From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F7606FA7 for ; Sun, 17 Sep 2023 20:16:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6C04C433C7; Sun, 17 Sep 2023 20:16:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694981818; bh=4JsY7IPnLqarNEYvlGBdpA2mhmxQqHs8ps85jbhos84=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WmWNlrAa394Vh4qgVI61s1vQOA7iPllZkxlcs/UcHIDsSNCvRCJW1G+bMiw1UxI2c SVB/9RLXRgfuZ17GgPRXo4V0AZwp3fjS0Vkhnhrh5MS4Mad6pUbtufhXV3TewdxgWt qx4oyE+OMn6qUcgp4lRcrCoEXPxiOmZ+lpyPBqog= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Peter Gonda , Pankaj Gupta , Sean Christopherson Subject: [PATCH 6.1 176/219] KVM: SVM: Skip VMSA init in sev_es_init_vmcb() if pointer is NULL Date: Sun, 17 Sep 2023 21:15:03 +0200 Message-ID: <20230917191047.338434419@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191040.964416434@linuxfoundation.org> References: <20230917191040.964416434@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson commit 1952e74da96fb3e48b72a2d0ece78c688a5848c1 upstream. Skip initializing the VMSA physical address in the VMCB if the VMSA is NULL, which occurs during intrahost migration as KVM initializes the VMCB before copying over state from the source to the destination (including the VMSA and its physical address). In normal builds, __pa() is just math, so the bug isn't fatal, but with CONFIG_DEBUG_VIRTUAL=y, the validity of the virtual address is verified and passing in NULL will make the kernel unhappy. Fixes: 6defa24d3b12 ("KVM: SEV: Init target VMCBs in sev_migrate_from") Cc: stable@vger.kernel.org Cc: Peter Gonda Reviewed-by: Peter Gonda Reviewed-by: Pankaj Gupta Link: https://lore.kernel.org/r/20230825022357.2852133-3-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/sev.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2951,9 +2951,12 @@ static void sev_es_init_vmcb(struct vcpu /* * An SEV-ES guest requires a VMSA area that is a separate from the * VMCB page. Do not include the encryption mask on the VMSA physical - * address since hardware will access it using the guest key. + * address since hardware will access it using the guest key. Note, + * the VMSA will be NULL if this vCPU is the destination for intrahost + * migration, and will be copied later. */ - svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa); + if (svm->sev_es.vmsa) + svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa); /* Can't intercept CR register access, HV can't modify CR registers */ svm_clr_intercept(svm, INTERCEPT_CR0_READ);