From: Paolo Bonzini Date: Mon, 18 Mar 2024 23:03:42 +0000 (-0400) Subject: Merge tag 'kvm-x86-asyncpf_abi-6.9' of https://github.com/kvm-x86/linux into HEAD X-Git-Tag: v6.9-rc3~33^2~6 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=c822a075ab2dbbcecb52b79331a5edd8395bdf4b;p=linux-2.6-block.git Merge tag 'kvm-x86-asyncpf_abi-6.9' of https://github.com/kvm-x86/linux into HEAD Guest-side KVM async #PF ABI cleanup for 6.9 Delete kvm_vcpu_pv_apf_data.enabled to fix a goof in KVM's async #PF ABI where the enabled field pushes the size of "struct kvm_vcpu_pv_apf_data" from 64 to 68 bytes, i.e. beyond a single cache line. The enabled field is purely a guest-side flag that Linux-as-a-guest uses to track whether or not the guest has enabled async #PF support. The actual flag that is passed to the host, i.e. to KVM proper, is a single bit in a synthetic MSR, MSR_KVM_ASYNC_PF_EN, i.e. is in a location completely unrelated to the shared kvm_vcpu_pv_apf_data structure. Simply drop the the field and use a dedicated guest-side per-CPU variable to fix the ABI, as opposed to fixing the documentation to match reality. KVM has never consumed kvm_vcpu_pv_apf_data.enabled, so the odds of the ABI change breaking anything are extremely low. --- c822a075ab2dbbcecb52b79331a5edd8395bdf4b