From: Gerd Hoffmann <kraxel@redhat.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: qemu-devel@nongnu.org, anthony@codemonkey.ws,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH 07/13] usb: Convert usb_packet_{map, unmap} to universal DMA helpers
Date: Tue, 19 Jun 2012 15:42:38 +0200 [thread overview]
Message-ID: <4FE081CE.1060001@redhat.com> (raw)
In-Reply-To: <1340087992-2399-8-git-send-email-benh@kernel.crashing.org>
Hi,
> Note that usb_packet_map() invokes dma_memory_map() with a NULL invalidate
> callback function. When IOMMU support is added, this will mean that
> usb_packet_map() and the corresponding usb_packet_unmap() must be called in
> close proximity without dropping the qemu device lock
Well, that isn't guaranteed ...
> - otherwise the guest
> might invalidate IOMMU mappings while they are still in use by the device
> code.
Guest tearing down mapping while usb packets using them are still in
flight would be a guest bug. Still not impossible to happen though. How
is this case supposed to be handled?
cheers,
Gerd
next prev parent reply other threads:[~2012-06-19 13:43 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 6:39 [Qemu-devel] [PATCH 00/13] iommu series Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 01/13] Better support for dma_addr_t variables Benjamin Herrenschmidt
2012-06-20 21:14 ` Anthony Liguori
2012-06-20 21:29 ` Benjamin Herrenschmidt
2012-06-21 1:44 ` David Gibson
2012-06-20 22:26 ` Peter Maydell
2012-06-20 22:59 ` Anthony Liguori
2012-06-21 7:54 ` Peter Maydell
2012-06-22 1:58 ` Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 02/13] Implement cpu_physical_memory_set() Benjamin Herrenschmidt
2012-06-20 21:15 ` Anthony Liguori
2012-06-20 21:30 ` Benjamin Herrenschmidt
2012-06-20 21:37 ` Anthony Liguori
2012-06-21 1:45 ` David Gibson
2012-06-21 1:46 ` David Gibson
2012-06-21 2:50 ` Benjamin Herrenschmidt
2012-06-22 1:58 ` Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 03/13] iommu: Add universal DMA helper functions Benjamin Herrenschmidt
2012-06-20 21:16 ` Anthony Liguori
2012-06-20 21:32 ` Michael S. Tsirkin
2012-06-20 21:38 ` Anthony Liguori
2012-06-20 21:42 ` Michael S. Tsirkin
2012-06-20 21:46 ` Anthony Liguori
2012-06-20 22:00 ` Michael S. Tsirkin
2012-06-20 21:33 ` Benjamin Herrenschmidt
2012-06-20 21:40 ` Michael S. Tsirkin
2012-06-20 22:01 ` Anthony Liguori
2012-06-21 1:48 ` David Gibson
2012-06-22 2:02 ` Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 04/13] usb-ohci: Use " Benjamin Herrenschmidt
2012-06-20 21:18 ` Anthony Liguori
2012-06-20 21:36 ` Benjamin Herrenschmidt
2012-06-20 21:40 ` Anthony Liguori
2012-06-20 22:02 ` Benjamin Herrenschmidt
2012-06-21 7:33 ` Michael S. Tsirkin
2012-06-21 12:55 ` Anthony Liguori
2012-06-21 14:10 ` Michael S. Tsirkin
2012-06-22 2:28 ` Benjamin Herrenschmidt
2012-06-21 6:43 ` Gerd Hoffmann
2012-06-19 6:39 ` [Qemu-devel] [PATCH 05/13] iommu: Make sglists and dma_bdrv helpers use new universal DMA helpers Benjamin Herrenschmidt
2012-06-20 21:21 ` Anthony Liguori
2012-06-20 21:37 ` Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 06/13] ide/ahci: Use universal DMA helper functions Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 07/13] usb: Convert usb_packet_{map, unmap} to universal DMA helpers Benjamin Herrenschmidt
2012-06-19 13:42 ` Gerd Hoffmann [this message]
2012-06-19 20:23 ` Benjamin Herrenschmidt
2012-06-20 3:14 ` David Gibson
2012-06-20 3:52 ` Benjamin Herrenschmidt
2012-06-21 1:42 ` David Gibson
2012-06-20 6:25 ` Gerd Hoffmann
2012-06-20 9:25 ` Benjamin Herrenschmidt
2012-06-20 9:54 ` Gerd Hoffmann
2012-06-19 6:39 ` [Qemu-devel] [PATCH 08/13] iommu: Introduce IOMMU emulation infrastructure Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 09/13] iommu: Add facility to cancel in-use dma memory maps Benjamin Herrenschmidt
2012-06-20 21:25 ` Anthony Liguori
2012-06-20 21:52 ` Benjamin Herrenschmidt
2012-06-22 3:18 ` Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 10/13] pseries: Convert sPAPR TCEs to use generic IOMMU infrastructure Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 11/13] iommu: Allow PCI to use " Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 12/13] pseries: Implement IOMMU and DMA for PAPR PCI devices Benjamin Herrenschmidt
2012-06-19 6:39 ` [Qemu-devel] [PATCH 13/13] Add a memory barrier to DMA functions Benjamin Herrenschmidt
2012-06-20 21:12 ` [Qemu-devel] [PATCH 00/13] iommu series Anthony Liguori
-- strict thread matches above, loose matches on Subject: below --
2012-05-10 4:48 [Qemu-devel] [PATCH 00/13] IOMMU infrastructure Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 07/13] usb: Convert usb_packet_{map, unmap} to universal DMA helpers Benjamin Herrenschmidt
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