From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MxJOU-0001d4-S0 for qemu-devel@nongnu.org; Mon, 12 Oct 2009 07:48:50 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MxJOQ-0001b2-ED for qemu-devel@nongnu.org; Mon, 12 Oct 2009 07:48:50 -0400 Received: from [199.232.76.173] (port=57185 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MxJOQ-0001ax-1t for qemu-devel@nongnu.org; Mon, 12 Oct 2009 07:48:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21393) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MxJOP-0005JQ-Cf for qemu-devel@nongnu.org; Mon, 12 Oct 2009 07:48:45 -0400 Date: Mon, 12 Oct 2009 13:48:41 +0200 From: Gleb Natapov Message-ID: <20091012114841.GF16702@redhat.com> References: <1255287547-28329-1-git-send-email-gleb@redhat.com> <1255287547-28329-3-git-send-email-gleb@redhat.com> <20091011215356.GC6411@redhat.com> <20091012065024.GS16702@redhat.com> <20091012095225.GA11741@redhat.com> <20091012100821.GE16702@redhat.com> <20091012110335.GA12546@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091012110335.GA12546@redhat.com> Subject: [Qemu-devel] Re: [PATCH 3/5] Use the correct mask to size the PCI option ROM BAR. List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: kevin@koconnor.net, qemu-devel@nongnu.org On Mon, Oct 12, 2009 at 01:03:36PM +0200, Michael S. Tsirkin wrote: > On Mon, Oct 12, 2009 at 12:08:21PM +0200, Gleb Natapov wrote: > > On Mon, Oct 12, 2009 at 11:52:25AM +0200, Michael S. Tsirkin wrote: > > > On Mon, Oct 12, 2009 at 08:50:24AM +0200, Gleb Natapov wrote: > > > > Send patch with your favorite interpretation to qemu pcbios/seabios. > > > > The regression concern from my previous mail applicable here as well. > > > > > > Okay. Can you ack the following? > > > > > I can if you'll add PCI spec reference for me to double check. > > > > Also I prefer strict spec reading :) > > OK, the issue is that reserved bits in BARs are not > defined as read-only. So here's a strict one: > can you ack? > > ---> > > seabios: fix ROM and I/O sizing > > For ROM BARs, bit 0 is writeable (enable bit), which we not > only don't want to set, but it will stick and make us think > it's an I/O port resource. > Further, PCI spec defines the following bits as reserved: > - bit 1 in I/O BAR > - bits 10:1 in ROM BAR > and we should be careful and write 0 there. > For memory, bits 0-3 are reserved, so it's safe to handle it > in the same way as I/O. > > See 6.2.5.1 for I/O and memory, and 6.2.5.2 for ROM; > pages 225 and 228 in PCI spec revision 3.0. > Section 6.2.5.1 says: Software saves the original value of the Base Address register, writes 0 FFFF FFFFh to the register, then reads it back. Section 6.2.5.2 says: Device independent configuration software can determine how much address space the device requires by writing a value of all 1's to the address portion of the register and then reading the value back. (address portion are bits 31-11). So we should write PCI_ROM_ADDRESS_MASK in case of ROM and 0xffffffff in case of regular BAR. > See also Qemu pcbios commit 6ddb9f5c742b2b82b1755d7ec2a127f6e20e3806 > > Signed-off-by: Michael S. Tsirkin > --- > src/pciinit.c | 8 +++++--- > 1 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/src/pciinit.c b/src/pciinit.c > index 1d0f784..29b3901 100644 > --- a/src/pciinit.c > +++ b/src/pciinit.c > @@ -139,11 +139,13 @@ static void pci_bios_init_device(u16 bdf) > int ofs; > u32 val, size; > > - if (i == PCI_ROM_SLOT) > + if (i == PCI_ROM_SLOT) { > ofs = PCI_ROM_ADDRESS; > - else > + pci_config_writel(bdf, ofs, PCI_ROM_ADDRESS_MASK); > + } else { > ofs = PCI_BASE_ADDRESS_0 + i * 4; > - pci_config_writel(bdf, ofs, 0xffffffff); > + pci_config_writel(bdf, ofs, PCI_BASE_ADDRESS_IO_MASK); > + } > val = pci_config_readl(bdf, ofs); > if (val != 0) { > size = (~(val & ~0xf)) + 1; > -- > 1.6.3.3 > > -- Gleb.