg2 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg2, (*val & 0xff));
+		if (ret < 0)
+			return ret;
+	} else if ((reg & 0xff00) == 0x8300) { /* for R channel */
+		reg2 = reg - 0x1000;
+		reg2 &= ~0x80;
+		ret = regmap_write(rt700->sdw_regmap,
+			reg2, ((*val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		ret = regmap_write(rt700->sdw_regmap, reg, (*val & 0xff));
+		if (ret < 0)
+			return ret;
+	} else if (mask == 0x9000) {
+		ret = regmap_write(rt700->sdw_regmap,
+			reg, ((*val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		reg2 = reg + 0x1000;
+		reg2 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg2, (*val & 0xff));
+		if (ret < 0)
+			return ret;
+	} else if (mask == 0xb000) {
+		ret = regmap_write(rt700->sdw_regmap, reg, *val);
+		if (ret < 0)
+			return ret;
+	} else {
+		ret = regmap_read(rt700->sdw_regmap, reg, val);
+		if (ret < 0)
+			return ret;
+		is_hda_reg = 0;
+	}
+
+	if (is_hda_reg || is_index_reg) {
+		sdw_data_3 = 0;
+		sdw_data_2 = 0;
+		sdw_data_1 = 0;
+		sdw_data_0 = 0;
+		ret = regmap_read(rt700->sdw_regmap,
+			RT700_READ_HDA_3, &sdw_data_3);
+		if (ret < 0)
+			return ret;
+		ret = regmap_read(rt700->sdw_regmap,
+			RT700_READ_HDA_2, &sdw_data_2);
+		if (ret < 0)
+			return ret;
+		ret = regmap_read(rt700->sdw_regmap,
+			RT700_READ_HDA_1, &sdw_data_1);
+		if (ret < 0)
+			return ret;
+		ret = regmap_read(rt700->sdw_regmap,
+			RT700_READ_HDA_0, &sdw_data_0);
+		if (ret < 0)
+			return ret;
+		*val = ((sdw_data_3 & 0xff) << 24) |
+			((sdw_data_2 & 0xff) << 16) |
+			((sdw_data_1 & 0xff) << 8) | (sdw_data_0 & 0xff);
+	}
+
+	if (is_hda_reg == 0)
+		dev_dbg(dev, "[%s] %04x => %08x\n", __func__, reg, *val);
+	else if (is_index_reg)
+		dev_dbg(dev, "[%s] %04x %04x %04x %04x => %08x\n",
+			__func__, reg, reg2, reg3, reg4, *val);
+	else
+		dev_dbg(dev, "[%s] %04x %04x => %08x\n",
+			__func__, reg, reg2, *val);
+
+	return 0;
+}
+
+static int rt700_sdw_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct device *dev = context;
+	struct rt700_priv *rt700 = dev_get_drvdata(dev);
+	unsigned int reg2 = 0, reg3, reg4, nid, mask, val2;
+	unsigned int is_index_reg = 0;
+	int ret;
+
+	if (reg > 0xffff)
+		is_index_reg = 1;
+
+	mask = reg & 0xf000;
+
+	if (is_index_reg) { /* index registers */
+		val2 = reg & 0xff;
+		reg = reg >> 8;
+		nid = reg & 0xff;
+		ret = regmap_write(rt700->sdw_regmap, reg, 0);
+		if (ret < 0)
+			return ret;
+		reg2 = reg + 0x1000;
+		reg2 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg2, val2);
+		if (ret < 0)
+			return ret;
+
+		reg3 = RT700_PRIV_DATA_W_H | nid;
+		ret = regmap_write(rt700->sdw_regmap,
+			reg3, ((val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		reg4 = reg3 + 0x1000;
+		reg4 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg4, (val & 0xff));
+		if (ret < 0)
+			return ret;
+		is_index_reg = 1;
+	} else if (reg < 0x4fff) {
+		ret = regmap_write(rt700->sdw_regmap, reg, val);
+		if (ret < 0)
+			return ret;
+	} else if (reg == 0xff01) {
+		ret = regmap_write(rt700->sdw_regmap, reg, val);
+		if (ret < 0)
+			return ret;
+	} else if (mask == 0x7000) {
+		ret = regmap_write(rt700->sdw_regmap,
+			reg, ((val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		reg2 = reg + 0x1000;
+		reg2 |= 0x80;
+		ret = regmap_write(rt700->sdw_regmap, reg2, (val & 0xff));
+		if (ret < 0)
+			return ret;
+	} else if ((reg & 0xff00) == 0x8300) {  /* for R channel */
+		reg2 = reg - 0x1000;
+		reg2 &= ~0x80;
+		ret = regmap_write(rt700->sdw_regmap,
+			reg2, ((val >> 8) & 0xff));
+		if (ret < 0)
+			return ret;
+		ret = regmap_write(rt700->sdw_regmap, reg, (val & 0xff));
+		if (ret < 0)
+			return ret;
+	}
+
+	if (reg2 == 0)
