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* Merge tag 'rproc-v4.16' of git://github.com/andersson/remoteprocLinus Torvalds2018-02-0511-204/+107
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull remoteproc updates from Bjorn Andersson: "This contains a few bug fixes and a cleanup up of the resource-table handling in the framework, which removes the need for drivers with no resource table to provide a fake one" * tag 'rproc-v4.16' of git://github.com/andersson/remoteproc: remoteproc: Reset table_ptr on stop remoteproc: Drop dangling find_rsc_table dummies remoteproc: Move resource table load logic to find remoteproc: Don't handle empty resource table remoteproc: Merge rproc_ops and rproc_fw_ops remoteproc: Clone rproc_ops in rproc_alloc() remoteproc: Cache resource table size remoteproc: Remove depricated crash completion virtio_remoteproc: correct put_device virtio_device.dev
| * remoteproc: Reset table_ptr on stopBjorn Andersson2018-01-151-0/+3
| | | | | | | | | | | | | | | | | | The installed resource table is no longer accessible after stopping the remote, so update table_ptr to point to the local copy. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Drop dangling find_rsc_table dummiesBjorn Andersson2018-01-157-58/+0
| | | | | | | | | | | | | | | | | | As the core now deals with the lack of a resource table, remove the dangling custom dummy implementations of find_rsc_table from drivers. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Move resource table load logic to findBjorn Andersson2018-01-154-50/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend the previous operation of finding the resource table in the ELF with the extra step of populating the rproc struct with a copy and the size. This allows drivers to override the mechanism used for acquiring the resource table, or omit it for firmware that is known not to have a resource table. This leaves the custom, dummy, find_rsc_table implementations found in some drivers dangling. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Don't handle empty resource tableBjorn Andersson2018-01-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | Allow a NULL table_ptr to have the same meaning as a table with 0 entries, allowing a subsequent patch to skip the assignment step. A few other places in the implementation does dereference table_ptr, but they are currently all coming from rproc_handle_resources(). Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Merge rproc_ops and rproc_fw_opsBjorn Andersson2018-01-158-90/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are currently a few different schemes used for overriding fw_ops or parts of fw_ops. Merge fw_ops into rproc_ops and expose the default ELF-loader symbols so that they can be assigned by the drivers. To keep backwards compatibility with the "default" case, a driver not specifying the "load" operation is assumed to want the full ELF-loader suit of functions. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Clone rproc_ops in rproc_alloc()Bjorn Andersson2018-01-152-2/+9
| | | | | | | | | | | | | | | | | | In order to allow rproc_alloc() to, in a future patch, update entries in the "ops" struct we need to make a local copy of it. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Cache resource table sizeBjorn Andersson2018-01-152-13/+9
| | | | | | | | | | | | | | | | | | | | | | We don't re-read the resource table during a recovery, so it is possible in the recovery path that the resource table has a different size than cached_table. Store the original size of cached_table to avoid these getting out of sync. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * remoteproc: Remove depricated crash completionBjorn Andersson2018-01-152-12/+0
| | | | | | | | | | | | | | | | | | The crash handling now happens in a single execution context, so there's no longer a need for a completion to synchronize this. Reviewed-By: Loic Pallardy <loic.pallardy@st.com> Tested-By: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * virtio_remoteproc: correct put_device virtio_device.devweiping zhang2018-01-021-1/+1
| | | | | | | | | | | | | | | | | | | | rproc_virtio_dev_release will be called iff virtio_device.dev's reference count drops to 0. Here we just put vdev.dev, and then rproc->dev's cleanup will be done in rproc_virtio_dev_release. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
* | Merge tag 'rpmsg-v4.16' of git://github.com/andersson/remoteprocLinus Torvalds2018-02-054-19/+55
