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[90.112.199.53]) by smtp.gmail.com with ESMTPSA id h3-20020adfe983000000b002bdf5832843sm21709112wrm.66.2023.01.23.07.04.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Jan 2023 07:04:20 -0800 (PST) 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" X-Inumbo-ID: 370f2c96-9b2f-11ed-91b6-6bf2151ebd3b DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:from:to:cc:subject :date:message-id:reply-to; bh=5Pe9H5M8lgqXN3yOFU7hWFYm28+tQNyxLI4UL9a/OLk=; b=ljCAeerSdzkiVajYOigDrT9dAlZCW1oVKmAu6HCCsvgCs04V0gwIVMVv2FU3py+MN6 sHau14/RWViTuE/hmz4Ji+c9rnnCccbAVycTnQpuLPCAGtY56UkRymXrdhNDTQ2QwtwY 7+xUjZhw7EWdi50mIJOvuapnCR9wZFtz+XzIs2Hnt9XaAdc4XsGfoVJ7LCPyuMlaJRaC zzafuhd9WJqvMWVUyKQSa+FylKOkMvILTUUO2bv1vRNkY++xgZw/ti9EEMOL07Pj36tA UtPNMPpnJhN6Q8h9Iv/Sw/11MNXCdvsgnBgbh7MkRcCRh/ecRcnjdXA/BvExD+PfOd20 bhHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=5Pe9H5M8lgqXN3yOFU7hWFYm28+tQNyxLI4UL9a/OLk=; b=ULlmbcm6hwGuWTufdoUQlnHYvAXOW8S0IiKMZFHTUT8UsufTx02TEgMFfMS7KGcmLy V/avaKMa5UQxOYl0tTMtlZLDzycRR044sAeqLQhp5bq+NPSH6QDksixEqtEkDMmUDlo2 yKwC4U9ZhSjEr/gimZ+nMk4YxUWZoCmN5RXs1xX9qv1UbMDx7Le0s+zF76+kJQN8h9Lw WRytQsMYN1cggAj1fajqYDwQSoQM8mRdC6/wFL3Wht+2OlZiyoOd478JiQZwYAjFET7X fuXcRIsIfTwBRslxbZ8eyzQqpcDM+UI+AyCvucyIgLarTCmQr64sVCCLAKZoRTCvXa8f nuEw== X-Gm-Message-State: AFqh2kqcmNgzKsrsuukn1XWoscjpFzE8RSWnFkFE188HaNrW4w7z2Eiv aL1WkUGCXHe+oWIfMxzJ+JM= X-Google-Smtp-Source: AMrXdXvdFEzRAEQiD7p9XHBsMlv7mTHqksXzITyIfe+eZ+1xWy+C73rR8qtrPgLOwzW1mLCvAm/Ttg== X-Received: by 2002:a5d:4c4e:0:b0:2bb:4b40:2d1a with SMTP id n14-20020a5d4c4e000000b002bb4b402d1amr22476897wrt.56.1674486260385; Mon, 23 Jan 2023 07:04:20 -0800 (PST) Message-ID: <61603a7c4ba09012fedbad48b3d7d028ffc9443c.camel@gmail.com> Subject: Re: [PATCH v1 07/14] xen/riscv: introduce exception handlers implementation From: Oleksii To: Jan Beulich Cc: Andrew Cooper , Stefano Stabellini , Gianluca Guida , Bob Eshleman , Alistair Francis , Connor Davis , xen-devel@lists.xenproject.org Date: Mon, 23 Jan 2023 17:04:19 +0200 In-Reply-To: References: <7a459ea843d5823ee2c50b0e44dded5bdb554ca6.1674226563.git.oleksii.kurochko@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.3 (3.46.3-1.fc37) MIME-Version: 1.0 On Mon, 2023-01-23 at 12:17 +0100, Jan Beulich wrote: > On 20.01.2023 15:59, Oleksii Kurochko wrote: > > --- /dev/null > > +++ b/xen/arch/riscv/entry.S > > @@ -0,0 +1,97 @@ > > +#include > > +#include > > +#include > > +#include > > + > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 .global handle_exception > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 .align 4 > > + > > +handle_exception: > > + > > +=C2=A0=C2=A0=C2=A0 /* Exceptions from xen */ > > +save_to_stack: > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* Save context to stack */ > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 REG_S=C2=A0=C2=A0 sp, (RISC= V_CPU_USER_REGS_OFFSET(sp) - > > RISCV_CPU_USER_REGS_SIZE) (sp) > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 addi=C2=A0=C2=A0=C2=A0 sp, = sp, -RISCV_CPU_USER_REGS_SIZE > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 REG_S=C2=A0=C2=A0 t0, RISCV= _CPU_USER_REGS_OFFSET(t0)(sp) > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 j=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0 save_context > > + > > +save_context: >=20 > Just curious: Why not simply fall through here, i.e. why the J which > really > is a NOP in this case? >=20 There is no any specific reason. I left it for future. Will remove it in the next patch version. > Jan