From patchwork Wed Sep 26 03:12:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 186939 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id F1A682C008F for ; Wed, 26 Sep 2012 13:35:50 +1000 (EST) Received: from localhost ([::1]:55111 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TGi2y-0006os-N5 for incoming@patchwork.ozlabs.org; Tue, 25 Sep 2012 23:12:24 -0400 Received: from eggs.gnu.org ([208.118.235.92]:48409) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TGi2I-00057i-KS for qemu-devel@nongnu.org; Tue, 25 Sep 2012 23:11:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TGi2H-0002iI-4c for qemu-devel@nongnu.org; Tue, 25 Sep 2012 23:11:42 -0400 Received: from ozlabs.org ([203.10.76.45]:55023) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TGi2G-0002hm-QZ; Tue, 25 Sep 2012 23:11:41 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id EE90E2C0094; Wed, 26 Sep 2012 13:11:38 +1000 (EST) From: David Gibson To: agraf@suse.de Date: Wed, 26 Sep 2012 13:12:20 +1000 Message-Id: <1348629141-8719-6-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1348629141-8719-1-git-send-email-david@gibson.dropbear.id.au> References: <1348629141-8719-1-git-send-email-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 203.10.76.45 Cc: aliguori@us.ibm.com, qemu-stable@nongnu.org, qemu-ppc@nongnu.org, qemu-devel@nongnu.org, David Gibson Subject: [Qemu-devel] [PATCH 5/6] pseries: Don't test for MSR_PR for hypercalls under KVM X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org PAPR hypercalls should only be invoked from the guest kernel, not guest user programs, that is, with MSR[PR]=0. Currently we check this in spapr_hypercall, returning H_PRIVILEGE if MSR[PR]=1. However, under KVM the state of MSR[PR] is already checked by the host kernel before passing the hypercall to qemu, making this check redundant. Worse, however, we don't generally synchronize KVM and qemu state on the hypercall path, meaning that qemu could incorrectly reject a hypercall because it has a stale MSR value. This patch fixes the problem by moving the privilege test exclusively to the TCG hypercall path. Cc: qemu-stable@nongnu.org Signed-off-by: David Gibson --- hw/spapr.c | 7 ++++++- hw/spapr_hcall.c | 5 ----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/hw/spapr.c b/hw/spapr.c index 079825a..e6bf522 100644 --- a/hw/spapr.c +++ b/hw/spapr.c @@ -573,7 +573,12 @@ static uint64_t translate_kernel_address(void *opaque, uint64_t addr) static void emulate_spapr_hypercall(CPUPPCState *env) { - env->gpr[3] = spapr_hypercall(env, env->gpr[3], &env->gpr[4]); + if (msr_pr) { + hcall_dprintf("Hypercall made with MSR[PR]=1\n"); + env->gpr[3] = H_PRIVILEGE; + } else { + env->gpr[3] = spapr_hypercall(env, env->gpr[3], &env->gpr[4]); + } } static void spapr_reset_htab(sPAPREnvironment *spapr) diff --git a/hw/spapr_hcall.c b/hw/spapr_hcall.c index 826ca67..194d9c2 100644 --- a/hw/spapr_hcall.c +++ b/hw/spapr_hcall.c @@ -681,11 +681,6 @@ void spapr_register_hypercall(target_ulong opcode, spapr_hcall_fn fn) target_ulong spapr_hypercall(CPUPPCState *env, target_ulong opcode, target_ulong *args) { - if (msr_pr) { - hcall_dprintf("Hypercall made with MSR[PR]=1\n"); - return H_PRIVILEGE; - } - if ((opcode <= MAX_HCALL_OPCODE) && ((opcode & 0x3) == 0)) { spapr_hcall_fn fn = papr_hypercall_table[opcode / 4];