From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (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 BD23D3DDDD9 for ; Thu, 9 Jul 2026 20:49:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783630194; cv=none; b=eTcDnRPRJJUIqM/ODH/nSugz8hjH1uF5UZOD9yxob+KXE8mzRo65Oyk/3fvQfbG8YIg13crsWoXTT8uUWkk5cE3yfbKaVtODT7a8QKuM0ztwpbM5SSqVSoxIYc6hMcA39Sfb0Tvqtn5nNItXfLarNsFUoTdqdXJwy7P/i8Jb9tc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783630194; c=relaxed/simple; bh=D16wG1JpsjsY8+b2Y4efBB7LzgesBQ4xo4znaJuIZ84=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=HetWGfyNMfbhvFtJNBW2aLUlwg9G3HfObMVBNVVHBJYSNXDicKA5DkTKtPuBWuWrhxh4E8jR+QFyjP5KWkasUEX1jzJN/37jqrJOGv8pcDLvAfeHIj6nHa1146IchQykVXUlNQRpf8L1QKDLMilvgJwISPxUtyb+TBTA1V+pkdM= 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=oRPm4859; arc=none smtp.client-ip=209.85.214.201 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="oRPm4859" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2cceabd70f5so3788205ad.1 for ; Thu, 09 Jul 2026 13:49:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783630192; x=1784234992; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:from:to:cc:subject:date:message-id :reply-to:content-type; bh=Sxcl/zg0lDasj6tApucmYo4lstURvUEcv++r2laaRN8=; b=oRPm4859ATQxGOtOANXubbFhGBNm88zZ/MUctrPK8YluYkuq3Z1wSoKkc+QfctuhTa 7g/qt2s8F8FF1cK73uZcxVwKZNDzIzEdv4vcvSwYUVJzsRHtF7WcvoCOWFrAOw00YbWL SAN6lVfVGVAWeEELhwD3UYDWKuw0FN9FRUv7HtBgdbBs0FWHRnXNgtBd0mDAMSTD5rKH tvA/cEzmIgzr2Lo1pK8W/nzgEdaCQBis6f53hx4BxyL2FX0lBH+hYmSwAV0NbSaJj+lY HNl/inKX7BzS+ITkUzi/o6u8qguDePvC0AFst8nxhzejhg5q20Wh6EeBkVSG0i0hc9kP h8iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783630192; x=1784234992; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to:content-type; bh=Sxcl/zg0lDasj6tApucmYo4lstURvUEcv++r2laaRN8=; b=o/74mJCuHNDtH0OqoOBYxIFvVWsBvC8/5W9MHJw9/QSFvSJAVcSPuogqIabn3h5Nsk W4NkMtDSdAN23OANjqCR5WSmuecKM3FH/mMIj+yZCD6ylCfUix8nhf3IU7MD87ifHyrZ QwEbrX2T+DIow3IuIb3rotP8d15u2+UDqFRK4MpIjo4IuofhygzCmMUArbDKTQaU++au WBH3kIxKcZ39ry7QU2qldxySTXbzD/hMCN324tmvtjCQQnILVx3+WAjMBuw6JB+0A7/0 fU2QdcjCoM52qBR8Qh0bOz89P3WmqtqAmmHhtr3LL+wFhG8GAiCgb2SNW1ENDpWsX+6r h/2w== X-Forwarded-Encrypted: i=1; AHgh+Rp9M788RnG51QKenpA+pd9bLnBYVJNMt8wjZJxPa6lg8DHwZLn0TKmZHaX0/bG0sBs22VqFHviXzjuUJKI=@vger.kernel.org X-Gm-Message-State: AOJu0YxJ1E00j27NhCTzUl6+I89e/wdGrBqqr5y7wShjKLo7A6E2/CA0 CcN7GNnvQrRhvMAERRRbLDZnc/kSm6SrC/ERnga7uPZuM2vAURUKva42b0GPvl7yg0z5ChuNG3Z HpRhJzw== X-Received: from plbmo3.prod.google.com ([2002:a17:903:a83:b0:2cc:5fd1:2d93]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:b86:b0:2ca:bb6:e7c6 with SMTP id d9443c01a7336-2ccea36e129mr92281685ad.37.1783630191940; Thu, 09 Jul 2026 13:49:51 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 9 Jul 2026 13:49:31 -0700 In-Reply-To: <20260709204948.1988414-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260709204948.1988414-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.795.g602f6c329a-goog Message-ID: <20260709204948.1988414-2-seanjc@google.com> Subject: [PATCH v4 01/18] KVM: SEV: Track the GPA of the guest-controlled VMSA used for SNP guests From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Roth , Hyunwoo Kim , Tom Lendacky , "=?UTF-8?q?J=C3=B6rg=20R=C3=B6del?