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2015-12-07virtio_ring: shadow available ring flags & indexVenkatesh Srinivas
Improves cacheline transfer flow of available ring header. Virtqueues are implemented as a pair of rings, one producer->consumer avail ring and one consumer->producer used ring; preceding the avail ring in memory are two contiguous u16 fields -- avail->flags and avail->idx. A producer posts work by writing to avail->idx and a consumer reads avail->idx. The flags and idx fields only need to be written by a producer CPU and only read by a consumer CPU; when the producer and consumer are running on different CPUs and the virtio_ring code is structured to only have source writes/sink reads, we can continuously transfer the avail header cacheline between 'M' states between cores. This flow optimizes core -> core bandwidth on certain CPUs. (see: "Software Optimization Guide for AMD Family 15h Processors", Section 11.6; similar language appears in the 10h guide and should apply to CPUs w/ exclusive caches, using LLC as a transfer cache) Unfortunately the existing virtio_ring code issued reads to the avail->idx and read-modify-writes to avail->flags on the producer. This change shadows the flags and index fields in producer memory; the vring code now reads from the shadows and only ever writes to avail->flags and avail->idx, allowing the cacheline to transfer core -> core optimally. In a concurrent version of vring_bench, the time required for 10,000,000 buffer checkout/returns was reduced by ~2% (average across many runs) on an AMD Piledriver (15h) CPU: (w/o shadowing): Performance counter stats for './vring_bench': 5,451,082,016 L1-dcache-loads ... 2.221477739 seconds time elapsed (w/ shadowing): Performance counter stats for './vring_bench': 5,405,701,361 L1-dcache-loads ... 2.168405376 seconds time elapsed The further away (in a NUMA sense) virtio producers and consumers are from each other, the more we expect to benefit. Physical implementations of virtio devices and implementations of virtio where the consumer polls vring avail indexes (vhost) should also benefit. Signed-off-by: Venkatesh Srinivas <venkateshs@google.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-12-07virtio: Do not drop __GFP_HIGH in alloc_indirectMichal Hocko
b92b1b89a33c ("virtio: force vring descriptors to be allocated from lowmem") tried to exclude highmem pages for descriptors so it cleared __GFP_HIGHMEM from a given gfp mask. The patch also cleared __GFP_HIGH which doesn't make much sense for this fix because __GFP_HIGH only controls access to memory reserves and it doesn't have any influence on the zone selection. Some of the call paths use GFP_ATOMIC and dropping __GFP_HIGH will reduce their changes for success because the lack of access to memory reserves. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mel Gorman <mgorman@techsingularity.net>
2015-12-07virtio: fix memory leak of virtio ida cache layersSuman Anna
The virtio core uses a static ida named virtio_index_ida for assigning index numbers to virtio devices during registration. The ida core may allocate some internal idr cache layers and an ida bitmap upon any ida allocation, and all these layers are truely freed only upon the ida destruction. The virtio_index_ida is not destroyed at present, leading to a memory leak when using the virtio core as a module and atleast one virtio device is registered and unregistered. Fix this by invoking ida_destroy() in the virtio core module exit. Cc: stable@vger.kernel.org Signed-off-by: Suman Anna <s-anna@ti.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-09-08virtio_balloon: do not change memory amount visible via /proc/meminfoDenis V. Lunev