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull rpmsg updates from Bjorn Andersson: "This fixes a few issues found in the SMD and GLINK drivers and corrects the handling of SMD channels that are found in an (previously) unexpected state" * tag 'rpmsg-v4.16' of git://github.com/andersson/remoteproc: rpmsg: smd: Fix double unlock in __qcom_smd_send() rpmsg: glink: Fix missing mutex_init() in qcom_glink_alloc_channel() rpmsg: smd: Don't hold the tx lock during wait rpmsg: smd: Fail send on a closed channel rpmsg: smd: Wake up all waiters rpmsg: smd: Create device for all channels rpmsg: smd: Perform handshake during open rpmsg: glink: smem: Ensure ordering during tx drivers: rpmsg: remove duplicate includes remoteproc: qcom: Use PTR_ERR_OR_ZERO() in glink prob
| * | rpmsg: smd: Fix double unlock in __qcom_smd_send()Dan Carpenter2018-01-191-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | We're not holding the lock here, so we shouldn't unlock. Fixes: 178f3f75bb4e ("rpmsg: smd: Don't hold the tx lock during wait") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> [bjorn: renamed "out" label to further distinguish the two exit paths] Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: glink: Fix missing mutex_init() in qcom_glink_alloc_channel()Wei Yongjun2018-01-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | qcom_glink_alloc_channel() allocates the mutex but not initialize it. Use mutex_init() on it to initialize it correctly. This is detected by Coccinelle semantic patch. Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: smd: Don't hold the tx lock during waitBjorn Andersson2017-12-191-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Holding the tx lock while waiting for tx-drain events from the remote side blocks try_send requests from failing quickly, so temporarily drop the tx lock while waiting. While this allows try_send to fail quickly it also could allow a subsequent send to succeed putting a smaller packet in the FIFO while we're waiting for room for our large packet. But as this lock is per channel we expect that clients with ordering concerns implements their own ordering mechanism. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: smd: Fail send on a closed channelBjorn Andersson2017-12-191-6/+8
| | | | | | | | | | | | | | | | | | | | | Move the check for a closed channel out from the tx-full loop to fail any send request on a non-open channel. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: smd: Wake up all waitersBjorn Andersson2017-12-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | It's possible to have multiple contexts waiting for new channel events and with an upcoming change it's possible to have multiple contexts waiting for a full FIFO. As such we need to wake them all up. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: smd: Create device for all channelsBjorn Andersson2017-12-191-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than selectively creating devices only for the channels that the remote have moved to "opening" state let's create devices for all channels found. The driver model will match drivers to the ones we care about and attempt to open these. The one case where this fails is if the user loads a firmware that lacks a particular channel of the previous firmware that was running, in which case we would find the old channel and attempt to probe it. The channel opening handshake will ensure this will result in a graceful failure. The result of this patch is that we will actively open the RPM channel even though it's left in a state other than "opening" after the boot loader's closing of the channel. Tested-by: Will Newton <will.newton@gmail.com> Reported-by: Jeremy McNicoll <jmcnicol@redhat.com> Reported-by: Will Newton <will.newton@gmail.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: smd: Perform handshake during openBjorn Andersson2017-12-191-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | Validate the the remote side is opening the channel that we've found by performing a handshake when opening the channel. Tested-by: Will Newton <will.newton@gmail.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | rpmsg: glink: smem: Ensure ordering during txBjorn Andersson2017-12-191-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure the ordering of the fifo write and the update of the write index, so that the index is not updated before the data has landed in the fifo. Acked-By: Chris Lew <clew@codeaurora.org> Reported-by: Arun Kumar Neelakantam <aneela@codeaurora.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | drivers: rpmsg: remove duplicate includesPravin Shedge2017-12-061-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | These duplicate includes have been found with scripts/checkincludes.pl but they have been removed manually to avoid removing false positives. Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| * | remoteproc: qcom: Use PTR_ERR_OR_ZERO() in glink probVasyl Gomonovych2017-11-291-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | Fix ptr_ret.cocci warnings: drivers/remoteproc/qcom_common.c:60:8-14: WARNING: PTR_ERR_OR_ZERO can be used Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR Generated by: scripts/coccinelle/api/ptr_ret.cocci Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
