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[37.24.206.209]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a6f1d8369casm168170166b.225.2024.06.10.08.00.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 10 Jun 2024 08:00:05 -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: 1fc514f8-273a-11ef-b4bb-af5377834399 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1718031606; x=1718636406; 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=A60tftk2W4ZZSJmfLCRU6alxBe9/4ElxSP0dkCVeOp4=; b=GU3URsnMKaas9MmDUpSvqkQM1l7ZvNho3duymTunOG1m5kC6v1nt1imvrxuEP+TuPS mPwhVzmQjoV6ubOZXb0hTbdYvr2WEIcuag1LrYFP/cZhEfgjfFWlxTb+NgQbuZnZg077 Dmt0bzvRiOamIqC5a18swQhWe1w1md9+s5jH86lAyrsCHWYP6Zyzb4WD4lvVaienSwHR SsSzvJ2F50Yf9e3RgJ4tregYpnDiVijcZDpArtBRSevqlX1tdy89DYqFCwrjk1twOjDX GZB4sYxKRVatQgjFMQOqEeBmh7Xk+nIGQ8ZXYojpi0fmHjuyGtbsXsEyBgTziw1y3o+A pRCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718031606; x=1718636406; 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=A60tftk2W4ZZSJmfLCRU6alxBe9/4ElxSP0dkCVeOp4=; b=DCcYy2oCQL0FxwjGWzadpwUnhP7jD5h8qrMOGv1QcKwcoTXGBAsSYZuMXieCTuey7p 6UWpKAyHaaIELqozGUzpK/zJhjidFkmxVT+Fc8hc2i0NsSgLNolxIjQl3RqheeWzeWxo dd8mpONGTnrYYGwn9uTWhQs5IeLO82bEN/LCKcYaiu07nOSzh1+RyhFfZ5py6NuUISQZ MnZmhB0MIXG/c8beKg7VKWyk3C4l21i4Wlc0HXxcsX/tc8N03TZSfXD7DTr84iBGZ9PO vZ6G4r0UVRphoeB9VSmB9SpiG7NI/9Bqa46f4a9zmUnf81MzjGO/bLzVkk4qnssVwyV0 6pWA== X-Gm-Message-State: AOJu0YwLIWHJx4wC0O9Z+P0NnD3cR/qXgn5t9PXJqAFDwynYiOJCbyDy EFsLgF0WELkr7A0vurMdu5A6dgx/HJ5Et+na4as81FFl9c/nY5d+9MdkBUT4pSrXF6lEEABYKDo = X-Google-Smtp-Source: AGHT+IE4ZHN11aSHdrnEkfqOLqDlff3wmihPd1/qlTTDooB0/fZcRP5H4FKX8NpeXPurJO2X2Tfhvg== X-Received: by 2002:a17:906:2b57:b0:a6f:1d8c:f22f with SMTP id a640c23a62f3a-a6f1d8cf68emr213049566b.26.1718031606165; Mon, 10 Jun 2024 08:00:06 -0700 (PDT) Message-ID: Date: Mon, 10 Jun 2024 17:00:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH for-4.19] x86/EPT: relax iPAT for "invalid" MFNs From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Oleksii Kurochko References: <56063a8f-f569-4130-ac25-f0f064e288a1@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: <56063a8f-f569-4130-ac25-f0f064e288a1@suse.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10.06.2024 16:58, Jan Beulich wrote: > mfn_valid() is RAM-focused; it will often return false for MMIO. Yet > access to actual MMIO space should not generally be restricted to UC > only; especially video frame buffer accesses are unduly affected by such > a restriction. Permit PAT use for directly assigned MMIO as long as the > domain is known to have been granted some level of cache control. > > Signed-off-by: Jan Beulich > --- > Considering that we've just declared PVH Dom0 "supported", this may well > qualify for 4.19. The issue was specifically very noticable there. Actually - meant to Cc Oleksii for this, and then forgot. Jan > The conditional may be more complex than really necessary, but it's in > line with what we do elsewhere. And imo better continue to be a little > too restrictive, than moving to too lax. > > --- a/xen/arch/x86/mm/p2m-ept.c > +++ b/xen/arch/x86/mm/p2m-ept.c > @@ -503,7 +503,8 @@ int epte_get_entry_emt(struct domain *d, > > if ( !mfn_valid(mfn) ) > { > - *ipat = true; > + *ipat = type != p2m_mmio_direct || > + (!is_iommu_enabled(d) && !cache_flush_permitted(d)); > return X86_MT_UC; > } >