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/asm-generic/error-injection.h | 43 +++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 include/asm-generic/error-injection.h (limited to 'include/asm-generic/error-injection.h') diff --git a/include/asm-generic/error-injection.h b/include/asm-generic/error-injection.h new file mode 100644 index 000000000..b05253f68 --- /dev/null +++ b/include/asm-generic/error-injection.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_ERROR_INJECTION_H +#define _ASM_GENERIC_ERROR_INJECTION_H + +#if defined(__KERNEL__) && !defined(__ASSEMBLY__) +enum { + EI_ETYPE_NULL, /* Return NULL if failure */ + EI_ETYPE_ERRNO, /* Return -ERRNO if failure */ + EI_ETYPE_ERRNO_NULL, /* Return -ERRNO or NULL if failure */ + EI_ETYPE_TRUE, /* Return true if failure */ +}; + +struct error_injection_entry { + unsigned long addr; + int etype; +}; + +struct pt_regs; + +#ifdef CONFIG_FUNCTION_ERROR_INJECTION +/* + * Whitelist generating macro. Specify functions which can be error-injectable + * using this macro. If you unsure what is required for the error-injectable + * functions, please read Documentation/fault-injection/fault-injection.rst + * 'Error Injectable Functions' section. + */ +#define ALLOW_ERROR_INJECTION(fname, _etype) \ +static struct error_injection_entry __used \ + __section("_error_injection_whitelist") \ + _eil_addr_##fname = { \ + .addr = (unsigned long)fname, \ + .etype = EI_ETYPE_##_etype, \ + } + +void override_function_with_return(struct pt_regs *regs); +#else +#define ALLOW_ERROR_INJECTION(fname, _etype) + +static inline void override_function_with_return(struct pt_regs *regs) { } +#endif +#endif + +#endif /* _ASM_GENERIC_ERROR_INJECTION_H */ -- cgit v1.3.1