* | Merge tag 'mmc-v4.16-2' of ↵Linus Torvalds2018-02-053-10/+161
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc Pull MMC host fixes from Ulf Hansson: - renesas_sdhi: Fix build error in case NO_DMA=y - sdhci: Implement a bounce buffer to address throughput regressions * tag 'mmc-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: mmc: MMC_SDHI_{SYS,INTERNAL}_DMAC should depend on HAS_DMA mmc: sdhci: Implement an SDHCI-specific bounce buffer
| * | mmc: MMC_SDHI_{SYS,INTERNAL}_DMAC should depend on HAS_DMAGeert Uytterhoeven2018-01-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If NO_DMA=y: ERROR: "bad_dma_ops" [drivers/mmc/host/renesas_sdhi_sys_dmac.ko] undefined! ERROR: "bad_dma_ops" [drivers/mmc/host/renesas_sdhi_internal_dmac.ko] undefined! Add dependencies on HAS_DMA to fix this. Fixes: e578afab6e5f57e7 ("mmc: renesas_sdhi: remove wrong depends on to enable compile test") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| * | mmc: sdhci: Implement an SDHCI-specific bounce bufferLinus Walleij2018-01-312-8/+159
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bounce buffer is gone from the MMC core, and now we found out that there are some (crippled) i.MX boards out there that have broken ADMA (cannot do scatter-gather), and also broken PIO so they must use SDMA. Closer examination shows a less significant slowdown also on SDMA-only capable Laptop hosts. SDMA sets down the number of segments to one, so that each segment gets turned into a singular request that ping-pongs to the block layer before the next request/segment is issued. Apparently it happens a lot that the block layer send requests that include a lot of physically discontiguous segments. My guess is that this phenomenon is coming from the file system. These devices that cannot handle scatterlists in hardware can see major benefits from a DMA-contiguous bounce buffer. This patch accumulates those fragmented scatterlists in a physically contiguous bounce buffer so that we can issue bigger DMA data chunks to/from the card. When tested with a PCI-integrated host (1217:8221) that only supports SDMA: 0b:00.0 SD Host controller: O2 Micro, Inc. OZ600FJ0/OZ900FJ0/OZ600FJS SD/MMC Card Reader Controller (rev 05) This patch gave ~1Mbyte/s improved throughput on large reads and writes when testing using iozone than without the patch. dmesg: sdhci-pci 0000:0b:00.0: SDHCI controller found [1217:8221] (rev 5) mmc0 bounce up to 128 segments into one, max segment size 65536 bytes mmc0: SDHCI controller on PCI [0000:0b:00.0] using DMA On the i.MX SDHCI controllers on the crippled i.MX 25 and i.MX 35 the patch restores the performance to what it was before we removed the bounce buffers. Cc: Pierre Ossman <pierre@ossman.eu> Cc: Benoît Thébaudeau <benoit@wsystem.com> Cc: Fabio Estevam <fabio.estevam@nxp.com> Cc: Benjamin Beckmeyer <beckmeyer.b@rittal.de> Cc: stable@vger.kernel.org # v4.14+ Fixes: de3ee99b097d ("mmc: Delete bounce buffer handling") Tested-by: Benjamin Beckmeyer <beckmeyer.b@rittal.de> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
* | | Merge tag 'pwm/for-4.16-rc1' of ↵Linus Torvalds2018-02-054-1/+30
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm Pull pwm updates from Thierry Reding: "The Meson PWM controller driver gains support for the AXG series and a minor bug is fixed for the STMPE driver. To round things off, the class is now set for PWM channels exported via sysfs which allows non-root access, provided that the system has been configured accordingly" * tag 'pwm/for-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: meson: Add clock source configuration for Meson-AXG dt-bindings: pwm: Update bindings for the Meson-AXG pwm: stmpe: Fix wrong register offset for hwpwm=2 case pwm: Set class for exported channels in sysfs
| * | | pwm: meson: Add clock source configuration for Meson-AXGJian Hu2017-12-051-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For PWM controller in the Meson-AXG SoC, the EE domain and AO domain have different clock sources. This patch tries to describe them in the DT compatible data. Signed-off-by: Jian Hu <jian.hu@amlogic.com> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
| * | | dt-bindings: pwm: Update bindings for the Meson-AXGJian Hu2017-12-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the doc to explicitly support Meson-AXG Signed-off-by: Jian Hu <jian.hu@amlogic.com> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
| * | | pwm: stmpe: Fix wrong register offset for hwpwm=2 caseAxel Lin2017-12-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix trivial copy/paste bug. Signed-off-by: Axel Lin <axel.lin@ingics.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Fixes: ef1f09eca74a ("pwm: Add a driver for the STMPE PWM") Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
