From: "Michael S. Tsirkin" <mst@redhat.com>
To: Alexey Korolev <alexey.korolev@endace.com>
Cc: sfd@endace.com, yamahata@valinux.co.jp,
Kevin O'Connor <kevin@koconnor.net>,
seabios@seabios.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 2/3] Add a new PCI region type to supports 64 bit ranges
Date: Thu, 29 Dec 2011 18:16:59 +0200 [thread overview]
Message-ID: <20111229161650.GC2300@redhat.com> (raw)
In-Reply-To: <4EFBFB75.1060609@endace.com>
On Thu, Dec 29, 2011 at 06:32:37PM +1300, Alexey Korolev wrote:
>
> >>@@ -69,6 +72,8 @@ static enum pci_region_type pci_addr_to_type(u32 addr)
> >> {
> >> if (addr& PCI_BASE_ADDRESS_SPACE_IO)
> >> return PCI_REGION_TYPE_IO;
> >>+ if (addr& PCI_BASE_ADDRESS_MEM_TYPE_64)
> >>+ return PCI_REGION_TYPE_PREFMEM_64;
> >This seems dangerous - a 64bit bar can be non-prefetchable - getting
> >this wrong could cause random (hard to debug) crashes.
> >
> Just out of curiosity - how this could happen? Having 64bit
> non-prefetchable BAR implies that the device is not behind
> any bridge (as bridges describe 64bit ranges for prefetchable
> memory only). Is it possible on nowadays systems?
Yes. qemu puts all devices directly on the root bus.
system devices are also commonly located on the root bus.
next prev parent reply other threads:[~2011-12-29 16:18 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-28 4:41 [Qemu-devel] [Seabios] [PATCH 0/3] 64bit PCI BARs allocations Alexey Korolev
2011-12-28 5:00 ` [Qemu-devel] [PATCH 1/3] Add new range above 4GB in _CRS table Alexey Korolev
2011-12-28 5:26 ` [Qemu-devel] [PATCH 2/3] Add a new PCI region type to supports 64 bit ranges Alexey Korolev
2011-12-28 11:30 ` Michael S. Tsirkin
2011-12-29 3:57 ` Alexey Korolev
2011-12-29 2:56 ` Kevin O'Connor
2011-12-29 5:00 ` Alexey Korolev
2011-12-30 5:57 ` Kevin O'Connor
2011-12-29 5:32 ` Alexey Korolev
2011-12-29 16:16 ` Michael S. Tsirkin [this message]
2012-01-03 15:14 ` Gerd Hoffmann
2012-01-04 3:10 ` Kevin O'Connor
2011-12-28 5:35 ` [Qemu-devel] [PATCH 3/3] Changes related to secondary buses and 64bit regions Alexey Korolev
2011-12-28 6:30 ` [Qemu-devel] [SeaBIOS] " Alexey Korolev
2011-12-28 11:43 ` [Qemu-devel] " Michael S. Tsirkin
2011-12-29 5:40 ` Alexey Korolev
2011-12-29 16:18 ` Michael S. Tsirkin
2011-12-30 4:56 ` Alexey Korolev
2011-12-29 5:41 ` Alexey Korolev
2011-12-29 16:19 ` Michael S. Tsirkin
2011-12-29 16:21 ` Michael S. Tsirkin
2011-12-30 5:10 ` Alexey Korolev
2011-12-30 6:02 ` Kevin O'Connor
2011-12-30 5:10 ` Alexey Korolev
2011-12-30 6:22 ` Kevin O'Connor
2011-12-30 7:05 ` Alexey Korolev
2011-12-30 5:03 ` Kevin O'Connor
2011-12-28 11:43 ` [Qemu-devel] [Seabios] [PATCH 0/3] 64bit PCI BARs allocations Michael S. Tsirkin
2011-12-29 9:20 ` Alexey Korolev
2011-12-29 16:21 ` Michael S. Tsirkin
2011-12-29 22:17 ` Alexey Korolev
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