Balloon device is frequently used as a mean of cooperative memory control in between guest and host to manage memory overcommitment. This is the typical case for any hosting workload when KVM guest is provided for end-user. Though there is a problem in this setup. The end-user and hosting provider have signed SLA agreement in which some amount of memory is guaranted for the guest. The good thing is that this memory will be given to the guest when the guest will really need it (f.e. with OOM in guest and with VIRTIO_BALLOON_F_DEFLATE_ON_OOM configuration flag set). The bad thing is that end-user does not know this. Balloon by default reduce the amount of memory exposed to the end-user each time when the page is stolen from guest or returned back by using adjust_managed_page_count and thus /proc/meminfo shows reduced amount of memory. Fortunately the solution is simple, we should just avoid to call adjust_managed_page_count with VIRTIO_BALLOON_F_DEFLATE_ON_OOM set. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-09-08virtio_ballon: change stub of release_pages_by_pfnDenis V. Lunev
and rename it to release_pages_balloon. The function originally takes arrays of pfns and now it takes pointer to struct virtio_ballon. This change is necessary to conditionally call adjust_managed_page_count in the next patch. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-09-08virtio_mmio: add ACPI probingGraeme Gregory
Added the match table and pointers for ACPI probing to the driver. This uses the same identifier for virt devices as being used for qemu ARM64 ACPI support. http://git.linaro.org/people/shannon.zhao/qemu.git/commit/d0bf1955a3ecbab4b51d46f8c5dda02b7e14a17e Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-08-06virtio-input: reset device and detach unused during removeJason Wang
Spec requires a device reset during cleanup, so do it and avoid warn in virtio core. And detach unused buffers to avoid memory leak. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-03Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio/vhost cross endian support from Michael Tsirkin: "I have just queued some more bugfix patches today but none fix regressions and none are related to these ones, so it looks like a good time for a merge for -rc1. The motivation for this is support for legacy BE guests on the new LE hosts. There are two redeeming properties that made me merge this: - It's a trivial amount of code: since we wrap host/guest accesses anyway, almost all of it is well hidden from drivers. - Sane platforms would never set flags like VHOST_CROSS_ENDIAN_LEGACY, and when it's clear, there's zero overhead (as some point it was tested by compiling with and without the patches, got the same stripped binary). Maybe we could create a Kconfig symbol to enforce the second point: prevent people from enabling it eg on x86. I will look into this" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio-pci: alloc only resources actually used. macvtap/tun: cross-endian support for little-endian hosts vhost: cross-endian support for legacy devices virtio: add explicit big-endian support to memory accessors vhost: introduce vhost_is_little_endian() helper vringh: introduce vringh_is_little_endian() helper macvtap: introduce macvtap_is_little_endian() helper tun: add tun_is_little_endian() helper virtio: introduce virtio_is_little_endian() helper
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-06-24virtio-pci: alloc only resources actually used.Gerd Hoffmann
Move resource allocation from common code to legacy and modern code. Only request resources actually used, i.e. bar0 in legacy mode and the bar(s) specified by capabilities in modern mode. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-23Merge tag 'pci-v4.2-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI changes for the v4.2 merge window: Enumeration - Move pci_ari_enabled() to global header (Alex Williamson) - Account for ARI in _PRT lookups (Alex Williamson) - Remove unused pci_scan_bus_parented() (Yijing Wang) Resource management - Use host bridge _CRS info on systems with >32 bit addressing (Bjorn Helgaas) - Use host bridge _CRS info on Foxconn K8M890-8237A (Bjorn Helgaas) - Fix pci_address_to_pio() conversion of CPU address to I/O port (Zhichang Yuan) - Add pci_bus_addr_t (Yinghai Lu) PCI device hotplug - Wait for pciehp command completion where necessary (Alex Williamson) - Drop