From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 301322D7388 for ; Wed, 10 Sep 2025 19:19:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757531988; cv=none; b=IJvBi/CRLOgG3wtHIu/fIghtjgX6xqx9zRFN+b8ProaK+w38yA1a+VAPfwgVxf0q4JItu2lc07LQkcHcZxmZzFnf+dq19A1CN8gHt2HGjP+PPcbO4ad1bRTvMUJEjBSq9g9glzZZufum6tXM+6RwTELdUbT54UfwHb/KqYYtJxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757531988; c=relaxed/simple; bh=qWueF42qwhO9/d4nulib23wqx9pkPXKoj4m8Enmbuag=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=tETwZVai2H4LRBUqYm/p08XS49duYghus+mj6DuzRLQ0Fl2Tdh2tgy3vIEs3WDp8aiBM62ktrU4X98tcCL6QJ5su8di8ntwijmEHFsqR3DxuE1DngVVBSopwjp7beYLn7yfhsLUcnxpHGT5ETXC/Pptw43MKAUEiwZmBGxXdFZ8= 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=RfNgrym+; arc=none smtp.client-ip=209.85.215.201 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="RfNgrym+" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-b4c928089fdso10567302a12.0 for ; Wed, 10 Sep 2025 12:19:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757531985; x=1758136785; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=VN/rggrH4digs9qBWZB1KbUoy16EnGUVMJIJH5xmr7E=; b=RfNgrym+tYbAWnYqtJTcZU17SPyOHkyDR4Q5WilKy+MgLEmjCxARjXZRNEeDw+nTOf XiRqj5L1LiJ6rHiYlXRxQfeo8paRSrLdnZWx848T7JO1535Dct1jL/7p6+jX+XpFmbxt pGgHzWt1iMMUOq/j5hSyN689xrDHYz/vMzvnnEhJZ7Dsu82dCCiVrGidifWSBC25Vr+O TBqUqz36L1+1uP9nRnWVP34biDAZdDmV27rEoWKOpRc1jNArTsL6X4FgriH3ZMDTuS1E pZnl3LOgiLhyIqFIOf+7OaSnvnVCvcPEVM7JS4LBoU/mvKWpgvgwJCR349lplWoE2/q9 /WvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757531985; x=1758136785; h=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; bh=VN/rggrH4digs9qBWZB1KbUoy16EnGUVMJIJH5xmr7E=; b=YKkPJdrhrDya9M+X/dXCwn3BimUf2bW0Whgi3J9xuaNxPUE7DvqlNKt8fgJKICa0Ck dgx+Pyar18ggabvFZT5C1XMGKXCD0vOd9bdfDjMpax5IIQ7cvsf836NVAe5zyfZxnCcp n9UySY/Z+LjEnveFUfonxACcN2QcrdocX+f5vK9BZe4l5CROZgbpnyocWm6lZOPqOdf9 gn9upoM4WwDFzplRw4yKU62XVtdEjPWZLvrGimOVfAtLHPDgQm4lnYdd2vSUfG5lx2gP 5aD7lX4WEEDj3To8vH9bgnkxsES7ImdBbqI0SXWqeIFimy+c7CpH3ABDGhbBdye+rmVg Sg1g== X-Forwarded-Encrypted: i=1; AJvYcCUJlWaIqNSfm/Z0YNfJhn2cNTOyUV5a23oJonPlfPXgcQH/UJSFiHC6kGgPTD6tH5Db9cTXEmn2kKTahQs=@vger.kernel.org X-Gm-Message-State: AOJu0YwjgJJVv1BQi2PKUKVqtmYSX9JB0oCT5BHKtmhNMmbMw9jB0AF2 KNBg1h408cbbSA50GOr/jA7QX1TrsiZKNwjsg9YIzz8UtZwVt77uSPtoqAG9YGZPZ3zUm/XBBAl SKJX0qg== X-Google-Smtp-Source: AGHT+IHX7UynOVRpi3If/F9N5K/tO9bGneP/KTRE0HxApIqGpBDwKgUOwjvsvvWc3ktK/GVAM4OFjpZif2s= X-Received: from pfqr14.prod.google.com ([2002:aa7:9ece:0:b0:772:750f:4e23]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:6d9c:b0:245:fdeb:d264 with SMTP id adf61e73a8af0-2533e576707mr26771465637.12.1757531985441; Wed, 10 Sep 2025 12:19:45 -0700 (PDT) Date: Wed, 10 Sep 2025 12:19:43 -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: Message-ID: Subject: Re: [RFC PATCH 1/4] KVM: SEV: Publish supported SEV-SNP policy bits From: Sean Christopherson To: Tom Lendacky Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-crypto@vger.kernel.org, Paolo Bonzini , Borislav Petkov , Dave Hansen , Ingo Molnar , Thomas Gleixner , Michael Roth , Ashish Kalra , Herbert Xu , David Miller Content-Type: text/plain; charset="us-ascii" On Fri, Aug 22, 2025, Tom Lendacky wrote: > Define the set of policy bits that KVM currently knows as not requiring > any implementation support within KVM. Provide this value to userspace > via the KVM_GET_DEVICE_ATTR ioctl. > > Signed-off-by: Tom Lendacky > --- > arch/x86/include/uapi/asm/kvm.h | 1 + > arch/x86/kvm/svm/sev.c | 11 ++++++++++- > 2 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h > index 0f15d683817d..90e9c4551fa6 100644 > --- a/arch/x86/include/uapi/asm/kvm.h > +++ b/arch/x86/include/uapi/asm/kvm.h > @@ -468,6 +468,7 @@ struct kvm_sync_regs { > /* vendor-specific groups and attributes for system fd */ > #define KVM_X86_GRP_SEV 1 > # define KVM_X86_SEV_VMSA_FEATURES 0 > +# define KVM_X86_SNP_POLICY_BITS 1 > > struct kvm_vmx_nested_state_data { > __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 2fbdebf79fbb..7e6ce092628a 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -78,6 +78,8 @@ static u64 sev_supported_vmsa_features; > SNP_POLICY_MASK_DEBUG | \ > SNP_POLICY_MASK_SINGLE_SOCKET) > > +static u64 snp_supported_policy_bits; This can be __ro_after_init. Hmm, off topic, but I bet we can give most of the variables confifugred by sev_hardware_setup() the same treatment. And really off topic, I have a patch somewhere to convert a bunch of KVM variables from __read_mostly to __ro_after_init...