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Re: [RESEND PATCH v3 0/4] iommu/iova: Solve longterm IOVA issue
by John Garry 15 Jan '21

15 Jan '21

+ linux-scsi (see https://lore.kernel.org/linux-iommu/1607538189-237944-4-git-send-email-john…) On 17/11/2020 10:25, John Garry wrote: > This series contains a patch to solve the longterm IOVA issue which > leizhen originally tried to address at [0]. > > A sieved kernel log is at the following, showing periodic dumps of IOVA > sizes, per CPU and per depot bin, per IOVA size granule: > https://raw.githubusercontent.com/hisilicon/kernel-dev/topic-iommu-5.10-iov… > > Notice, for example, the following logs: > [13175.355584] print_iova1 cpu_total=40135 depot_total=3866 total=44001 > [83483.457858] print_iova1 cpu_total=62532 depot_total=24476 total=87008 > > Where total IOVA rcache size has grown from 44K->87K over a long time. > JFYI, I am able to reproduce this aging issue on another storage card, an LSI SAS 3008, so now it's harder to say it's an issue specific to a (buggy) single driver. A log of the IOVA size dumps is here: https://raw.githubusercontent.com/hisilicon/kernel-dev/064c4dc8869b3f2ad07e… Notice again how the total IOVA size goes up over time, like: [ 68.176914] print_iova1 cpu_total=23663 depot_total=256 total=23919 [ 2337.008194] print_iova1 cpu_total=67361 depot_total=9088 total=76449 [17141.860078] print_iova1 cpu_total=73397 depot_total=10368 total=83765 [27087.850830] print_iova1 cpu_total=73386 depot_total=10624 total=84010 [10434.042877] print_iova1 cpu_total=90652 depot_total=12928 total=103580 I had to change some settings for that storage card to reproduce, though [0]. Could explain why no other reports. So please consider this issue again... Thanks, john [0] https://lore.kernel.org/linux-scsi/dd8e6fdc-397d-b6ad-3371-0b65d1932ad1@hua… > Along with this patch, I included the following: > - A smaller helper to clear all IOVAs for a domain > - Change polarity of the IOVA magazine helpers > - Small optimisation from Cong Wang included, which was never applied [1]. > There was some debate of the other patches in that series, but this one > is quite straightforward. > > Differnces to v2: > - Update commit message for patch 3/4

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[RFC PATCH] sched/fair: first try to fix the scheduling impact of NUMA diameter > 2
by Barry Song 15 Jan '21

15 Jan '21

This patch is a follow-up of the 3-hops issue reported by Valentin Schneider: [1] https://lore.kernel.org/lkml/jhjtux5edo2.mognet@arm.com/ [2] https://lore.kernel.org/lkml/20201110184300.15673-1-valentin.schneider@arm.… Here is a brief summary of the background: For a NUMA system with 3-hops, sched_group for NUMA 2-hops could be not a subset of sched_domain. For example, for a system with the below topology(two cpus in each NUMA node): node 0 1 2 3 0: 10 12 20 22 1: 12 10 22 24 2: 20 22 10 12 3: 22 24 12 10 For CPU0, domain-2 will span 0-5, but its group will span 0-3, 4-7. 4-7 isn't a subset of 0-5. CPU0 attaching sched-domain(s): domain-0: span=0-1 level=MC groups: 0:{ span=0 cap=989 }, 1:{ span=1 cap=1016 } domain-1: span=0-3 level=NUMA groups: 0:{ span=0-1 cap=2005 }, 2:{ span=2-3 cap=2028 } domain-2: span=0-5 level=NUMA groups: 0:{ span=0-3 cap=4033 }, 4:{ span=4-7 cap=3909 } ERROR: groups don't span domain->span domain-3: span=0-7 level=NUMA groups: 0:{ span=0-5 mask=0-1 cap=6062 }, 6:{ span=4-7 mask=6-7 cap=3928 } All other cpus also have the same issue: sched_group could be not a subset of sched_domain. Here I am trying to figure out the scheduling impact of this issue from two aspects: 1. find busiest cpu in load_balance 2. find idlest cpu in fork/exec/wake balance For case 1, load_balance() seems to be handling this issue correctly as it only fills cpus in sched_domain to the cpus of lb_env. Also, find_busiest_group() and find_busiest_queue() will result in scanning cpus within env.cpus only: static int load_balance(int this_cpu, struct rq *this_rq, struct sched_domain *sd, enum cpu_idle_type idle, int *continue_balancing) {` ... struct lb_env env = { ... .cpus = cpus, .fbq_type = all, .tasks = LIST_HEAD_INIT(env.tasks), }; /* added by barry: only cpus in sched_domain are put in lb_env */ cpumask_and(cpus, sched_domain_span(sd), cpu_active_mask); ... /* * added by barry: the below functions are only scanning cpus * in env.cpus */ group = find_busiest_group(&env); ... busiest = find_busiest_queue(&env, group); ... } But one thing which looks wrong is that update_sg_lb_stats() is only counting tasks in sched_domain, but sgs->group_capacity and sgs->group_weight are counting all cpus in the sched_group. Then finally, update_sg_lb_stats() uses the load of cpus which are in the sched_domain to calculate group_type and avg_load which can be seriously underestimated. This is explained in detail as the comments added by me in the code: static inline void update_sg_lb_stats() { int i, nr_running, local_group; /* added by barry: here it only counts cpu in the sched_domain */ for_each_cpu_and(i, sched_group_span(group), env->cpus) { ... sgs->group_load += cpu_load(rq); sgs->group_util += cpu_util(i); sgs->group_runnable += cpu_runnable(rq); sgs->sum_h_nr_running += rq->cfs.h_nr_running; nr_running = rq->nr_running; sgs->sum_nr_running += nr_running; ... } ... /* added by barry: here it count all cpus which might not be in the domain */ sgs->group_capacity = group->sgc->capacity; sgs->group_weight = group->group_weight; /* added by barry: finally the group_type and avg_load could be wrong */ sgs->group_type = group_classify(env->sd->imbalance_pct, group, sgs); if (sgs->group_type == group_overloaded) sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) / sgs->group_capacity; ... } For example, if we have 2 cpus in sched_domain and 4 cpus in sched_group, the code is using the load of 2 cpus to calculate the group_type and avg_load of 4 cpus, the sched_group is likely to get much lower load than the real case. This patch fixed it by only counting cpus within sched_domain for group_capacity and group_weight. For case 2, find_idlest_group() and find_idlest_group_cpu() don't use sched_domain for scanning at all. They are scanning all cpus in the sched_group though sched_group isn't a subset of sched_domain. So they can result in picking an idle cpu outside the sched_domain but inside the sched_group. This patch moved to only scan cpus within the sched_domain, which would be similar with load_balance(). For this moment, this is pretty much PoC code to get feedback. Signed-off-by: Barry Song <song.bao.hua(a)hisilicon.com> --- kernel/sched/fair.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 04a3ce20da67..f183dba4961e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5901,7 +5901,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu); * find_idlest_group_cpu - find the idlest CPU among the CPUs in the group. */ static int -find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) +find_idlest_group_cpu(struct sched_domain *sd, struct sched_group *group, struct task_struct *p, int this_cpu) { unsigned long load, min_load = ULONG_MAX; unsigned int min_exit_latency = UINT_MAX; @@ -5916,6 +5916,10 @@ find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this /* Traverse only the allowed CPUs */ for_each_cpu_and(i, sched_group_span(group), p->cpus_ptr) { + /* when sched_group isn't a subset of sched_domain */ + if (!cpumask_test_cpu(i, sched_domain_span(sd))) + continue; + if (sched_idle_cpu(i)) return i; @@ -5984,7 +5988,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p continue; } - new_cpu = find_idlest_group_cpu(group, p, cpu); + new_cpu = find_idlest_group_cpu(sd, group, p, cpu); if (new_cpu == cpu) { /* Now try balancing at a lower domain level of 'cpu': */ sd = sd->child; @@ -8416,6 +8420,8 @@ static inline void update_sg_lb_stats(struct lb_env *env, if ((env->flags & LBF_NOHZ_STATS) && update_nohz_stats(rq, false)) env->flags |= LBF_NOHZ_AGAIN; + sgs->group_capacity += capacity_of(i); + sgs->group_weight++; sgs->group_load += cpu_load(rq); sgs->group_util += cpu_util(i); sgs->group_runnable += cpu_runnable(rq); @@ -8462,10 +8468,6 @@ static inline void update_sg_lb_stats(struct lb_env *env, sgs->group_asym_packing = 1; } - sgs->group_capacity = group->sgc->capacity; - - sgs->group_weight = group->group_weight; - sgs->group_type = group_classify(env->sd->imbalance_pct, group, sgs); /* Computing avg_load makes sense only when group is overloaded */ @@ -8688,10 +8690,12 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd, memset(sgs, 0, sizeof(*sgs)); - for_each_cpu(i, sched_group_span(group)) { + for_each_cpu_and(i, sched_group_span(group), sched_domain_span(sd)) { struct rq *rq = cpu_rq(i); unsigned int local; + sgs->group_capacity += capacity_of(i); + sgs->group_weight++; sgs->group_load += cpu_load_without(rq, p); sgs->group_util += cpu_util_without(i, p); sgs->group_runnable += cpu_runnable_without(rq, p); @@ -8715,10 +8719,6 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd, sgs->group_misfit_task_load = 1; } - sgs->group_capacity = group->sgc->capacity; - - sgs->group_weight = group->group_weight; - sgs->group_type = group_classify(sd->imbalance_pct, group, sgs); /* -- 2.25.1