pointless ACPI-based "slot detection" check (Rafael J. Wysocki) - Check ignore_hotplug for all downstream devices (Rafael J. Wysocki) - Propagate the "ignore hotplug" setting to parent (Rafael J. Wysocki) - Inline pciehp "handle event" functions into the ISR (Bjorn Helgaas) - Clean up pciehp debug logging (Bjorn Helgaas) Power management - Remove redundant PCIe port type checking (Yijing Wang) - Add dev->has_secondary_link to track downstream PCIe links (Yijing Wang) - Use dev->has_secondary_link to find downstream links for ASPM (Yijing Wang) - Drop __pci_disable_link_state() useless "force" parameter (Bjorn Helgaas) - Simplify Clock Power Management setting (Bjorn Helgaas) Virtualization - Add ACS quirks for Intel 9-series PCH root ports (Alex Williamson) - Add function 1 DMA alias quirk for Marvell 9120 (Sakari Ailus) MSI - Disable MSI at enumeration even if kernel doesn't support MSI (Michael S. Tsirkin) - Remove unused pci_msi_off() (Bjorn Helgaas) - Rename msi_set_enable(), msix_clear_and_set_ctrl() (Michael S. Tsirkin) - Export pci_msi_set_enable(), pci_msix_clear_and_set_ctrl() (Michael S. Tsirkin) - Drop pci_msi_off() calls during probe (Michael S. Tsirkin) APM X-Gene host bridge driver - Add APM X-Gene v1 PCIe MSI/MSIX termination driver (Duc Dang) - Add APM X-Gene PCIe MSI DTS nodes (Duc Dang) - Disable Configuration Request Retry Status for v1 silicon (Duc Dang) - Allow config access to Root Port even when link is down (Duc Dang) Broadcom iProc host bridge driver - Allow override of device tree IRQ mapping function (Hauke Mehrtens) - Add BCMA PCIe driver (Hauke Mehrtens) - Directly add PCI resources (Hauke Mehrtens) - Free resource list after registration (Hauke Mehrtens) Freescale i.MX6 host bridge driver - Add speed change timeout message (Troy Kisky) - Rename imx6_pcie_start_link() to imx6_pcie_establish_link() (Bjorn Helgaas) Freescale Layerscape host bridge driver - Use dw_pcie_link_up() consistently (Bjorn Helgaas) - Factor out ls_pcie_establish_link() (Bjorn Helgaas) Marvell MVEBU host bridge driver - Remove mvebu_pcie_scan_bus() (Yijing Wang) NVIDIA Tegra host bridge driver - Remove tegra_pcie_scan_bus() (Yijing Wang) Synopsys DesignWare host bridge driver - Consolidate outbound iATU programming functions (Jisheng Zhang) - Use iATU0 for cfg and IO, iATU1 for MEM (Jisheng Zhang) - Add support for x8 links (Zhou Wang) - Wait for link to come up with consistent style (Bjorn Helgaas) - Use pci_scan_root_bus() for simplicity (Yijing Wang) TI DRA7xx host bridge driver - Use dw_pcie_link_up() consistently (Bjorn Helgaas) Miscellaneous - Include <linux/pci.h>, not <asm/pci.h> (Bjorn Helgaas) - Remove unnecessary #includes of <asm/pci.h> (Bjorn Helgaas) - Remove unused pcibios_select_root() (again) (Bjorn Helgaas) - Remove unused pci_dma_burst_advice() (Bjorn Helgaas) - xen/pcifront: Don't use deprecated function pci_scan_bus_parented() (Arnd Bergmann)" * tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits) PCI: pciehp: Inline the "handle event" functions into the ISR PCI: pciehp: Rename queue_interrupt_event() to pciehp_queue_interrupt_event() PCI: pciehp: Make queue_interrupt_event() void PCI: xgene: Allow config access to Root Port even when link is down PCI: xgene: Disable Configuration Request Retry Status for v1 silicon PCI: pciehp: Clean up debug logging x86/PCI: Use host bridge _CRS info on systems with >32 bit addressing PCI: imx6: Add #define PCIE_RC_LCSR PCI: imx6: Use "u32", not "uint32_t" PCI: Remove unused pci_scan_bus_parented() xen/pcifront: Don't use deprecated function pci_scan_bus_parented() PCI: imx6: Add speed change timeout message PCI/ASPM: Simplify Clock Power Management setting PCI: designware: Wait for link to come up with consistent style PCI: layerscape: Factor out ls_pcie_establish_link() PCI: layerscape: Use dw_pcie_link_up() consistently PCI: dra7xx: Use dw_pcie_link_up() consistently x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A PCI: pciehp: Wait for hotplug command completion where necessary PCI: Remove unused pci_dma_burst_advice() ...
