From: Mark Rutland <mark.rutland@xxxxxxx> [ Upstream commit 8eca7f6d5100b6997df4f532090bc3f7e0203bef ] Now that the host eagerly saves its own FPSIMD/SVE/SME state, non-protected KVM never needs to save the host FPSIMD/SVE/SME state, and the code to do this is never used. Protected KVM still needs to save/restore the host FPSIMD/SVE state to avoid leaking guest state to the host (and to avoid revealing to the host whether the guest used FPSIMD/SVE/SME), and that code needs to be retained. Remove the unused code and data structures. To avoid the need for a stub copy of kvm_hyp_save_fpsimd_host() in the VHE hyp code, the nVHE/hVHE version is moved into the shared switch header, where it is only invoked when KVM is in protected mode. Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Reviewed-by: Mark Brown <broonie@xxxxxxxxxx> Tested-by: Mark Brown <broonie@xxxxxxxxxx> Acked-by: Will Deacon <will@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Fuad Tabba <tabba@xxxxxxxxxx> Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Oliver Upton <oliver.upton@xxxxxxxxx> Reviewed-by: Oliver Upton <oliver.upton@xxxxxxxxx> Link: https://lore.kernel.org/r/20250210195226.1215254-3-mark.rutland@xxxxxxx Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/fpsimd.c | 2 -- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ---- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 1 - 4 files changed, 8 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 6a165ec5d3b74ece3e98e7bf45f3ea94cc30e6ec..3891963d42e00c8f999886dc5d7322bbacbc6c7f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -535,7 +535,6 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch vcpu_debug_state; struct kvm_guest_debug_arch external_debug_state; - struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ struct task_struct *parent_task; struct { diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 8b55de502c8c220e15e3a6b782d5012b9349b612..7c36d2a7aa3196056f76acfe8f9c41763ed67d9d 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -49,8 +49,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) if (ret) return ret; - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); - /* * We need to keep current's task_struct pinned until its data has been * unshared with the hypervisor to make sure it is not re-used by the diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 9cfe6bd1dbe459cb3588bccd94359369a546947e..1cdc8d161e7dd3aeeb6b03170e239b0c1ace7790 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -321,10 +321,6 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) } isb(); - /* Write out the host state if it's in the registers */ - if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); - /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 67cc07283e642ab07e1c98c5745e2c6a2dd4f36e..8390173f7f5b38e01c04ae6563853df11a1c3df2 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -41,7 +41,6 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.fp_state = host_vcpu->arch.fp_state; hyp_vcpu->vcpu.arch.debug_ptr = kern_hyp_va(host_vcpu->arch.debug_ptr); - hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state; hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2; -- 2.39.5
