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[37.24.206.209]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-39d893f0b14sm1634041f8f.65.2025.04.09.06.17.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Apr 2025 06:17:38 -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: 028995cc-1545-11f0-9eab-5ba50f476ded DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1744204658; x=1744809458; 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=+WBgpIGZijaunSknpbdMvhEhWqabmIbHp9KZM49gqIg=; b=Xngs/F50saxzORVCUSwVGFyfYEh7N5WIKtvfyw9CT9c/F5aVFWGxGAvneslNiYjWKg boXlf6ghV9TNSV7geseyOHiw9eyUd3c39uveFLM+p+S1Ii8dMNqOayLSREce59VLalDm XQpmf9SYmgYAvpidG5XJtGNrosZTnWfJBp5FapN9DCe9pFLDaixFQ4Fi7GyLL1bIIaiW TMDYjzU6Mzy/mjXEI+i2T3c9zobynkZM3zYNcFdRgOnx5d3KeYjylQQo5PBhhb9Y/yF/ nOuCdaHtM3p5L/TkWrjsRmuI4m0HlrswVbJcXcCmnTtk98St9i0pwuHMT+pqDtqJyMq7 FyIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744204658; x=1744809458; 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=+WBgpIGZijaunSknpbdMvhEhWqabmIbHp9KZM49gqIg=; b=QZWb0xmq3p1eKt45pzF1H4HVfS9qmDo/PacTa1jp7yXoiOfKanxUrL+E5ydUbpZlds OLxPpBi2zCZD8RgAsGJQZ3ITAsusqiBzrHEQzQWQmV62pWHVm7EfpakFaahvy5a23o3Z 5vGWa7JbdvB4zbkhYulkbLnqrtLHCHoSPmXlsJ7iYU/+lXMq8nJlHSl9iguuEh+kofYz q5N7rK8TstbFbxHDyKrLmrS3K3GqbyEYbcr/fhr9Gbp6QEO/wws8bRjikbAuFAx0tTrd vQvLoBMD6sGUD8EHldPcdW1jdd4REMX7+byNwO5KSL/tqJrq1Y76AyxrD0lMiYp116mA kzFw== X-Gm-Message-State: AOJu0Yxw+dobowLCUJMAgAXG2kEAb7feEwjKizWS//hol6tCUrqMtb+s /05hVa8/vvvPf7Q86YmuW2hLLT0CjiWtL5xdH1l9d6V8cROWyWv5H4BSN6nKMeqPlt+0pYOnzcE = X-Gm-Gg: ASbGncuvCt4MpnZK3gAqkS8RppZP2ZhRdUnDe9So7MzdWamJNiQOn5tkMs0/yJw/VAv lVPmkNA9D/xzi76oA6ntooECulZ79DEYkDXktyqbasbiKMO4BVSPxIWogmZymtVsf9f8lN4r7+u IlYxlCj31XBTDhwMq1b8EbrrTsag8i8Vvcryzc+hZKWcjH4y/UfZc3o0BWbP5hjYTxtk2tjFQoQ qxrl84jAyQFAyixtetpz/Bt+UZUwLHb75GkDdRyOVOORWaY3++YvJ20b90v0atIBMp0ztKXigLd KHnvr4bU76nEti80Gs4Lfn9Q4jKazCVH74eMGdj3cGWutp0IKA2akdWtqn+IlVPv2gLh1xnuc6M jS6iI+sZ5H9vHBw/exts1N4G3Ew== X-Google-Smtp-Source: AGHT+IF865JH7by6iBsNz4B6dY3pcY4yWaOQEa+Vq0KEK+MOs2N36CzfXVC3s9zAnY4YoVtTR1qLIA== X-Received: by 2002:a05:600c:19cf:b0:43c:e2dd:98f3 with SMTP id 5b1f17b1804b1-43f1ff3ba52mr17752025e9.21.1744204658374; Wed, 09 Apr 2025 06:17:38 -0700 (PDT) Message-ID: <055d3235-7ee0-472b-b520-6426b51d3927@suse.com> Date: Wed, 9 Apr 2025 15:17:37 +0200 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/HVM: improve local variable use in hvm_hap_nested_page_fault() 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 First gfn can be set just once, rather than (conditionally) twice. And then gfn can be used in two function calls, rather than re- calculating the value there. Signed-off-by: Jan Beulich Acked-by: Andrew Cooper --- I wasn't quite sure about continuing to use an open-coded shift. PFN_DOWN() could be used, or paddr_to_pfn(). Neither looks to be an overly good fit to translate a gaddr to a gfn, yet gaddr_to_gfn() can't be used quite nicely either as long as gfn isn't of type gfn_t. --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -1794,7 +1794,7 @@ void hvm_inject_event(const struct x86_e int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long gla, struct npfec npfec) { - unsigned long gfn = gpa >> PAGE_SHIFT; + unsigned long gfn; p2m_type_t p2mt; p2m_access_t p2ma; mfn_t mfn; @@ -1841,12 +1841,13 @@ int hvm_hap_nested_page_fault(paddr_t gp hvm_inject_hw_exception(X86_EXC_GP, 0); return 1; case NESTEDHVM_PAGEFAULT_L0_ERROR: - /* gpa is now translated to l1 guest address, update gfn. */ - gfn = gpa >> PAGE_SHIFT; + /* gpa is now translated to l1 guest address. */ break; } } + gfn = gpa >> PAGE_SHIFT; + /* * No need to do the P2M lookup for internally handled MMIO, benefiting * - 32-bit WinXP (& older Windows) on AMD CPUs for LAPIC accesses, @@ -1854,7 +1855,7 @@ int hvm_hap_nested_page_fault(paddr_t gp */ if ( !nestedhvm_vcpu_in_guestmode(curr) && hvm_mmio_internal(gpa) ) { - if ( !handle_mmio_with_translation(gla, gpa >> PAGE_SHIFT, npfec) ) + if ( !handle_mmio_with_translation(gla, gfn, npfec) ) hvm_inject_hw_exception(X86_EXC_GP, 0); rc = 1; goto out; @@ -1982,7 +1983,7 @@ int hvm_hap_nested_page_fault(paddr_t gp (npfec.write_access && (p2m_is_discard_write(p2mt) || (p2mt == p2m_ioreq_server))) ) { - if ( !handle_mmio_with_translation(gla, gpa >> PAGE_SHIFT, npfec) ) + if ( !handle_mmio_with_translation(gla, gfn, npfec) ) hvm_inject_hw_exception(X86_EXC_GP, 0); rc = 1; goto out_put_gfn;