From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF3D128152D; Wed, 23 Apr 2025 15:29:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745422175; cv=none; b=Ptb5mJIejI8bzxkMoJpGv8cRyPCOEKPbzeJyvZUhJXySDio9NO0Xqqg0IyrMxS2XGENxvXaIIwhBsLPMXgMSAGz0vZ/ZCtO0M+y716V+19ZOpNHh1xp/rSFW1WttxT+Bs91d/jAMfnMwAD1QplGTJPrZNG5tgRr6mEeKtt5Kv3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745422175; c=relaxed/simple; bh=KzS8Suj0ApsMWf6eQZ+dD7NmKNotmYkubPF4grzKEus=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DE9xt65diCb4se4IRJWvjKRjTAVBwB9wiLPTtuwDoB6hmcZb8NFVwJCX4iayvIK2sT79BNiJhacbVA6T0V1UZKnYd0IcunqDq/2JFDXBW4PbG6yNNZsxTMHy89n3NQg0ixiC+ZFOrDy/gdJzdLovo21jm4ZHUMVXGOPvR5fvWKU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xZrKLBCa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xZrKLBCa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00F8DC4CEE2; Wed, 23 Apr 2025 15:29:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745422175; bh=KzS8Suj0ApsMWf6eQZ+dD7NmKNotmYkubPF4grzKEus=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xZrKLBCaR/hlRPp0jigj4yGW4e9PoMkRP+CvycT+4CcbrqiHEhOZtrwbsWTxczZ4M WoXtRsJvvazfIqLJO2RhINJsRqz4NJoRIltithsRvCrxtaL+09RbDWC179pNd5klte 1jDBX3OiTU17taS64Gb6JxGykHhD+tcd3jLxQFB4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mark Rutland , Mark Brown , Will Deacon , Catalin Marinas , Fuad Tabba , Marc Zyngier , Oliver Upton Subject: [PATCH 6.1 250/291] KVM: arm64: Remove host FPSIMD saving for non-protected KVM Date: Wed, 23 Apr 2025 16:43:59 +0200 Message-ID: <20250423142634.642902378@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250423142624.409452181@linuxfoundation.org> References: <20250423142624.409452181@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland [ 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 Reviewed-by: Mark Brown Tested-by: Mark Brown Acked-by: Will Deacon Cc: Catalin Marinas Cc: Fuad Tabba Cc: Marc Zyngier Cc: Oliver Upton Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20250210195226.1215254-3-mark.rutland@arm.com Signed-off-by: Marc Zyngier Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/fpsimd.c | 2 -- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ---- 3 files changed, 7 deletions(-) --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -380,7 +380,6 @@ 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 { --- 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_ 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 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -207,10 +207,6 @@ static bool kvm_hyp_handle_fpsimd(struct } 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);