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[RFC PATCH 0/2] EDAC/ghes: Add EDAC device for recording the CPU cache error count
by Shiju Jose 14 Jan '21

14 Jan '21

ARM64 server chip Kunpeng 920 occasionally detected L2 cache corrected errors on few hardware. Thus the probability of the CPU cache errors occurring often exists. The earlier failure detection by monitoring the cache corrected errors for the frequent occurrences and taking preventive action could prevent more serious hardware faults. For the firmware-first error handling, especially on ARM64 architectures, there is no provision for recording the CPU cache corrected error count is present. For Intel architectures cache corrected errors reporting and offline the cores is done through more architecture specific method. http://www.mcelog.org/cache.html For this purpose, the suggestion was to create the CPU EDAC device for the CPU caches for recording the cache error count. The EDAC device blocks for the CPU caches would be created based on the cache information obtained from the cpu_cacheinfo. User-space application could monitor the recorded corrected error count for the earlier hardware failure detection and could take preventive action. Changes: RFC V1 -> RFC V2: 1. Fixed feedback by Boris. 1.1. Added reason of this patch. 1.2. Changed CPU errors to CPU cache errors in the drivers/edac/Kconfig 1.3 Changed EDAC cache list to percpu variables. 2. Changes in the descriptions. Shiju Jose (2): EDAC/ghes: Add EDAC device for reporting the CPU cache errors ACPI / APEI: Add reporting ARM64 CPU cache corrected error count Documentation/ABI/testing/sysfs-devices-edac | 15 ++ drivers/acpi/apei/ghes.c | 76 +++++++- drivers/edac/Kconfig | 10 + drivers/edac/ghes_edac.c | 181 +++++++++++++++++++ include/acpi/ghes.h | 27 +++ include/linux/cper.h | 4 + 6 files changed, 309 insertions(+), 4 deletions(-) -- 2.17.1

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[PATCH v2] input - mk712: remove the driver as it is obsolete and causes kernel crash
by Barry Song 13 Jan '21

