linux/include/xen, branch v3.6-rc6

Revert "xen PVonHVM: move shared_info to MMIO before kexec"

2012-08-16T17:05:25Z

This reverts commit 00e37bdb0113a98408de42db85be002f21dbffd3. During shutdown of PVHVM guests with more than 2VCPUs on certain machines we can hit the race where the replaced shared_info is not replaced fast enough and the PV time clock retries reading the same area over and over without any any success and is stuck in an infinite loop. Acked-by: Olaf Hering Signed-off-by: Konrad Rzeszutek Wilk

xen PVonHVM: move shared_info to MMIO before kexec

2012-07-19T19:52:05Z

Currently kexec in a PVonHVM guest fails with a triple fault because the new kernel overwrites the shared info page. The exact failure depends on the size of the kernel image. This patch moves the pfn from RAM into MMIO space before the kexec boot. The pfn containing the shared_info is located somewhere in RAM. This will cause trouble if the current kernel is doing a kexec boot into a new kernel. The new kernel (and its startup code) can not know where the pfn is, so it can not reserve the page. The hypervisor will continue to update the pfn, and as a result memory corruption occours in the new kernel. One way to work around this issue is to allocate a page in the xen-platform pci device's BAR memory range. But pci init is done very late and the shared_info page is already in use very early to read the pvclock. So moving the pfn from RAM to MMIO is racy because some code paths on other vcpus could access the pfn during the small window when the old pfn is moved to the new pfn. There is even a small window were the old pfn is not backed by a mfn, and during that time all reads return -1. Because it is not known upfront where the MMIO region is located it can not be used right from the start in xen_hvm_init_shared_info. To minimise trouble the move of the pfn is done shortly before kexec. This does not eliminate the race because all vcpus are still online when the syscore_ops will be called. But hopefully there is no work pending at this point in time. Also the syscore_op is run last which reduces the risk further. Signed-off-by: Olaf Hering Signed-off-by: Konrad Rzeszutek Wilk

xen/pv-on-hvm kexec: shutdown watches from old kernel

2012-07-19T19:52:02Z

Add xs_reset_watches function to shutdown watches from old kernel after kexec boot. The old kernel does not unregister all watches in the shutdown path. They are still active, the double registration can not be detected by the new kernel. When the watches fire, unexpected events will arrive and the xenwatch thread will crash (jumps to NULL). An orderly reboot of a hvm guest will destroy the entire guest with all its resources (including the watches) before it is rebuilt from scratch, so the missing unregister is not an issue in that case. With this change the xenstored is instructed to wipe all active watches for the guest. However, a patch for xenstored is required so that it accepts the XS_RESET_WATCHES request from a client (see changeset 23839:42a45baf037d in xen-unstable.hg). Without the patch for xenstored the registration of watches will fail and some features of a PVonHVM guest are not available. The guest is still able to boot, but repeated kexec boots will fail. Signed-off-by: Olaf Hering Signed-off-by: Konrad Rzeszutek Wilk

xen/pcpu: Xen physical cpus online/offline sys interface

2012-07-19T19:51:39Z

This patch provide Xen physical cpus online/offline sys interface. User can use it for their own purpose, like power saving: by offlining some cpus when light workload it save power greatly. Its basic workflow is, user online/offline cpu via sys interface, then hypercall xen to implement, after done xen inject virq back to dom0, and then dom0 sync cpu status. Signed-off-by: Jiang, Yunhong Signed-off-by: Liu, Jinsong Signed-off-by: Konrad Rzeszutek Wilk

xen/mce: Add mcelog support for Xen platform

2012-07-19T19:51:36Z

When MCA error occurs, it would be handled by Xen hypervisor first, and then the error information would be sent to initial domain for logging. This patch gets error information from Xen hypervisor and convert Xen format error into Linux format mcelog. This logic is basically self-contained, not touching other kernel components. By using tools like mcelog tool users could read specific error information, like what they did under native Linux. To test follow directions outlined in Documentation/acpi/apei/einj.txt Acked-and-tested-by: Borislav Petkov Signed-off-by: Ke, Liping Signed-off-by: Jiang, Yunhong Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Liu, Jinsong Signed-off-by: Konrad Rzeszutek Wilk

xen: do not map the same GSI twice in PVHVM guests.