2015-06-04virtio_pci: Clear stale cpumask when setting irq affinityJiang Liu
The cpumask vp_dev->msix_affinity_masks[info->msix_vector] may contain staled information when vp_set_vq_affinity() gets called, so clear it before setting the new cpu bit mask. Cc: stable@vger.kernel.org Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-05-28kernel/params: constify struct kernel_param_ops usesLuis R. Rodriguez
Most code already uses consts for the struct kernel_param_ops, sweep the kernel for the last offending stragglers. Other than include/linux/moduleparam.h and kernel/params.c all other changes were generated with the following Coccinelle SmPL patch. Merge conflicts between trees can be handled with Coccinelle. In the future git could get Coccinelle merge support to deal with patch --> fail --> grammar --> Coccinelle --> new patch conflicts automatically for us on patches where the grammar is available and the patch is of high confidence. Consider this a feature request. Test compiled on x86_64 against: * allnoconfig * allmodconfig * allyesconfig @ const_found @ identifier ops; @@ const struct kernel_param_ops ops = { }; @ const_not_found depends on !const_found @ identifier ops; @@ -struct kernel_param_ops ops = { +const struct kernel_param_ops ops = { }; Generated-by: Coccinelle SmPL Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Junio C Hamano <gitster@pobox.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: cocci@systeme.lip6.fr Cc: linux-kernel@vger.kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-07virtio_pci: drop pci_msi_off() call during probeMichael S. Tsirkin
The PCI core now disables MSI and MSI-X for all devices during enumeration regardless of CONFIG_PCI_MSI. Remove device-specific code to disable MSI/MSI-X. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-04-15virtio: drop virtio_device_is_legacy_onlyMichael S. Tsirkin
virtio_device_is_legacy_only is now unused, drop it from core. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15virtio_pci: support non-legacy balloon devicesMichael S. Tsirkin
virtio_device_is_legacy_only is always false now, drop the test from virtio pci. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15virtio_mmio: support non-legacy balloon devicesMichael S. Tsirkin
virtio_device_is_legacy_only is always false now, drop the test from virtio mmio. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15virtio: balloon might not be a legacy deviceMichael S. Tsirkin
We added transitional device support to balloon driver, so we don't need to black-list it in core anymore. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15virtio_balloon: transitional interfaceMichael S. Tsirkin
Virtio 1.0 doesn't include a modern balloon device. But it's not a big change to support a transitional balloon device: this has the advantage of supporting existing drivers, transparently. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-01virtio_pci_modern: switch to type-safe io accessorsMichael S. Tsirkin
As Rusty noted, we were accessing queue_enable with an incorrect width. Switch to type-safe accessors so we don't make this mistake again in the future. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-01virtio_pci_modern: type-safe io accessorsMichael S. Tsirkin
The spec is very clear on this: 4.1.3.1 Driver Requirements: PCI Device Layout The driver MUST access each field using the “natural” access method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit fields and 8-bit accesses for 8-bit fields. Add type-safe wrappers to prevent access with incorrect width. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-29Add virtio-input driver.Gerd Hoffmann
virtio-input is basically evdev-events-over-virtio, so this driver isn't much more than reading configuration from config space and forwarding incoming events to the linux input layer. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-17virtio_mmio: fix access width for mmioMichael S. Tsirkin
Going over the virtio mmio code, I noticed that it doesn't correctly access modern device config values using "natural" accessors: it uses readb to get/set them byte by byte, while the virtio 1.0 spec explicitly states: 4.2.2.2 Driver Requirements: MMIO Device Register Layout ... The driver MUST only use 32 bit wide and aligned reads and writes to access the control registers described in table 4.1. For the device-specific configuration space, the driver MUST use 8 bit wide accesses for 8 bit wide fields, 16 bit wide and aligned accesses for 16 bit wide fields and 32 bit wide and aligned accesses for 32 and 64 bit wide fields. Borrow code from virtio_pci_modern to do this correctly. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-13virtio_mmio: generation supportMichael S. Tsirkin
virtio_mmio currently lacks generation support which makes multi-byte field access racy. Fix by getting the value at offset 0xfc for version 2 devices. Nothing we can do for version 1, so return generation id 0. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-10virtio-balloon: do not call blocking ops when !TASK_RUNNINGMichael S. Tsirkin