13 Jan '21

While debugging other issues, I enabled mk712 then I got the below crash during arm64 linux boot: [ 1.150412] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) [ 1.150541] pc : logic_outb+0x3c/0xa8 [ 1.150657] lr : mk712_init+0x74/0x1ec [ 1.150745] sp : ffff800011efbd40 [ 1.150950] x29: ffff800011efbd40 x28: 0000000000000000 [ 1.151098] x27: ffff800011681078 x26: ffff8000115d04b8 [ 1.151192] x25: ffff8000116ff6b4 x24: ffff8000115bac10 [ 1.151287] x23: ffff800011dfa000 x22: ffff800011b8dbe0 [ 1.151421] x21: ffff800011eac000 x20: 0000000000000000 [ 1.151527] x19: fffffbfffe800266 x18: 0000000000000000 [ 1.151674] x17: ffff800010a7bc38 x16: ffff800010a7b0e0 [ 1.151944] x15: 0000a0d665e7ee58 x14: 000000000000011a [ 1.152060] x13: 0000000000000001 x12: 0000000000000000 [ 1.152149] x11: 0000000000000000 x10: 0000000000000a60 [ 1.152291] x9 : 0000000000000000 x8 : ffff0000c0a2a480 [ 1.152429] x7 : 0000000000000000 x6 : ffff0000c0b0c9b8 [ 1.152522] x5 : 0000000000001000 x4 : ffff0000c03613b0 [ 1.152614] x3 : 0000000000000267 x2 : 0000000000000260 [ 1.152731] x1 : fffffbfffe800000 x0 : 0000000000ffbffe [ 1.153135] Call trace: [ 1.153342] logic_outb+0x3c/0xa8 [ 1.153434] mk712_init+0x74/0x1ec [ 1.153571] do_one_initcall+0x54/0x1b8 [ 1.153705] kernel_init_freeable+0x1d0/0x238 [ 1.153860] kernel_init+0x14/0x118 [ 1.153960] ret_from_fork+0x10/0x30 [ 1.154304] Code: d2bfd001 f2df7fe1 f2ffffe1 8b010273 (39000274) [ 1.155013] ---[ end trace f9b157c311d20edd ]--- [ 1.155854] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.156236] SMP: stopping secondary CPUs The driver is very old and resources are totally hardcoded, no bus model. And it seems there is no way to stop users from enabling it in Kconfig. Plus, it is likely that there is no "Gateway AOL Connected Touchpad computers" running 5.x kernel any more. So remove this driver. Cc: Daniel Quinlan <quinlan(a)pathname.com> Cc: Vojtech Pavlik <vojtech(a)suse.cz> Signed-off-by: Barry Song <song.bao.hua(a)hisilicon.com> --- drivers/input/touchscreen/Kconfig | 11 -- drivers/input/touchscreen/Makefile | 1 - drivers/input/touchscreen/mk712.c | 215 ----------------------------- 3 files changed, 227 deletions(-) delete mode 100644 drivers/input/touchscreen/mk712.c diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig index cc18f54ea887..0638ec5d1bd7 100644 --- a/drivers/input/touchscreen/Kconfig +++ b/drivers/input/touchscreen/Kconfig @@ -630,17 +630,6 @@ config TOUCHSCREEN_INEXIO To compile this driver as a module, choose M here: the module will be called inexio. -config TOUCHSCREEN_MK712 - tristate "ICS MicroClock MK712 touchscreen" - help - Say Y here if you have the ICS MicroClock MK712 touchscreen - controller chip in your system. - - If unsure, say N. - - To compile this driver as a module, choose M here: the - module will be called mk712. - config TOUCHSCREEN_HP600 tristate "HP Jornada 6xx touchscreen" depends on SH_HP6XX && SH_ADC diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile index 6233541e9173..75a60b8282b4 100644 --- a/drivers/input/touchscreen/Makefile +++ b/drivers/input/touchscreen/Makefile @@ -60,7 +60,6 @@ obj-$(CONFIG_TOUCHSCREEN_MELFAS_MIP4) += melfas_mip4.o obj-$(CONFIG_TOUCHSCREEN_MIGOR) += migor_ts.o obj-$(CONFIG_TOUCHSCREEN_MMS114) += mms114.o obj-$(CONFIG_TOUCHSCREEN_MTOUCH) += mtouch.o -obj-$(CONFIG_TOUCHSCREEN_MK712) += mk712.o obj-$(CONFIG_TOUCHSCREEN_HP600) += hp680_ts_input.o obj-$(CONFIG_TOUCHSCREEN_HP7XX) += jornada720_ts.o obj-$(CONFIG_TOUCHSCREEN_IPAQ_MICRO) += ipaq-micro-ts.o diff --git a/drivers/input/touchscreen/mk712.c b/drivers/input/touchscreen/mk712.c deleted file mode 100644 index 753d9cc1de1f..000000000000 --- a/drivers/input/touchscreen/mk712.c +++ /dev/null @@ -1,215 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * ICS MK712 touchscreen controller driver - * - * Copyright (c) 1999-2002 Transmeta Corporation - * Copyright (c) 2005 Rick Koch <n1gp(a)hotmail.com> - * Copyright (c) 2005 Vojtech Pavlik <vojtech(a)suse.cz> - */ - - -/* - * This driver supports the ICS MicroClock MK712 TouchScreen controller, - * found in Gateway AOL Connected Touchpad computers. - * - * Documentation for ICS MK712 can be found at: - * https://www.idt.com/general-parts/mk712-touch-screen-controller - */ - -/* - * 1999-12-18: original version, Daniel Quinlan - * 1999-12-19: added anti-jitter code, report pen-up events, fixed mk712_poll - * to use queue_empty, Nathan Laredo - * 1999-12-20: improved random point rejection, Nathan Laredo - * 2000-01-05: checked in new anti-jitter code, changed mouse protocol, fixed - * queue code, added module options, other fixes, Daniel Quinlan - * 2002-03-15: Clean up for kernel merge <alan(a)redhat.com> - * Fixed multi open race, fixed memory checks, fixed resource - * allocation, fixed close/powerdown bug, switched to new init - * 2005-01-18: Ported to 2.6 from 2.4.28, Rick Koch - * 2005-02-05: Rewritten for the input layer, Vojtech Pavlik - * - */ - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/errno.h> -#include <linux/delay.h> -#include <linux/ioport.h> -#include <linux/interrupt.h> -#include <linux/input.h> -#include <asm/io.h> - -MODULE_AUTHOR("Daniel Quinlan <quinlan(a)pathname.com>, Vojtech Pavlik <vojtech(a)suse.cz>"); -MODULE_DESCRIPTION("ICS MicroClock MK712 TouchScreen driver"); -MODULE_LICENSE("GPL"); - -static unsigned int mk712_io = 0x260; /* Also 0x200, 0x208, 0x300 */ -module_param_hw_named(io, mk712_io, uint, ioport, 0); -MODULE_PARM_DESC(io, "I/O base address of MK712 touchscreen controller"); - -static unsigned int mk712_irq = 10; /* Also 12, 14, 15 */ -module_param_hw_named(irq, mk712_irq, uint, irq, 0); -MODULE_PARM_DESC(irq, "IRQ of MK712 touchscreen controller"); - -/* eight 8-bit registers */ -#define MK712_STATUS 0 -#define MK712_X 2 -#define MK712_Y 4 -#define MK712_CONTROL 6 -#define MK712_RATE 7 - -/* status */ -#define MK712_STATUS_TOUCH 0x10 -#define MK712_CONVERSION_COMPLETE 0x80 - -/* control */ -#define MK712_ENABLE_INT 0x01 -#define MK712_INT_ON_CONVERSION_COMPLETE 0x02 -#define MK712_INT_ON_CHANGE_IN_TOUCH_STATUS 0x04 -#define MK712_ENABLE_PERIODIC_CONVERSIONS 0x10 -#define MK712_READ_ONE_POINT 0x20 -#define MK712_POWERUP 0x40 - -static struct input_dev *mk712_dev; -static DEFINE_SPINLOCK(mk712_lock); - -static irqreturn_t mk712_interrupt(int irq, void *dev_id) -{ - unsigned char status; - static int debounce = 1; - static unsigned short last_x; - static unsigned short last_y; - - spin_lock(&mk712_lock); - - status = inb(mk712_io + MK712_STATUS); - - if (~status & MK712_CONVERSION_COMPLETE) { - debounce = 1; - goto end; - } - - if (~status & MK712_STATUS_TOUCH) { - debounce = 1; - input_report_key(mk712_dev, BTN_TOUCH, 0); - goto end; - } - - if (debounce) { - debounce = 0; - goto end; - } - - input_report_key(mk712_dev, BTN_TOUCH, 1); - input_report_abs(mk712_dev, ABS_X, last_x); - input_report_abs(mk712_dev, ABS_Y, last_y); - - end: - last_x = inw(mk712_io + MK712_X) & 0x0fff; - last_y = inw(mk712_io + MK712_Y) & 0x0fff; - input_sync(mk712_dev); - spin_unlock(&mk712_lock); - return IRQ_HANDLED; -} - -static int mk712_open(struct input_dev *dev) -{ - unsigned long flags; - - spin_lock_irqsave(&mk712_lock, flags); - - outb(0, mk712_io + MK712_CONTROL); /* Reset */ - - outb(MK712_ENABLE_INT | MK712_INT_ON_CONVERSION_COMPLETE | - MK712_INT_ON_CHANGE_IN_TOUCH_STATUS | - MK712_ENABLE_PERIODIC_CONVERSIONS | - MK712_POWERUP, mk712_io + MK712_CONTROL); - - outb(10, mk712_io + MK712_RATE); /* 187 points per second */ - - spin_unlock_irqrestore(&mk712_lock, flags); - - return 0; -} - -static void mk712_close(struct input_dev *dev) -{ - unsigned long flags; - - spin_lock_irqsave(&mk712_lock, flags); - - outb(0, mk712_io + MK712_CONTROL); - - spin_unlock_irqrestore(&mk712_lock, flags); -} - -static int __init mk712_init(void) -{ - int err; - - if (!request_region(mk712_io, 8, "mk712")) { - printk(KERN_WARNING "mk712: unable to get IO region\n"); - return -ENODEV; - } - - outb(0, mk712_io + MK712_CONTROL); - - if ((inw(mk712_io + MK712_X) & 0xf000) || /* Sanity check */ - (inw(mk712_io + MK712_Y) & 0xf000) || - (inw(mk712_io + MK712_STATUS) & 0xf333)) { - printk(KERN_WARNING "mk712: device not present\n"); - err = -ENODEV; - goto fail1; - } - - mk712_dev = input_allocate_device(); - if (!mk712_dev) { - printk(KERN_ERR "mk712: not enough memory\n"); - err = -ENOMEM; - goto fail1; - } - - mk712_dev->name = "ICS MicroClock MK712 TouchScreen"; - mk712_dev->phys = "isa0260/input0"; - mk712_dev->id.bustype = BUS_ISA; - mk712_dev->id.vendor = 0x0005; - mk712_dev->id.product = 0x0001; - mk712_dev->id.version = 0x0100; - - mk712_dev->open = mk712_open; - mk712_dev->close = mk712_close; - - mk712_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); - mk712_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); - input_set_abs_params(mk712_dev, ABS_X, 0, 0xfff, 88, 0); - input_set_abs_params(mk712_dev, ABS_Y, 0, 0xfff, 88, 0); - - if (request_irq(mk712_irq, mk712_interrupt, 0, "mk712", mk712_dev)) { - printk(KERN_WARNING "mk712: unable to get IRQ\n"); - err = -EBUSY; - goto fail1; - } - - err = input_register_device(mk712_dev); - if (err) - goto fail2; - - return 0; - - fail2: free_irq(mk712_irq, mk712_dev); - fail1: input_free_device(mk712_dev); - release_region(mk712_io, 8); - return err; -} - -static void __exit mk712_exit(void) -{ - input_unregister_device(mk712_dev); - free_irq(mk712_irq, mk712_dev); - release_region(mk712_io, 8); -} - -module_init(mk712_init); -module_exit(mk712_exit); -- 2.25.1

