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, 27 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-generic.h b/drivers/usb/phy/phy-generic.h
new file mode 100644
index 000000000..7ee80211a
--- /dev/null
+++ b/drivers/usb/phy/phy-generic.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _PHY_GENERIC_H_
+#define _PHY_GENERIC_H_
+
+#include <linux/usb/usb_phy_generic.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+struct usb_phy_generic {
+	struct usb_phy phy;
+	struct device *dev;
+	struct clk *clk;
+	struct regulator *vcc;
+	struct gpio_desc *gpiod_reset;
+	struct gpio_desc *gpiod_vbus;
+	struct regulator *vbus_draw;
+	bool vbus_draw_enabled;
+	unsigned long mA;
+	unsigned int vbus;
+};
+
+int usb_gen_phy_init(struct usb_phy *phy);
+void usb_gen_phy_shutdown(struct usb_phy *phy);
+
+int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop);
+
+#endif