| * | | pwm: Set class for exported channels in sysfsGottfried Haider2017-12-051-0/+1
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Notifications for devices without bus or class set get dropped by dev_uevent_filter(). Adding the class to the exported child matches what the GPIO subsystem is doing. With this change exporting a channel triggers a udev event, which gives userspace a chance to fixup permissions and makes it possible for non-root users to make use of the PWM subsystem. Signed-off-by: Gottfried Haider <gottfried.haider@gmail.com> CC: Thierry Reding <thierry.reding@gmail.com> CC: H Hartley Sweeten <hsweeten@visionengravers.com> CC: linux-pwm@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-rpi-kernel@lists.infradead.org Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* | | net: mediatek: Explicitly include pinctrl headersThierry Reding2018-02-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Mediatek ethernet driver fails to build after commit 23c35f48f5fb ("pinctrl: remove include file from <linux/device.h>") because it relies on the pinctrl/consumer.h and pinctrl/devinfo.h being pulled in by the device.h header implicitly. Include these headers explicitly to avoid the build failure. Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mmc: meson-gx-mmc: Explicitly include pinctr/consumer.hThierry Reding2018-02-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Meson GX MMC driver fails to build after commit 23c35f48f5fb ("pinctrl: remove include file from <linux/device.h>") because it relies on the pinctrl/consumer.h being pulled in by the device.h header implicitly. Include the header explicitly to avoid the build failure. Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | drm/rockchip: lvds: Explicitly include pinctrl headersThierry Reding2018-02-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Rockchip LVDS driver fails to build after commit 23c35f48f5fb ("pinctrl: remove include file from <linux/device.h>") because it relies on the pinctrl/consumer.h and pinctrl/devinfo.h being pulled in by the device.h header implicitly. Include these headers explicitly to avoid the build failure. Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | pinctrl: files should directly include apis they useStephen Rothwell2018-02-051-0/+1
| | | | | | | | | | | | | | | | | | Fixes: 23c35f48f5fb ("pinctrl: remove include file from <linux/device.h>") Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-02-0438-554/+977
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull spectre/meltdown updates from Thomas Gleixner: "The next round of updates related to melted spectrum: - The initial set of spectre V1 mitigations: - Array index speculation blocker and its usage for syscall, fdtable and the n180211 driver. - Speculation barrier and its usage in user access functions - Make indirect calls in KVM speculation safe - Blacklisting of known to be broken microcodes so IPBP/IBSR are not touched. - The initial IBPB support and its usage in context switch - The exposure of the new speculation MSRs to KVM guests. - A fix for a regression in x86/32 related to the cpu entry area - Proper whitelisting for known to be safe CPUs from the mitigations. - objtool fixes to deal proper with retpolines and alternatives - Exclude __init functions from retpolines which speeds up the boot process. - Removal of the syscall64 fast path and related cleanups and simplifications - Removal of the unpatched paravirt mode which is yet another source of indirect unproteced calls. - A new and undisputed version of the module mismatch warning - A couple of cleanup and correctness fixes all over the place Yet another step towards full mitigation. There are a few things still missing like the RBS underflow mitigation for Skylake and other small details, but that's being worked on. That said, I'm taking a belated christmas vacation for a week and hope that everything is magically solved when I'm back on Feb 12th" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/x86: Add IBPB support KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL x86/pti: Mark constant arrays as __initconst x86/spectre: Simplify spectre_v2 command line parsing x86/retpoline: Avoid retpolines for built-in __init functions x86/kvm: Update spectre-v1 mitigation KVM: VMX: make MSR bitmaps per-VCPU x86/paravirt: Remove 'noreplace-paravirt' cmdline option x86/speculation: Use Indirect Branch Prediction Barrier in context switch x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable" x86/spectre: Report get_user mitigation for spectre_v1 nl80211: Sanitize array index in parse_txq_params vfs, fdtable: Prevent bounds-check bypass via speculative execution x86/syscall: Sanitize syscall table de-references under speculation x86/get_user: Use pointer masking to limit speculation ...
| * | | KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRLKarimAllah Ahmed2018-02-031-0/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ] ... basically doing exactly what we do for VMX: - Passthrough SPEC_CTRL to guests (if enabled in guest CPUID) - Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest actually used it. Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de
| * | | KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRLKarimAllah Ahmed2018-02-033-6/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on a patch from Ashok Raj <ashok.raj@intel.com> ] Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for guests that will only mitigate Spectre V2 through IBRS+IBPB and will not be using a retpoline+IBPB based approach. To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for guests that do not actually use the MSR, only start saving and restoring when a non-zero is written to it. No attempt is made to handle STIBP here, intentionally. Filtering STIBP may be added in a future patch, which may require trapping all writes if we don't want to pass it through directly to the guest. [dwmw2: Clean up CPUID bits, save/restore manually, handle reset] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-5-git-send-email-karahmed@amazon.de
| * | | KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIESKarimAllah Ahmed2018-02-033-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the contents will come directly from the hardware, but user-space can still override it. [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de
| * | | KVM/x86: Add IBPB supportAshok Raj2018-02-033-3/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Indirect Branch Predictor Barrier (IBPB) is an indirect branch control mechanism. It keeps earlier branches from influencing later ones. Unlike IBRS and STIBP, IBPB does not define a new mode of operation. It's a command that ensures predicted branch targets aren't used after the barrier. Although IBRS and IBPB are enumerated by the same CPUID enumeration, IBPB is very different. IBPB helps mitigate against three potential attacks: * Mitigate guests from being attacked by other guests. - This is addressed by issing IBPB when we do a guest switch. * Mitigate attacks from guest/ring3->host/ring3. These would require a IBPB during context switch in host, or after VMEXIT. The host process has two ways to mitigate - Either it can be compiled with retpoline - If its going through context switch, and has set !dumpable then there is a IBPB in that path. (Tim's patch: https://patchwork.kernel.org/patch/10192871) - The case where after a VMEXIT you return back to Qemu might make Qemu attackable from guest when Qemu isn't compiled with retpoline. There are issues reported when doing IBPB on every VMEXIT that resulted in some tsc calibration woes in guest. * Mitigate guest/ring0->host/ring0 attacks. When host kernel is using retpoline it is safe against these attacks. If host kernel isn't using retpoline we might need to do a IBPB flush on every VMEXIT. Even when using retpoline for indirect calls, in certain conditions 'ret' can use the BTB on Skylake-era CPUs. There are other mitigations available like RSB stuffing/clearing. * IBPB is issued only for SVM during svm_free_vcpu(). VMX has a vmclear and SVM doesn't. Follow discussion here: https://lkml.org/lkml/2018/1/15/146 Please refer to the following spec for more details on the enumeration and control. Refer here to get documentation about mitigations. https://software.intel.com/en-us/side-channel-security-support [peterz: rebase and changelog rewrite] [karahmed: - rebase - vmx: expose PRED_CMD if guest has it in CPUID - svm: only pass through IBPB if guest has it in CPUID - vmx: support !cpu_has_vmx_msr_bitmap()] - vmx: support nested] [dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS) PRED_CMD is a write-only MSR] Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: kvm@vger.kernel.org Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de
| * | | KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDXKarimAllah Ahmed2018-02-032-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [dwmw2: Stop using KF() for bits in it, too] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Link: https://lkml.kernel.org/r/1517522386-18410-2-git-send-email-karahmed@amazon.de
| * | | Merge branch 'msr-bitmaps' of git://git.kernel.org/pub/scm/virt/kvm/kvm into ↵Thomas Gleixner2018-02-031-254/+186
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | x86/pti Pull the KVM prerequisites so the IBPB patches apply.