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[PATCH 0/2] hisi_sas: Expose hw queues for v2 hw and remove unused code
by John Garry 13 Jan '21

13 Jan '21

Patch "scsi: hisi_sas: Expose HW queues for v2 hw" was not merged for v5.11, so resending for v5.12. Unused module param auto_affine_msi_experimental for v3 hw is also removed in the other patch. John Garry (2): scsi: hisi_sas: Remove auto_affine_msi_experimental module_param scsi: hisi_sas: Expose HW queues for v2 hw drivers/scsi/hisi_sas/hisi_sas.h | 4 ++ drivers/scsi/hisi_sas/hisi_sas_main.c | 11 +++++ drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 66 +++++++++++++++++++++----- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 5 -- 4 files changed, 68 insertions(+), 18 deletions(-) -- 2.26.2

2 5

[RFC PATCH 0/2] EDAC/ghes: Add EDAC device for recording the CPU cache error count
by Shiju Jose 12 Jan '21

12 Jan '21

ARM64 server chip Kunpeng 920 occasionally detected L2 cache corrected errors on few hardware. Thus CPU cache errors seems not uncommon. The earlier failure detection by monitoring the cache corrected errors and taking preventive action could prevent more serious hardware failures. For the firmware-first error handling on ARM64 hardware platforms, CPU cache corrected error count is not recorded. For this purpose, the suggestion was to create an CPU EDAC device and device blocks for the CPU caches. The EDAC device blocks would be created based on the cache information obtained from the cpu_cacheinfo. User-space application could monitor the recorded corrected error count for the earlier hardware failure detection and could take preventive action. Changes: RFC V1 -> RFC V2: 1. Fixed feedback by Boris. 1.1. Added reason of this patch. 1.2. Changed CPU errors to CPU cache errors in the drivers/edac/Kconfig 1.3 Changed EDAC cache list to percpu variables. 2. Changes in the descriptions. Shiju Jose (2): EDAC/ghes: Add EDAC device for reporting the CPU cache errors ACPI / APEI: Add reporting ARM64 CPU cache corrected error count Documentation/ABI/testing/sysfs-devices-edac | 15 ++ drivers/acpi/apei/ghes.c | 76 +++++++- drivers/edac/Kconfig | 10 + drivers/edac/ghes_edac.c | 181 +++++++++++++++++++ include/acpi/ghes.h | 27 +++ include/linux/cper.h | 4 + 6 files changed, 309 insertions(+), 4 deletions(-) -- 2.17.1

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[PATCH] input - mk712: fix the kernel crash while mk712 is selected
by Barry Song 12 Jan '21

