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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 C5701C79F82 for ; Tue, 8 Sep 2026 14:17:07 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1412099.1642594 (Exim 4.92) (envelope-from ) id 1x3wd6-00041m-IK; Tue, 08 Sep 2026 14:16:56 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1412099.1642594; Tue, 08 Sep 2026 14:16:56 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1x3wd6-00041f-Fj; Tue, 08 Sep 2026 14:16:56 +0000 Received: by outflank-mailman (input) for mailman id 1412099; Tue, 08 Sep 2026 14:16:55 +0000 Received: from mx.expurgate.net ([195.190.135.10]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1x3wd5-00040c-9Z for xen-devel@lists.xenproject.org; Tue, 08 Sep 2026 14:16:55 +0000 Received: from mx.expurgate.net (helo=localhost) by mx.expurgate.net with esmtp id 1x3wd4-00HS4H-Mb for xen-devel@lists.xenproject.org; Tue, 08 Sep 2026 16:16:54 +0200 Received: from [10.42.69.5] (helo=localhost) by localhost with ESMTP (eXpurgate MTA 0.9.1) (envelope-from ) id 6aa018cb-e002-0a2a0a5209dd-0a2a4505cc84-24 for ; Tue, 08 Sep 2026 16:16:50 +0200 Received: from [209.85.128.46] (helo=mail-wm1-f46.google.com) by tlsNG-c201ff.mxtls.expurgate.net with ESMTPS (eXpurgate 4.57.1) (envelope-from ) id 6aa018d2-4cb1-0a2a45050019-d155802eadbe-3 for ; Tue, 08 Sep 2026 16:16:50 +0200 Received: by mail-wm1-f46.google.com with SMTP id 5b1f17b1804b1-49b0dd3c9a0so45248615e9.1 for ; Tue, 08 Sep 2026 07:16:50 -0700 (PDT) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49cee7fec25sm562374895e9.13.2026.09.08.07.16.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 08 Sep 2026 07:16:49 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Authentication-Results: eu.smtp.expurgate.cloud; dkim=pass header.s=google header.d=suse.com header.i="@suse.com" header.h="Content-Transfer-Encoding:Content-Type:In-Reply-To:Autocrypt:From:Content-Language:References:Cc:To:Subject:User-Agent:MIME-Version:Date:Message-ID" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1788877010; x=1789481810; darn=lists.xenproject.org; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=vkFu4wHmCm79gU+WiRRgAh0ocsuf24N8LsJQC8PS9Ss=; b=O1C0M+3XTJXjvs6YwwePoDnJluQQKIJYxkcLvtP+P6Q7/vHmGh5gdsfn2yXMeWxEFG 2UNn0mygdWEJcqdzabS3pQu/itMLDKxs2u36S23U/UcG5r/3rc6n1RC9N+onzw5JeDD7 8QVIh0y1CfpWl91Jyb793Ug6EOjd+5t3K4ep58oFekDf3iY1pyrDbOkQMjAZEJZvdBJc dqQL1i1uyB84C6SWd0bbTmtAfc4Qo1N/2QnMhxnBRSMG1ASj5+bpSq+TwNJb4OfoIroR 4s+PYx4o9Ceobqj+CUq4a/8fJ8pC3Icy8Shmsnqeuu4EGL1RtImN40Uw90BxoCyaDmWG ZjKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788877010; x=1789481810; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=vkFu4wHmCm79gU+WiRRgAh0ocsuf24N8LsJQC8PS9Ss=; b=f3tA/eusPjDD8mEw5QUjhRVAWRBo1uRK4TVawyYQh2YlFnzgkkiy1ZPsngLmn0ED+j 3kq3v5oZ6Abl7UwX9q1PNHfbEYya1OS9EV1ApiLlqxDfhwiSwUd59W7SgBJLT9WswR/1 YOm4ee4riT3Tzd8EWsCrhQ3+0Pyy7ImVM+PfRwu0HTQNXV5Spz40c//Vea/5FvjVklWL /WAPTJEwrmMZwOHHV4aLhbL0BNZ+ee1j2yxS0H6F7MDLOSAT6obzQPzCIE1GbCpueLcS TwICrwcKAlTE5HXUOh4SUhud6Ewu8CDGQLMw6egqWcsXSdDHEdo/GhwiYBAGzMPR/69v 00yw== X-Forwarded-Encrypted: i=1; AKwUvBwE+ceDG4ANudjO3yQ1mLFztEmF1mdZ7BP6f1qC/vNK1IGbbGyKW1AeV2Uc/9gvzIEgkO2jjj1B3ko=@lists.xenproject.org X-Gm-Message-State: AFuF++nfzETZJhM0DFcLQEBbUAD13O9EoXun5s0/Mqvqzz9eeDpV302n TDr+WTyWwhaj/JWLFHct+tYtYvqRAFzTVaj6B+62amAr7FBKkKcTeRCctUtgp7j4Kw== X-Gm-Gg: AYBFou2Nubok2JQ/x2rIKm2JYJ3YWAtoFzFeW+0u+c52GGpaXa1mSrR84H6wPvAo6PO Acqbr/dPAxh8AYy754bnQXg4CFCxaBX6adstflTlzxfk15ZRVKfCCCT3USIaVSZGu4Ekqb5oftl CIpWzAxVWy+9ClbLJR40kMFm15eGHPew4CecflfqgkmYaiUpPLkpycvDv2Yu+qo+Fm+xvyPDp6C Lp2tk2kpxa5yDP+uODG8bmrLzmb2emtUzmR7VOjcXbCZAZrfYh2YI8p2PNSvstrzXjRgJqkq9We +IDCSOkUUNoDZoHOvjAY1me7UQ+lr3xq0UG6ZJOXaBFJ1GiJNNuB4O45oDwXMD50r05nuLoNg/j I0fyLpjM6jIGMkegzn3JtVKFklo69MkffzCYa9xcnvUQJ2a55ldDmTYw8NtK17bAXmVJj1mX9fL