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/thunderbolt/ctl.h | 144 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 drivers/thunderbolt/ctl.h (limited to 'drivers/thunderbolt/ctl.h') diff --git a/drivers/thunderbolt/ctl.h b/drivers/thunderbolt/ctl.h new file mode 100644 index 000000000..db1646eb4 --- /dev/null +++ b/drivers/thunderbolt/ctl.h @@ -0,0 +1,144 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Thunderbolt driver - control channel and configuration commands + * + * Copyright (c) 2014 Andreas Noever + * Copyright (C) 2018, Intel Corporation + */ + +#ifndef _TB_CFG +#define _TB_CFG + +#include +#include + +#include "nhi.h" +#include "tb_msgs.h" + +/* control channel */ +struct tb_ctl; + +typedef bool (*event_cb)(void *data, enum tb_cfg_pkg_type type, + const void *buf, size_t size); + +struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int index, int timeout_msec, + event_cb cb, void *cb_data); +void tb_ctl_start(struct tb_ctl *ctl); +void tb_ctl_stop(struct tb_ctl *ctl); +void tb_ctl_free(struct tb_ctl *ctl); + +/* configuration commands */ + +struct tb_cfg_result { + u64 response_route; + u32 response_port; /* + * If err = 1 then this is the port that send the + * error. + * If err = 0 and if this was a cfg_read/write then + * this is the upstream port of the responding + * switch. + * Otherwise the field is set to zero. + */ + int err; /* negative errors, 0 for success, 1 for tb errors */ + enum tb_cfg_error tb_error; /* valid if err == 1 */ +}; + +struct ctl_pkg { + struct tb_ctl *ctl; + void *buffer; + struct ring_frame frame; +}; + +/** + * struct tb_cfg_request - Control channel request + * @kref: Reference count + * @ctl: Pointer to the control channel structure. Only set when the + * request is queued. + * @request: Request is stored here + * @request_size: Size of the request packet (in bytes) + * @request_type: Type of the request packet + * @response: Response is stored here + * @response_size: Maximum size of one response packet + * @response_type: Expected type of the response packet + * @npackets: Number of packets expected to be returned with this request + * @match: Function used to match the incoming packet + * @copy: Function used to copy the incoming packet to @response + * @callback: Callback called when the request is finished successfully + * @callback_data: Data to be passed to @callback + * @flags: Flags for the request + * @work: Work item used to complete the request + * @result: Result after the request has been completed + * @list: Requests are queued using this field + * + * An arbitrary request over Thunderbolt control channel. For standard + * control channel message, one should use tb_cfg_read/write() and + * friends if possible. + */ +struct tb_cfg_request { + struct kref kref; + struct tb_ctl *ctl; + const void *request; + size_t request_size; + enum tb_cfg_pkg_type request_type; + void *response; + size_t response_size; + enum tb_cfg_pkg_type response_type; + size_t npackets; + bool (*match)(const struct tb_cfg_request *req, + const struct ctl_pkg *pkg); + bool (*copy)(struct tb_cfg_request *req, const struct ctl_pkg *pkg); + void (*callback)(void *callback_data); + void *callback_data; + unsigned long flags; + struct work_struct work; + struct tb_cfg_result result; + struct list_head list; +}; + +#define TB_CFG_REQUEST_ACTIVE 0 +#define TB_CFG_REQUEST_CANCELED 1 + +struct tb_cfg_request *tb_cfg_request_alloc(void); +void tb_cfg_request_get(struct tb_cfg_request *req); +void tb_cfg_request_put(struct tb_cfg_request *req); +int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req, + void (*callback)(void *), void *callback_data); +void tb_cfg_request_cancel(struct tb_cfg_request *req, int err); +struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl, + struct tb_cfg_request *req, int timeout_msec); + +static inline u64 tb_cfg_get_route(const struct tb_cfg_header *header) +{ + return (u64) header->route_hi << 32 | header->route_lo; +} + +static inline struct tb_cfg_header tb_cfg_make_header(u64 route) +{ + struct tb_cfg_header header = { + .route_hi = route >> 32, + .route_lo = route, + }; + /* check for overflow, route_hi is not 32 bits! */ + WARN_ON(tb_cfg_get_route(&header) != route); + return header; +} + +int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route, + const struct cfg_error_pkg *error); +int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug); +struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route); +struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer, + u64 route, u32 port, + enum tb_cfg_space space, u32 offset, + u32 length, int timeout_msec); +struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer, + u64 route, u32 port, + enum tb_cfg_space space, u32 offset, + u32 length, int timeout_msec); +int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, + enum tb_cfg_space space, u32 offset, u32 length); +int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port, + enum tb_cfg_space space, u32 offset, u32 length); +int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route); + +#endif -- cgit v1.3.1