From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50421) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VL5vv-0008HJ-Sc for qemu-devel@nongnu.org; Sun, 15 Sep 2013 02:35:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VL5vo-0005J7-Hx for qemu-devel@nongnu.org; Sun, 15 Sep 2013 02:35:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57890) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VL5vo-0005J2-6t for qemu-devel@nongnu.org; Sun, 15 Sep 2013 02:35:40 -0400 Message-ID: <1379226946.2117.2.camel@localhost.localdomain> From: Marcel Apfelbaum Date: Sun, 15 Sep 2013 09:35:46 +0300 In-Reply-To: <20130914210846.GA4480@redhat.com> References: <1378725696-13590-1-git-send-email-marcel.a@redhat.com> <1378725696-13590-3-git-send-email-marcel.a@redhat.com> <20130914210846.GA4480@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH RFC v3 2/2] hw/pci: handle unassigned pci addresses List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: pbonzini@redhat.com, aliguori@us.ibm.com, jan.kiszka@siemens.com, qemu-devel@nongnu.org, peter.maydell@linaro.org On Sun, 2013-09-15 at 00:08 +0300, Michael S. Tsirkin wrote: > On Mon, Sep 09, 2013 at 02:21:36PM +0300, Marcel Apfelbaum wrote: > > Created a MemoryRegion with negative priority that > > spans over all the pci address space. > > It "intercepts" the accesses to unassigned pci > > address space and will follow the pci spec: > > 1. returns -1 on read > > 2. does nothing on write > > 3. sets the RECEIVED MASTER ABORT bit in the STATUS register > > of the device that initiated the transaction > > > > Note: This implementation assumes that all the reads/writes to > > the pci address space are done by the cpu. > > > > Signed-off-by: Marcel Apfelbaum > > --- > > Changes from v1: > > - "pci-unassigned-mem" MemoryRegion resides now in PCIBus and not on > > various Host Bridges > > - "pci-unassgined-mem" does not have a ".valid.accept" field and > > implements read write methods > > > > hw/pci/pci.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > > include/hw/pci/pci_bus.h | 1 + > > 2 files changed, 47 insertions(+) > > > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > > index d00682e..b6a8026 100644 > > --- a/hw/pci/pci.c > > +++ b/hw/pci/pci.c > > @@ -283,6 +283,43 @@ const char *pci_root_bus_path(PCIDevice *dev) > > return rootbus->qbus.name; > > } > > > > +static void unassigned_mem_access(PCIBus *bus) > > +{ > > + /* FIXME assumption: memory access to the pci address > > + * space is always initiated by the host bridge > > + * (device 0 on the bus) */ > > + PCIDevice *d = bus->devices[0]; > > + if (!d) { > > + return; > > + } > > + > > + pci_word_test_and_set_mask(d->config + PCI_STATUS, > > + PCI_STATUS_REC_MASTER_ABORT); > > +} > > + > > +static uint64_t unassigned_mem_read(void *opaque, hwaddr addr, unsigned size) > > +{ > > + PCIBus *bus = opaque; > > + unassigned_mem_access(bus); > > + > > + return -1ULL; > > +} > > + > > +static void unassigned_mem_write(void *opaque, hwaddr addr, uint64_t val, > > + unsigned size) > > +{ > > + PCIBus *bus = opaque; > > + unassigned_mem_access(bus); > > +} > > + > > +static const MemoryRegionOps unassigned_mem_ops = { > > + .read = unassigned_mem_read, > > + .write = unassigned_mem_write, > > + .endianness = DEVICE_NATIVE_ENDIAN, > > +}; > > + > > +#define UNASSIGNED_MEM_PRIORITY -1 > > + > > This really should be "lowest available priority" correct? Yes, it should > > So how about making it INT_MIN then? Seems right, thanks Marcel > > > static void pci_bus_init(PCIBus *bus, DeviceState *parent, > > const char *name, > > MemoryRegion *address_space_mem, > > @@ -294,6 +331,15 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent, > > bus->address_space_mem = address_space_mem; > > bus->address_space_io = address_space_io; > > > > + > > + memory_region_init_io(&bus->unassigned_mem, OBJECT(bus), > > + &unassigned_mem_ops, bus, "pci-unassigned", > > + memory_region_size(bus->address_space_mem)); > > + memory_region_add_subregion_overlap(bus->address_space_mem, > > + bus->address_space_mem->addr, > > + &bus->unassigned_mem, > > + UNASSIGNED_MEM_PRIORITY); > > + > > /* host bridge */ > > QLIST_INIT(&bus->child); > > > > diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h > > index 9df1788..4cc25a3 100644 > > --- a/include/hw/pci/pci_bus.h > > +++ b/include/hw/pci/pci_bus.h > > @@ -23,6 +23,7 @@ struct PCIBus { > > PCIDevice *parent_dev; > > MemoryRegion *address_space_mem; > > MemoryRegion *address_space_io; > > + MemoryRegion unassigned_mem; > > > > QLIST_HEAD(, PCIBus) child; /* this will be replaced by qdev later */ > > QLIST_ENTRY(PCIBus) sibling;/* this will be replaced by qdev later */ > > -- > > 1.8.3.1