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, 396 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/itd1000.c b/drivers/media/dvb-frontends/itd1000.c
new file mode 100644
index 000000000..f5f023639
--- /dev/null
+++ b/drivers/media/dvb-frontends/itd1000.c
@@ -0,0 +1,396 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Driver for the Integrant ITD1000 "Zero-IF Tuner IC for Direct Broadcast Satellite"
+ *
+ *  Copyright (c) 2007-8 Patrick Boettcher <pb@linuxtv.org>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/delay.h>
+#include <linux/dvb/frontend.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+
+#include <media/dvb_frontend.h>
+
+#include "itd1000.h"
+#include "itd1000_priv.h"
+
+/* Max transfer size done by I2C transfer functions */
+#define MAX_XFER_SIZE  64
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");
+
+#define itd_dbg(args...)  do { \
+	if (debug) { \
+		printk(KERN_DEBUG   "ITD1000: " args);\
+	} \
+} while (0)
+
+#define itd_warn(args...) do { \
+	printk(KERN_WARNING "ITD1000: " args); \
+} while (0)
+
+#define itd_info(args...) do { \
+	printk(KERN_INFO    "ITD1000: " args); \
+} while (0)
+
+/* don't write more than one byte with flexcop behind */
+static int itd1000_write_regs(struct itd1000_state *state, u8 reg, u8 v[], u8 len)
+{
+	u8 buf[MAX_XFER_SIZE];
+	struct i2c_msg msg = {
+		.addr = state->cfg->i2c_address, .flags = 0, .buf = buf, .len = len+1
+	};
+
+	if (1 + len > sizeof(buf)) {
+		printk(KERN_WARNING
+		       "itd1000: i2c wr reg=%04x: len=%d is too big!\n",
+		       reg, len);
+		return -EINVAL;
+	}
+
+	buf[0] = reg;
+	memcpy(&buf[1], v, len);
+
+	/* itd_dbg("wr %02x: %02x\n", reg, v[0]); */
+
+	if (i2c_transfer(state->i2c, &msg, 1) != 1) {
+		printk(KERN_WARNING "itd1000 I2C write failed\n");
+		return -EREMOTEIO;
+	}
+	return 0;
+}
+
+static int itd1000_read_reg(struct itd1000_state *state, u8 reg)
+{
+	u8 val;
+	struct i2c_msg msg[2] = {
+		{ .addr = state->cfg->i2c_address, .flags = 0,        .buf = &reg, .len = 1 },
+		{ .addr = state->cfg->i2c_address, .flags = I2C_M_RD, .buf = &val, .len = 1 },
+	};
+
+	/* ugly flexcop workaround */
+	itd1000_write_regs(state, (reg - 1) & 0xff, &state->shadow[(reg - 1) & 0xff], 1);
+
+	if (i2c_transfer(state->i2c, msg, 2) != 2) {
+		itd_warn("itd1000 I2C read failed\n");
+		return -EREMOTEIO;
+	}
+	return val;
+}
+
+static inline int itd1000_write_reg(struct itd1000_state *state, u8 r, u8 v)
+{
+	u8 tmp = v; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+	int ret = itd1000_write_regs(state, r, &tmp, 1);
+	state->shadow[r] = tmp;
+	return ret;
+}
+
+
+static struct {
+	u32 symbol_rate;
+	u8  pgaext  : 4; /* PLLFH */
+	u8  bbgvmin : 4; /* BBGVMIN */
+} itd1000_lpf_pga[] = {
+	{        0, 0x8, 0x3 },
+	{  5200000, 0x8, 0x3 },
+	{ 12200000, 0x4, 0x3 },
+	{ 15400000, 0x2, 0x3 },
+	{ 19800000, 0x2, 0x3 },
+	{ 21500000, 0x2, 0x3 },
