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 --- include/trace/syscall.h | 57 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 include/trace/syscall.h (limited to 'include/trace/syscall.h') diff --git a/include/trace/syscall.h b/include/trace/syscall.h new file mode 100644 index 000000000..0dd7f2b33 --- /dev/null +++ b/include/trace/syscall.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TRACE_SYSCALL_H +#define _TRACE_SYSCALL_H + +#include +#include +#include +#include + +#include + + +/* + * A syscall entry in the ftrace syscalls array. + * + * @name: name of the syscall + * @syscall_nr: number of the syscall + * @nb_args: number of parameters it takes + * @user_arg_is_str: set if the arg for @user_arg_size is a string + * @user_arg_size: holds @arg that has size of the user space to read + * @user_mask: mask of @args that will read user space + * @types: list of types as strings + * @args: list of args as strings (args[i] matches types[i]) + * @enter_fields: list of fields for syscall_enter trace event + * @enter_event: associated syscall_enter trace event + * @exit_event: associated syscall_exit trace event + */ +struct syscall_metadata { + const char *name; + int syscall_nr; + u8 nb_args:7; + u8 user_arg_is_str:1; + s8 user_arg_size; + short user_mask; + const char **types; + const char **args; + struct list_head enter_fields; + + struct trace_event_call *enter_event; + struct trace_event_call *exit_event; +}; + +#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS) +static inline void syscall_tracepoint_update(struct task_struct *p) +{ + if (test_syscall_work(SYSCALL_TRACEPOINT)) + set_task_syscall_work(p, SYSCALL_TRACEPOINT); + else + clear_task_syscall_work(p, SYSCALL_TRACEPOINT); +} +#else +static inline void syscall_tracepoint_update(struct task_struct *p) +{ +} +#endif + +#endif /* _TRACE_SYSCALL_H */ -- cgit v1.3.1