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[37.24.206.209]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a6f1c99d8f1sm426917466b.175.2024.06.12.06.16.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Jun 2024 06:16:39 -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: 01116f7b-28be-11ef-90a3-e314d9c70b13 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1718198199; x=1718802999; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=IIBq/heXgaX7T28VY8MGlPRmzmqXncKPkrU8y33t/6Q=; b=Mmh7EiEOBFRwDyV91f2ap5XTMIEWo3YTypsleYMGQq48N5g/fWTtGxLmmNYp1rozSo UVcZOKQzihLQM4ul+x5MJweNkukTQrgXmdtj+jdLgDQWQHwWgXIMTFtDtQ48rWKUb8GW yf+KDfcHXdKeXi9/p+Qyo0ATyAWwFxhZyUH6jIFs8CP5DBX4fMd8kMoKf0LsF0YsboN8 d0GEYo3ABWaoVkqDeYiyMzAMwpSDeN+dzFMbMlLd9uCXfRcWYdhLOCfOaBcqwXoaHgrw s0HJOcQXF7ygNGhXDq79hLFJn8vkCo0dZYGQP0T9/p5WmyRHSkonaecVMMeflWuvbTam 0kZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718198199; x=1718802999; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IIBq/heXgaX7T28VY8MGlPRmzmqXncKPkrU8y33t/6Q=; b=dbugReXPgfwlbgbsTeqCh6qlCxC+iWIqKY4zwDeo8dgi1RyFZK9qt/VaWHNjHEwJ6z xxiXtjFF+eWPgWlog1wPqnIkrX8l4hObP9frktUBYGj/6koFz/juj+TLz/yyrNxY1kF7 XDAhKFlLt26y7BTXdRXd+xOpjAR9hY/lr75Ji84TvQpqkao6ljCVDxuenspnJzEgLZ7f pRXwN5pdpNyQTJp8iZCwGNHj4TG2MRLhA7UfLyBVRMmHXgx4UDFqNvcAFI9GkDlUaD64 gz73X19f+oFZQw03SZKGpXYQv4h2eNBwL+nezhyONF82t4NsiVRUnhQZE8KjSdxyq/7w obzg== X-Gm-Message-State: AOJu0Yx4hbdML/XNA2gvAGDI079bLlhWWCHfYLL43Hcj2o2Dng0cue9E aczJgGNl2OnbQnp3UN/ojiCHK2FXniy75RronRELkxKCKijxlChjUp+DQXxEO7tN5PfiYzgLlyA = X-Google-Smtp-Source: AGHT+IGa7qIcGL9sb6ucqx2qnH+S/tl++sd2dtseLK+/TzKRMt3cKSekBFUIbqMltkXqp/I+pnl8CQ== X-Received: by 2002:a17:906:d972:b0:a6f:6ef:225 with SMTP id a640c23a62f3a-a6f47c9c2dcmr115080166b.19.1718198199385; Wed, 12 Jun 2024 06:16:39 -0700 (PDT) Message-ID: <175df1a2-a95f-462b-ad49-3a0fef727658@suse.com> Date: Wed, 12 Jun 2024 15:16:37 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [PATCH v2 for-4.19 1/3] x86/EPT: correct special page checking in epte_get_entry_emt() From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , =?utf-8?q?Roger_Pau_Monn?= =?utf-8?q?=C3=A9?= , Oleksii Kurochko References: <2936ffad-5395-45fd-877f-7fb2ca8b9dc8@suse.com> Content-Language: en-US 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: <2936ffad-5395-45fd-877f-7fb2ca8b9dc8@suse.com> mfn_valid() granularity is (currently) 256Mb. Therefore the start of a 1Gb page passing the test doesn't necessarily mean all parts of such a range would also pass. Yet using the result of mfn_to_page() on an MFN which doesn't pass mfn_valid() checking is liable to result in a crash (the invocation of mfn_to_page() alone is presumably "just" UB in such a case). Fixes: ca24b2ffdbd9 ("x86/hvm: set 'ipat' in EPT for special pages") Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné --- Of course we could leverage mfn_valid() granularity here to do an increment by more than 1 if mfn_valid() returned false. Yet doing so likely would want a suitable helper to be introduced first, rather than open-coding such logic here. --- v2: New. --- a/xen/arch/x86/mm/p2m-ept.c +++ b/xen/arch/x86/mm/p2m-ept.c @@ -519,8 +519,12 @@ int epte_get_entry_emt(struct domain *d, } for ( special_pgs = i = 0; i < (1ul << order); i++ ) - if ( is_special_page(mfn_to_page(mfn_add(mfn, i))) ) + { + mfn_t cur = mfn_add(mfn, i); + + if ( mfn_valid(cur) && is_special_page(mfn_to_page(cur)) ) special_pgs++; + } if ( special_pgs ) {