virtio balloon has this code: wait_event_interruptible(vb->config_change, (diff = towards_target(vb)) != 0 || vb->need_stats_update || kthread_should_stop() || freezing(current)); Which is a problem because towards_target() call might block after wait_event_interruptible sets task state to TAST_INTERRUPTIBLE, causing the task_struct::state collision typical of nesting of sleeping primitives See also http://lwn.net/Articles/628628/ or Thomas's bug report http://article.gmane.org/gmane.linux.kernel.virtualization/24846 for a fuller explanation. To fix, rewrite using wait_woken. Cc: stable@vger.kernel.org Reported-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-10virtio_balloon: set DRIVER_OK before using deviceMichael S. Tsirkin
virtio spec requires that all drivers set DRIVER_OK before using devices. While balloon isn't yet included in the virtio 1 spec, previous spec versions also required this. virtio balloon might violate this rule: probe calls kthread_run before setting DRIVER_OK, which might run immediately and cause balloon to inflate/deflate. To fix, call virtio_device_ready before running the kthread. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2015-02-17virtio: don't set VIRTIO_CONFIG_S_DRIVER_OK twice.Rusty Russell
I noticed this with the console device. It's not *wrong*, just a bit weird. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-11virtio_pci: use 16-bit accessor for queue_enable.Rusty Russell
Since PCI is little endian, 8-bit access might work, but the spec section is very clear on this: 4.1.3.1 Driver Requirements: PCI Device Layout The driver MUST access each field using the “natural” access method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit fields and 8-bit accesses for 8-bit fields. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2015-02-11virtio: Avoid possible kernel panic if DEBUG is enabled.Tetsuo Handa
The virtqueue_add() calls START_USE() upon entry. The virtqueue_kick() is called if vq->num_added == (1 << 16) - 1 before calling END_USE(). The virtqueue_kick_prepare() called via virtqueue_kick() calls START_USE() upon entry, and will call panic() if DEBUG is enabled. Move this virtqueue_kick() call to after END_USE() call. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-23virtio-mmio: Update the device to OASIS spec versionPawel Moll
This patch add a support for second version of the virtio-mmio device, which follows OASIS "Virtual I/O Device (VIRTIO) Version 1.0" specification. Main changes: 1. The control register symbolic names use the new device/driver nomenclature rather than the old guest/host one. 2. The driver detect the device version (version 1 is the pre-OASIS spec, version 2 is compatible with fist revision of the OASIS spec) and drives the device accordingly. 3. New version uses direct addressing (64 bit address split into two low/high register) instead of the guest page size based one, and addresses each part of the queue (descriptors, available, used) separately. 4. The device activity is now explicitly triggered by writing to the "queue ready" register. 5. Whole 64 bit features are properly handled now (both ways). Signed-off-by: Pawel Moll <pawel.moll@arm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci_modern: drop an unused functionMichael S. Tsirkin
release function in modern driver is unused: it's a left-over from when each driver had to have its own release. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-21virtio_pci: add module param to force legacy modeMichael S. Tsirkin
If set, try legacy interface first, modern one if that fails. Useful to work around device/driver bugs, and for compatibility testing. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci: add an option to disable legacy driverMichael S. Tsirkin
Useful for testing device virtio 1 compatibility. Based on patch by Rusty - couldn't resist putting that flying car joke in there! Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci: drop Kconfig warningsMichael S. Tsirkin
The ABI *is* stable, and has been for a while now. Drop Kconfig warning saying that it's not guaranteed to work. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci: Kconfig grammar fixMichael S. Tsirkin
This drivers -> this driver. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_ring: coding style fixMichael S. Tsirkin
Most of our code has struct foo { } Fix one instances where ring is inconsistent. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_balloon: coding style fixesMichael S. Tsirkin
Most of our code has struct foo { } Fix two instances where balloon is inconsistent. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci_modern: support devices with no configMichael S. Tsirkin
Virtio 1.0 spec lists device config as optional. Set get/set callbacks to NULL. Drivers can check that and fail gracefully. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci_modern: reduce number of mappingsMichael S. Tsirkin
