From patchwork Tue Apr 26 08:21:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 567869 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32BB2C433FE for ; Tue, 26 Apr 2022 08:54:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245083AbiDZI5z (ORCPT ); Tue, 26 Apr 2022 04:57:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345869AbiDZI4r (ORCPT ); Tue, 26 Apr 2022 04:56:47 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5747814A5; Tue, 26 Apr 2022 01:41:23 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 67650B81D0A; Tue, 26 Apr 2022 08:41:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D95E3C385A0; Tue, 26 Apr 2022 08:41:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650962481; bh=BwezHAYAX5zda3TQxBa8HvpHICs3ULxiWMTyV4MwdJE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DS2V2cQPQRjzcXQ8T+lcTchFgBAW/GIQkerAkyGSpixud2SwzKBMu1FX5mek3d94w FRcNBIR5a/yOodOFt6bPWlOZ9KYSJyiw4AvI1fiupYamKP6Hd1qoEaQmkpLLm+TrEp Ii8CcPixL0N1o5aoYvJuL+Jnq+/3SYr4iaYw4Rt0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@vger.kerel.org, Sean Christopherson , Mingwei Zhang , Paolo Bonzini Subject: [PATCH 5.15 110/124] KVM: SVM: Flush when freeing encrypted pages even on SME_COHERENT CPUs Date: Tue, 26 Apr 2022 10:21:51 +0200 Message-Id: <20220426081750.421291090@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081747.286685339@linuxfoundation.org> References: <20220426081747.286685339@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mingwei Zhang commit d45829b351ee6ec5f54dd55e6aca1f44fe239fe6 upstream. Use clflush_cache_range() to flush the confidential memory when SME_COHERENT is supported in AMD CPU. Cache flush is still needed since SME_COHERENT only support cache invalidation at CPU side. All confidential cache lines are still incoherent with DMA devices. Cc: stable@vger.kerel.org Fixes: add5e2f04541 ("KVM: SVM: Add support for the SEV-ES VMSA") Reviewed-by: Sean Christopherson Signed-off-by: Mingwei Zhang Message-Id: <20220421031407.2516575-3-mizhang@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/sev.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1990,11 +1990,14 @@ static void sev_flush_guest_memory(struc unsigned long len) { /* - * If hardware enforced cache coherency for encrypted mappings of the - * same physical page is supported, nothing to do. + * If CPU enforced cache coherency for encrypted mappings of the + * same physical page is supported, use CLFLUSHOPT instead. NOTE: cache + * flush is still needed in order to work properly with DMA devices. */ - if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) + if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) { + clflush_cache_range(va, PAGE_SIZE); return; + } /* * If the VM Page Flush MSR is supported, use it to flush the page