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 --- io_uring/poll.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 io_uring/poll.h (limited to 'io_uring/poll.h') diff --git a/io_uring/poll.h b/io_uring/poll.h new file mode 100644 index 000000000..5647c5138 --- /dev/null +++ b/io_uring/poll.h @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +#define IO_POLL_ALLOC_CACHE_MAX 32 + +enum { + IO_APOLL_OK, + IO_APOLL_ABORTED, + IO_APOLL_READY +}; + +struct io_poll { + struct file *file; + struct wait_queue_head *head; + __poll_t events; + int retries; + struct wait_queue_entry wait; +}; + +struct async_poll { + struct io_poll poll; + struct io_poll *double_poll; +}; + +/* + * Must only be called inside issue_flags & IO_URING_F_MULTISHOT, or + * potentially other cases where we already "own" this poll request. + */ +static inline void io_poll_multishot_retry(struct io_kiocb *req) +{ + atomic_inc(&req->poll_refs); +} + +int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_poll_add(struct io_kiocb *req, unsigned int issue_flags); + +int io_poll_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags); + +struct io_cancel_data; +int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned issue_flags); +int io_arm_apoll(struct io_kiocb *req, unsigned issue_flags, __poll_t mask); +int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags); +bool io_poll_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all); + +void io_poll_task_func(struct io_tw_req tw_req, io_tw_token_t tw); -- cgit v1.3.1