From f8553be3140a1f77ab3c4e218ecc79437534d1ea Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 26 Jan 2018 02:21:25 +0100 Subject: [PATCH 1/4] qdev: Fix assert in PCI address property when used by vfio-pci RH-Author: Alex Williamson Message-id: <20180126021938.25889.98354.stgit@gimli.home> Patchwork-id: 78707 O-Subject: [RHEL-7.5 qemu-kvm PATCH] qdev: Fix assert in PCI address property when used by vfio-pci Bugzilla: 1538866 RH-Acked-by: Auger Eric RH-Acked-by: Eduardo Habkost RH-Acked-by: Laszlo Ersek From: Daniel Oram Allow the PCIHostDeviceAddress structure to work as the host property in vfio-pci when it has it's default value of all fields set to ~0. In this form the property indicates a non-existant device but given the field bit sizes gets asserted as excess (and invalid) precision overflows the string buffer. The BDF of an invalid device "FFFF:FF:FF.F" is returned instead. Signed-off-by: Daniel Oram Reviewed-by: Alex Williamson Message-Id: <71f06765c4ba16dcd71cbf78e877619948f04ed9.1478777270.git.daniel.oram@gmail.com> Signed-off-by: Eduardo Habkost (cherry picked from commit 00b8702581f312aa46f797a8b3153d9b2892d967) Signed-off-by: Miroslav Rezanina --- hw/core/qdev-properties.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c index dc8ae69..a61250e 100644 --- a/hw/core/qdev-properties.c +++ b/hw/core/qdev-properties.c @@ -728,13 +728,19 @@ static void get_pci_host_devaddr(Object *obj, Visitor *v, void *opaque, DeviceState *dev = DEVICE(obj); Property *prop = opaque; PCIHostDeviceAddress *addr = qdev_get_prop_ptr(dev, prop); - char buffer[] = "xxxx:xx:xx.x"; + char buffer[] = "ffff:ff:ff.f"; char *p = buffer; int rc = 0; - rc = snprintf(buffer, sizeof(buffer), "%04x:%02x:%02x.%d", - addr->domain, addr->bus, addr->slot, addr->function); - assert(rc == sizeof(buffer) - 1); + /* + * Catch "invalid" device reference from vfio-pci and allow the + * default buffer representing the non-existant device to be used. + */ + if (~addr->domain || ~addr->bus || ~addr->slot || ~addr->function) { + rc = snprintf(buffer, sizeof(buffer), "%04x:%02x:%02x.%0d", + addr->domain, addr->bus, addr->slot, addr->function); + assert(rc == sizeof(buffer) - 1); + } visit_type_str(v, &p, name, errp); } -- 1.8.3.1