From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A8E530ACEE for ; Thu, 13 Aug 2026 23:47:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786664825; cv=none; b=Le9q3iHXYcwQCRp6u7Lor5Wo+BJfHhgviIzTTPWG02EilweodD7oGv3rFvYxcLOi8lXWqmHoSEAQpm4YP1tA4GMvMlzeSC4iVCzxz5xHUUFeqTIraWI0h/pqBN3DM2bRXQLANZP3Cd3g5i1BFlcL8FDfJYjxueglQT8JulhSWeM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786664825; c=relaxed/simple; bh=zp5+WItBeQBsyncdAdjSae2AKjZo8igsIiraO/m9VbM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=rgCtWOwbR/0tcj0EdEyMOesKzJi7HIHa88aIBJZviQftFAspOUvMblA5wKBuvGnxFEJnFOo5LPukRsZ/VMGbv1+waW0kWZXYsvGfk77mgXgi0u0nq5qOHQgWp7m3tHKyT5gwHL/wlUaK5zSLLXm/kotcDXw/BOMmLQalQHY8Ah8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=b8b66lox; arc=none smtp.client-ip=209.85.216.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="b8b66lox" Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-38ea32e57e2so714279a91.1 for ; Thu, 13 Aug 2026 16:47:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786664824; x=1787269624; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=VnPLset0fgUp/N6cL01J88RlEaFM2/Zb6Kz0PUF7QRU=; b=b8b66loxBKgxHmTScXIv3XUnu24fE/eIpKlrO77LLslXE9CjRBq/hEMzTggEywKbxY BZMwyFfkQ5VHO3ON02NuaVLSkPh+iriPJD3b5t1eEJgS2yo+JIW7Th+wEnEMczgBGE+g iqxPIR4zeUlsIDO2A0iu+c6+/g5ls2B4r+2G+ToZR5tvt+mXcAZ1KIMnpn6ZjJcYzA1T NvSEjjmjlXjKEoyRXGESjBsycHowNEPcAFP/0dRwT/DRygegbQ5oz44SEK8GeBSpEQVR FAD0L75wS5TTmA8arANSPZaQtmmTh4xOHbKHXgnKrgf0VVE/9UG/QeGIMOuxBhPmG4B4 LTkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786664824; x=1787269624; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=VnPLset0fgUp/N6cL01J88RlEaFM2/Zb6Kz0PUF7QRU=; b=anLyxDT19zh01mxlgo4/xRgvRLjpC/rmEa0mwgyb82hA6DTi1Zvt7FITVPaSPAEoVp ROujxyTEZrLEagjw9PMKVxEHIg84L1pY72otj5z91fJ1EKdLkMtv0qV4vyJosSugS0bK zGoogNt6HBrd5FuY0JnN+splxtRiwQF+ry1PYJSpqu2hA8EatmMjNSLespa6++Ttrral Fe8h0+4GJ2IFFEksiUQ53Iqk9M6HfJTtLjDayjXqOOUrG/kz1K4ZgONWzFh/XL6S7E5d WDr8zcLG+jSoSmdV1JyD0O2cXcKij0anUdqAyyVAraNqS6cXOcfWPTCuENZfNO84Xqg7 1Q1A== X-Forwarded-Encrypted: i=1; AHgh+RqVKOCBYP1XJHaHxODNNiJkZG857P04hQ8vhugmkM0O9EKqbl4dzp8X1eglbqseAWhRf8GMvZotjBwzSvs=@vger.kernel.org X-Gm-Message-State: AOJu0YyZ75Ri9PAQOIEhu2cejs4ksvTr9eii5Eo2Vgf1bzT0mUf2MwaQ vLQKmsMHKxlKBJSVwAvAZ5YvLQBYEJj0MswRaYjI+l8ZlatBBMFSsG54e+lnATwxpYaXAHqwzXV r+rD7fw== X-Received: from pgch28.prod.google.com ([2002:a05:6a02:509c:b0:cbe:e700:725d]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:3a83:b0:3c4:2036:3032 with SMTP id adf61e73a8af0-3cc71f9de41mr1678436637.34.1786664823529; Thu, 13 Aug 2026 16:47:03 -0700 (PDT) Date: Thu, 13 Aug 2026 16:47:02 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260129063653.3553076-1-shivansh.dhiman@amd.com> <20260129063653.3553076-8-shivansh.dhiman@amd.com> Message-ID: Subject: Re: [PATCH 7/7] KVM: SVM: Enable save/restore of FRED MSRs From: Sean Christopherson To: "Nikunj A. Dadhania" Cc: Shivansh Dhiman , pbonzini@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, xin@zytor.com, nikunj.dadhania@amd.com, santosh.shukla@amd.com Content-Type: text/plain; charset="us-ascii" On Thu, Aug 13, 2026, Nikunj A. Dadhania wrote: > On 8/13/2026 4:57 AM, Sean Christopherson wrote: > > On Mon, Aug 10, 2026, Shivansh Dhiman wrote: > >> Would you prefer it handled in svm_recalc_fred_msr_intercepts() instead > >> while setting intercepts? Or is there a better way to deal with this? > > > > Take a hard dependency on an upcoming APM update that states the control area > > is valid after shutdown, and rework KVM to not clobber control fields on shutdown > > interception. > > AMD APM 3.45 [1] is now publicly available and has the updated wording: > > "After an intercepted shutdown, the VMCB control area is valid (with > the exception of offsets 60h, 61h, and 68h) and the VMCB state save > area is undefined." Very tangential side topic: are combined versions (all five volumes in one PDF) of the APM available? Having to open five different PDFs to find information is a pain in the rear, especially since I can never remember what's in which volume. I can manually splice the PDFs together, but that's far from ideal.