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, 280 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-ulpi.c b/drivers/usb/phy/phy-ulpi.c
new file mode 100644
index 000000000..4df63e67b
--- /dev/null
+++ b/drivers/usb/phy/phy-ulpi.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Generic ULPI USB transceiver support
+ *
+ * Copyright (C) 2009 Daniel Mack <daniel@caiaq.de>
+ *
+ * Based on sources from
+ *
+ *   Sascha Hauer <s.hauer@pengutronix.de>
+ *   Freescale Semiconductors
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/usb.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/ulpi.h>
+
+
+struct ulpi_info {
+	unsigned int	id;
+	char		*name;
+};
+
+#define ULPI_ID(vendor, product) (((vendor) << 16) | (product))
+#define ULPI_INFO(_id, _name)		\
+	{				\
+		.id	= (_id),	\
+		.name	= (_name),	\
+	}
+
+/* ULPI hardcoded IDs, used for probing */
+static struct ulpi_info ulpi_ids[] = {
+	ULPI_INFO(ULPI_ID(0x04cc, 0x1504), "NXP ISP1504"),
+	ULPI_INFO(ULPI_ID(0x0424, 0x0006), "SMSC USB331x"),
+	ULPI_INFO(ULPI_ID(0x0424, 0x0007), "SMSC USB3320"),
+	ULPI_INFO(ULPI_ID(0x0424, 0x0009), "SMSC USB334x"),
+	ULPI_INFO(ULPI_ID(0x0451, 0x1507), "TI TUSB1210"),
+};
+
+static int ulpi_set_otg_flags(struct usb_phy *phy)
+{
+	unsigned int flags = ULPI_OTG_CTRL_DP_PULLDOWN |
+			     ULPI_OTG_CTRL_DM_PULLDOWN;
+
+	if (phy->flags & ULPI_OTG_ID_PULLUP)
+		flags |= ULPI_OTG_CTRL_ID_PULLUP;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for Dp/DmPulldown is enabled.
+	 */
+	if (phy->flags & ULPI_OTG_DP_PULLDOWN_DIS)
+		flags &= ~ULPI_OTG_CTRL_DP_PULLDOWN;
+
+	if (phy->flags & ULPI_OTG_DM_PULLDOWN_DIS)
+		flags &= ~ULPI_OTG_CTRL_DM_PULLDOWN;
+
+	if (phy->flags & ULPI_OTG_EXTVBUSIND)
+		flags |= ULPI_OTG_CTRL_EXTVBUSIND;
+
+	return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
+}
+
+static int ulpi_set_fc_flags(struct usb_phy *phy)
+{
+	unsigned int flags = 0;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for XcvrSelect is Full Speed.
+	 */
+	if (phy->flags & ULPI_FC_HS)
+		flags |= ULPI_FUNC_CTRL_HIGH_SPEED;
+	else if (phy->flags & ULPI_FC_LS)
+		flags |= ULPI_FUNC_CTRL_LOW_SPEED;
+	else if (phy->flags & ULPI_FC_FS4LS)
+		flags |= ULPI_FUNC_CTRL_FS4LS;
+	else
+		flags |= ULPI_FUNC_CTRL_FULL_SPEED;
+
+	if (phy->flags & ULPI_FC_TERMSEL)
+		flags |= ULPI_FUNC_CTRL_TERMSELECT;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for OpMode is Normal Operation.
+	 */
+	if (phy->flags & ULPI_FC_OP_NODRV)
+		flags |= ULPI_FUNC_CTRL_OPMODE_NONDRIVING;
+	else if (phy->flags & ULPI_FC_OP_DIS_NRZI)
+		flags |= ULPI_FUNC_CTRL_OPMODE_DISABLE_NRZI;
+	else if (phy->flags & ULPI_FC_OP_NSYNC_NEOP)
+		flags |= ULPI_FUNC_CTRL_OPMODE_NOSYNC_NOEOP;
+	else
+		flags |= ULPI_FUNC_CTRL_OPMODE_NORMAL;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for SuspendM is Powered.