=" , Fuad Tabba , Ackerley Tng Content-Type: text/plain; charset="UTF-8" Track the GPA of the guest-provided VMSA used after AP_CREATION events when running SNP guests, instead of simply tracking whether or not the vCPU is using a guest-provided VMSA. KVM needs to know the GPA of the VMSA that's actively being used so that it can react to MMU invalidation events, i.e. so that KVM can drop the VMSA if its backing guest_memfd page is punched out of existence. Opportunistically rename snp_vmsa_gpa to clarify that it tracks the pending VMSA GPA, whereas snp_guest_vmsa_gpa now tracks the in-use VMSA GPA. Note! Take care to track the GPA, not the GFN, as VALID_PAGE() won't behave correctly if an invalid GFN is converted to a GPA for checking. Note #2! Keep snp_has_guest_vmsa so that switching to a guest-provided VMSA is sticky, even if the guest-provided VMSA becomes invalid. No functional change intended. Cc: stable@vger.kernel.org # 6.12.x Reviewed-by: Michael Roth Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/sev.c | 14 +++++++++----- arch/x86/kvm/svm/svm.h | 3 ++- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 74fb15551e83..827f5dc06102 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -4003,6 +4003,7 @@ static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) /* Clear use of the VMSA */ svm->vmcb->control.vmsa_pa = INVALID_PAGE; + svm->sev_es.snp_guest_vmsa_gpa = INVALID_PAGE; /* * When replacing the VMSA during SEV-SNP AP creation, @@ -4010,11 +4011,11 @@ static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) */ vmcb_mark_all_dirty(svm->vmcb); - if (!VALID_PAGE(svm->sev_es.snp_vmsa_gpa)) + if (!VALID_PAGE(svm->sev_es.snp_pending_vmsa_gpa)) return; - gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa); - svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; + gfn = gpa_to_gfn(svm->sev_es.snp_pending_vmsa_gpa); + svm->sev_es.snp_pending_vmsa_gpa = INVALID_PAGE; slot = gfn_to_memslot(vcpu->kvm, gfn); if (!slot) @@ -4039,6 +4040,7 @@ static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) svm->sev_es.snp_has_guest_vmsa = true; /* Use the new VMSA */ + svm->sev_es.snp_guest_vmsa_gpa = gfn_to_gpa(gfn); svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn); /* Mark the vCPU as runnable */ @@ -4105,10 +4107,10 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm) return -EINVAL; } - target_svm->sev_es.snp_vmsa_gpa = svm->vmcb->control.exit_info_2; + target_svm->sev_es.snp_pending_vmsa_gpa = svm->vmcb->control.exit_info_2; break; case SVM_VMGEXIT_AP_DESTROY: - target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; + target_svm->sev_es.snp_pending_vmsa_gpa = INVALID_PAGE; break; default: vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n", @@ -4791,6 +4793,8 @@ int sev_vcpu_create(struct kvm_vcpu *vcpu) return -ENOMEM; svm->sev_es.vmsa = page_address(vmsa_page); + svm->sev_es.snp_pending_vmsa_gpa = INVALID_PAGE; + svm->sev_es.snp_guest_vmsa_gpa = INVALID_PAGE; vcpu->arch.guest_tsc_protected = snp_is_secure_tsc_enabled(vcpu->kvm); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 716be21fba33..d077783c287e 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -271,7 +271,8 @@ struct vcpu_sev_es_state { u64 ghcb_registered_gpa; struct mutex snp_vmsa_mutex; /* Used to handle concurrent updates of VMSA. */ - gpa_t snp_vmsa_gpa; + gpa_t snp_pending_vmsa_gpa; + gpa_t snp_guest_vmsa_gpa; bool snp_ap_waiting_for_reset; bool snp_has_guest_vmsa; }; -- 2.55.0.795.g602f6c329a-goog