We don't know the # of VQs that drivers are going to use so it's hard to predict how much memory we'll need to map. However, the relevant capability does give us an upper limit. If that's below a page, we can reduce the number of required mappings by mapping it all once ahead of the time. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci: macros for PCI layout offsetsRusty Russell
QEMU wants it, so why not? Trust, but verify. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-21virtio_pci: modern driverMichael S. Tsirkin
Lightly tested against qemu. One thing *not* implemented here is separate mappings for descriptor/avail/used rings. That's nice to have, will be done later after we have core support. This also exposes the PCI layout to userspace, and adds macros for PCI layout offsets: QEMU wants it, so why not? Trust, but verify. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-21virtio_pci: move probe/remove code to commonMichael S. Tsirkin
Most of initialization is device-independent. Let's move it to common. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio_pci: drop useless del_vqs callSasha Levin
Device VQs were getting freed twice: once in every device's removal functions, and then again in virtio_pci_legacy_remove(). The ones in devices are called first, so drop the useless second call. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21virtio/balloon: verify device has config spaceMichael S. Tsirkin
Some devices might not implement config space access (e.g. remoteproc used not to - before 3.9). virtio/balloon needs config space access so make it fail gracefully if not there. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-06virtio_pci: document why we defer kfreeMichael S. Tsirkin
The reason we defer kfree until release function is because it's a general rule for kobjects: kfree of the reference counter itself is only legal in the release function. Previous patch didn't make this clear, document this in code. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-06virtio_pci: defer kfree until release callbackSasha Levin
A struct device which has just been unregistered can live on past the point at which a driver decides to drop it's initial reference to the kobject gained on allocation. This implies that when releasing a virtio device, we can't free a struct virtio_device until the underlying struct device has been released, which might not happen immediately on device_unregister(). Unfortunately, this is exactly what virtio pci does: it has an empty release callback, and frees memory immediately after unregistering the device. This causes an easy to reproduce crash if CONFIG_DEBUG_KOBJECT_RELEASE it enabled. To fix, free the memory only once we know the device is gone in the release callback. Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-06virtio_pci: device-specific release callbackMichael S. Tsirkin
It turns out we need to add device-specific code in release callback. Move it to virtio_pci_legacy.c. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-06virtio: make del_vqs idempotentMichael S. Tsirkin
Our code calls del_vqs multiple times, assuming it's idempotent. commit 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 virtio_pci: free up vq->priv broke this assumption, by adding kfree there, so multiple calls cause double free. Fix it up. Fixes: 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-18Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio fixes from Michael S Tsirkin: "virtio 1.0 related fixes Most importantly, this fixes using virtio_pci as a module. Further, the big virtio 1.0 conversion missed a couple of places. This fixes them up. This isn't 100% sparse-clean yet because on many architectures get_user triggers sparse warnings when used with __bitwise tag (when same tag is on both pointer and value read). I posted a patchset to fix it up by adding __force on all arches that don't already have it (many do), when that's merged these warnings will go away" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio_pci: restore module attributes mic/host: fix up virtio 1.0 APIs vringh: update for virtio 1.0 APIs vringh: 64 bit features tools/virtio: add virtio 1.0 in vringh_test tools/virtio: add virtio 1.0 in virtio_test tools/virtio: enable -Werror tools/virtio: 64 bit features tools/virtio: fix vringh test tools/virtio: more stubs virtio: core support for config generation virtio_pci: add VIRTIO_PCI_NO_LEGACY virtio_pci: move probe to common file virtio_pci_common.h: drop VIRTIO_PCI_NO_LEGACY virtio_config: fix virtio_cread_bytes virtio: set VIRTIO_CONFIG_S_FEATURES_OK on restore
2014-12-17Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio updates from Rusty Russell: "A balloon enhancement, and a minor race-on-module-unload theoretical bug which doesn't merit cc: stable. All the exciting stuff went via MST this cycle" * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: virtio_balloon: free some memory from balloon on OOM virtio_balloon: return the amount of freed memory from leak_balloon() virtio_blk: fix race at module removal virtio: Fix comment typo 'CONFIG_S_FAILED'