From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 110D1C282EC for ; Thu, 13 Mar 2025 17:14:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:In-Reply-To:Date:From:Cc:To:Subject: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:References:List-Owner; bh=BD4C2CooRIuuXtnQa3rBKr3sNDaXuUBNEr/qKJGr5pc=; b=GiQSBprB+gFeJbI8me6/Ljt77b iVi12cnzx4tQbzf44JybjHlQae5++Gtyh6StdCebPQZy+8ImVgASF0ThYCnpM7ueg2lqu2Jbccnbx 8fKqHi8GBqs3NMZYbqy4f28HIq9R/8VpOQbPXhzYj2tIopj4kgLgh9JLNoYmL2iNRBpM5Vv1ud67i 1NZ//0PPD03whCYcRqgKVELz1mO1OSLUUMJbQxZz6be5Yi8j+qpYYrjn8sCB/Ov8pRCFXOYdD4a5L WVqNBLEd9BQ9Nouadn8Mw3VTHV6OKJo3/0e7wn7WGQ1wGVd6jxyefl3SoDL+dAW1+qPH6GafwkWht Hs0nzVeQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tsm8R-0000000Bwfu-2YJb; Thu, 13 Mar 2025 17:14:19 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tsl80-0000000BlWi-3rUp for linux-arm-kernel@lists.infradead.org; Thu, 13 Mar 2025 16:09:50 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 45087A476C1; Thu, 13 Mar 2025 16:04:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C5F1C4CEDD; Thu, 13 Mar 2025 16:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741882187; bh=iLEcM7CRsEhgH3AoVf5axNTbLRjxupxjKJH4QnQmn/s=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=Cr27gCADSZQRyVbCE8hq0rnOnlpI75kvciln5zPLPlpzFmHtYbtnpQiMHYRAmXW8h C+Kl7RSOiqqZNpmlLtmTqg4RJP4Rfk+P8ddpXyZIwvemx5msckc5002289Youi+nee mKT+W8Olo2TLsoEfdYnGL9CnvBpanSzZEQeEGdx4= Subject: Patch "KVM: arm64: Remove host FPSIMD saving for non-protected KVM" has been added to the 6.13-stable tree To: broonie@kernel.org,catalin.marinas@arm.com,gregkh@linuxfoundation.org,joey.gouly@arm.com,kvmarm@lists.linux.dev,linux-arm-kernel@lists.infradead.org,mark.rutland@arm.com,maz@kernel.org,oliver.upton@linux.dev,suzuki.poulose@arm.com,tabba@google.com,will@kernel.org Cc: From: Date: Thu, 13 Mar 2025 17:09:29 +0100 In-Reply-To: <20250312-stable-sve-6-13-v1-3-c7ba07a6f4f7@kernel.org> Message-ID: <2025031329-mullets-shining-4736@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250313_090949_096317_1BCF06E9 X-CRM114-Status: GOOD ( 28.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This is a note to let you know that I've just added the patch titled KVM: arm64: Remove host FPSIMD saving for non-protected KVM to the 6.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-arm64-remove-host-fpsimd-saving-for-non-protected-kvm.patch and it can be found in the queue-6.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From stable+bounces-124194-greg=kroah.com@vger.kernel.org Thu Mar 13 00:50:09 2025 From: Mark Brown Date: Wed, 12 Mar 2025 23:49:11 +0000 Subject: KVM: arm64: Remove host FPSIMD saving for non-protected KVM To: Greg Kroah-Hartman , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Catalin Marinas , Will Deacon Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Mark Brown , Mark Rutland , Fuad Tabba Message-ID: <20250312-stable-sve-6-13-v1-3-c7ba07a6f4f7@kernel.org> 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 [CPACR_EL1_ZEN -> CPACR_ELx_ZEN -- broonie] Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/kvm_host.h | 18 ++++-------------- arch/arm64/kvm/arm.c | 8 -------- arch/arm64/kvm/fpsimd.c | 2 -- arch/arm64/kvm/hyp/include/hyp/switch.h | 25 +++++++++++++++++++++++-- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 2 +- arch/arm64/kvm/hyp/nvhe/switch.c | 28 ---------------------------- arch/arm64/kvm/hyp/vhe/switch.c | 8 -------- 7 files changed, 28 insertions(+), 63 deletions(-) --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -613,23 +613,13 @@ struct kvm_host_data { struct kvm_cpu_context host_ctxt; /* - * All pointers in this union are hyp VA. + * Hyp VA. * sve_state is only used in pKVM and if system_supports_sve(). */ - union { - struct user_fpsimd_state *fpsimd_state; - struct cpu_sve_state *sve_state; - }; + struct cpu_sve_state *sve_state; - union { - /* HYP VA pointer to the host storage for FPMR */ - u64 *fpmr_ptr; - /* - * Used by pKVM only, as it needs to provide storage - * for the host - */ - u64 fpmr; - }; + /* Used by pKVM only. */ + u64 fpmr; /* Ownership of the FP regs */ enum { --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2468,14 +2468,6 @@ static void finalize_init_hyp_mode(void) per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->sve_state = kern_hyp_va(sve_state); } - } else { - for_each_possible_cpu(cpu) { - struct user_fpsimd_state *fpsimd_state; - - fpsimd_state = &per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->host_ctxt.fp_regs; - per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->fpsimd_state = - kern_hyp_va(fpsimd_state); - } } } --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -64,8 +64,6 @@ void kvm_arch_vcpu_load_fp(struct kvm_vc */ fpsimd_save_and_flush_cpu_state(); *host_data_ptr(fp_owner) = FP_STATE_FREE; - *host_data_ptr(fpsimd_state) = NULL; - *host_data_ptr(fpmr_ptr) = NULL; vcpu_clear_flag(vcpu, HOST_SVE_ENABLED); if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -375,7 +375,28 @@ static inline void __hyp_sve_save_host(v true); } -static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu); +static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu) +{ + /* + * Non-protected kvm relies on the host restoring its sve state. + * Protected kvm restores the host's sve state as not to reveal that + * fpsimd was used by a guest nor leak upper sve bits. + */ + if (system_supports_sve()) { + __hyp_sve_save_host(); + + /* Re-enable SVE traps if not supported for the guest vcpu. */ + if (!vcpu_has_sve(vcpu)) + cpacr_clear_set(CPACR_ELx_ZEN, 0); + + } else { + __fpsimd_save_state(host_data_ptr(host_ctxt.fp_regs)); + } + + if (kvm_has_fpmr(kern_hyp_va(vcpu->kvm))) + *host_data_ptr(fpmr) = read_sysreg_s(SYS_FPMR); +} + /* * We trap the first access to the FP/SIMD to save the host context and @@ -425,7 +446,7 @@ static bool kvm_hyp_handle_fpsimd(struct isb(); /* Write out the host state if it's in the registers */ - if (host_owns_fp_regs()) + if (is_protected_kvm_enabled() && host_owns_fp_regs()) kvm_hyp_save_fpsimd_host(vcpu); /* Restore the guest state */ --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -83,7 +83,7 @@ static void fpsimd_sve_sync(struct kvm_v if (system_supports_sve()) __hyp_sve_restore_host(); else - __fpsimd_restore_state(*host_data_ptr(fpsimd_state)); + __fpsimd_restore_state(host_data_ptr(host_ctxt.fp_regs)); if (has_fpmr) write_sysreg_s(*host_data_ptr(fpmr), SYS_FPMR); --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -193,34 +193,6 @@ static bool kvm_handle_pvm_sys64(struct kvm_handle_pvm_sysreg(vcpu, exit_code)); } -static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu) -{ - /* - * Non-protected kvm relies on the host restoring its sve state. - * Protected kvm restores the host's sve state as not to reveal that - * fpsimd was used by a guest nor leak upper sve bits. - */ - if (unlikely(is_protected_kvm_enabled() && system_supports_sve())) { - __hyp_sve_save_host(); - - /* Re-enable SVE traps if not supported for the guest vcpu. */ - if (!vcpu_has_sve(vcpu)) - cpacr_clear_set(CPACR_ELx_ZEN, 0); - - } else { - __fpsimd_save_state(*host_data_ptr(fpsimd_state)); - } - - if (kvm_has_fpmr(kern_hyp_va(vcpu->kvm))) { - u64 val = read_sysreg_s(SYS_FPMR); - - if (unlikely(is_protected_kvm_enabled())) - *host_data_ptr(fpmr) = val; - else - **host_data_ptr(fpmr_ptr) = val; - } -} - static const exit_handler_fn hyp_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] = NULL, [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -309,14 +309,6 @@ static bool kvm_hyp_handle_eret(struct k return true; } -static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu) -{ - __fpsimd_save_state(*host_data_ptr(fpsimd_state)); - - if (kvm_has_fpmr(vcpu->kvm)) - **host_data_ptr(fpmr_ptr) = read_sysreg_s(SYS_FPMR); -} - static bool kvm_hyp_handle_tlbi_el2(struct kvm_vcpu *vcpu, u64 *exit_code) { int ret = -EINVAL; Patches currently in stable-queue which might be from broonie@kernel.org are queue-6.13/kvm-arm64-remove-host-fpsimd-saving-for-non-protected-kvm.patch queue-6.13/kvm-arm64-mark-some-header-functions-as-inline.patch queue-6.13/kvm-arm64-eagerly-switch-zcr_el-1-2.patch queue-6.13/kvm-arm64-unconditionally-save-flush-host-fpsimd-sve-sme-state.patch queue-6.13/kvm-arm64-refactor-exit-handlers.patch queue-6.13/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.zen.patch queue-6.13/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.smen.patch queue-6.13/kvm-arm64-calculate-cptr_el2-traps-on-activating-traps.patch