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 --- Documentation/sphinx/kernel_abi.py | 173 +++++++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) create mode 100644 Documentation/sphinx/kernel_abi.py (limited to 'Documentation/sphinx/kernel_abi.py') diff --git a/Documentation/sphinx/kernel_abi.py b/Documentation/sphinx/kernel_abi.py new file mode 100644 index 000000000..5667f207d --- /dev/null +++ b/Documentation/sphinx/kernel_abi.py @@ -0,0 +1,173 @@ +# -*- coding: utf-8; mode: python -*- +# coding=utf-8 +# SPDX-License-Identifier: GPL-2.0 +# +""" + kernel-abi + ~~~~~~~~~~ + + Implementation of the ``kernel-abi`` reST-directive. + + :copyright: Copyright (C) 2016 Markus Heiser + :copyright: Copyright (C) 2016-2020 Mauro Carvalho Chehab + :maintained-by: Mauro Carvalho Chehab + :license: GPL Version 2, June 1991 see Linux/COPYING for details. + + The ``kernel-abi`` (:py:class:`KernelCmd`) directive calls the + AbiParser class to parse the Kernel ABI files. + + Overview of directive's argument and options. + + .. code-block:: rst + + .. kernel-abi:: + :debug: + + The argument ```` is required. It contains the + location of the ABI files to be parsed. + + ``debug`` + Inserts a code-block with the *raw* reST. Sometimes it is helpful to see + what reST is generated. + +""" + +import os +import re +import sys + +from docutils import nodes, statemachine +from docutils.statemachine import ViewList +from docutils.parsers.rst import directives, Directive +from sphinx.util.docutils import switch_source_input +from sphinx.util import logging + +srctree = os.path.abspath(os.environ["srctree"]) +sys.path.insert(0, os.path.join(srctree, "tools/lib/python")) + +from abi.abi_parser import AbiParser + +__version__ = "1.0" + +logger = logging.getLogger('kernel_abi') +path = os.path.join(srctree, "Documentation/ABI") + +_kernel_abi = None + +def get_kernel_abi(): + """ + Initialize kernel_abi global var, if not initialized yet. + + This is needed to avoid warnings during Sphinx module initialization. + """ + global _kernel_abi + + if not _kernel_abi: + # Parse ABI symbols only once + _kernel_abi = AbiParser(path, logger=logger) + _kernel_abi.parse_abi() + _kernel_abi.check_issues() + + return _kernel_abi + +def setup(app): + + app.add_directive("kernel-abi", KernelCmd) + return { + "version": __version__, + "parallel_read_safe": True, + "parallel_write_safe": True + } + + +class KernelCmd(Directive): + """KernelABI (``kernel-abi``) directive""" + + required_arguments = 1 + optional_arguments = 3 + has_content = False + final_argument_whitespace = True + parser = None + + option_spec = { + "debug": directives.flag, + "no-symbols": directives.flag, + "no-files": directives.flag, + } + + def run(self): + kernel_abi = get_kernel_abi() + + doc = self.state.document + if not doc.settings.file_insertion_enabled: + raise self.warning("docutils: file insertion disabled") + + env = self.state.document.settings.env + content = ViewList() + node = nodes.section() + + abi_type = self.arguments[0] + + if "no-symbols" in self.options: + show_symbols = False + else: + show_symbols = True + + if "no-files" in self.options: + show_file = False + else: + show_file = True + + tab_width = self.options.get('tab-width', + self.state.document.settings.tab_width) + + old_f = None + n = 0 + n_sym = 0 + for msg, f, ln in kernel_abi.doc(show_file=show_file, + show_symbols=show_symbols, + filter_path=abi_type): + n_sym += 1 + msg_list = statemachine.string2lines(msg, tab_width, + convert_whitespace=True) + if "debug" in self.options: + lines = [ + "", "", ".. code-block:: rst", + " :linenos:", "" + ] + for m in msg_list: + lines.append(" " + m) + else: + lines = msg_list + + for line in lines: + # sphinx counts lines from 0 + content.append(line, f, ln - 1) + n += 1 + + if f != old_f: + # Add the file to Sphinx build dependencies if the file exists + fname = os.path.join(srctree, f) + if os.path.isfile(fname): + env.note_dependency(fname) + + old_f = f + + # Sphinx doesn't like to parse big messages. So, let's + # add content symbol by symbol + if content: + self.do_parse(content, node) + content = ViewList() + + if show_symbols and not show_file: + logger.verbose("%s ABI: %i symbols (%i ReST lines)" % (abi_type, n_sym, n)) + elif not show_symbols and show_file: + logger.verbose("%s ABI: %i files (%i ReST lines)" % (abi_type, n_sym, n)) + else: + logger.verbose("%s ABI: %i data (%i ReST lines)" % (abi_type, n_sym, n)) + + return node.children + + def do_parse(self, content, node): + with switch_source_input(self.state, content): + self.state.nested_parse(content, 0, node, match_titles=1) -- cgit v1.3.1