12 Jan '21

While debugging other issues, I enabled mk712 then I got the below crash during arm64 linux boot: [ 1.150412] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) [ 1.150541] pc : logic_outb+0x3c/0xa8 [ 1.150657] lr : mk712_init+0x74/0x1ec [ 1.150745] sp : ffff800011efbd40 [ 1.150950] x29: ffff800011efbd40 x28: 0000000000000000 [ 1.151098] x27: ffff800011681078 x26: ffff8000115d04b8 [ 1.151192] x25: ffff8000116ff6b4 x24: ffff8000115bac10 [ 1.151287] x23: ffff800011dfa000 x22: ffff800011b8dbe0 [ 1.151421] x21: ffff800011eac000 x20: 0000000000000000 [ 1.151527] x19: fffffbfffe800266 x18: 0000000000000000 [ 1.151674] x17: ffff800010a7bc38 x16: ffff800010a7b0e0 [ 1.151944] x15: 0000a0d665e7ee58 x14: 000000000000011a [ 1.152060] x13: 0000000000000001 x12: 0000000000000000 [ 1.152149] x11: 0000000000000000 x10: 0000000000000a60 [ 1.152291] x9 : 0000000000000000 x8 : ffff0000c0a2a480 [ 1.152429] x7 : 0000000000000000 x6 : ffff0000c0b0c9b8 [ 1.152522] x5 : 0000000000001000 x4 : ffff0000c03613b0 [ 1.152614] x3 : 0000000000000267 x2 : 0000000000000260 [ 1.152731] x1 : fffffbfffe800000 x0 : 0000000000ffbffe [ 1.153135] Call trace: [ 1.153342] logic_outb+0x3c/0xa8 [ 1.153434] mk712_init+0x74/0x1ec [ 1.153571] do_one_initcall+0x54/0x1b8 [ 1.153705] kernel_init_freeable+0x1d0/0x238 [ 1.153860] kernel_init+0x14/0x118 [ 1.153960] ret_from_fork+0x10/0x30 [ 1.154304] Code: d2bfd001 f2df7fe1 f2ffffe1 8b010273 (39000274) [ 1.155013] ---[ end trace f9b157c311d20edd ]--- [ 1.155854] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.156236] SMP: stopping secondary CPUs The driver is very old and resources are totally hardcoded, no bus model. It seems the simplest way to fix this issue is disabling it by parameter. If someone really needs the old driver, it should enable the parameter by cmdline. Signed-off-by: Barry Song <song.bao.hua(a)hisilicon.com> --- drivers/input/touchscreen/mk712.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/input/touchscreen/mk712.c b/drivers/input/touchscreen/mk712.c index 753d9cc1de1f..8a3110f27ce7 100644 --- a/drivers/input/touchscreen/mk712.c +++ b/drivers/input/touchscreen/mk712.c @@ -53,6 +53,9 @@ static unsigned int mk712_irq = 10; /* Also 12, 14, 15 */ module_param_hw_named(irq, mk712_irq, uint, irq, 0); MODULE_PARM_DESC(irq, "IRQ of MK712 touchscreen controller"); +static bool mk712_enabled; +module_param(mk712_enabled, bool, 0); + /* eight 8-bit registers */ #define MK712_STATUS 0 #define MK712_X 2 @@ -149,6 +152,11 @@ static int __init mk712_init(void) { int err; + if (!mk712_enabled) { + printk(KERN_WARNING "mk712: device is not enabled\n"); + return -ENODEV; + } + if (!request_region(mk712_io, 8, "mk712")) { printk(KERN_WARNING "mk712: unable to get IO region\n"); return -ENODEV; -- 2.25.1

3 2

Re: [PATCH 2/2] KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
by Shameerali Kolothum Thodi 11 Jan '21

11 Jan '21

Hi Marc, > -----Original Message----- > From: Marc Zyngier [mailto:maz@kernel.org] > Sent: 08 January 2021 17:12 > To: linux-arm-kernel(a)lists.infradead.org; kvmarm(a)lists.cs.columbia.edu > Cc: Shameerali Kolothum Thodi <shameerali.kolothum.thodi(a)huawei.com>; > James Morse <james.morse(a)arm.com>; Julien Thierry > <julien.thierry.kdev(a)gmail.com>; Suzuki K Poulose > <suzuki.poulose(a)arm.com>; Ard Biesheuvel <ardb(a)kernel.org>; > kernel-team(a)android.com > Subject: [PATCH 2/2] KVM: arm64: Workaround firmware wrongly advertising > GICv2-on-v3 compatibility > > It looks like we have broken firmware out there that wrongly advertises > a GICv2 compatibility interface, despite the CPUs not being able to deal > with it. > > To work around this, check that the CPU initialising KVM is actually able > to switch to MMIO instead of system registers, and use that as a > precondition to enable GICv2 compatibility in KVM. > > Note that the detection happens on a single CPU. If the firmware is > lying *and* that the CPUs are asymetric, all hope is lost anyway. > > Reported-by: Shameerali Kolothum Thodi > <shameerali.kolothum.thodi(a)huawei.com> > Signed-off-by: Marc Zyngier <maz(a)kernel.org> > --- > arch/arm64/kvm/hyp/vgic-v3-sr.c | 34 +++++++++++++++++++++++++++++++-- > arch/arm64/kvm/vgic/vgic-v3.c | 8 ++++++-- > 2 files changed, 38 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c > b/arch/arm64/kvm/hyp/vgic-v3-sr.c > index 005daa0c9dd7..d504499ab917 100644 > --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c > +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c > @@ -408,11 +408,41 @@ void __vgic_v3_init_lrs(void) > /* > * Return the GIC CPU configuration: > * - [31:0] ICH_VTR_EL2 > - * - [63:32] RES0 > + * - [62:32] RES0 > + * - [63] MMIO (GICv2) capable > */ > u64 __vgic_v3_get_gic_config(void) > { > - return read_gicreg(ICH_VTR_EL2); > + u64 sre = read_gicreg(ICC_SRE_EL1); > + unsigned long flags = 0; > + bool v2_capable; > + > + /* > + * To check whether we have a MMIO-based (GICv2 compatible) > + * CPU interface, we need to disable the system register > + * view. To do that safely, we have to prevent any interrupt > + * from firing (which would be deadly). > + * > + * Note that this only makes sense on VHE, as interrupts are > + * already masked for nVHE as part of the exception entry to > + * EL2. > + */ > + if (has_vhe()) > + flags = local_daif_save(); > + > + write_gicreg(0, ICC_SRE_EL1); > + isb(); > + > + v2_capable = !(read_gicreg(ICC_SRE_EL1) & ICC_SRE_EL1_SRE); > + > + write_gicreg(sre, ICC_SRE_EL1); > + isb(); > + > + if (has_vhe()) > + local_daif_restore(flags); > + > + return (read_gicreg(ICH_VTR_EL2) | > + v2_capable ? (1ULL << 63) : 0); > } Thanks for sending this out. I had a go with this series and unfortunately it didn't work on a system with faulty BIOS. It looks like the culprit here is the ?: operator. There seems to be an operator precedence at play here and it returns, vgic_v3_probe: ich_vtr_el2 0x8000000000000000 And with the below change, return (read_gicreg(ICH_VTR_EL2) | - v2_capable ? (1ULL << 63) : 0); + (v2_capable ? (1ULL << 63) : 0)); } It returns, vgic_v3_probe: ich_vtr_el2 0x90080003 and works correctly. [ 18.918738] kvm [1]: disabling GICv2 emulation Thanks, Shameer > u64 __vgic_v3_read_vmcr(void) > diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c > index 8e7bf3151057..67b27b47312b 100644 > --- a/arch/arm64/kvm/vgic/vgic-v3.c > +++ b/arch/arm64/kvm/vgic/vgic-v3.c > @@ -584,8 +584,10 @@ early_param("kvm-arm.vgic_v4_enable", > early_gicv4_enable); > int vgic_v3_probe(const struct gic_kvm_info *info) > { > u64 ich_vtr_el2 = kvm_call_hyp_ret(__vgic_v3_get_gic_config); > + bool has_v2; > int ret; > > + has_v2 = ich_vtr_el2 >> 63; > ich_vtr_el2 = (u32)ich_vtr_el2; > > /* > @@ -605,13 +607,15 @@ int vgic_v3_probe(const struct gic_kvm_info *info) > gicv4_enable ? "en" : "dis"); > } > > + kvm_vgic_global_state.vcpu_base = 0; > + > if (!info->vcpu.start) { > kvm_info("GICv3: no GICV resource entry\n"); > - kvm_vgic_global_state.vcpu_base = 0; > + } else if (!has_v2) { > + pr_warn("CPU interface incapable of MMIO access\n"); > } else if (!PAGE_ALIGNED(info->vcpu.start)) { > pr_warn("GICV physical address 0x%llx not page aligned\n", > (unsigned long long)info->vcpu.start); > - kvm_vgic_global_state.vcpu_base = 0; > } else { > kvm_vgic_global_state.vcpu_base = info->vcpu.start; > kvm_vgic_global_state.can_emulate_gicv2 = true; > -- > 2.29.2