rNG+iROecaWBG9BSaqQIr/ISa4INnDCeVvyePAjwHSIZoXUwFbgsPbJUDN8/7f0Ke5e6tGMseVZ bwuVdJN5y2N5ssGS/ZBCcBXa+eQ6adocRVYyigrmyGpj9wh X-Received: by 2002:a05:600c:3496:b0:49d:1deb:a629 with SMTP id 5b1f17b1804b1-49d1deba75cmr49158825e9.2.1788877009658; Tue, 08 Sep 2026 07:16:49 -0700 (PDT) Message-ID: Date: Tue, 8 Sep 2026 16:16:47 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 19/39] xen/riscv: implement trap redirection to a guest To: Oleksii Kurochko Cc: Romain Caritey , Baptiste Le Duc , Zheng Zhang , Alistair Francis , Connor Davis , Andrew Cooper , Anthony PERARD , Michal Orzel , Julien Grall , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Stefano Stabellini , xen-devel@lists.xenproject.org References: <583b0a190bad7121eae9bc99bd1e13dc1743efe4.1787838835.git.oleksii.kurochko@gmail.com> Content-Language: en-US From: Jan Beulich Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <583b0a190bad7121eae9bc99bd1e13dc1743efe4.1787838835.git.oleksii.kurochko@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-purgate-ID: tlsNG-c201ff/1788877010-F66B52A1-0899C172/0/0 X-purgate-type: clean X-purgate-size: 2882 On 27.08.2026 17:21, Oleksii Kurochko wrote: > --- a/xen/arch/riscv/include/asm/riscv_encoding.h > +++ b/xen/arch/riscv/include/asm/riscv_encoding.h > @@ -109,6 +109,12 @@ > #define SIP_SSIP MIP_SSIP > #define SIP_STIP MIP_STIP > > +/* stvec/vstvec: MODE is bits [1:0], BASE is bits [XLEN-1:2] */ > +#define STVEC_MODE_MASK _UL(0x3) > +#define STVEC_MODE_DIRECT _UL(0x0) > +#define STVEC_MODE_VECTORED _UL(0x1) As on earlier occasions: Do the 0x here actually add any value? There are none ... > +#define STVEC_BASE_MASK (~STVEC_MODE_MASK) > + > #define PRV_U _UL(0) > #define PRV_S _UL(1) > #define PRV_M _UL(3) ... here, for example. > --- a/xen/arch/riscv/traps.c > +++ b/xen/arch/riscv/traps.c > @@ -294,5 +294,53 @@ enum mc_disposition arch_do_multicall_call(struct mc_state *state) > /* Redirect trap to Guest. */ > void trap_redirect(const struct trap_info *trap) > { > - BUG_ON("unimplemented"); > + struct cpu_user_regs *regs = vcpu_guest_cpu_user_regs(current); > + unsigned long vsstatus = csr_read(CSR_VSSTATUS); > + > + /* > + * Redirecting a trap makes sense only if the trap was taken from > + * virtualized mode, i.e. sret is going to return to VS-mode. > + */ > + ASSERT(regs->hstatus & HSTATUS_SPV); > + > + /* > + * Only synchronous exceptions can be redirected. Interrupts must be > + * injected via hvip instead, so that the hardware itself performs > + * VS-mode trap entry, respecting vsstatus.SIE and the vectored > + * dispatch (BASE + 4 * cause) if vstvec is configured so. > + */ > + ASSERT(!(trap->scause & CAUSE_IRQ_FLAG)); > + > + /* Change Guest SSTATUS.SPP bit */ > + vsstatus &= ~SSTATUS_SPP; > + if ( regs->sstatus & SSTATUS_SPP ) > + vsstatus |= SSTATUS_SPP; > + > + /* Change Guest SSTATUS.SPIE bit */ > + vsstatus &= ~SSTATUS_SPIE; > + if ( vsstatus & SSTATUS_SIE ) > + vsstatus |= SSTATUS_SPIE; > + > + /* Clear Guest SSTATUS.SIE bit */ > + vsstatus &= ~SSTATUS_SIE; > + > + /* Update Guest SSTATUS */ > + csr_write(CSR_VSSTATUS, vsstatus); > + > + /* Update Guest SCAUSE, STVAL, and SEPC */ > + csr_write(CSR_VSCAUSE, trap->scause); > + csr_write(CSR_VSTVAL, trap->stval); > + csr_write(CSR_VSEPC, trap->sepc); > + > + /* > + * Set Guest PC to Guest exception vector. > + * > + * vstvec's MODE field is not part of the address. Exceptions always > + * target BASE regardless of MODE, so mask it off explicitly instead of > + * relying on the hardwired zero bit of sepc to drop it. > + */ > + regs->sepc = csr_read(CSR_VSTVEC) & STVEC_BASE_MASK; Nit: Given how much the comment talks about MODE, imo using ~STVEC_MODE_MASK here directly (and dropping STVEC_BASE_MASK) might be better. Jan