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/net/ppp/pppox.c | 172 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 drivers/net/ppp/pppox.c (limited to 'drivers/net/ppp/pppox.c') diff --git a/drivers/net/ppp/pppox.c b/drivers/net/ppp/pppox.c new file mode 100644 index 000000000..a6f72c813 --- /dev/null +++ b/drivers/net/ppp/pppox.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** -*- linux-c -*- *********************************************************** + * Linux PPP over X/Ethernet (PPPoX/PPPoE) Sockets + * + * PPPoX --- Generic PPP encapsulation socket family + * PPPoE --- PPP over Ethernet (RFC 2516) + * + * Version: 0.5.2 + * + * Author: Michal Ostrowski + * + * 051000 : Initialization cleanup + * + * License: + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +static const struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1]; + +int register_pppox_proto(int proto_num, const struct pppox_proto *pp) +{ + if (proto_num < 0 || proto_num > PX_MAX_PROTO) + return -EINVAL; + if (pppox_protos[proto_num]) + return -EALREADY; + pppox_protos[proto_num] = pp; + return 0; +} + +void unregister_pppox_proto(int proto_num) +{ + if (proto_num >= 0 && proto_num <= PX_MAX_PROTO) + pppox_protos[proto_num] = NULL; +} + +void pppox_unbind_sock(struct sock *sk) +{ + /* Clear connection to ppp device, if attached. */ + + if (sk->sk_state & (PPPOX_BOUND | PPPOX_CONNECTED)) { + ppp_unregister_channel(&pppox_sk(sk)->chan); + sk->sk_state = PPPOX_DEAD; + } +} + +EXPORT_SYMBOL(register_pppox_proto); +EXPORT_SYMBOL(unregister_pppox_proto); +EXPORT_SYMBOL(pppox_unbind_sock); + +int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) +{ + struct sock *sk = sock->sk; + struct pppox_sock *po = pppox_sk(sk); + int rc; + + lock_sock(sk); + + switch (cmd) { + case PPPIOCGCHAN: { + struct sk_buff *skb; + int index; + + rc = -ENOTCONN; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + rc = -EINVAL; + index = ppp_channel_index(&po->chan); + if (put_user(index , (int __user *) arg)) + break; + + rc = 0; + /* PPPIOCGCHAN historically marks the userspace handoff to + * generic PPP; pppd then attaches the returned channel to + * /dev/ppp. + */ + sk->sk_state |= PPPOX_BOUND; + /* Let lockless receive paths finish queueing against the old + * state. + */ + synchronize_net(); + /* Drain packets queued before the handoff because a bound + * socket is no longer readable. + */ + while ((skb = skb_dequeue(&sk->sk_receive_queue))) { + skb_orphan(skb); + ppp_input(&po->chan, skb); + } + break; + } + default: + rc = pppox_protos[sk->sk_protocol]->ioctl ? + pppox_protos[sk->sk_protocol]->ioctl(sock, cmd, arg) : -ENOTTY; + } + + release_sock(sk); + return rc; +} + +EXPORT_SYMBOL(pppox_ioctl); + +#ifdef CONFIG_COMPAT +int pppox_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) +{ + return pppox_ioctl(sock, cmd, (unsigned long)compat_ptr(arg)); +} + +EXPORT_SYMBOL(pppox_compat_ioctl); +#endif + +static int pppox_create(struct net *net, struct socket *sock, int protocol, + int kern) +{ + int rc = -EPROTOTYPE; + + if (protocol < 0 || protocol > PX_MAX_PROTO) + goto out; + + rc = -EPROTONOSUPPORT; + if (!pppox_protos[protocol]) + request_module("net-pf-%d-proto-%d", PF_PPPOX, protocol); + if (!pppox_protos[protocol] || + !try_module_get(pppox_protos[protocol]->owner)) + goto out; + + rc = pppox_protos[protocol]->create(net, sock, kern); + + module_put(pppox_protos[protocol]->owner); +out: + return rc; +} + +static const struct net_proto_family pppox_proto_family = { + .family = PF_PPPOX, + .create = pppox_create, + .owner = THIS_MODULE, +}; + +static int __init pppox_init(void) +{ + return sock_register(&pppox_proto_family); +} + +static void __exit pppox_exit(void) +{ + sock_unregister(PF_PPPOX); +} + +module_init(pppox_init); +module_exit(pppox_exit); + +MODULE_AUTHOR("Michal Ostrowski "); +MODULE_DESCRIPTION("PPP over Ethernet driver (generic socket layer)"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(PF_PPPOX); -- cgit v1.3.1