+	{ 24500000, 0x2, 0x3 },
+	{ 28400000, 0x2, 0x3 },
+	{ 33400000, 0x2, 0x3 },
+	{ 34400000, 0x1, 0x4 },
+	{ 34400000, 0x1, 0x4 },
+	{ 38400000, 0x1, 0x4 },
+	{ 38400000, 0x1, 0x4 },
+	{ 40400000, 0x1, 0x4 },
+	{ 45400000, 0x1, 0x4 },
+};
+
+static void itd1000_set_lpf_bw(struct itd1000_state *state, u32 symbol_rate)
+{
+	u8 i;
+	u8 con1    = itd1000_read_reg(state, CON1)    & 0xfd;
+	u8 pllfh   = itd1000_read_reg(state, PLLFH)   & 0x0f;
+	u8 bbgvmin = itd1000_read_reg(state, BBGVMIN) & 0xf0;
+	u8 bw      = itd1000_read_reg(state, BW)      & 0xf0;
+
+	itd_dbg("symbol_rate = %d\n", symbol_rate);
+
+	/* not sure what is that ? - starting to download the table */
+	itd1000_write_reg(state, CON1, con1 | (1 << 1));
+
+	for (i = 0; i < ARRAY_SIZE(itd1000_lpf_pga); i++)
+		if (symbol_rate < itd1000_lpf_pga[i].symbol_rate) {
+			itd_dbg("symrate: index: %d pgaext: %x, bbgvmin: %x\n", i, itd1000_lpf_pga[i].pgaext, itd1000_lpf_pga[i].bbgvmin);
+			itd1000_write_reg(state, PLLFH,   pllfh | (itd1000_lpf_pga[i].pgaext << 4));
+			itd1000_write_reg(state, BBGVMIN, bbgvmin | (itd1000_lpf_pga[i].bbgvmin));
+			itd1000_write_reg(state, BW,      bw | (i & 0x0f));
+			break;
+		}
+
+	itd1000_write_reg(state, CON1, con1 | (0 << 1));
+}
+
+static struct {
+	u8 vcorg;
+	u32 fmax_rg;
+} itd1000_vcorg[] = {
+	{  1,  920000 },
+	{  2,  971000 },
+	{  3, 1031000 },
+	{  4, 1091000 },
+	{  5, 1171000 },
+	{  6, 1281000 },
+	{  7, 1381000 },
+	{  8,  500000 },	/* this is intentional. */
+	{  9, 1451000 },
+	{ 10, 1531000 },
+	{ 11, 1631000 },
+	{ 12, 1741000 },
+	{ 13, 1891000 },
+	{ 14, 2071000 },
+	{ 15, 2250000 },
+};
+
+static void itd1000_set_vco(struct itd1000_state *state, u32 freq_khz)
+{
+	u8 i;
+	u8 gvbb_i2c     = itd1000_read_reg(state, GVBB_I2C) & 0xbf;
+	u8 vco_chp1_i2c = itd1000_read_reg(state, VCO_CHP1_I2C) & 0x0f;
+	u8 adcout;
+
+	/* reserved bit again (reset ?) */
+	itd1000_write_reg(state, GVBB_I2C, gvbb_i2c | (1 << 6));
+
+	for (i = 0; i < ARRAY_SIZE(itd1000_vcorg); i++) {
+		if (freq_khz < itd1000_vcorg[i].fmax_rg) {
+			itd1000_write_reg(state, VCO_CHP1_I2C, vco_chp1_i2c | (itd1000_vcorg[i].vcorg << 4));
+			msleep(1);
+
+			adcout = itd1000_read_reg(state, PLLLOCK) & 0x0f;
+
+			itd_dbg("VCO: %dkHz: %d -> ADCOUT: %d %02x\n", freq_khz, itd1000_vcorg[i].vcorg, adcout, vco_chp1_i2c);
+
+			if (adcout > 13) {
+				if (!(itd1000_vcorg[i].vcorg == 7 || itd1000_vcorg[i].vcorg == 15))
+					itd1000_write_reg(state, VCO_CHP1_I2C, vco_chp1_i2c | ((itd1000_vcorg[i].vcorg + 1) << 4));
+			} else if (adcout < 2) {
+				if (!(itd1000_vcorg[i].vcorg == 1 || itd1000_vcorg[i].vcorg == 9))
+					itd1000_write_reg(state, VCO_CHP1_I2C, vco_chp1_i2c | ((itd1000_vcorg[i].vcorg - 1) << 4));
+			}
+			break;
+		}
+	}
+}
+
+static const struct {
+	u32 freq;
+	u8 values[10]; /* RFTR, RFST1 - RFST9 */
+} itd1000_fre_values[] = {