+	 */
+	flags |= ULPI_FUNC_CTRL_SUSPENDM;
+
+	return usb_phy_io_write(phy, flags, ULPI_FUNC_CTRL);
+}
+
+static int ulpi_set_ic_flags(struct usb_phy *phy)
+{
+	unsigned int flags = 0;
+
+	if (phy->flags & ULPI_IC_AUTORESUME)
+		flags |= ULPI_IFC_CTRL_AUTORESUME;
+
+	if (phy->flags & ULPI_IC_EXTVBUS_INDINV)
+		flags |= ULPI_IFC_CTRL_EXTERNAL_VBUS;
+
+	if (phy->flags & ULPI_IC_IND_PASSTHRU)
+		flags |= ULPI_IFC_CTRL_PASSTHRU;
+
+	if (phy->flags & ULPI_IC_PROTECT_DIS)
+		flags |= ULPI_IFC_CTRL_PROTECT_IFC_DISABLE;
+
+	return usb_phy_io_write(phy, flags, ULPI_IFC_CTRL);
+}
+
+static int ulpi_set_flags(struct usb_phy *phy)
+{
+	int ret;
+
+	ret = ulpi_set_otg_flags(phy);
+	if (ret)
+		return ret;
+
+	ret = ulpi_set_ic_flags(phy);
+	if (ret)
+		return ret;
+
+	return ulpi_set_fc_flags(phy);
+}
+
+static int ulpi_check_integrity(struct usb_phy *phy)
+{
+	int ret, i;
+	unsigned int val = 0x55;
+
+	for (i = 0; i < 2; i++) {
+		ret = usb_phy_io_write(phy, val, ULPI_SCRATCH);
+		if (ret < 0)
+			return ret;
+
+		ret = usb_phy_io_read(phy, ULPI_SCRATCH);
+		if (ret < 0)
+			return ret;
+
+		if (ret != val) {
+			pr_err("ULPI integrity check: failed!");
+			return -ENODEV;
+		}
+		val = val << 1;
+	}
+
+	pr_info("ULPI integrity check: passed.\n");
+
+	return 0;
+}
+
+static int ulpi_init(struct usb_phy *phy)
+{
+	int i, vid, pid, ret;
+	u32 ulpi_id = 0;
+
+	for (i = 0; i < 4; i++) {
+		ret = usb_phy_io_read(phy, ULPI_PRODUCT_ID_HIGH - i);
+		if (ret < 0)
+			return ret;
+		ulpi_id = (ulpi_id << 8) | ret;
+	}
+	vid = ulpi_id & 0xffff;
+	pid = ulpi_id >> 16;
+
+	pr_info("ULPI transceiver vendor/product ID 0x%04x/0x%04x\n", vid, pid);
+
+	for (i = 0; i < ARRAY_SIZE(ulpi_ids); i++) {
+		if (ulpi_ids[i].id == ULPI_ID(vid, pid)) {
+			pr_info("Found %s ULPI transceiver.\n",
+				ulpi_ids[i].name);
+			break;
+		}
+	}
+
+	ret = ulpi_check_integrity(phy);
+	if (ret)
+		return ret;
+
+	return ulpi_set_flags(phy);
+}
+
+static int ulpi_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+	struct usb_phy *phy = otg->usb_phy;
+	unsigned int flags = usb_phy_io_read(phy, ULPI_IFC_CTRL);
+
+	if (!host) {
+		otg->host = NULL;
+		return 0;
+	}
+
+	otg->host = host;
+
+	flags &= ~(ULPI_IFC_CTRL_6_PIN_SERIAL_MODE |
+		   ULPI_IFC_CTRL_3_PIN_SERIAL_MODE |
+		   ULPI_IFC_CTRL_CARKITMODE);
+
+	if (phy->flags & ULPI_IC_6PIN_SERIAL)
+		flags |= ULPI_IFC_CTRL_6_PIN_SERIAL_MODE;
+	else if (phy->flags & ULPI_IC_3PIN_SERIAL)
+		flags |= ULPI_IFC_CTRL_3_PIN_SERIAL_MODE;
+	else if (phy->flags & ULPI_IC_CARKIT)
+		flags |= ULPI_IFC_CTRL_CARKITMODE;
+
+	return usb_phy_io_write(phy, flags, ULPI_IFC_CTRL);
+}
+
+static int ulpi_set_vbus(struct usb_otg *otg, bool on)
+{
+	struct usb_phy *phy = otg->usb_phy;
+	unsigned int flags = usb_phy_io_read(phy, ULPI_OTG_CTRL);
+
+	flags &= ~(ULPI_OTG_CTRL_DRVVBUS | ULPI_OTG_CTRL_DRVVBUS_EXT);
+
+	if (on) {
+		if (phy->flags & ULPI_OTG_DRVVBUS)
+			flags |= ULPI_OTG_CTRL_DRVVBUS;
+
+		if (phy->flags & ULPI_OTG_DRVVBUS_EXT)
+			flags |= ULPI_OTG_CTRL_DRVVBUS_EXT;
+	}
+
+	return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
+}
+
+static void otg_ulpi_init(struct usb_phy *phy, struct usb_otg *otg,
+			  struct usb_phy_io_ops *ops,
+			  unsigned int flags)
+{
+	phy->label	= "ULPI";
+	phy->flags	= flags;
+	phy->io_ops	= ops;
+	phy->otg	= otg;
+	phy->init	= ulpi_init;
+
+	otg->usb_phy	= phy;
+	otg->set_host	= ulpi_set_host;
+	otg->set_vbus	= ulpi_set_vbus;
+}
+
+struct usb_phy *
+devm_otg_ulpi_create(struct device *dev,
+		     struct usb_phy_io_ops *ops,
+		     unsigned int flags)
+{
+	struct usb_phy *phy;
+	struct usb_otg *otg;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return NULL;
+
+	otg = devm_kzalloc(dev, sizeof(*otg), GFP_KERNEL);
+	if (!otg) {
+		devm_kfree(dev, phy);
+		return NULL;
+	}
+
+	otg_ulpi_init(phy, otg, ops, flags);
+
+	return phy;
+}
+EXPORT_SYMBOL_GPL(devm_otg_ulpi_create);