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2012-06-27Add a memory barrier to DMA functionsBenjamin Herrenschmidt1-2/+51
The emulated devices can run simultaneously with the guest, so we need to be careful with ordering of load and stores done by them to the guest system memory, which need to be observed in the right order by the guest operating system. This adds a barrier call to the basic DMA read/write ops which is currently implemented as a smp_mb(), but could be later improved for more fine grained control of barriers. Additionally, a _relaxed() variant of the accessors is provided to easily convert devices who would be performance sensitive and negatively impacted by the change. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-06-27iommu: Introduce IOMMU emulation infrastructureDavid Gibson1-21/+87
This patch adds the basic infrastructure necessary to emulate an IOMMU visible to the guest. The DMAContext structure is extended with information and a callback describing the translation, and the various DMA functions used by devices will now perform IOMMU translation using this callback. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-06-27iommu: Make sglists and dma_bdrv helpers use new universal DMA helpersDavid Gibson1-1/+2
dma-helpers.c contains a number of helper functions for doing scatter/gather DMA, and various block device related DMA. Currently, these directly access guest memory using cpu_physical_memory_*(), assuming no IOMMU translation. This patch updates this code to use the new universal DMA helper functions. qemu_sglist_init() now takes a DMAContext * to describe the DMA address space in which the scatter/gather will take place. We minimally update the callers qemu_sglist_init() to pass NULL (i.e. no translation, same as current behaviour). Some of those callers should pass something else in some cases to allow proper IOMMU translation in future, but that will be fixed in later patches. Cc: Kevin Wolf <kwolf@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-06-27iommu: Add universal DMA helper functionsDavid Gibson1-0/+95
Not that long ago, every device implementation using DMA directly accessed guest memory using cpu_physical_memory_*(). This meant that adding support for a guest visible IOMMU would require changing every one of these devices to go through IOMMU translation. Shortly before qemu 1.0, I made a start on fixing this by providing helper functions for PCI DMA. These are currently just stubs which call the direct access functions, but mean that an IOMMU can be implemented in one place, rather than for every PCI device. Clearly, this doesn't help for non PCI devices, which could also be IOMMU translated on some platforms. It is also problematic for the devices which have both PCI and non-PCI version (e.g. OHCI, AHCI) - we cannot use the the pci_dma_*() functions, because they assume the presence of a PCIDevice, but we don't want to have to check between pci_dma_*() and cpu_physical_memory_*() every time we do a DMA in the device code. This patch makes the first step on addressing both these problems, by introducing new (stub) dma helper functions which can be used for any DMA capable device. These dma functions take a DMAContext *, a new (currently empty) variable describing the DMA address space in which the operation is to take place. NULL indicates untranslated DMA directly into guest physical address space. The intention is that in future non-NULL values will given information about any necessary IOMMU translation. DMA using devices must obtain a DMAContext (or, potentially, contexts) from their bus or platform. For now this patch just converts the PCI wrappers to be implemented in terms of the universal wrappers, converting other drivers can take place over time. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-06-27Better support for dma_addr_t variablesDavid Gibson1-0/+1
A while back, we introduced the dma_addr_t type, which is supposed to be used for bus visible memory addresses. At present, this is an alias for target_phys_addr_t, but this will change when we eventually add support for guest visible IOMMUs. There are some instances of target_phys_addr_t in the code now which should really be dma_addr_t, but can't be trivially converted due to missing features which this patch corrects. * We add DMA_ADDR_BITS analagous to TARGET_PHYS_ADDR_BITS. This is important where we need to make a compile-time (#if) based on the size of dma_addr_t. * We add a new helper macro to create device properties which take a dma_addr_t, currently an alias to DEFINE_PROP_TADDR(). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-04-10Merge remote-tracking branch 'kwolf/for-anthony' into stagingAnthony Liguori1-6/+6
* kwolf/for-anthony: (46 commits) qed: remove incoming live migration blocker qed: honor BDRV_O_INCOMING for incoming live migration migration: clear BDRV_O_INCOMING flags on end of incoming live migration qed: add bdrv_invalidate_cache to be called after incoming live migration blockdev: open images with BDRV_O_INCOMING on incoming live migration block: add a function to clear incoming live migration flags block: Add new BDRV_O_INCOMING flag to notice incoming live migration block stream: close unused files and update ->backing_hd qemu-iotests: Fix call syntax for qemu-io qemu-iotests: Fix call syntax for qemu-img qemu-iotests: Test unknown qcow2 header extensions qemu-iotests: qcow2.py sheepdog: fix send req helpers sheepdog: implement SD_OP_FLUSH_VDI operation block: bdrv_append() fixes qed: track dirty flag status qemu-img: add dirty flag status qed: image fragmentation statistics qemu-img: add image fragmentation statistics block: document job API ...
