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 --- lib/errname.c | 225 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 225 insertions(+) create mode 100644 lib/errname.c (limited to 'lib/errname.c') diff --git a/lib/errname.c b/lib/errname.c new file mode 100644 index 000000000..4f9112b38 --- /dev/null +++ b/lib/errname.c @@ -0,0 +1,225 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +/* + * Ensure these tables do not accidentally become gigantic if some + * huge errno makes it in. On most architectures, the first table will + * only have about 140 entries, but mips and parisc have more sparsely + * allocated errnos (with EHWPOISON = 257 on parisc, and EDQUOT = 1133 + * on mips), so this wastes a bit of space on those - though we + * special case the EDQUOT case. + */ +#define E(err) [err + BUILD_BUG_ON_ZERO(err <= 0 || err > 300)] = "-" #err +static const char *names_0[] = { + E(E2BIG), + E(EACCES), + E(EADDRINUSE), + E(EADDRNOTAVAIL), + E(EADV), + E(EAFNOSUPPORT), + E(EAGAIN), /* EWOULDBLOCK */ + E(EALREADY), + E(EBADE), + E(EBADF), + E(EBADFD), + E(EBADMSG), + E(EBADR), + E(EBADRQC), + E(EBADSLT), + E(EBFONT), + E(EBUSY), + E(ECANCELED), /* ECANCELLED */ + E(ECHILD), + E(ECHRNG), + E(ECOMM), + E(ECONNABORTED), + E(ECONNREFUSED), /* EREFUSED */ + E(ECONNRESET), + E(EDEADLK), /* EDEADLOCK */ +#if EDEADLK != EDEADLOCK /* mips, sparc, powerpc */ + E(EDEADLOCK), +#endif + E(EDESTADDRREQ), + E(EDOM), + E(EDOTDOT), +#ifndef CONFIG_MIPS + E(EDQUOT), +#endif + E(EEXIST), + E(EFAULT), + E(EFBIG), + E(EHOSTDOWN), + E(EHOSTUNREACH), + E(EHWPOISON), + E(EIDRM), + E(EILSEQ), +#ifdef EINIT + E(EINIT), +#endif + E(EINPROGRESS), + E(EINTR), + E(EINVAL), + E(EIO), + E(EISCONN), + E(EISDIR), + E(EISNAM), + E(EKEYEXPIRED), + E(EKEYREJECTED), + E(EKEYREVOKED), + E(EL2HLT), + E(EL2NSYNC), + E(EL3HLT), + E(EL3RST), + E(ELIBACC), + E(ELIBBAD), + E(ELIBEXEC), + E(ELIBMAX), + E(ELIBSCN), + E(ELNRNG), + E(ELOOP), + E(EMEDIUMTYPE), + E(EMFILE), + E(EMLINK), + E(EMSGSIZE), + E(EMULTIHOP), + E(ENAMETOOLONG), + E(ENAVAIL), + E(ENETDOWN), + E(ENETRESET), + E(ENETUNREACH), + E(ENFILE), + E(ENOANO), + E(ENOBUFS), + E(ENOCSI), + E(ENODATA), + E(ENODEV), + E(ENOENT), + E(ENOEXEC), + E(ENOKEY), + E(ENOLCK), + E(ENOLINK), + E(ENOMEDIUM), + E(ENOMEM), + E(ENOMSG), + E(ENONET), + E(ENOPKG), + E(ENOPROTOOPT), + E(ENOSPC), + E(ENOSR), + E(ENOSTR), + E(ENOSYS), + E(ENOTBLK), + E(ENOTCONN), + E(ENOTDIR), + E(ENOTEMPTY), + E(ENOTNAM), + E(ENOTRECOVERABLE), + E(ENOTSOCK), + E(ENOTTY), + E(ENOTUNIQ), + E(ENXIO), + E(EOPNOTSUPP), + E(EOVERFLOW), + E(EOWNERDEAD), + E(EPERM), + E(EPFNOSUPPORT), + E(EPIPE), +#ifdef EPROCLIM + E(EPROCLIM), +#endif + E(EPROTO), + E(EPROTONOSUPPORT), + E(EPROTOTYPE), + E(ERANGE), + E(EREMCHG), +#ifdef EREMDEV + E(EREMDEV), +#endif + E(EREMOTE), + E(EREMOTEIO), + E(ERESTART), + E(ERFKILL), + E(EROFS), +#ifdef ERREMOTE + E(ERREMOTE), +#endif + E(ESHUTDOWN), + E(ESOCKTNOSUPPORT), + E(ESPIPE), + E(ESRCH), + E(ESRMNT), + E(ESTALE), + E(ESTRPIPE), + E(ETIME), + E(ETIMEDOUT), + E(ETOOMANYREFS), + E(ETXTBSY), + E(EUCLEAN), + E(EUNATCH), + E(EUSERS), + E(EXDEV), + E(EXFULL), +}; +#undef E + +#ifdef EREFUSED /* parisc */ +static_assert(EREFUSED == ECONNREFUSED); +#endif +#ifdef ECANCELLED /* parisc */ +static_assert(ECANCELLED == ECANCELED); +#endif +static_assert(EAGAIN == EWOULDBLOCK); /* everywhere */ + +#define E(err) [err - 512 + BUILD_BUG_ON_ZERO(err < 512 || err > 550)] = "-" #err +static const char *names_512[] = { + E(ERESTARTSYS), + E(ERESTARTNOINTR), + E(ERESTARTNOHAND), + E(ENOIOCTLCMD), + E(ERESTART_RESTARTBLOCK), + E(EPROBE_DEFER), + E(EOPENSTALE), + E(ENOPARAM), + + E(EBADHANDLE), + E(ENOTSYNC), + E(EBADCOOKIE), + E(ENOTSUPP), + E(ETOOSMALL), + E(ESERVERFAULT), + E(EBADTYPE), + E(EJUKEBOX), + E(EIOCBQUEUED), + E(ERECALLCONFLICT), +}; +#undef E + +static const char *__errname(unsigned err) +{ + if (err < ARRAY_SIZE(names_0)) + return names_0[err]; + if (err >= 512 && err - 512 < ARRAY_SIZE(names_512)) + return names_512[err - 512]; + /* But why? */ + if (IS_ENABLED(CONFIG_MIPS) && err == EDQUOT) /* 1133 */ + return "-EDQUOT"; + return NULL; +} + +/* + * errname(EIO) -> "EIO" + * errname(-EIO) -> "-EIO" + */ +const char *errname(int err) +{ + const char *name = __errname(abs(err)); + if (!name) + return NULL; + + return err > 0 ? name + 1 : name; +} +EXPORT_SYMBOL(errname); -- cgit v1.3.1