| | * | | KVM: VMX: make MSR bitmaps per-VCPUPaolo Bonzini2018-01-311-123/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Place the MSR bitmap in struct loaded_vmcs, and update it in place every time the x2apic or APICv state can change. This is rare and the loop can handle 64 MSRs per iteration, in a similar fashion as nested_vmx_prepare_msr_bitmap. This prepares for choosing, on a per-VM basis, whether to intercept the SPEC_CTRL and PRED_CMD MSRs. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | KVM: VMX: introduce alloc_loaded_vmcsPaolo Bonzini2018-01-271-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Group together the calls to alloc_vmcs and loaded_vmcs_init. Soon we'll also allocate an MSR bitmap there. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | KVM: nVMX: Eliminate vmcs02 poolJim Mattson2018-01-271-123/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The potential performance advantages of a vmcs02 pool have never been realized. To simplify the code, eliminate the pool. Instead, a single vmcs02 is allocated per VCPU when the VCPU enters VMX operation. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Ameya More <ameya.more@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALLDarren Kenny2018-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes: 117cc7a908c83 ("x86/retpoline: Fill return stack buffer on vmexit") Signed-off-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180202191220.blvgkgutojecxr3b@starbug-vm.ie.oracle.com
| * | | | x86/pti: Mark constant arrays as __initconstArnd Bergmann2018-02-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm seeing build failures from the two newly introduced arrays that are marked 'const' and '__initdata', which are mutually exclusive: arch/x86/kernel/cpu/common.c:882:43: error: 'cpu_no_speculation' causes a section type conflict with 'e820_table_firmware_init' arch/x86/kernel/cpu/common.c:895:43: error: 'cpu_no_meltdown' causes a section type conflict with 'e820_table_firmware_init' The correct annotation is __initconst. Fixes: fec9434a12f3 ("x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Thomas Garnier <thgarnie@google.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180202213959.611210-1-arnd@arndb.de
| * | | | x86/spectre: Simplify spectre_v2 command line parsingKarimAllah Ahmed2018-02-021-30/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [dwmw2: Use ARRAY_SIZE] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: peterz@infradead.org Cc: bp@alien8.de Link: https://lkml.kernel.org/r/1517484441-1420-3-git-send-email-dwmw@amazon.co.uk
| * | | | x86/retpoline: Avoid retpolines for built-in __init functionsDavid Woodhouse2018-02-021-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no point in building init code with retpolines, since it runs before any potentially hostile userspace does. And before the retpoline is actually ALTERNATIVEd into place, for much of it. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: karahmed@amazon.de Cc: peterz@infradead.org Cc: bp@alien8.de Link: https://lkml.kernel.org/r/1517484441-1420-2-git-send-email-dwmw@amazon.co.uk
| * | | | x86/kvm: Update spectre-v1 mitigationDan Williams2018-02-011-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 75f139aaf896 "KVM: x86: Add memory barrier on vmcs field lookup" added a raw 'asm("lfence");' to prevent a bounds check bypass of 'vmcs_field_to_offset_table'. The lfence can be avoided in this path by using the array_index_nospec() helper designed for these types of fixes. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Andrew Honig <ahonig@google.com> Cc: kvm@vger.kernel.org Cc: Jim Mattson <jmattson@google.com> Link: https://lkml.kernel.org/r/151744959670.6342.3001723920950249067.stgit@dwillia2-desk3.amr.corp.intel.com
| * | | | x86/paravirt: Remove 'noreplace-paravirt' cmdline optionJosh Poimboeuf2018-01-312-16/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'noreplace-paravirt' option disables paravirt patching, leaving the original pv indirect calls in place. That's highly incompatible with retpolines, unless we want to uglify paravirt even further and convert the paravirt calls to retpolines. As far as I can tell, the option doesn't seem to be useful for much other than introducing surprising corner cases and making the kernel vulnerable to Spectre v2. It was probably a debug option from the early paravirt days. So just remove it. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Link: https://lkml.kernel.org/r/20180131041333.2x6blhxirc2kclrq@treble
| * | | | x86/speculation: Use Indirect Branch Prediction Barrier in context switchTim Chen2018-01-302-1/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flush indirect branches when switching into a process that marked itself non dumpable. This protects high value processes like gpg better, without having too high performance overhead. If done naïvely, we could switch to a kernel idle thread and then back to the original process, such as: process A -> idle -> process A In such scenario, we do not have to do IBPB here even though the process is non-dumpable, as we are switching back to the same process after a hiatus. To avoid the redundant IBPB, which is expensive, we track the last mm user context ID. The cost is to have an extra u64 mm context id to track the last mm we were using before switching to the init_mm used by idle. Avoiding the extra IBPB is probably worth the extra memory for this common scenario. For those cases where tlb_defer_switch_to_init_mm() returns true (non PCID), lazy tlb will defer switch to init_mm, so we will not be changing the mm for the process A -> idle -> process A switch. So IBPB will be skipped for this case. Thanks to the reviewers and Andy Lutomirski for the suggestion of using ctx_id which got rid of the problem of mm pointer recycling. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ak@linux.intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: linux@dominikbrodowski.net Cc: peterz@infradead.org Cc: bp@alien8.de Cc: luto@kernel.org Cc: pbonzini@redhat.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517263487-3708-1-git-send-email-dwmw@amazon.co.uk