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/kunit/try-catch.h | 63 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 include/kunit/try-catch.h (limited to 'include/kunit/try-catch.h') diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h new file mode 100644 index 000000000..d4e1a5b98 --- /dev/null +++ b/include/kunit/try-catch.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * An API to allow a function, that may fail, to be executed, and recover in a + * controlled manner. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins + */ + +#ifndef _KUNIT_TRY_CATCH_H +#define _KUNIT_TRY_CATCH_H + +#include + +typedef void (*kunit_try_catch_func_t)(void *); + +struct kunit; + +/** + * struct kunit_try_catch - provides a generic way to run code which might fail. + * @test: The test case that is currently being executed. + * @try_result: Contains any errno obtained while running test case. + * @try: The function, the test case, to attempt to run. + * @catch: The function called if @try bails out. + * @context: used to pass user data to the try and catch functions. + * + * kunit_try_catch provides a generic, architecture independent way to execute + * an arbitrary function of type kunit_try_catch_func_t which may bail out by + * calling kunit_try_catch_throw(). If kunit_try_catch_throw() is called, @try + * is stopped at the site of invocation and @catch is called. + * + * struct kunit_try_catch provides a generic interface for the functionality + * needed to implement kunit->abort() which in turn is needed for implementing + * assertions. Assertions allow stating a precondition for a test simplifying + * how test cases are written and presented. + * + * Assertions are like expectations, except they abort (call + * kunit_try_catch_throw()) when the specified condition is not met. This is + * useful when you look at a test case as a logical statement about some piece + * of code, where assertions are the premises for the test case, and the + * conclusion is a set of predicates, rather expectations, that must all be + * true. If your premises are violated, it does not makes sense to continue. + */ +struct kunit_try_catch { + /* private: internal use only. */ + struct kunit *test; + int try_result; + kunit_try_catch_func_t try; + kunit_try_catch_func_t catch; + unsigned long timeout; + void *context; +}; + +void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context); + +void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch); + +static inline int kunit_try_catch_get_result(struct kunit_try_catch *try_catch) +{ + return try_catch->try_result; +} + +#endif /* _KUNIT_TRY_CATCH_H */ -- cgit v1.3.1