2012-05-21T18:11:36Z

PV on HVM guests map GSIs into event channels. At restore time the event channels are resumed by restore_pirqs. Device drivers might try to register the same GSI again through ACPI at restore time, but the GSI has already been mapped and bound by restore_pirqs. This patch detects these situations and avoids mapping the same GSI multiple times. Without this patch we get: (XEN) irq.c:2235: dom4: pirq 23 or emuirq 28 already mapped and waste a pirq. CC: stable@kernel.org Signed-off-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk

xenbus: Add support for xenbus backend in stub domain

2012-05-21T13:53:18Z

Add an ioctl to the /dev/xen/xenbus_backend device allowing the xenbus backend to be started after the kernel has booted. This allows xenstore to run in a different domain from the dom0. Signed-off-by: Daniel De Graaf Signed-off-by: Konrad Rzeszutek Wilk

xen/acpi/sleep: Enable ACPI sleep via the __acpi_os_prepare_sleep

2012-05-07T19:33:18Z

Provide the registration callback to call in the Xen's ACPI sleep functionality. This means that during S3/S5 we make a hypercall XENPF_enter_acpi_sleep with the proper PM1A/PM1B registers. Based of Ke Yu's initial idea. [ From http://xenbits.xensource.com/linux-2.6.18-xen.hg change c68699484a65 ] [v1: Added Copyright and license] [v2: Added check if PM1A/B the 16-bits MSB contain something. The spec only uses 16-bits but might have more in future] Signed-off-by: Liang Tang Signed-off-by: Konrad Rzeszutek Wilk

Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

2012-04-05T00:13:43Z

Pull DMA mapping branch from Marek Szyprowski: "Short summary for the whole series: A few limitations have been identified in the current dma-mapping design and its implementations for various architectures. There exist more than one function for allocating and freeing the buffers: currently these 3 are used dma_{alloc, free}_coherent, dma_{alloc,free}_writecombine, dma_{alloc,free}_noncoherent. For most of the systems these calls are almost equivalent and can be interchanged. For others, especially the truly non-coherent ones (like ARM), the difference can be easily noticed in overall driver performance. Sadly not all architectures provide implementations for all of them, so the drivers might need to be adapted and cannot be easily shared between different architectures. The provided patches unify all these functions and hide the differences under the already existing dma attributes concept. The thread with more references is available here: http://www.spinics.net/lists/linux-sh/msg09777.html These patches are also a prerequisite for unifying DMA-mapping implementation on ARM architecture with the common one provided by dma_map_ops structure and extending it with IOMMU support. More information is available in the following thread: http://thread.gmane.org/gmane.linux.kernel.cross-arch/12819 More works on dma-mapping framework are planned, especially in the area of buffer sharing and managing the shared mappings (together with the recently introduced dma_buf interface: commit d15bd7ee445d "dma-buf: Introduce dma buffer sharing mechanism"). The patches in the current set introduce a new alloc/free methods (with support for memory attributes) in dma_map_ops structure, which will later replace dma_alloc_coherent and dma_alloc_writecombine functions." People finally started piping up with support for merging this, so I'm merging it as the last of the pending stuff from the merge window. Looks like pohmelfs is going to wait for 3.5 and more external support for merging. * 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: common: DMA-mapping: add NON-CONSISTENT attribute common: DMA-mapping: add WRITE_COMBINE attribute common: dma-mapping: introduce mmap method common: dma-mapping: remove old alloc_coherent and free_coherent methods Hexagon: adapt for dma_map_ops changes Unicore32: adapt for dma_map_ops changes Microblaze: adapt for dma_map_ops changes SH: adapt for dma_map_ops changes Alpha: adapt for dma_map_ops changes SPARC: adapt for dma_map_ops changes PowerPC: adapt for dma_map_ops changes MIPS: adapt for dma_map_ops changes X86 & IA64: adapt for dma_map_ops changes common: dma-mapping: introduce generic alloc() and free() methods

Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

2012-03-28T22:58:21Z

Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...