From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BBF747F4A for ; Fri, 23 May 2025 18:39:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748025547; cv=none; b=BeC3tCDYm10IGTamvGlAJKDsc9C2jtnlKXN28afzVsFpOXVyK0WbUyPbkW5eA1P5LVXfcX3yOC5U0ly2YmCyFrNDbXAnKZkSG79Ouo2FNxFy+RAYbewN6xx3+Dx1dbU8HdfBQOAnW4uXkikdROQ0kUEFd7CDRCbqAI63vehEGgQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748025547; c=relaxed/simple; bh=sm7CqC4WkQU8Rs7RoFNINgIkwM4zl0GJTRDwvhiASto=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pIM6UCBehGG2km66WqtDsl3H8jtJsrXR00+Zpze+gxJuyurnPXrKUl+425X9IiZIhnFq+SGbc/niSgkStuxgrizgwA1qAjVb8Aii3zZzqnW5lGl78lEjJrrvlAJQ+eIimGGTUWiSDBYFAkx9lMnMKGfPnRal5ntFOgtCfjXtilQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com; spf=pass smtp.mailfrom=rivosinc.com; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b=wyGRVvgO; arc=none smtp.client-ip=209.85.214.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="wyGRVvgO" Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-2341814895bso369835ad.0 for ; Fri, 23 May 2025 11:39:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1748025545; x=1748630345; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=Brp4+tqBANTAovFCP7pOokKjsZ8jKRtxHJAFYCZnyiw=; b=wyGRVvgOlImg/zqqQf0ymijykUY1lSQijEsrkZ1TH5I+UUvFWjlMFStdUg0l51pfae bs9CyS5TLewmUF/FqSTDb3yVtDjXW5zE6Hxhs7zePnjOT1XBzmFLgSUkDeT9m8tQ0ZdG T0o1qRoUMyVDqhY1MquqC36G+eAqJaTP2w4Cs8UxJyWmdd3nFZRfmDZu7p7jvCSqj42W i4LoD8rBSrvb/DEuGVvTpBHiYOP3FIEQB/7aXrPcDHjRyH/MEsKcVAqdAKvk6G09XDiu u1HWeZXpKukOfJZXdv3BGOkiXpTowegB7Yql28IAsx/kgFpb+Sk1+aUGFq1a9PaXDUu8 YG0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748025545; x=1748630345; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Brp4+tqBANTAovFCP7pOokKjsZ8jKRtxHJAFYCZnyiw=; b=TAUJsVbkzlBQTxx6WuXUX2iltRXZRZu0V40/duoAP+5B8MyOZx/CJSqirkryX/zrMJ yZQSNKxMHWYnQy2upvT6IbnWUuhfOaC4gvr+9Kg8U44fGXMfkmNJtXcQQS1bpZgXIw9W NYMSuUGOu7YNiHHlydTvS1xkVwFKQMmiU+ym4wn10H5vTqS1l8EiGWczQQFq0L2K8zxD 2no7m9LG6JABFmnDyUIlBAb0THeZSXXBwJTs+ahm34s6d/6ybxdRfUUv6o2olR4TTPaT +g/PAJZJkJt5zYkEkthIlj4tZAfHrY1sYBb3xZ9NITgfijvmCoaWvi6PEg3ZO8xgEeRK w84A== X-Forwarded-Encrypted: i=1; AJvYcCXY3l/qDa8yJTqe3iaL1xqf8FObxEvH91A5Kic+AIdR8YWULkTLAF3aeMo8CaJdmUX8alQ=@vger.kernel.org X-Gm-Message-State: AOJu0YzE22rEV2QhiZ1zrA2792//fByRX6xyT6qap+9GUIzhdVy/2lK0 +BEOA8w/DGEVE+v+w0sx9VB0pmyK8I4mo8q6VQyWNBG3eg1GNQBA3yL8kLSw3W1NzfU= X-Gm-Gg: ASbGncsUmZKd1PRHvB6qBytWq6BjcpMhytp+0qCg+FFtp4MWXsmVFuERbjTkl+5Vw3z yGgcPjq5KnrAcxT/MlA6EXFiHXqqIDXG2AlrdVmVFEBacwGE8MvtH5urAzxl9imthvIOT/RegnK ErkLTDuBgRwt6uwsdIJ867DDnZNnizeWGVrsIyKI3yaYDmfYTkPlKlgA9mPgoFIe1qJkYWxCbFF EO2V5m2PffgO/2+uI0TIyQRT06liryVnh6pfTD4Os/JaD/35/u46IBT2eXFFJFMWdbQ0eUVVmkl v/L5ojmOslXjvZBpBaDqIvtUVtetf121MDxcARhEceRCDOw= X-Google-Smtp-Source: AGHT+IF/W7rgN2cGONT1rL6VsHTy6gKpmlK8jFDydK2LaE8qLgbyfqjrk3Jd1cMhblWh+YfsU/FBoQ== X-Received: by 2002:a17:903:b8d:b0:224:93e:b5d7 with SMTP id d9443c01a7336-23414fb2593mr7004755ad.34.1748025544999; Fri, 23 May 2025 11:39:04 -0700 (PDT) Received: from ghost ([2601:647:6700:64d0:bb2c:c7d9:9014:13ab]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-231d4ed2508sm127432885ad.221.2025.05.23.11.39.