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 0925A6D11 for ; Wed, 19 May 2021 13:53:15 +0000 (UTC) Received: from cap.home.8bytes.org (p549ad305.dip0.t-ipconnect.de [84.154.211.5]) (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 7FCAC50F; Wed, 19 May 2021 15:53:12 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org, Hyunwook Baek Cc: Joerg Roedel , 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 , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 8/8] x86/sev-es: Propagate #GP if getting linear instruction address failed Date: Wed, 19 May 2021 15:52:51 +0200 Message-Id: <20210519135251.30093-9-joro@8bytes.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210519135251.30093-1-joro@8bytes.org> References: <20210519135251.30093-1-joro@8bytes.org> 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 When an instruction is fetched from user-space, segmentation needs to be taken into account. This means that getting the linear address of an instruction can fail. Hardware would raise a #GP exception in that case, but the #VC exception handler would emulate it as a page-fault. The insn_fetch_from_user*() functions now provide the relevant information in case of an failure. Use that and propagate a #GP when the linear address of an instruction to fetch could not be calculated. Signed-off-by: Joerg Roedel --- arch/x86/kernel/sev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 1edb6cd5e308..4736290361e4 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -261,11 +261,16 @@ static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt) int insn_bytes = 0, res; res = insn_fetch_from_user_inatomic(ctxt->regs, buffer, &insn_bytes); - if (res) { + if (res == -EFAULT) { ctxt->fi.vector = X86_TRAP_PF; ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; ctxt->fi.cr2 = ctxt->regs->ip; return ES_EXCEPTION; + } else if (res == -EINVAL) { + ctxt->fi.vector = X86_TRAP_GP; + ctxt->fi.error_code = 0; + ctxt->fi.cr2 = 0; + return ES_EXCEPTION; } if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes)) -- 2.31.1