+		dev_dbg(dev, "[%s] %04x <= %04x\n", __func__, reg, val);
+	else if (is_index_reg)
+		dev_dbg(dev, "[%s] %04x %04x %04x %04x <= %04x %04x\n",
+			__func__, reg, reg2, reg3, reg4, val2, val);
+	else
+		dev_dbg(dev, "[%s] %04x %04x <= %04x\n",
+			__func__, reg, reg2, val);
+
+	return 0;
+}
+
+static const struct regmap_config rt700_regmap = {
+	.reg_bits = 24,
+	.val_bits = 32,
+	.readable_reg = rt700_readable_register,
+	.volatile_reg = rt700_volatile_register,
+	.max_register = 0x755800,
+	.reg_defaults = rt700_reg_defaults,
+	.num_reg_defaults = ARRAY_SIZE(rt700_reg_defaults),
+	.cache_type = REGCACHE_MAPLE,
+	.use_single_read = true,
+	.use_single_write = true,
+	.reg_read = rt700_sdw_read,
+	.reg_write = rt700_sdw_write,
+};
+
+static const struct regmap_config rt700_sdw_regmap = {
+	.name = "sdw",
+	.reg_bits = 32,
+	.val_bits = 8,
+	.readable_reg = rt700_readable_register,
+	.max_register = 0xff01,
+	.cache_type = REGCACHE_NONE,
+	.use_single_read = true,
+	.use_single_write = true,
+};
+
+static int rt700_update_status(struct sdw_slave *slave,
+					enum sdw_slave_status status)
+{
+	struct rt700_priv *rt700 = dev_get_drvdata(&slave->dev);
+
+	if (status == SDW_SLAVE_UNATTACHED)
+		rt700->hw_init = false;
+
+	/*
+	 * Perform initialization only if slave status is present and
+	 * hw_init flag is false
+	 */
+	if (rt700->hw_init || status != SDW_SLAVE_ATTACHED)
+		return 0;
+
+	/* perform I/O transfers required for Slave initialization */
+	return rt700_io_init(&slave->dev, slave);
+}
+
+static int rt700_read_prop(struct sdw_slave *slave)
+{
+	struct sdw_slave_prop *prop = &slave->prop;
+	int nval, i;
+	u32 bit;
+	unsigned long addr;
+	struct sdw_dpn_prop *dpn;
+
+	prop->scp_int1_mask = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH |
+		SDW_SCP_INT1_PARITY;
+	prop->quirks = SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY;
+
+	prop->paging_support = false;
+
+	/* first we need to allocate memory for set bits in port lists */
+	prop->source_ports = 0x14; /* BITMAP: 00010100 */
+	prop->sink_ports = 0xA; /* BITMAP:  00001010 */
+
+	nval = hweight32(prop->source_ports);
+	prop->src_dpn_prop = devm_kcalloc(&slave->dev, nval,
+						sizeof(*prop->src_dpn_prop),
+						GFP_KERNEL);
+	if (!prop->src_dpn_prop)
+		return -ENOMEM;
+
+	i = 0;
+	dpn = prop->src_dpn_prop;
+	addr = prop->source_ports;
+	for_each_set_bit(bit, &addr, 32) {
+		dpn[i].num = bit;
+		dpn[i].type = SDW_DPN_FULL;
+		dpn[i].simple_ch_prep_sm = true;
+		dpn[i].ch_prep_timeout = 10;
+		i++;
+	}
+
+	/* do this again for sink now */
+	nval = hweight32(prop->sink_ports);
+	prop->sink_dpn_prop = devm_kcalloc(&slave->dev, nval,
+						sizeof(*prop->sink_dpn_prop),
+						GFP_KERNEL);
+	if (!prop->sink_dpn_prop)
+		return -ENOMEM;
+
+	i = 0;
+	dpn = prop->sink_dpn_prop;
+	addr = prop->sink_ports;
+	for_each_set_bit(bit, &addr, 32) {
+		dpn[i].num = bit;
+		dpn[i].type = SDW_DPN_FULL;
+		dpn[i].simple_ch_prep_sm = true;
+		dpn[i].ch_prep_timeout = 10;
+		i++;
+	}
+
+	/* set the timeout values */
+	prop->clk_stop_timeout = 20;
+
+	/* wake-up event */
+	prop->wake_capable = 1;
+
+	return 0;
+}
+
+static int rt700_bus_config(struct sdw_slave *slave,
+				struct sdw_bus_params *params)
+{
+	struct rt700_priv *rt700 = dev_get_drvdata(&slave->dev);
+	int ret;
+
+	memcpy(&rt700->params, params, sizeof(*params));
+
+	ret = rt700_clock_config(&slave->dev);
+	if (ret < 0)
+		dev_err(&slave->dev, "Invalid clk config");
+
+	return ret;
+}
+
+static int rt700_interrupt_callback(struct sdw_slave *slave,
+					struct sdw_slave_intr_status *status)
+{
+	struct rt700_priv *rt700 = dev_get_drvdata(&slave->dev);
+
+	dev_dbg(&slave->dev,
+		"%s control_port_stat=%x", __func__, status->control_port);
