From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38410) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsyzD-0005Yk-8S for qemu-devel@nongnu.org; Fri, 15 Sep 2017 18:21:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dsyz8-0008HJ-A1 for qemu-devel@nongnu.org; Fri, 15 Sep 2017 18:21:23 -0400 Date: Fri, 15 Sep 2017 19:21:13 -0300 From: Eduardo Habkost Message-ID: <20170915222113.GB10621@localhost.localdomain> References: <20170915090643.6043-1-otubo@redhat.com> <0d4bdcbb-3153-0064-d280-d9ca4f0671e4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0d4bdcbb-3153-0064-d280-d9ca4f0671e4@redhat.com> Subject: Re: [Qemu-devel] [PATCH] dma/i82374: avoid double creation of i82374 device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Eduardo Otubo , qemu-devel@nongnu.org, qemu-trivial@nongnu.org, Michael Tokarev , Markus Armbruster , Alexander Graf On Fri, Sep 15, 2017 at 12:18:11PM +0200, Paolo Bonzini wrote: > On 15/09/2017 11:06, Eduardo Otubo wrote: > > QEMU fails when used with the following command line: > > > > ./ppc64-softmmu/qemu-system-ppc64 -S -machine 40p,accel=tcg -device i82374 > > qemu-system-ppc64: hw/isa/isa-bus.c:110: isa_bus_dma: Assertion `!bus->dma[0] && !bus->dma[1]' failed. > > Aborted (core dumped) > > > > The 40p machine type already creates the device i82374. If specified in the > > command line, it will try to create it again, hence generating the error. The > > function isa_bus_dma() isn't supposed to be called twice for the same bus. One > > way to avoid this problem is to set user_creatable=false. > > > > A possible fix in a near future would be making > > isa_bus_dma()/DMA_init()/i82374_realize() return an error instead of asserting > > as well. > > > > Signed-off-by: Eduardo Otubo > > --- > > hw/dma/i82374.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/hw/dma/i82374.c b/hw/dma/i82374.c > > index 6c0f975df0..e76dea8dc7 100644 > > --- a/hw/dma/i82374.c > > +++ b/hw/dma/i82374.c > > @@ -139,6 +139,11 @@ static void i82374_class_init(ObjectClass *klass, void *data) > > dc->realize = i82374_realize; > > dc->vmsd = &vmstate_i82374; > > dc->props = i82374_properties; > > + dc->user_creatable = false; > > + /* > > + * Reason: i82374_realize() crashes (assertion failure inside isa_bus_dma() > > + * if the device is instantiated twice. > > + */ > > } > > > > static const TypeInfo i82374_info = { > > > > This breaks "make check", doesn't it? Why would it? I don't see any test code using -device i82374. (endianness-test uses -device i82378). > > v2 should be the one that returns an error instead of asserting. I agree that returning an error is better. -- Eduardo