+	{ 1075000, { 0x59, 0x1d, 0x1c, 0x17, 0x16, 0x0f, 0x0e, 0x0c, 0x0b, 0x0a } },
+	{ 1250000, { 0x89, 0x1e, 0x1d, 0x17, 0x15, 0x0f, 0x0e, 0x0c, 0x0b, 0x0a } },
+	{ 1450000, { 0x89, 0x1e, 0x1d, 0x17, 0x15, 0x0f, 0x0e, 0x0c, 0x0b, 0x0a } },
+	{ 1650000, { 0x69, 0x1e, 0x1d, 0x17, 0x15, 0x0f, 0x0e, 0x0c, 0x0b, 0x0a } },
+	{ 1750000, { 0x69, 0x1e, 0x17, 0x15, 0x14, 0x0f, 0x0e, 0x0c, 0x0b, 0x0a } },
+	{ 1850000, { 0x69, 0x1d, 0x17, 0x16, 0x14, 0x0f, 0x0e, 0x0d, 0x0b, 0x0a } },
+	{ 1900000, { 0x69, 0x1d, 0x17, 0x15, 0x14, 0x0f, 0x0e, 0x0d, 0x0b, 0x0a } },
+	{ 1950000, { 0x69, 0x1d, 0x17, 0x16, 0x14, 0x13, 0x0e, 0x0d, 0x0b, 0x0a } },
+	{ 2050000, { 0x69, 0x1e, 0x1d, 0x17, 0x16, 0x14, 0x13, 0x0e, 0x0b, 0x0a } },
+	{ 2150000, { 0x69, 0x1d, 0x1c, 0x17, 0x15, 0x14, 0x13, 0x0f, 0x0e, 0x0b } }
+};
+
+
+#define FREF 16
+
+static void itd1000_set_lo(struct itd1000_state *state, u32 freq_khz)
+{
+	int i, j;
+	u32 plln, pllf;
+	u64 tmp;
+
+	plln = (freq_khz * 1000) / 2 / FREF;
+
+	/* Compute the factional part times 1000 */
+	tmp  = plln % 1000000;
+	plln /= 1000000;
+
+	tmp *= 1048576;
+	do_div(tmp, 1000000);
+	pllf = (u32) tmp;
+
+	state->frequency = ((plln * 1000) + (pllf * 1000)/1048576) * 2*FREF;
+	itd_dbg("frequency: %dkHz (wanted) %dkHz (set), PLLF = %d, PLLN = %d\n", freq_khz, state->frequency, pllf, plln);
+
+	itd1000_write_reg(state, PLLNH, 0x80); /* PLLNH */
+	itd1000_write_reg(state, PLLNL, plln & 0xff);
+	itd1000_write_reg(state, PLLFH, (itd1000_read_reg(state, PLLFH) & 0xf0) | ((pllf >> 16) & 0x0f));
+	itd1000_write_reg(state, PLLFM, (pllf >> 8) & 0xff);
+	itd1000_write_reg(state, PLLFL, (pllf >> 0) & 0xff);
+
+	for (i = 0; i < ARRAY_SIZE(itd1000_fre_values); i++) {
+		if (freq_khz <= itd1000_fre_values[i].freq) {
+			itd_dbg("fre_values: %d\n", i);
+			itd1000_write_reg(state, RFTR, itd1000_fre_values[i].values[0]);
+			for (j = 0; j < 9; j++)
+				itd1000_write_reg(state, RFST1+j, itd1000_fre_values[i].values[j+1]);
+			break;
+		}
+	}
+
+	itd1000_set_vco(state, freq_khz);
+}
+
+static int itd1000_set_parameters(struct dvb_frontend *fe)
+{
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	struct itd1000_state *state = fe->tuner_priv;
+	u8 pllcon1;
+
+	itd1000_set_lo(state, c->frequency);
+	itd1000_set_lpf_bw(state, c->symbol_rate);
+
+	pllcon1 = itd1000_read_reg(state, PLLCON1) & 0x7f;
+	itd1000_write_reg(state, PLLCON1, pllcon1 | (1 << 7));
+	itd1000_write_reg(state, PLLCON1, pllcon1);
+
+	return 0;
+}
+
+static int itd1000_get_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	struct itd1000_state *state = fe->tuner_priv;
+	*frequency = state->frequency;
+	return 0;
+}
+
+static int itd1000_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
+{
+	return 0;
+}
+
+static u8 itd1000_init_tab[][2] = {
+	{ PLLCON1,       0x65 }, /* Register does not change */
+	{ PLLNH,         0x80 }, /* Bits [7:6] do not change */
+	{ RESERVED_0X6D, 0x3b },
+	{ VCO_CHP2_I2C,  0x12 },