2 1

Re: [PATCH v11 12/13] vfio/pci: Register a DMA fault response region
by Shameerali Kolothum Thodi 08 Jan '21

08 Jan '21

Hi Eric, > -----Original Message----- > From: Eric Auger [mailto:eric.auger@redhat.com] > Sent: 16 November 2020 11:00 > To: eric.auger.pro(a)gmail.com; eric.auger(a)redhat.com; > iommu(a)lists.linux-foundation.org; linux-kernel(a)vger.kernel.org; > kvm(a)vger.kernel.org; kvmarm(a)lists.cs.columbia.edu; will(a)kernel.org; > joro(a)8bytes.org; maz(a)kernel.org; robin.murphy(a)arm.com; > alex.williamson(a)redhat.com > Cc: jean-philippe(a)linaro.org; zhangfei.gao(a)linaro.org; > zhangfei.gao(a)gmail.com; vivek.gautam(a)arm.com; Shameerali Kolothum > Thodi <shameerali.kolothum.thodi(a)huawei.com>; > jacob.jun.pan(a)linux.intel.com; yi.l.liu(a)intel.com; tn(a)semihalf.com; > nicoleotsuka(a)gmail.com; yuzenghui <yuzenghui(a)huawei.com> > Subject: [PATCH v11 12/13] vfio/pci: Register a DMA fault response region > > In preparation for vSVA, let's register a DMA fault response region, > where the userspace will push the page responses and increment the > head of the buffer. The kernel will pop those responses and inject them > on iommu side. > > Signed-off-by: Eric Auger <eric.auger(a)redhat.com> > --- > drivers/vfio/pci/vfio_pci.c | 114 +++++++++++++++++++++++++--- > drivers/vfio/pci/vfio_pci_private.h | 5 ++ > drivers/vfio/pci/vfio_pci_rdwr.c | 39 ++++++++++ > include/uapi/linux/vfio.h | 32 ++++++++ > 4 files changed, 181 insertions(+), 9 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index 65a83fd0e8c0..e9a904ce3f0d 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -318,9 +318,20 @@ static void vfio_pci_dma_fault_release(struct > vfio_pci_device *vdev, > kfree(vdev->fault_pages); > } > > -static int vfio_pci_dma_fault_mmap(struct vfio_pci_device *vdev, > - struct vfio_pci_region *region, > - struct vm_area_struct *vma) > +static void > +vfio_pci_dma_fault_response_release(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region) > +{ > + if (vdev->dma_fault_response_wq) > + destroy_workqueue(vdev->dma_fault_response_wq); > + kfree(vdev->fault_response_pages); > + vdev->fault_response_pages = NULL; > +} > + > +static int __vfio_pci_dma_fault_mmap(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vm_area_struct *vma, > + u8 *pages) > { > u64 phys_len, req_len, pgoff, req_start; > unsigned long long addr; > @@ -333,14 +344,14 @@ static int vfio_pci_dma_fault_mmap(struct > vfio_pci_device *vdev, > ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1); > req_start = pgoff << PAGE_SHIFT; > > - /* only the second page of the producer fault region is mmappable */ > + /* only the second page of the fault region is mmappable */ > if (req_start < PAGE_SIZE) > return -EINVAL; > > if (req_start + req_len > phys_len) > return -EINVAL; > > - addr = virt_to_phys(vdev->fault_pages); > + addr = virt_to_phys(pages); > vma->vm_private_data = vdev; > vma->vm_pgoff = (addr >> PAGE_SHIFT) + pgoff; > > @@ -349,13 +360,29 @@ static int vfio_pci_dma_fault_mmap(struct > vfio_pci_device *vdev, > return ret; > } > > -static int vfio_pci_dma_fault_add_capability(struct vfio_pci_device *vdev, > - struct vfio_pci_region *region, > - struct vfio_info_cap *caps) > +static int vfio_pci_dma_fault_mmap(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vm_area_struct *vma) > +{ > + return __vfio_pci_dma_fault_mmap(vdev, region, vma, > vdev->fault_pages); > +} > + > +static int > +vfio_pci_dma_fault_response_mmap(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vm_area_struct *vma) > +{ > + return __vfio_pci_dma_fault_mmap(vdev, region, vma, > vdev->fault_response_pages); > +} > + > +static int __vfio_pci_dma_fault_add_capability(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vfio_info_cap *caps, > + u32 cap_id) > { > struct vfio_region_info_cap_sparse_mmap *sparse = NULL; > struct vfio_region_info_cap_fault cap = { > - .header.id = VFIO_REGION_INFO_CAP_DMA_FAULT, > + .header.id = cap_id, > .header.version = 1, > .version = 1, > }; > @@ -383,6 +410,14 @@ static int vfio_pci_dma_fault_add_capability(struct > vfio_pci_device *vdev, > return ret; > } > > +static int vfio_pci_dma_fault_add_capability(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vfio_info_cap *caps) > +{ > + return __vfio_pci_dma_fault_add_capability(vdev, region, caps, > + VFIO_REGION_INFO_CAP_DMA_FAULT); > +} > + > static const struct vfio_pci_regops vfio_pci_dma_fault_regops = { > .rw = vfio_pci_dma_fault_rw, > .release = vfio_pci_dma_fault_release, > @@ -390,6 +425,13 @@ static const struct vfio_pci_regops > vfio_pci_dma_fault_regops = { > .add_capability = vfio_pci_dma_fault_add_capability, > }; > > +static const struct vfio_pci_regops vfio_pci_dma_fault_response_regops = { > + .rw = vfio_pci_dma_fault_response_rw, > + .release = vfio_pci_dma_fault_response_release, > + .mmap = vfio_pci_dma_fault_response_mmap, > + .add_capability = vfio_pci_dma_fault_add_capability, > +}; > + > int vfio_pci_iommu_dev_fault_handler(struct iommu_fault *fault, void *data) > { > struct vfio_pci_device *vdev = (struct vfio_pci_device *)data; > @@ -500,6 +542,55 @@ static int vfio_pci_dma_fault_init(struct > vfio_pci_device *vdev) > return ret; > } > > +#define DMA_FAULT_RESPONSE_RING_LENGTH 512 > + > +static int vfio_pci_dma_fault_response_init(struct vfio_pci_device *vdev) > +{ > + struct vfio_region_dma_fault_response *header; > + struct iommu_domain *domain; > + size_t size; > + bool nested; > + int ret; > + > + domain = iommu_get_domain_for_dev(&vdev->pdev->dev); > + ret = iommu_domain_get_attr(domain, DOMAIN_ATTR_NESTING, > &nested); The above will fail((Thanks to Zengtao for reporting this) if the Guest is booted in "enable_unsafe_noiommu_mode" (CONFIG_VFIO_NOIOMMU) and dpdk testpmd is attempted. This is because even though there is an iommu group created for this mode, no iommu domain gets attached to it. And results in below crash, root@ubuntu:/mnt/dpdk/build/app# ./testpmd -w 0000:00:02.0 --file-prefix socket0 -l 0-1 -n 2 -- -i EAL: Detected 8 lcore(s) EAL: Detected 1 NUMA nodes EAL: Multi-process socket /var/run/dpdk/socket0/mp_socket EAL: Selected IOVA mode 'PA' EAL: No available hugepages reported in hugepages-32768kB EAL: No available hugepages reported in hugepages-64kB EAL: No available hugepages reported in hugepages-1048576kB EAL: Probing VFIO support... EAL: VFIO support initialized EAL: Invalid NUMA socket, default to 0 EAL: using IOMMU type 8 (No-IOMMU) [ 