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 May 2025 11:39:04 -0700 (PDT) Date: Fri, 23 May 2025 11:39:02 -0700 From: Charlie Jenkins To: =?iso-8859-1?Q?Cl=E9ment_L=E9ger?= Cc: Paul Walmsley , Palmer Dabbelt , Anup Patel , Atish Patra , Shuah Khan , Jonathan Corbet , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-kselftest@vger.kernel.org, Samuel Holland , Andrew Jones , Deepak Gupta Subject: Re: [PATCH v8 10/14] riscv: misaligned: add a function to check misalign trap delegability Message-ID: References: <20250523101932.1594077-1-cleger@rivosinc.com> <20250523101932.1594077-11-cleger@rivosinc.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250523101932.1594077-11-cleger@rivosinc.com> On Fri, May 23, 2025 at 12:19:27PM +0200, Clément Léger wrote: > Checking for the delegability of the misaligned access trap is needed > for the KVM FWFT extension implementation. Add a function to get the > delegability of the misaligned trap exception. > > Signed-off-by: Clément Léger > Reviewed-by: Andrew Jones Reviewed-by: Charlie Jenkins Tested-by: Charlie Jenkins > --- > arch/riscv/include/asm/cpufeature.h | 6 ++++++ > arch/riscv/kernel/traps_misaligned.c | 17 +++++++++++++++-- > 2 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h > index 2bfa4ef383ed..fbd0e4306c93 100644 > --- a/arch/riscv/include/asm/cpufeature.h > +++ b/arch/riscv/include/asm/cpufeature.h > @@ -81,6 +81,12 @@ static inline bool unaligned_ctl_available(void) > > #if defined(CONFIG_RISCV_MISALIGNED) > DECLARE_PER_CPU(long, misaligned_access_speed); > +bool misaligned_traps_can_delegate(void); > +#else > +static inline bool misaligned_traps_can_delegate(void) > +{ > + return false; > +} > #endif > > bool __init check_vector_unaligned_access_emulated_all_cpus(void); > diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c > index 7ecaa8103fe7..93043924fe6c 100644 > --- a/arch/riscv/kernel/traps_misaligned.c > +++ b/arch/riscv/kernel/traps_misaligned.c > @@ -724,10 +724,10 @@ static int cpu_online_check_unaligned_access_emulated(unsigned int cpu) > } > #endif > > -#ifdef CONFIG_RISCV_SBI > - > static bool misaligned_traps_delegated; > > +#ifdef CONFIG_RISCV_SBI > + > static int cpu_online_sbi_unaligned_setup(unsigned int cpu) > { > if (sbi_fwft_set(SBI_FWFT_MISALIGNED_EXC_DELEG, 1, 0) && > @@ -763,6 +763,7 @@ static int cpu_online_sbi_unaligned_setup(unsigned int cpu __always_unused) > { > return 0; > } > + > #endif > > int cpu_online_unaligned_access_init(unsigned int cpu) > @@ -775,3 +776,15 @@ int cpu_online_unaligned_access_init(unsigned int cpu) > > return cpu_online_check_unaligned_access_emulated(cpu); > } > + > +bool misaligned_traps_can_delegate(void) > +{ > + /* > + * Either we successfully requested misaligned traps delegation for all > + * CPUs, or the SBI does not implement the FWFT extension but delegated > + * the exception by default. > + */ > + return misaligned_traps_delegated || > + all_cpus_unaligned_scalar_access_emulated(); > +} > +EXPORT_SYMBOL_GPL(misaligned_traps_can_delegate); > -- > 2.49.0 >