+	{ 0x72,          0xf9 }, /* No such regsister defined */
+	{ RESERVED_0X73, 0xff },
+	{ RESERVED_0X74, 0xb2 },
+	{ RESERVED_0X75, 0xc7 },
+	{ EXTGVBBRF,     0xf0 },
+	{ DIVAGCCK,      0x80 },
+	{ BBTR,          0xa0 },
+	{ RESERVED_0X7E, 0x4f },
+	{ 0x82,          0x88 }, /* No such regsister defined */
+	{ 0x83,          0x80 }, /* No such regsister defined */
+	{ 0x84,          0x80 }, /* No such regsister defined */
+	{ RESERVED_0X85, 0x74 },
+	{ RESERVED_0X86, 0xff },
+	{ RESERVED_0X88, 0x02 },
+	{ RESERVED_0X89, 0x16 },
+	{ RFST0,         0x1f },
+	{ RESERVED_0X94, 0x66 },
+	{ RESERVED_0X95, 0x66 },
+	{ RESERVED_0X96, 0x77 },
+	{ RESERVED_0X97, 0x99 },
+	{ RESERVED_0X98, 0xff },
+	{ RESERVED_0X99, 0xfc },
+	{ RESERVED_0X9A, 0xba },
+	{ RESERVED_0X9B, 0xaa },
+};
+
+static u8 itd1000_reinit_tab[][2] = {
+	{ VCO_CHP1_I2C, 0x8a },
+	{ BW,           0x87 },
+	{ GVBB_I2C,     0x03 },
+	{ BBGVMIN,      0x03 },
+	{ CON1,         0x2e },
+};
+
+
+static int itd1000_init(struct dvb_frontend *fe)
+{
+	struct itd1000_state *state = fe->tuner_priv;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(itd1000_init_tab); i++)
+		itd1000_write_reg(state, itd1000_init_tab[i][0], itd1000_init_tab[i][1]);
+
+	for (i = 0; i < ARRAY_SIZE(itd1000_reinit_tab); i++)
+		itd1000_write_reg(state, itd1000_reinit_tab[i][0], itd1000_reinit_tab[i][1]);
+
+	return 0;
+}
+
+static int itd1000_sleep(struct dvb_frontend *fe)
+{
+	return 0;
+}
+
+static void itd1000_release(struct dvb_frontend *fe)
+{
+	kfree(fe->tuner_priv);
+	fe->tuner_priv = NULL;
+}
+
+static const struct dvb_tuner_ops itd1000_tuner_ops = {
+	.info = {
+		.name              = "Integrant ITD1000",
+		.frequency_min_hz  =  950 * MHz,
+		.frequency_max_hz  = 2150 * MHz,
+		.frequency_step_hz =  125 * kHz,
+	},
+
+	.release       = itd1000_release,
+
+	.init          = itd1000_init,
+	.sleep         = itd1000_sleep,
+
+	.set_params    = itd1000_set_parameters,
+	.get_frequency = itd1000_get_frequency,
+	.get_bandwidth = itd1000_get_bandwidth
+};
+
+
+struct dvb_frontend *itd1000_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct itd1000_config *cfg)
+{
+	struct itd1000_state *state = NULL;
+	u8 i = 0;
+
+	state = kzalloc_obj(struct itd1000_state);
+	if (state == NULL)
+		return NULL;
+
+	state->cfg = cfg;
+	state->i2c = i2c;
+
+	i = itd1000_read_reg(state, 0);
+	if (i != 0) {
+		kfree(state);
+		return NULL;
+	}
+	itd_info("successfully identified (ID: %d)\n", i);
+
+	memset(state->shadow, 0xff, sizeof(state->shadow));
+	for (i = 0x65; i < 0x9c; i++)
+		state->shadow[i] = itd1000_read_reg(state, i);
+
+	memcpy(&fe->ops.tuner_ops, &itd1000_tuner_ops, sizeof(struct dvb_tuner_ops));
+
+	fe->tuner_priv = state;
+
+	return fe;
+}
+EXPORT_SYMBOL_GPL(itd1000_attach);
+
+MODULE_AUTHOR("Patrick Boettcher <pb@linuxtv.org>");
+MODULE_DESCRIPTION("Integrant ITD1000 driver");
+MODULE_LICENSE("GPL");