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[5.69.147.124]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-438bd4d29cesm138447475e9.35.2025.01.27.07.42.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 27 Jan 2025 07:42:13 -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: 47a5f12b-dcc5-11ef-a0e6-8be0dac302b0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloud.com; s=cloud; t=1737992533; x=1738597333; darn=lists.xenproject.org; h=in-reply-to:references:subject:cc:to:from:message-id:date :content-transfer-encoding:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=gSkl1wl1YC4U0b4FAYXFX54TDNI/uy0DhxmaQ2DSBNk=; b=i7yyZsY7ARrukaenQejy4E3e3NTIYjh4bfgbNYJvmfvY60qSF2UnHc+D04xpc8gLN5 wTh96pRqpJwLvCH0YEAaeHLxztSWqXg5jFH578RwSXLubQUIxbi+B/euwECqj7S1WJBL LkZMutF18tPvh0M3LcF+L6OBhTClv3nhHoQRQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737992533; x=1738597333; h=in-reply-to:references:subject:cc:to:from:message-id:date :content-transfer-encoding:mime-version:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=gSkl1wl1YC4U0b4FAYXFX54TDNI/uy0DhxmaQ2DSBNk=; b=PHTO+N4pIrnJbVDWqniT/a4egoFdSlaqXL8hu60naIlj2KJ9fpF5muEp4GuRnMqUhN 40tPDExSLOZ6oZmPVXcm0Q796nElyGIhJ3VN4hKFSfEqIulPNGPyF1I34seG34QQ1/M3 aWooKgTrI3w07Aiz9YFP5EXXBG3qOaEFayvyOODQOjMYPMNL27sKs9g3KDo2wExpoNPw GO0OBo0OSJcNANTKGoUGiLscYyW64EIO5IkQ4SZ+ePMogMrfJeh/WEOkPIh0sZ/KCl11 DYwKhuTXMqVqyJnKEfJWGdsMDCwLsZP4/4TUynFPcHRwhlcIcCc8RzcsMxiaTNYXBMdH MDVg== X-Forwarded-Encrypted: i=1; AJvYcCWxXSbvqYa3xNjKo2X1Pik51vfNx/b/eUvxZEnxTmwDBhRlKrsSafAHuOenSAVCHV2P79S12fwA/UM=@lists.xenproject.org X-Gm-Message-State: AOJu0YzjZUmt9Ta7C9S9sALWBCatSju2JdBr+viG3lrs968otmHmuZvo UKMnmXsULQ1wDFt+wfWQedwhtcqWxc1THETITswG86+6jCKr3yNLl5H9BnOjGDc= X-Gm-Gg: ASbGnctCMmxAYnu6RMxbOy1h6lSTBV158Lfcacub1ni4/53fywwzCi0utXeieJX5DP7 sHHU3CHthdnOmfWa2GSV31l/DuDPX6QnQhSwAkelqmpqdifusCsiRI5qPqVFNoCttW940eK+mhG g14Zu0POrbCmA7VIUG/lOagqureVS9CqiBeGk2zwYaCj2xEK8VhcioaODF/GW87D7x38EI9vO54 vvlfkrWt3rHWD/PE3cavGkAP2UHwSoEpl+t+zJATlOxyXsmOD0lgE1cenLAq+oARAjiVIUsFzhi HbbzA0J+3T40uedSlXR6V1ayhvTQsNjBQEE= X-Google-Smtp-Source: AGHT+IHNLljYHE20Xfl5207+xztZS+SWYcBTVHHouHQ63+TB8V9W/RCROcw8vYT56EwbfQ0UvW+PPA== X-Received: by 2002:a05:600c:34c9:b0:436:f975:29d with SMTP id 5b1f17b1804b1-438913bffd9mr376568835e9.6.1737992533584; Mon, 27 Jan 2025 07:42:13 -0800 (PST) Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 27 Jan 2025 15:42:09 +0000 Message-Id: From: "Alejandro Vallejo" To: "Jan Beulich" Cc: "Andrew Cooper" , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Subject: Re: [PATCH v3 08/12] x86/emulator: Refactor FXSAVE_AREA to use wrappers X-Mailer: aerc 0.18.2 References: <20250110132823.24348-1-alejandro.vallejo@cloud.com> <20250110132823.24348-9-alejandro.vallejo@cloud.com> In-Reply-To: On Mon Jan 27, 2025 at 10:52 AM GMT, Jan Beulich wrote: > On 10.01.2025 14:28, Alejandro Vallejo wrote: > > Adds an UNMAP primitive to make use of vcpu_unmap_xsave_area() when > > linked into xen. unmap is a no-op during tests. > >=20 > > Signed-off-by: Alejandro Vallejo > > Acked-by: Jan Beulich Thanks, > despite ... > > > --- a/xen/arch/x86/x86_emulate/blk.c > > +++ b/xen/arch/x86/x86_emulate/blk.c > > @@ -11,9 +11,12 @@ > > !defined(X86EMUL_NO_SIMD) > > # ifdef __XEN__ > > # include > > -# define FXSAVE_AREA ((void *)¤t->arch.xsave_area->fpu_sse) > > +/* Has a fastpath for `current`, so there's no actual map */ > > +# define FXSAVE_AREA ((void *)VCPU_MAP_XSAVE_AREA(current)) > > +# define UNMAP_FXSAVE_AREA(x) VCPU_UNMAP_XSAVE_AREA(current, x) > > ... the comment here kind of suggesting that ... > > > # else > > # define FXSAVE_AREA get_fpu_save_area() > > +# define UNMAP_FXSAVE_AREA(x) ((void)(x)) > > ... use of this new construct is solely decoration, and could hence as > well be omitted. > > Jan It seems like a dangerous proposition to abuse knowledge of an implementati= on in order to skip parts of its interface. The fact that no such map is requi= red at this point in x86_emulate does not mean it never will be. Predicting the future is hard, but being consistent today is less so (imo). Cheers, Alejandro