From patchwork Tue Feb 28 03:18:07 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 143318 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 51D3CB6FA3 for ; Tue, 28 Feb 2012 14:18:38 +1100 (EST) Received: from localhost ([::1]:45382 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S2DaG-0007nh-26 for incoming@patchwork.ozlabs.org; Mon, 27 Feb 2012 22:18:36 -0500 Received: from eggs.gnu.org ([208.118.235.92]:35410) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S2Da8-0007na-M0 for qemu-devel@nongnu.org; Mon, 27 Feb 2012 22:18:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S2Da6-0000NT-Em for qemu-devel@nongnu.org; Mon, 27 Feb 2012 22:18:28 -0500 Received: from ozlabs.org ([203.10.76.45]:38724) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S2Da6-0000N7-2c; Mon, 27 Feb 2012 22:18:26 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 25AF4B6F62; Tue, 28 Feb 2012 14:18:22 +1100 (EST) From: David Gibson To: agraf@suse.de Date: Tue, 28 Feb 2012 14:18:07 +1100 Message-Id: <1330399093-20384-2-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 1.7.9 In-Reply-To: <1330399093-20384-1-git-send-email-david@gibson.dropbear.id.au> References: <1330399093-20384-1-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: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, anthony@codemonkey.ws, David Gibson Subject: [Qemu-devel] [PATCH 1/7] pseries: Don't try to munmap() a malloc()ed TCE table 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 For the pseries machine, TCE (IOMMU) tables can either be directly malloc()ed in qemu or, when running on a KVM which supports it, mmap()ed from a KVM ioctl. The latter option is used when available, because it allows the (frequent bottlenext) H_PUT_TCE hypercall to be KVM accelerated. However, even when KVM is persent, TCE acceleration is not always possible. Only KVM HV supports this ioctl(), not KVM PR, or the kernel could run out of contiguous memory to allocate the new table. In this case we need to fall back on the malloc()ed table. When a device is removed, and we need to remove the TCE table, we need to either munmap() or free() the table as appropriate for how it was allocated. The code is supposed to do that, but we buggily fail to initialize the tcet->fd variable in the malloc() case, which is used as a flag to determine which is the right choice. This patch fixes the bug, and cleans up error messages relating to this path while we're at it. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: David Gibson --- target-ppc/kvm.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 50cfa02..90c6941 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -843,12 +843,18 @@ void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd) int fd; void *table; + /* Must set fd to -1 so we don't try to munmap when called for + * destroying the table, which the upper layers -will- do + */ + *pfd = -1; if (!cap_spapr_tce) { return NULL; } fd = kvm_vm_ioctl(kvm_state, KVM_CREATE_SPAPR_TCE, &args); if (fd < 0) { + fprintf(stderr, "KVM: Failed to create TCE table for liobn 0x%x\n", + liobn); return NULL; } @@ -857,6 +863,8 @@ void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd) table = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (table == MAP_FAILED) { + fprintf(stderr, "KVM: Failed to map TCE table for liobn 0x%x\n", + liobn); close(fd); return NULL; } @@ -876,8 +884,8 @@ int kvmppc_remove_spapr_tce(void *table, int fd, uint32_t window_size) len = (window_size / SPAPR_VIO_TCE_PAGE_SIZE)*sizeof(VIOsPAPR_RTCE); if ((munmap(table, len) < 0) || (close(fd) < 0)) { - fprintf(stderr, "KVM: Unexpected error removing KVM SPAPR TCE " - "table: %s", strerror(errno)); + fprintf(stderr, "KVM: Unexpected error removing TCE table: %s", + strerror(errno)); /* Leak the table */ }