2012-04-07remove useless comments in dmaWanpeng Li1-1/+0
This comment is useless, just removes it and makes the codes clear. Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-04-05Use DMADirection type for dma_bdrv_ioDavid Gibson1-6/+6
Currently dma_bdrv_io() takes a 'to_dev' boolean parameter to determine the direction of DMA it is emulating. We already have a DMADirection enum designed specifically to encode DMA directions. This patch uses it for dma_bdrv_io() as well. This involves removing the DMADirection definition from the #ifdef it was inside, but since that only existed to protect the definition of dma_addr_t from places where config.h is not included, there wasn't any reason for it to be there in the first place. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Reviewed-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-22dma-helpers: add accounting wrappersPaolo Bonzini1-0/+3
The length of the transfer is already in the sglist, the wrapper simply fetches it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-02-22dma-helpers: add dma_buf_read and dma_buf_writePaolo Bonzini1-0/+3
These helpers do a full transfer from an in-memory buffer to target memory, with support for scatter/gather lists. It will be used to store the reply of an emulated command into a QEMUSGList provided by the adapter. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-02-22dma-helpers: make QEMUSGList target independentPaolo Bonzini1-7/+7
scsi-disk will manage scatter/gather list, but it does not create single entries so it remains target-independent. Make QEMUSGList available to it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-11-01Use dma_addr_t type for scatter/gather codeDavid Gibson1-5/+4
This patch uses the newly created dma_addr_t type throughout the scatter/gather handling code in dma-helpers.c whenever we need to represent a dma bus address. This makes a better distinction as to what is a bus address and what is a cpu physical address. Since we don't support IOMMUs yet, they can't be very different for now, but that will change in future, and this preliminary helps clarify what's going on. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-01Define DMA address and direction typesDavid Gibson1-0/+9
As a preliminary to adding more extensive DMA and IOMMU infrastructure support into qemu, this patch defines a dma_addr_t for storing DMA bus addresses and a DMADirection enum which describes whether a DMA is from an external device to main memory or from main memory to an external device. For now dma_addr_t is just defined to be target_phys_addr_t, but in future, we can change this to support machines where we have bus addresses which don't necessarily have the same format as CPU physical addresses. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-09-20dma-helpers: allow including from target-independent codePaolo Bonzini1-2/+6
Target-independent code cannot construct sglists, but it can take them from the outside as a black box. Allow this. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-19dma-helpers: rename is_write to to_devPaolo Bonzini1-1/+1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-04move QEMUSGList typedefGerd Hoffmann1-2/+2
Move the QEMUSGList typedef to qemu-common so it can easily be used. The actual struct definition stays in dma.h. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2011-06-15make dma_bdrv_io available to driversChristoph Hellwig1-0/+8
Make dma_bdrv_io available for drivers, and pass an explicit I/O function instead of hardcoding bdrv_aio_readv/bdrv_aio_writev. This is required to implement non-READ/WRITE dma commands in the ide driver, e.g. the upcoming TRIM support. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-10-01Revert "Get rid of _t suffix"Anthony Liguori1-5/+5
In the very least, a change like this requires discussion on the list. The naming convention is goofy and it causes a massive merge problem. Something like this _must_ be presented on the list first so people can provide input and cope with it. This reverts commit 99a0949b720a0936da2052cb9a46db04ffc6db29. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-01Get rid of _t suffixmalc1-5/+5
Some not so obvious bits, slirp and Xen were left alone for the time being. Signed-off-by: malc <av1474@comtv.ru>
2009-05-27fully split aio_pool from BlockDriverChristoph Hellwig1-2/+0
Now that we have a separate aio pool structure we can remove those aio pool details from BlockDriver. Every driver supporting AIO now needs to declare a static AIOPool with the aiocb size and the cancellation method. This cleans up the current code considerably and will make it cleaner and more obvious to support two different aio implementations behind a single BlockDriver. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-19Hardware convenience libraryPaul Brook1-1/+2
The only target dependency for most hardware is sizeof(target_phys_addr_t). Build these files into a convenience library, and use that instead of building for every target. Remove and poison various target specific macros to avoid bogus target dependencies creeping back in. Big/Little endian is not handled because devices should not know or care about this to start with. Signed-off-by: Paul Brook <paul@codesourcery.com>
2009-03-20Implement cancellation method for dma async I/O (Avi Kivity)aliguori1-0/+1
Move the dma helpers to a private aio pool, and implement a cancellation method for them. Should prevent issues when cancelling I/O while dma is in progress. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6872 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-05Introduce block dma helpers (Avi Kivity)aliguori1-0/+8
These helpers perform read/write requests on entire scatter/gather lists, relieving the device emulation code from mapping and unmapping physical memory, and from looping when map resources are exhausted. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6524 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-05Add a scatter-gather list type and accessors (Avi Kivity)aliguori1-0/+33
Scatter-gather lists are used extensively in dma-capable devices; a single data structure allows more code reuse later on. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6522 c046a42c-6fe2-441c-8c8c-71466251a162
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