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/loop.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 io_uring/loop.h (limited to 'io_uring/loop.h') diff --git a/io_uring/loop.h b/io_uring/loop.h new file mode 100644 index 000000000..4dd4fb3ae --- /dev/null +++ b/io_uring/loop.h @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_LOOP_H +#define IOU_LOOP_H + +#include + +struct iou_loop_params { + /* + * The CQE index to wait for. Only serves as a hint and can still be + * woken up earlier. + */ + __u32 cq_wait_idx; +}; + +enum { + IOU_LOOP_CONTINUE = 0, + IOU_LOOP_STOP, +}; + +static inline bool io_has_loop_ops(struct io_ring_ctx *ctx) +{ + return data_race(ctx->loop_step); +} + +int io_run_loop(struct io_ring_ctx *ctx); + +static inline struct iou_ctx *io_loop_mangle_ctx(struct io_ring_ctx *ctx) +{ + return (struct iou_ctx *)ctx; +} + +static inline struct io_ring_ctx *io_loop_demangle_ctx(struct iou_ctx *ctx) +{ + return (struct io_ring_ctx *)ctx; +} + +#endif -- cgit v1.3.1