For all intents and purposes, this is an x86/mmu series, but it touches s390 and common KVM code because KVM_REQ_MMU_RELOAD is currently a generic request despite its use being encapsulated entirely within arch code. The meat of the series is to zap only obsolete (a.k.a. invalid) roots in response to KVM marking a root obsolete/invalid due to it being zapped. KVM currently drops/zaps all roots, which, aside from being a performance hit if the guest is using multiple roots, complicates x86 KVM paths that load a new root because it raises the question of what should be done if there's a pending KVM_REQ_MMU_RELOAD, i.e. if the path _knows_ that any root it loads will be obliterated. Paolo, I'm hoping you can squash patch 01 with your patch it "fixes". I'm also speculating that this will be applied after my patch to remove KVM_REQ_GPC_INVALIDATE, otherwise the changelog in patch 06 will be wrong. v2: - Collect reviews. [Claudio, Janosch] - Rebase to latest kvm/queue. v1: https://lore.kernel.org/all/20211209060552.2956723-1-seanjc@xxxxxxxxxx Sean Christopherson (7): KVM: x86: Remove spurious whitespaces from kvm_post_set_cr4() KVM: x86: Invoke kvm_mmu_unload() directly on CR4.PCIDE change KVM: Drop kvm_reload_remote_mmus(), open code request in x86 users KVM: x86/mmu: Zap only obsolete roots if a root shadow page is zapped KVM: s390: Replace KVM_REQ_MMU_RELOAD usage with arch specific request KVM: Drop KVM_REQ_MMU_RELOAD and update vcpu-requests.rst documentation KVM: WARN if is_unsync_root() is called on a root without a shadow page Documentation/virt/kvm/vcpu-requests.rst | 7 +- arch/s390/include/asm/kvm_host.h | 2 + arch/s390/kvm/kvm-s390.c | 8 +-- arch/s390/kvm/kvm-s390.h | 2 +- arch/x86/include/asm/kvm_host.h | 2 + arch/x86/kvm/mmu.h | 1 + arch/x86/kvm/mmu/mmu.c | 83 ++++++++++++++++++++---- arch/x86/kvm/x86.c | 10 +-- include/linux/kvm_host.h | 4 +- virt/kvm/kvm_main.c | 5 -- 10 files changed, 90 insertions(+), 34 deletions(-) base-commit: f4bc051fc91ab9f1d5225d94e52d369ef58bec58 -- 2.35.1.574.g5d30c73bfb-goog