+
+	guard(mutex)(&rt700->disable_irq_lock);
+	if (status->control_port & 0x4 && !rt700->disable_irq) {
+		mod_delayed_work(system_power_efficient_wq,
+			&rt700->jack_detect_work, msecs_to_jiffies(250));
+	}
+
+	return 0;
+}
+
+/*
+ * slave_ops: callbacks for get_clock_stop_mode, clock_stop and
+ * port_prep are not defined for now
+ */
+static const struct sdw_slave_ops rt700_slave_ops = {
+	.read_prop = rt700_read_prop,
+	.interrupt_callback = rt700_interrupt_callback,
+	.update_status = rt700_update_status,
+	.bus_config = rt700_bus_config,
+};
+
+static int rt700_sdw_probe(struct sdw_slave *slave,
+				const struct sdw_device_id *id)
+{
+	struct regmap *sdw_regmap, *regmap;
+
+	/* Regmap Initialization */
+	sdw_regmap = devm_regmap_init_sdw(slave, &rt700_sdw_regmap);
+	if (IS_ERR(sdw_regmap))
+		return PTR_ERR(sdw_regmap);
+
+	regmap = devm_regmap_init(&slave->dev, NULL,
+		&slave->dev, &rt700_regmap);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return rt700_init(&slave->dev, sdw_regmap, regmap, slave);
+}
+
+static void rt700_sdw_remove(struct sdw_slave *slave)
+{
+	struct rt700_priv *rt700 = dev_get_drvdata(&slave->dev);
+
+	cancel_delayed_work_sync(&rt700->jack_detect_work);
+	cancel_delayed_work_sync(&rt700->jack_btn_check_work);
+
+	pm_runtime_disable(&slave->dev);
+}
+
+static const struct sdw_device_id rt700_id[] = {
+	SDW_SLAVE_ENTRY_EXT(0x025d, 0x700, 0x1, 0, 0),
+	{},
+};
+MODULE_DEVICE_TABLE(sdw, rt700_id);
+
+static int rt700_dev_suspend(struct device *dev)
+{
+	struct rt700_priv *rt700 = dev_get_drvdata(dev);
+
+	if (!rt700->hw_init)
+		return 0;
+
+	cancel_delayed_work_sync(&rt700->jack_detect_work);
+	cancel_delayed_work_sync(&rt700->jack_btn_check_work);
+
+	regcache_cache_only(rt700->regmap, true);
+
+	return 0;
+}
+
+static int rt700_dev_system_suspend(struct device *dev)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
+	struct rt700_priv *rt700 = dev_get_drvdata(dev);
+	int ret;
+
+	if (!rt700->hw_init)
+		return 0;
+
+	/*
+	 * prevent new interrupts from being handled after the
+	 * deferred work completes and before the parent disables
+	 * interrupts on the link
+	 */
+	scoped_guard(mutex, &rt700->disable_irq_lock) {
+		rt700->disable_irq = true;
+		ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1,
+				       SDW_SCP_INT1_IMPL_DEF, 0);
+	}
+
+	if (ret < 0) {
+		/* log but don't prevent suspend from happening */
+		dev_dbg(&slave->dev, "%s: could not disable imp-def interrupts\n:", __func__);
+	}
+
+	return rt700_dev_suspend(dev);
+}
+
+#define RT700_PROBE_TIMEOUT 5000
+
+static int rt700_dev_resume(struct device *dev)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
+	struct rt700_priv *rt700 = dev_get_drvdata(dev);
+	int ret;
+
+	if (!rt700->first_hw_init)
+		return 0;
+
+	ret = sdw_slave_wait_for_init(slave, RT700_PROBE_TIMEOUT);
+	if (ret) {
+		sdw_show_ping_status(slave->bus, true);
+		return ret;
+	}
+
+	regcache_cache_only(rt700->regmap, false);
+	regcache_sync_region(rt700->regmap, 0x3000, 0x8fff);
+	regcache_sync_region(rt700->regmap, 0x752010, 0x75206b);
+
+	return 0;
+}
+
+static const struct dev_pm_ops rt700_pm = {
+	SYSTEM_SLEEP_PM_OPS(rt700_dev_system_suspend, rt700_dev_resume)
+	RUNTIME_PM_OPS(rt700_dev_suspend, rt700_dev_resume, NULL)
+};
+
+static struct sdw_driver rt700_sdw_driver = {
+	.driver = {
+		.name = "rt700",
+		.pm = pm_ptr(&rt700_pm),
+	},
+	.probe = rt700_sdw_probe,
+	.remove = rt700_sdw_remove,
+	.ops = &rt700_slave_ops,
+	.id_table = rt700_id,
+};
+module_sdw_driver(rt700_sdw_driver);
+
+MODULE_DESCRIPTION("ASoC RT700 driver SDW");
+MODULE_AUTHOR("Shuming Fan <shumingf@realtek.com>");
+MODULE_LICENSE("GPL v2");