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 A53E9221DA7; Tue, 29 Apr 2025 17:50:23 +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=1745949023; cv=none; b=YrNsmTgY0/szjHSx46Pe5imthk37RfHhLuymYHOpsW1thpbZXrlwatZE1VJFw591QirOvL9fD6JBDz5mE+3vP+fVP7XlMbixrFuWK4GNZpn2dz3KgO7TDuD871epSPfFFovagjQaF3bccdVG3LcLtXP+h/j3yshcupyF6XjQK6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745949023; c=relaxed/simple; bh=bhDLgdOS2CdJOMn9B2z27ExmfkmqxnBvKxE4rz3C/OM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RtvdCjA3W55UcDsvTR9VD+3EZB3t55y3cKsqzzZEiuH93qJV+Y2GJYQVuP7rBhIbvHl/s3h2O23sj6OPboM+YTI6+VOIzByzqr0iVzwcsAm+rGJh0krs+eY4fKTsFqmMVIzovdx2IPZ5C9a7ezsnwZqumvVRL2BWwt/tZL6nU8M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HI7un3yv; 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="HI7un3yv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 386DBC4CEE3; Tue, 29 Apr 2025 17:50:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745949023; bh=bhDLgdOS2CdJOMn9B2z27ExmfkmqxnBvKxE4rz3C/OM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HI7un3yvU4lqrvI4SwFLSWoiaMPWHhL6R3FMCBsv4HT42BKvq54BuC4n4KxmtBVjG DRyM/ZhOiKptK0mf59VMaHxKC9Nw++7jKmi7EW0iMVKLxoaMO82PVnsY6X60dIn5Na ef8KMi/lhNrk8Nv9Vg5LXuXVNuIvJOhePpVD0bUY= 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 5.15 193/373] KVM: arm64: Remove host FPSIMD saving for non-protected KVM Date: Tue, 29 Apr 2025 18:41:10 +0200 Message-ID: <20250429161131.107038205@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161123.119104857@linuxfoundation.org> References: <20250429161123.119104857@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-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 | 1 - arch/arm64/kvm/hyp/include/hyp/switch.h | 6 +----- 3 files changed, 1 insertion(+), 7 deletions(-) --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -333,7 +333,6 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch external_debug_state; struct thread_info *host_thread_info; /* hyp VA */ - struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ struct { /* {Break,watch}point registers */ --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -55,7 +55,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_ } vcpu->arch.host_thread_info = kern_hyp_va(ti); - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); error: return ret; } --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -251,11 +251,7 @@ static inline bool __hyp_handle_fpsimd(s } isb(); - if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); - vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; - } - + /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); else