84.942213] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 [ 84.943047] Mem abort info: --- I have pushed a temp fix for this in my test branch here, https://github.com/hisilicon/kernel-dev/commit/7784d96fbac9c48e8093ec9dbf43… Please take a look. (I am seeing another issue with testpmd + vsmmu. I will explain that in another thread). Thanks, Shameer > + if (ret || !nested) > + return ret; > + > + mutex_init(&vdev->fault_response_queue_lock); > + > + /* > + * We provision 1 page for the header and space for > + * DMA_FAULT_RING_LENGTH fault records in the ring buffer. > + */ > + size = ALIGN(sizeof(struct iommu_page_response) * > + DMA_FAULT_RESPONSE_RING_LENGTH, PAGE_SIZE) + > PAGE_SIZE; > + > + vdev->fault_response_pages = kzalloc(size, GFP_KERNEL); > + if (!vdev->fault_response_pages) > + return -ENOMEM; > + > + ret = vfio_pci_register_dev_region(vdev, > + VFIO_REGION_TYPE_NESTED, > + VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT_RESPONSE, > + &vfio_pci_dma_fault_response_regops, size, > + VFIO_REGION_INFO_FLAG_READ | > VFIO_REGION_INFO_FLAG_WRITE | > + VFIO_REGION_INFO_FLAG_MMAP, > + vdev->fault_response_pages); > + if (ret) > + goto out; > + > + header = (struct vfio_region_dma_fault_response > *)vdev->fault_response_pages; > + header->entry_size = sizeof(struct iommu_page_response); > + header->nb_entries = DMA_FAULT_RESPONSE_RING_LENGTH; > + header->offset = PAGE_SIZE; > + > + return 0; > +out: > + vdev->fault_response_pages = NULL; > + return ret; > +} > + > static int vfio_pci_enable(struct vfio_pci_device *vdev) > { > struct pci_dev *pdev = vdev->pdev; > @@ -602,6 +693,10 @@ static int vfio_pci_enable(struct vfio_pci_device > *vdev) > if (ret) > goto disable_exit; > > + ret = vfio_pci_dma_fault_response_init(vdev); > + if (ret) > + goto disable_exit; > + > vfio_pci_probe_mmaps(vdev); > > return 0; > @@ -2227,6 +2322,7 @@ static int vfio_pci_probe(struct pci_dev *pdev, const > struct pci_device_id *id) > INIT_LIST_HEAD(&vdev->ioeventfds_list); > mutex_init(&vdev->vma_lock); > INIT_LIST_HEAD(&vdev->vma_list); > + INIT_LIST_HEAD(&vdev->dummy_resources_list); > init_rwsem(&vdev->memory_lock); > > ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); > diff --git a/drivers/vfio/pci/vfio_pci_private.h > b/drivers/vfio/pci/vfio_pci_private.h > index e180b5435c8f..035634521cd0 100644 > --- a/drivers/vfio/pci/vfio_pci_private.h > +++ b/drivers/vfio/pci/vfio_pci_private.h > @@ -144,7 +144,9 @@ struct vfio_pci_device { > struct eventfd_ctx *err_trigger; > struct eventfd_ctx *req_trigger; > u8 *fault_pages; > + u8 *fault_response_pages; > struct mutex fault_queue_lock; > + struct mutex fault_response_queue_lock; > struct list_head dummy_resources_list; > struct mutex ioeventfds_lock; > struct list_head ioeventfds_list; > @@ -189,6 +191,9 @@ extern long vfio_pci_ioeventfd(struct vfio_pci_device > *vdev, loff_t offset, > extern size_t vfio_pci_dma_fault_rw(struct vfio_pci_device *vdev, > char __user *buf, size_t count, > loff_t *ppos, bool iswrite); > +extern size_t vfio_pci_dma_fault_response_rw(struct vfio_pci_device *vdev, > + char __user *buf, size_t count, > + loff_t *ppos, bool iswrite); > > extern int vfio_pci_init_perm_bits(void); > extern void vfio_pci_uninit_perm_bits(void); > diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c > index 164120607469..efde0793360b 100644 > --- a/drivers/vfio/pci/vfio_pci_rdwr.c > +++ b/drivers/vfio/pci/vfio_pci_rdwr.c > @@ -400,6 +400,45 @@ size_t vfio_pci_dma_fault_rw(struct vfio_pci_device > *vdev, char __user *buf, > return ret; > } > > +size_t vfio_pci_dma_fault_response_rw(struct vfio_pci_device *vdev, char > __user *buf, > + size_t count, loff_t *ppos, bool iswrite) > +{ > + unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - > VFIO_PCI_NUM_REGIONS; > + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; > + void *base = vdev->region[i].data; > + int ret = -EFAULT; > + > + if (pos >= vdev->region[i].size) > + return -EINVAL; > + > + count = min(count, (size_t)(vdev->region[i].size - pos)); > + > + if (iswrite) { > + struct vfio_region_dma_fault_response *header = > + (struct vfio_region_dma_fault_response *)base; > + uint32_t new_head; > + > + if (pos != 0 || count != 4) > + return -EINVAL; > + > + if (copy_from_user((void *)&new_head, buf, count)) > + return -EFAULT; > + > + if (new_head >= header->nb_entries) > + return -EINVAL; > + > + mutex_lock(&vdev->fault_response_queue_lock); > + header->head = new_head; > + mutex_unlock(&vdev->fault_response_queue_lock); > + } else { > + if (copy_to_user(buf, base + pos, count)) > + return -EFAULT; > + } > + *ppos += count; > + ret = count; > + return ret; > +} > + > static void vfio_pci_ioeventfd_do_write(struct vfio_pci_ioeventfd *ioeventfd, > bool test_mem) > { > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 1e5c82f9d14d..5d106db7a4c5 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -345,6 +345,7 @@ struct vfio_region_info_cap_type { > > #define VFIO_REGION_TYPE_NESTED (2) > #define VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT (1) > +#define VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT_RESPONSE (2) > > /** > * struct vfio_region_gfx_edid - EDID region layout. > @@ -1022,6 +1023,17 @@ struct vfio_region_info_cap_fault { > __u32 version; > }; > > +/* > + * Capability exposed by the DMA fault response region > + * @version: ABI version > + */ > +#define VFIO_REGION_INFO_CAP_DMA_FAULT_RESPONSE 7 > + > +struct vfio_region_info_cap_fault_response { > + struct vfio_info_cap_header header; > + __u32 version; > +}; > + > /* > * DMA Fault Region Layout > * @tail: index relative to the start of the ring buffer at which the > @@ -1042,6 +1054,26 @@ struct vfio_region_dma_fault { > __u32 head; > }; > > +/* > + * DMA Fault Response Region Layout > + * @head: index relative to the start of the ring buffer at which the > + * producer (userspace) insert responses into the buffer > + * @entry_size: fault ring buffer entry size in bytes > + * @nb_entries: max capacity of the fault ring buffer > + * @offset: ring buffer offset relative to the start of the region > + * @tail: index relative to the start of the ring buffer at which the > + * consumer (kernel) finds the next item in the buffer > + */ > +struct vfio_region_dma_fault_response { > + /* Write-Only */ > + __u32 head; > + /* Read-Only */ > + __u32 entry_size; > + __u32 nb_entries; > + __u32 offset; > + __u32 tail; > +}; > + > /* -------- API for Type1 VFIO IOMMU -------- */ > > /** > -- > 2.21.3

