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[37.24.206.209]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3997f9a3f2asm19586034f8f.30.2025.03.27.02.54.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 Mar 2025 02:54:24 -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" X-Inumbo-ID: 77441ed1-0af1-11f0-9ea3-5ba50f476ded DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1743069265; x=1743674065; darn=lists.xenproject.org; h=content-transfer-encoding:autocrypt:subject:from:cc:to :content-language:user-agent:mime-version:date:message-id:from:to:cc :subject:date:message-id:reply-to; bh=9kZ99uvO3U9iWS7fBj8q9WZwSKRMIl7XeYlMoKltxFk=; b=e78+Q8ZRKpxeAb1gjtwdBeyCffts04gDYORdhlu7OUVTfV4Q9Av4WtjlYYpqo2rQCC lncv8Ire6o0G1LF083Qyw1vxnt1JBpPVTnrUaUSGcdvVeu0k84Ge8MmRed2BTVkEf+MD QFNAVc2RaWy7vZhZqvye/BM4y4bRxs5jCbdZBS6VuQjCFFjNyW9WeaUzTXeaaQbhh2pJ n5jjduJ28ZXaWk1DmIw/jEOkohh4ywdSRXz8Zqn8gYfcezEZqP+rYvQh9KdnV618UvLg ZJoSEWbCX0NwaQULQHt4EfUhgzra7A3EPBICjZIWxQNOimZAXQyWwwp9944FpWfFRAxo DUXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743069265; x=1743674065; h=content-transfer-encoding:autocrypt:subject:from:cc:to :content-language:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=9kZ99uvO3U9iWS7fBj8q9WZwSKRMIl7XeYlMoKltxFk=; b=R858DsPD32VK9WQv9xbut7/YFaCSFBoSIcmkfVQwnfRXVT54nCQlxmgTlMwNrb8GMG WBgLmZ1OH0/UHFXOiTiTQxrnXcTtM62muCh288ICogek3QsPirR1/eGfjZ2phhgXTpo3 TJYeQlgB5pmx4kjARczRXwL5MgBPtbfDCPOU9uyr2fu+4VX9eF3zlE+vkmIXwuEdHpO1 areae3+Ul+TYZhqyxHyA6mv22U8IBGa84SlG/b5giPa54bM6/VYh9QubqLSo2Qr9CQSK hEWokBVPP+1KaPNWqDrF9VU1BNUrMeWXtK7TLgdz5O8/xiZaxrPOCcnWSKxjWRg2hZj4 /W8g== X-Gm-Message-State: AOJu0YwzCfyYtDa5Nxrvc8euAlg0YqlpA57WE7IjF34an1mAT7D9rs6y zGfPDVAE0ANhgprxcnIZbEUv44sck8WE63NRo+AtSdX9H6ajN0lhDV5rGNKzjEgg9gJwnRNkJbA = X-Gm-Gg: ASbGncuJ0YW7xaPiLIbXCmh1hYXJtY1DyPwY4daN9mMv119NnFKFZEfYKdHCU18xpOk Nh4Hxo7oq7ntIUgbgNdYwNjlQe6Gbnwo2lDwdslnjv9qaMc/5f3HILOebs3pyXhMeztDfTprioE G8hy6TM5lLEuogreURtYtlVpk7qf5MpG4xxpZuNgn15BsD0x9k3GCj0vH3nVyq/eFOVyT+cIr8t CsHMeuo+dO8B2WkKqiW4ukNoEDmTmpJHetSyPnXr2pSUR8RwXDMh0WHOn4OW7FjYyXdovDwybP4 koUPKeBYlUVw8uWqbRSnCuyNbpzkfXtDMlh8Ar2YlUlZRCSVlK8DMgCWCoUL6rLgArxUF9lVA+s XuWRqo7g59o+ZrZyq5lH1yX+orwNAew== X-Google-Smtp-Source: AGHT+IHq99HvJEAEPeqXO/96W8GlVmu6cPHVfkvlFqIkVBKeTVtc+2AtQkkN0OjkxV/NhVouzmSAMQ== X-Received: by 2002:a05:6000:4211:b0:391:3157:7717 with SMTP id ffacd0b85a97d-39ad177b815mr2303349f8f.34.1743069264879; Thu, 27 Mar 2025 02:54:24 -0700 (PDT) Message-ID: <56fbfae0-aac7-4841-ab3c-a7e00dda3744@suse.com> Date: Thu, 27 Mar 2025 10:54:23 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , =?utf-8?q?Roger_Pau_Monn?= =?utf-8?q?=C3=A9?= From: Jan Beulich Subject: [PATCH] x86/MTRR: constrain AP sync and BSP restore 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 mtrr_set_all() has quite a bit of overhead, which is entirely useless when set_mtrr_state() really does nothing. Furthermore, with mtrr_state.def_type never initialized from hardware, post_set()'s unconditional writing of the MSR means would leave us running in UC mode after the sync. Signed-off-by: Jan Beulich Acked-by: Roger Pau Monné --- a/xen/arch/x86/cpu/mtrr/main.c +++ b/xen/arch/x86/cpu/mtrr/main.c @@ -605,13 +605,15 @@ void mtrr_aps_sync_begin(void) void mtrr_aps_sync_end(void) { - set_mtrr(~0U, 0, 0, 0); + if (mtrr_if) + set_mtrr(~0U, 0, 0, 0); hold_mtrr_updates_on_aps = 0; } void mtrr_bp_restore(void) { - mtrr_set_all(); + if (mtrr_if) + mtrr_set_all(); } static int __init cf_check mtrr_init_finialize(void)