This is the combination of Kevin's WBNOINVD series[1] with Zheyun's targeted flushing series[2]. The combined goal is to use WBNOINVD instead of WBINVD when doing cached maintenance to prevent data corruption due to C-bit aliasing, and to reduce the number of cache invalidations by only performing flushes on CPUs that have entered the relevant VM since the last cache flush.
Assuming I get the appropate acks (and that I didn't manage to break anything when rebasing), my plan is to take this through the kvm-x86 tree in the 6.17 timeframe. v2: - Add a missing -ENOMEM in __sev_guest_init(). [Tom] - Collect reviews. [Kai, Tom] - Fix stub prototypes. [Zheyun] - Kill off dead pr_err() code on DRM's wbinvd_on_all_cpus() usage. v1: https://lore.kernel.org/all/20250227014858.3244505-1-sea...@google.com [1] https://lore.kernel.org/all/20250201000259.3289143-1-kevinlough...@google.com [2] https://lore.kernel.org/all/20250128015345.7929-1-szy0...@sjtu.edu.cn Kevin Loughlin (2): x86, lib: Add WBNOINVD helper functions KVM: SEV: Prefer WBNOINVD over WBINVD for cache maintenance efficiency Sean Christopherson (3): drm/gpu: Remove dead checks on wbinvd_on_all_cpus()'s return value x86, lib: Drop the unused return value from wbinvd_on_all_cpus() KVM: x86: Use wbinvd_on_cpu() instead of an open-coded equivalent Zheyun Shen (3): KVM: SVM: Remove wbinvd in sev_vm_destroy() x86, lib: Add wbinvd and wbnoinvd helpers to target multiple CPUs KVM: SVM: Flush cache only on CPUs running SEV guest arch/x86/include/asm/smp.h | 23 ++++++-- arch/x86/include/asm/special_insns.h | 19 ++++++- arch/x86/kvm/svm/sev.c | 81 +++++++++++++++++++--------- arch/x86/kvm/svm/svm.h | 1 + arch/x86/kvm/x86.c | 11 +--- arch/x86/lib/cache-smp.c | 26 ++++++++- drivers/gpu/drm/drm_cache.c | 9 ++-- 7 files changed, 125 insertions(+), 45 deletions(-) base-commit: 7ef51a41466bc846ad794d505e2e34ff97157f7f -- 2.49.0.1112.g889b7c5bd8-goog