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[PATCH] dma-mapping: benchmark: fix kernel crash when dma_map_single fails
by Barry Song 08 Jan '21

08 Jan '21

if dma_map_single() fails, kernel will give the below oops since task_struct has been destroyed and we are running into the memory corruption due to use-after-free in kthread_stop(): [ 48.095310] Unable to handle kernel paging request at virtual address 000000c473548040 [ 48.095736] Mem abort info: [ 48.095864] ESR = 0x96000004 [ 48.096025] EC = 0x25: DABT (current EL), IL = 32 bits [ 48.096268] SET = 0, FnV = 0 [ 48.096401] EA = 0, S1PTW = 0 [ 48.096538] Data abort info: [ 48.096659] ISV = 0, ISS = 0x00000004 [ 48.096820] CM = 0, WnR = 0 [ 48.097079] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104639000 [ 48.098099] [000000c473548040] pgd=0000000000000000, p4d=0000000000000000 [ 48.098832] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 48.099232] Modules linked in: [ 48.099387] CPU: 0 PID: 2 Comm: kthreadd Tainted: G W [ 48.099887] Hardware name: linux,dummy-virt (DT) [ 48.100078] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) [ 48.100516] pc : __kmalloc_node+0x214/0x368 [ 48.100944] lr : __kmalloc_node+0x1f4/0x368 [ 48.101458] sp : ffff800011f0bb80 [ 48.101843] x29: ffff800011f0bb80 x28: ffff0000c0098ec0 [ 48.102330] x27: 0000000000000000 x26: 00000000001d4600 [ 48.102648] x25: ffff0000c0098ec0 x24: ffff800011b6a000 [ 48.102988] x23: 00000000ffffffff x22: ffff0000c0098ec0 [ 48.103333] x21: ffff8000101d7a54 x20: 0000000000000dc0 [ 48.103657] x19: ffff0000c0001e00 x18: 0000000000000000 [ 48.104069] x17: 0000000000000000 x16: 0000000000000000 [ 48.105449] x15: 000001aa0304e7b9 x14: 00000000000003b1 [ 48.106401] x13: ffff8000122d5000 x12: ffff80001228d000 [ 48.107296] x11: ffff0000c0154340 x10: 0000000000000000 [ 48.107862] x9 : ffff80000fffffff x8 : ffff0000c473527f [ 48.108326] x7 : ffff800011e62f58 x6 : ffff0000c01c8ed8 [ 48.108778] x5 : ffff0000c0098ec0 x4 : 0000000000000000 [ 48.109223] x3 : 00000000001d4600 x2 : 0000000000000040 [ 48.109656] x1 : 0000000000000001 x0 : ff0000c473548000 [ 48.110104] Call trace: [ 48.110287] __kmalloc_node+0x214/0x368 [ 48.110493] __vmalloc_node_range+0xc4/0x298 [ 48.110805] copy_process+0x2c8/0x15c8 [ 48.111133] kernel_clone+0x5c/0x3c0 [ 48.111373] kernel_thread+0x64/0x90 [ 48.111604] kthreadd+0x158/0x368 [ 48.111810] ret_from_fork+0x10/0x30 [ 48.112336] Code: 17ffffe9 b9402a62 b94008a1 11000421 (f8626802) [ 48.112884] ---[ end trace d4890e21e75419d5 ]--- Signed-off-by: Barry Song <song.bao.hua(a)hisilicon.com> --- kernel/dma/map_benchmark.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c index b1496e744c68..1b1b8ff875cb 100644 --- a/kernel/dma/map_benchmark.c +++ b/kernel/dma/map_benchmark.c @@ -147,8 +147,10 @@ static int do_map_benchmark(struct map_benchmark_data *map) atomic64_set(&map->sum_sq_unmap, 0); atomic64_set(&map->loops, 0); - for (i = 0; i < threads; i++) + for (i = 0; i < threads; i++) { + get_task_struct(tsk[i]); wake_up_process(tsk[i]); + } msleep_interruptible(map->bparam.seconds * 1000); @@ -183,6 +185,8 @@ static int do_map_benchmark(struct map_benchmark_data *map) } out: + for (i = 0; i < threads; i++) + put_task_struct(tsk[i]); put_device(map->dev); kfree(tsk); return ret; -- 2.25.1

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