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 BCBCA224B1C for ; Fri, 21 Mar 2025 17:29:08 +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=1742578148; cv=none; b=E+JNGQM1gYaUHo+I0RWstkukvo1MYLBVaWMVBDU9Z9WtnxRY0vOWukYxs6Q4Yezhb9qqXep3/17qTdTcWbtgxnnk9lr1jHlqjCazkvOvbm0jRNigt38+v6BfZzSBDROmk4KDiAOxH9gX11bfEot+LVeYymdmT3jg1IwODB0uo5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742578148; c=relaxed/simple; bh=llkXDMjV7n1YOetlq+MNIbK4HQtu8VJyaIJ/GtBPVQE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=X9GPZuSXcmaUvrkjUKC0v2osVY+u0xsgMB9c35fvpowOW/0/6fK/nhbNExMiZCSAc+7Npz26i+3Ru6NQxq2SaUT59NXgk06Vy93tZX4fNQKa7+n6o+GaEQGl/XRngCpUrZE0WAMDFyz+GBZejYFxrLpHtA/yWTOCtxkPwyl3b8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bRoLxTDg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bRoLxTDg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE880C4CEE3; Fri, 21 Mar 2025 17:29:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742578148; bh=llkXDMjV7n1YOetlq+MNIbK4HQtu8VJyaIJ/GtBPVQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bRoLxTDguwTXI4ovh1cR032juCc75iF3DNIac53S+lEEtb6VE9m1FLQ419l5KC5Y7 vrxq3ja1ngXMv97Cl/qXeHjrKGHSYCkOsBNs9ocbsCg+4XG+/rytNb+dAyFwE/PJ6i KoGou7UneBbzEhG32sPh4W2Mvtu5CYSHsS2IMOH68+RPgt5XB5l9z9AMmLJwF277Ob oe9+osXxnFBh34RVWLqRMIv8Qpx6z9MEA7LbdmX7AAan0XutzypQQKaFfX8aPrh/Jk aScinW5eO+uSzfY6h/6XgVvsYdFOhuisGCdMcweAic3fBOywg430dQVDpEjFNWuRp7 BoXhLw//+mXCw== From: Sasha Levin To: stable@vger.kernel.org Cc: Mark Brown , Sasha Levin Subject: Re: [PATCH 6.6 2/8] KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state Date: Fri, 21 Mar 2025 13:28:56 -0400 Message-Id: <20250321114948-06a3584c009ef0d1@stable.kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250321-stable-sve-6-6-v1-2-0b3a6a14ea53@kernel.org> References: Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Sasha's backport helper bot ] Hi, ✅ All tests passed successfully. No issues detected. No action required from the submitter. The upstream commit SHA1 provided is correct: fbc7e61195e23f744814e78524b73b59faa54ab4 WARNING: Author mismatch between patch and upstream commit: Backport author: Mark Brown Commit author: Mark Rutland Status in newer kernel trees: 6.13.y | Present (different SHA1: 8361da508047) 6.12.y | Present (different SHA1: 6942e1f47a00) Note: The patch differs from the upstream commit: --- 1: fbc7e61195e23 ! 1: 2d0c224eda446 KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state @@ Metadata ## Commit message ## KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state + [ Upstream commit fbc7e61195e23f744814e78524b73b59faa54ab4 ] + There are several problems with the way hyp code lazily saves the host's FPSIMD/SVE state, including: @@ Commit message Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20250210195226.1215254-2-mark.rutland@arm.com Signed-off-by: Marc Zyngier + [ Mark: Handle vcpu/host flag conflict ] + Signed-off-by: Mark Rutland + Signed-off-by: Mark Brown ## arch/arm64/kernel/fpsimd.c ## @@ arch/arm64/kernel/fpsimd.c: void fpsimd_signal_preserve_current_state(void) @@ arch/arm64/kvm/fpsimd.c: void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) + * When the host may use SME, fpsimd_save_and_flush_cpu_state() ensures + * that PSTATE.{SM,ZA} == {0,0}. */ -- *host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED; -- *host_data_ptr(fpsimd_state) = kern_hyp_va(¤t->thread.uw.fpsimd_state); -- *host_data_ptr(fpmr_ptr) = kern_hyp_va(¤t->thread.uw.fpmr); +- vcpu->arch.fp_state = FP_STATE_HOST_OWNED; + 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->arch.fp_state = FP_STATE_FREE; - host_data_clear_flag(HOST_SVE_ENABLED); + vcpu_clear_flag(vcpu, HOST_SVE_ENABLED); if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) @@ arch/arm64/kvm/fpsimd.c: void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) - host_data_clear_flag(HOST_SME_ENABLED); + vcpu_clear_flag(vcpu, HOST_SME_ENABLED); if (read_sysreg(cpacr_el1) & CPACR_EL1_SMEN_EL0EN) - host_data_set_flag(HOST_SME_ENABLED); + vcpu_set_flag(vcpu, HOST_SME_ENABLED); - - /* - * If PSTATE.SM is enabled then save any pending FP @@ arch/arm64/kvm/fpsimd.c: void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) - * been saved, this is very unlikely to happen. - */ - if (read_sysreg_s(SYS_SVCR) & (SVCR_SM_MASK | SVCR_ZA_MASK)) { -- *host_data_ptr(fp_owner) = FP_STATE_FREE; +- vcpu->arch.fp_state = FP_STATE_FREE; - fpsimd_save_and_flush_cpu_state(); - } } + } - /* --- Results of testing on various branches: | Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-6.12.y | Success | Success |