From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) (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 0C6843FE2 for ; Mon, 13 Sep 2021 15:56:30 +0000 (UTC) Received: from cap.home.8bytes.org (p549ad441.dip0.t-ipconnect.de [84.154.212.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id B198F10A2; Mon, 13 Sep 2021 17:56:23 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Cc: Eric Biederman , kexec@lists.infradead.org, Joerg Roedel , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , Arvind Sankar , Joerg Roedel , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 11/12] x86/sev: Handle CLFLUSH MMIO events Date: Mon, 13 Sep 2021 17:56:02 +0200 Message-Id: <20210913155603.28383-12-joro@8bytes.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913155603.28383-1-joro@8bytes.org> References: <20210913155603.28383-1-joro@8bytes.org> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Joerg Roedel Handle CLFLUSH instruction to MMIO memory in the #VC handler. The instruction is ignored by the handler, as the Hypervisor is responsible for cache management of emulated MMIO memory. Signed-off-by: Joerg Roedel --- arch/x86/kernel/sev-shared.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index a7a0793c4f98..682fa202444f 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -632,6 +632,15 @@ static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb, long *reg_data; switch (insn->opcode.bytes[1]) { + /* CLFLUSH */ + case 0xae: + /* + * Ignore CLFLUSHes - those go to emulated MMIO anyway and the + * hypervisor is responsible for cache management. + */ + ret = ES_OK; + break; + /* MMIO Read w/ zero-extension */ case 0xb6: bytes = 1; -- 2.33.0