From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cGiUj-0000cA-JI for qemu-devel@nongnu.org; Tue, 13 Dec 2016 03:31:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cGiUe-0008OV-OY for qemu-devel@nongnu.org; Tue, 13 Dec 2016 03:31:29 -0500 Received: from mga04.intel.com ([192.55.52.120]:33775) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cGiUe-0008N4-Fo for qemu-devel@nongnu.org; Tue, 13 Dec 2016 03:31:24 -0500 Date: Mon, 12 Dec 2016 16:16:50 +0800 From: "Liu, Yi L" Message-ID: <20161212081650.GA13155@gmail.com> References: <1481020588-4245-1-git-send-email-peterx@redhat.com> <1481020588-4245-2-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1481020588-4245-2-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [RFC PATCH 01/13] intel_iommu: allocate new key when creating new address space List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, tianyu.lan@intel.com, kevin.tian@intel.com, mst@redhat.com, jan.kiszka@siemens.com, bd.aviv@gmail.com, alex.williamson@redhat.com, jasowang@redhat.com, yi.liu@intel.com On Tue, Dec 06, 2016 at 06:36:16PM +0800, Peter Xu wrote: > From: Jason Wang > > We use the pointer to stack for key for new address space, this will > break hash table searching, fixing by g_malloc() a new key instead. > > Cc: Michael S. Tsirkin > Cc: Paolo Bonzini > Cc: Richard Henderson > Cc: Eduardo Habkost > Acked-by: Peter Xu > Signed-off-by: Jason Wang > Signed-off-by: Peter Xu > --- > hw/i386/intel_iommu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index 708770e..92e4064 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -2426,12 +2426,13 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn) > VTDAddressSpace *vtd_dev_as; > > if (!vtd_bus) { > + uintptr_t *new_key = g_malloc(sizeof(*new_key)); > + *new_key = (uintptr_t)bus; > /* No corresponding free() */ > vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \ > X86_IOMMU_PCI_DEVFN_MAX); > vtd_bus->bus = bus; > - key = (uintptr_t)bus; > - g_hash_table_insert(s->vtd_as_by_busptr, &key, vtd_bus); > + g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus); Hi Peter, Your fix seems to answer an issue I encountered back in Oct. The symptom is: use the same bus value to searcha previous inserted entry in s->vtd_as_by_busptr, the result is not found. really grt fix. could explain it a bit on why this change would fix the issue? Regards, Yi L > } > > vtd_dev_as = vtd_bus->dev_as[devfn]; > -- > 2.7.4 > >