From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40117) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UzrmX-0006XJ-TE for qemu-devel@nongnu.org; Thu, 18 Jul 2013 13:14:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UzrmW-00029I-OT for qemu-devel@nongnu.org; Thu, 18 Jul 2013 13:14:21 -0400 Message-ID: <51E82268.3060809@suse.de> Date: Thu, 18 Jul 2013 19:14:16 +0200 From: =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= MIME-Version: 1.0 References: <1373946643-10609-1-git-send-email-qiudayu@linux.vnet.ibm.com> <51E80954.1030708@linux.vnet.ibm.com> In-Reply-To: <51E80954.1030708@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] Bug Fix:Segmentation fault when use usb-ehci device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mike Qiu Cc: agraf@suse.de, aik@ozlabs.ru, qemu-devel@nongnu.org, xiaoguangrong@linux.vnet.ibm.com, qemu-ppc@nongnu.org, Gerd Hoffmann , Paolo Bonzini Hi, Am 18.07.2013 17:27, schrieb Mike Qiu: > Hi all >=20 > Any comments ? You should've CCed the USB maintainer whose file you are touching for review rather than just ppc people, see ./MAINTAINERS. There's some typos in the commit message, but the change looks okay to me - although there were discussions to catch this on the memory API side of things instead. Regards, Andreas >=20 > Thanks > Mike > 2013/7/16 11:50, Mike Qiu wrote: >> For usb-ehci in qemu, its caps just has read() operation, >> the write() operation does not exist. >> >> This cause a Segmentation fault when use usb-ehci device in ppc64 >> platform. >> >> here is gdb output: >> >> Program received signal SIGSEGV, Segmentation fault. >> [Switching to Thread 0x3fffa7fcef20 (LWP 6793)] >> 0x00000000103f5244 in memory_region_oldmmio_write_accessor >> (opaque=3D0x113e9e78, addr=3D9, value=3D0x3fffa7fce088, >> size=3D1, shift=3D0, mask=3D255) at /home/Mike/qemu-impreza/memory.c:3= 84 >> 384 mr->ops->old_mmio.write[ctz32(size)](mr->opaque, addr, tmp); >> (gdb) p *mr->ops >> $1 =3D {read =3D @0x10716f68: 0x1020699c , write =3D 0= , >> endianness =3D DEVICE_LITTLE_ENDIAN, valid =3D {min_access_size =3D= 1, >> max_access_size =3D 4, unaligned =3D false, accepts =3D 0}, impl =3D >> {min_access_size =3D 1, max_access_size =3D 1, unaligned =3D false}= , >> old_mmio =3D {read =3D {0, 0, 0}, write =3D {0, 0, 0}}} >> >> Becasue function write() of mr->ops has not been implement, in >> function memory_region_dispatch_write(), it call >> oldmmio write accessor, but at the same time old_mmio still not >> been implement by default. >> >> That is the root cause of the Segmentation fault. >> >> To solve this problem, add empty function: ehci_caps_write() >> >> Signed-off-by: Mike Qiu >> --- >> hw/usb/hcd-ehci.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c >> index 67e4b24..6c8a439 100644 >> --- a/hw/usb/hcd-ehci.c >> +++ b/hw/usb/hcd-ehci.c >> @@ -1072,6 +1072,12 @@ static void ehci_port_write(void *ptr, hwaddr a= ddr, >> trace_usb_ehci_portsc_change(addr + s->portscbase, addr >> 2, *po= rtsc, old); >> } >> >> +static void ehci_caps_write(void *ptr, hwaddr addr, uint64_t val, >> + unsigned size) >> +{ >> + /* nothing */ >> +} >> + >> static void ehci_opreg_write(void *ptr, hwaddr addr, >> uint64_t val, unsigned size) >> { >> @@ -2380,6 +2386,7 @@ static void ehci_frame_timer(void *opaque) >> >> static const MemoryRegionOps ehci_mmio_caps_ops =3D { >> .read =3D ehci_caps_read, >> + .write =3D ehci_caps_write, >> .valid.min_access_size =3D 1, >> .valid.max_access_size =3D 4, >> .impl.min_access_size =3D 1, >=20 >=20 --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=C3=B6rffer; HRB 16746 AG N=C3=BC= rnberg