From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration 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 Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- drivers/usb/misc/ehset.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 drivers/usb/misc/ehset.c (limited to 'drivers/usb/misc/ehset.c') diff --git a/drivers/usb/misc/ehset.c b/drivers/usb/misc/ehset.c new file mode 100644 index 000000000..36b6e9fa7 --- /dev/null +++ b/drivers/usb/misc/ehset.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include + +#define TEST_SE0_NAK_PID 0x0101 +#define TEST_J_PID 0x0102 +#define TEST_K_PID 0x0103 +#define TEST_PACKET_PID 0x0104 +#define TEST_HS_HOST_PORT_SUSPEND_RESUME 0x0106 +#define TEST_SINGLE_STEP_GET_DEV_DESC 0x0107 +#define TEST_SINGLE_STEP_SET_FEATURE 0x0108 + +extern const struct usb_device_id *usb_device_match_id(struct usb_device *udev, + const struct usb_device_id *id); + +/* + * A list of USB hubs which requires to disable the power + * to the port before starting the testing procedures. + */ +static const struct usb_device_id ehset_hub_list[] = { + { USB_DEVICE(0x0424, 0x4502) }, + { USB_DEVICE(0x0424, 0x4913) }, + { USB_DEVICE(0x0451, 0x8027) }, + { } +}; + +static int ehset_prepare_port_for_testing(struct usb_device *hub_udev, u16 portnum) +{ + int ret = 0; + + /* + * The USB2.0 spec chapter 11.24.2.13 says that the USB port which is + * going under test needs to be put in suspend before sending the + * test command. Most hubs don't enforce this precondition, but there + * are some hubs which needs to disable the power to the port before + * starting the test. + */ + if (usb_device_match_id(hub_udev, ehset_hub_list)) { + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_CLEAR_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_ENABLE, + portnum, NULL, 0, 1000, GFP_KERNEL); + /* + * Wait for the port to be disabled. It's an arbitrary value + * which worked every time. + */ + msleep(100); + } else { + /* + * For the hubs which are compliant with the spec, + * put the port in SUSPEND. + */ + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_SUSPEND, + portnum, NULL, 0, 1000, GFP_KERNEL); + } + return ret; +} + +static int ehset_probe(struct usb_interface *intf, + const struct usb_device_id *id) +{ + int ret = -EINVAL; + struct usb_device *dev = interface_to_usbdev(intf); + struct usb_device *hub_udev = dev->parent; + struct usb_device_descriptor buf; + u8 portnum = dev->portnum; + u16 test_pid = le16_to_cpu(dev->descriptor.idProduct); + + switch (test_pid) { + case TEST_SE0_NAK_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_SE0_NAK << 8) | portnum, + NULL, 0, 1000, GFP_KERNEL); + break; + case TEST_J_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_J << 8) | portnum, NULL, 0, + 1000, GFP_KERNEL); + break; + case TEST_K_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_K << 8) | portnum, NULL, 0, + 1000, GFP_KERNEL); + break; + case TEST_PACKET_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_PACKET << 8) | portnum, + NULL, 0, 1000, GFP_KERNEL); + break; + case TEST_HS_HOST_PORT_SUSPEND_RESUME: + /* Test: wait for 15secs -> suspend -> 15secs delay -> resume */ + msleep(15 * 1000); + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_SUSPEND, + portnum, NULL, 0, 1000, GFP_KERNEL); + if (ret < 0) + break; + + msleep(15 * 1000); + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_CLEAR_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_SUSPEND, + portnum, NULL, 0, 1000, GFP_KERNEL); + break; + case TEST_SINGLE_STEP_GET_DEV_DESC: + /* Test: wait for 15secs -> GetDescriptor request */ + msleep(15 * 1000); + + ret = usb_control_msg_recv(dev, 0, USB_REQ_GET_DESCRIPTOR, + USB_DIR_IN, USB_DT_DEVICE << 8, 0, + &buf, USB_DT_DEVICE_SIZE, + USB_CTRL_GET_TIMEOUT, GFP_KERNEL); + break; + case TEST_SINGLE_STEP_SET_FEATURE: + /* + * GetDescriptor SETUP request -> 15secs delay -> IN & STATUS + * + * Note, this test is only supported on root hubs since the + * SetPortFeature handling can only be done inside the HCD's + * hub_control callback function. + */ + if (hub_udev != dev->bus->root_hub) { + dev_err(&intf->dev, "SINGLE_STEP_SET_FEATURE test only supported on root hub\n"); + break; + } + + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (6 << 8) | portnum, NULL, 0, + 60 * 1000, GFP_KERNEL); + + break; + default: + dev_err(&intf->dev, "%s: unsupported PID: 0x%x\n", + __func__, test_pid); + } + + return ret; +} + +static void ehset_disconnect(struct usb_interface *intf) +{ +} + +static const struct usb_device_id ehset_id_table[] = { + { USB_DEVICE(0x1a0a, TEST_SE0_NAK_PID) }, + { USB_DEVICE(0x1a0a, TEST_J_PID) }, + { USB_DEVICE(0x1a0a, TEST_K_PID) }, + { USB_DEVICE(0x1a0a, TEST_PACKET_PID) }, + { USB_DEVICE(0x1a0a, TEST_HS_HOST_PORT_SUSPEND_RESUME) }, + { USB_DEVICE(0x1a0a, TEST_SINGLE_STEP_GET_DEV_DESC) }, + { USB_DEVICE(0x1a0a, TEST_SINGLE_STEP_SET_FEATURE) }, + { } /* Terminating entry */ +}; +MODULE_DEVICE_TABLE(usb, ehset_id_table); + +static struct usb_driver ehset_driver = { + .name = "usb_ehset_test", + .probe = ehset_probe, + .disconnect = ehset_disconnect, + .id_table = ehset_id_table, +}; + +module_usb_driver(ehset_driver); + +MODULE_DESCRIPTION("USB Driver for EHSET Test Fixture"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1