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/hid/hid-wiimote-debug.c | 212 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 212 insertions(+) create mode 100644 drivers/hid/hid-wiimote-debug.c (limited to 'drivers/hid/hid-wiimote-debug.c') diff --git a/drivers/hid/hid-wiimote-debug.c b/drivers/hid/hid-wiimote-debug.c new file mode 100644 index 000000000..5f7491778 --- /dev/null +++ b/drivers/hid/hid-wiimote-debug.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Debug support for HID Nintendo Wii / Wii U peripherals + * Copyright (c) 2011-2013 David Herrmann + */ + +/* + */ + +#include +#include +#include +#include +#include +#include "hid-wiimote.h" + +struct wiimote_debug { + struct wiimote_data *wdata; + struct dentry *eeprom; + struct dentry *drm; +}; + +static ssize_t wiidebug_eeprom_read(struct file *f, char __user *u, size_t s, + loff_t *off) +{ + struct wiimote_debug *dbg = f->private_data; + struct wiimote_data *wdata = dbg->wdata; + unsigned long flags; + ssize_t ret; + char buf[16]; + __u16 size = 0; + + if (s == 0) + return -EINVAL; + if (*off > 0xffffff) + return 0; + if (s > 16) + s = 16; + + ret = wiimote_cmd_acquire(wdata); + if (ret) + return ret; + + spin_lock_irqsave(&wdata->state.lock, flags); + wdata->state.cmd_read_size = s; + wdata->state.cmd_read_buf = buf; + wiimote_cmd_set(wdata, WIIPROTO_REQ_RMEM, *off & 0xffff); + wiiproto_req_reeprom(wdata, *off, s); + spin_unlock_irqrestore(&wdata->state.lock, flags); + + ret = wiimote_cmd_wait(wdata); + if (!ret) + size = wdata->state.cmd_read_size; + + spin_lock_irqsave(&wdata->state.lock, flags); + wdata->state.cmd_read_buf = NULL; + spin_unlock_irqrestore(&wdata->state.lock, flags); + + wiimote_cmd_release(wdata); + + if (ret) + return ret; + else if (size == 0) + return -EIO; + + if (copy_to_user(u, buf, size)) + return -EFAULT; + + *off += size; + ret = size; + + return ret; +} + +static const struct file_operations wiidebug_eeprom_fops = { + .owner = THIS_MODULE, + .open = simple_open, + .read = wiidebug_eeprom_read, + .llseek = generic_file_llseek, +}; + +static const char *wiidebug_drmmap[] = { + [WIIPROTO_REQ_NULL] = "NULL", + [WIIPROTO_REQ_DRM_K] = "K", + [WIIPROTO_REQ_DRM_KA] = "KA", + [WIIPROTO_REQ_DRM_KE] = "KE", + [WIIPROTO_REQ_DRM_KAI] = "KAI", + [WIIPROTO_REQ_DRM_KEE] = "KEE", + [WIIPROTO_REQ_DRM_KAE] = "KAE", + [WIIPROTO_REQ_DRM_KIE] = "KIE", + [WIIPROTO_REQ_DRM_KAIE] = "KAIE", + [WIIPROTO_REQ_DRM_E] = "E", + [WIIPROTO_REQ_DRM_SKAI1] = "SKAI1", + [WIIPROTO_REQ_DRM_SKAI2] = "SKAI2", + [WIIPROTO_REQ_MAX] = NULL +}; + +static int wiidebug_drm_show(struct seq_file *f, void *p) +{ + struct wiimote_debug *dbg = f->private; + const char *str = NULL; + unsigned long flags; + __u8 drm; + + spin_lock_irqsave(&dbg->wdata->state.lock, flags); + drm = dbg->wdata->state.drm; + spin_unlock_irqrestore(&dbg->wdata->state.lock, flags); + + if (drm < WIIPROTO_REQ_MAX) + str = wiidebug_drmmap[drm]; + if (!str) + str = "unknown"; + + seq_printf(f, "%s\n", str); + + return 0; +} + +static int wiidebug_drm_open(struct inode *i, struct file *f) +{ + return single_open(f, wiidebug_drm_show, i->i_private); +} + +static ssize_t wiidebug_drm_write(struct file *f, const char __user *u, + size_t s, loff_t *off) +{ + struct seq_file *sf = f->private_data; + struct wiimote_debug *dbg = sf->private; + unsigned long flags; + char buf[16]; + ssize_t len; + int i; + + if (s == 0) + return -EINVAL; + + len = min((size_t) 15, s); + if (copy_from_user(buf, u, len)) + return -EFAULT; + + buf[len] = 0; + + for (i = 0; i < WIIPROTO_REQ_MAX; ++i) { + if (!wiidebug_drmmap[i]) + continue; + if (!strcasecmp(buf, wiidebug_drmmap[i])) + break; + } + + if (i == WIIPROTO_REQ_MAX) + i = simple_strtoul(buf, NULL, 16); + + spin_lock_irqsave(&dbg->wdata->state.lock, flags); + dbg->wdata->state.flags &= ~WIIPROTO_FLAG_DRM_LOCKED; + wiiproto_req_drm(dbg->wdata, (__u8) i); + if (i != WIIPROTO_REQ_NULL) + dbg->wdata->state.flags |= WIIPROTO_FLAG_DRM_LOCKED; + spin_unlock_irqrestore(&dbg->wdata->state.lock, flags); + + return len; +} + +static const struct file_operations wiidebug_drm_fops = { + .owner = THIS_MODULE, + .open = wiidebug_drm_open, + .read = seq_read, + .llseek = seq_lseek, + .write = wiidebug_drm_write, + .release = single_release, +}; + +int wiidebug_init(struct wiimote_data *wdata) +{ + struct wiimote_debug *dbg; + unsigned long flags; + + dbg = kzalloc_obj(*dbg); + if (!dbg) + return -ENOMEM; + + dbg->wdata = wdata; + + dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR, + dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops); + + dbg->drm = debugfs_create_file("drm", S_IRUSR, + dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops); + + spin_lock_irqsave(&wdata->state.lock, flags); + wdata->debug = dbg; + spin_unlock_irqrestore(&wdata->state.lock, flags); + + return 0; + +} + +void wiidebug_deinit(struct wiimote_data *wdata) +{ + struct wiimote_debug *dbg = wdata->debug; + unsigned long flags; + + if (!dbg) + return; + + spin_lock_irqsave(&wdata->state.lock, flags); + wdata->debug = NULL; + spin_unlock_irqrestore(&wdata->state.lock, flags); + + debugfs_remove(dbg->drm); + debugfs_remove(dbg->eeprom); + kfree(dbg); +} -- cgit v1.3.1