kernel.git/arch/x86/kernel/cpu/intel_rdt.c, branch linux-4.20.y

x86/resctrl: Fix rdt_find_domain() return value and checks

2019-01-26T08:20:45Z

[ Upstream commit 52eb74339a6233c69f4e3794b69ea7c98eeeae1b ] rdt_find_domain() returns an ERR_PTR() that is generated from a provided domain id when the value is negative. Care needs to be taken when creating an ERR_PTR() from this value because a subsequent check using IS_ERR() expects the error to be within the MAX_ERRNO range. Using an invalid domain id as an ERR_PTR() does work at this time since this is currently always -1. Using this undocumented assumption is fragile since future users of rdt_find_domain() may not be aware of thus assumption. Two related issues are addressed: - Ensure that rdt_find_domain() always returns a valid error value by forcing the error to be -ENODEV when a negative domain id is provided. - In a few instances the return value of rdt_find_domain() is just checked for NULL - fix these to include a check of ERR_PTR. Fixes: d89b7379015f ("x86/intel_rdt/cqm: Add mon_data") Fixes: 521348b011d6 ("x86/intel_rdt: Introduce utility to obtain CDP peer") Signed-off-by: Reinette Chatre Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Tony Luck Cc: fenghua.yu@intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: x86-ml Link: https://lkml.kernel.org/r/b88cd4ff6a75995bf8db9b0ea546908fe50f69f3.1544479852.git.reinette.chatre@intel.com Signed-off-by: Sasha Levin

x86/intel_rdt: Prevent pseudo-locking from using stale pointers

2018-10-19T12:54:28Z

When the last CPU in an rdt_domain goes offline, its rdt_domain struct gets freed. Current pseudo-locking code is unaware of this scenario and tries to dereference the freed structure in a few places. Add checks to prevent pseudo-locking code from doing this. While further work is needed to seamlessly restore resource groups (not just pseudo-locking) to their configuration when the domain is brought back online, the immediate issue of invalid pointers is addressed here. Fixes: f4e80d67a5274 ("x86/intel_rdt: Resctrl files reflect pseudo-locked information") Fixes: 443810fe61605 ("x86/intel_rdt: Create debugfs files for pseudo-locking testing") Fixes: 746e08590b864 ("x86/intel_rdt: Create character device exposing pseudo-locked region") Fixes: 33dc3e410a0d9 ("x86/intel_rdt: Make CPU information accessible for pseudo-locked regions") Signed-off-by: Jithu Joseph Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/231f742dbb7b00a31cc104416860e27dba6b072d.1539384145.git.reinette.chatre@intel.com

x86/intel_rdt: Switch to bitmap_zalloc()

2018-10-03T19:53:49Z

Switch to bitmap_zalloc() to show clearly what is allocated. Besides that it returns a pointer of bitmap type instead of opaque void *. Signed-off-by: Andy Shevchenko Signed-off-by: Thomas Gleixner Acked-by: Fenghua Yu Cc: "H. Peter Anvin" Link: https://lkml.kernel.org/r/20180830115039.63430-1-andriy.shevchenko@linux.intel.com

x86/intel_rdt: Ensure RDT cleanup on exit

2018-06-23T11:03:50Z

The RDT system's initialization does not have the corresponding exit handling to ensure everything initialized on load is cleaned up also. Introduce the cleanup routines that complement all initialization. This includes the removal of a duplicate rdtgroup_init() declaration. Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: vikas.shivappa@linux.intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/a9e3a2bbd731d13915d2d7bf05d4f675b4fa109b.1529706536.git.reinette.chatre@intel.com

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-06-10T16:44:53Z

Pull x86 updates and fixes from Thomas Gleixner: - Fix the (late) fallout from the vector management rework causing hlist corruption and irq descriptor reference leaks caused by a missing sanity check. The straight forward fix triggered another long standing issue to surface. The pre rework code hid the issue due to being way slower, but now the chance that user space sees an EBUSY error return when updating irq affinities is way higher, though quite a bunch of userspace tools do not handle it properly despite the fact that EBUSY could be returned for at least 10 years. It turned out that the EBUSY return can be avoided completely by utilizing the existing delayed affinity update mechanism for irq remapped scenarios as well. That's a bit more error handling in the kernel, but avoids fruitless fingerpointing discussions with tool developers. - Decouple PHYSICAL_MASK from AMD SME as its going to be required for the upcoming Intel memory encryption support as well. - Handle legacy device ACPI detection properly for newer platforms - Fix the wrong argument ordering in the vector allocation tracepoint - Simplify the IDT setup code for the APIC=n case - Use the proper string helpers in the MTRR code - Remove a stale unused VDSO source file - Convert the microcode update lock to a raw spinlock as its used in atomic context. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel_rdt: Enable CMT and MBM on new Skylake stepping x86/apic/vector: Print APIC control bits in debugfs genirq/affinity: Defer affinity setting if irq chip is busy x86/platform/uv: Use apic_ack_irq() x86/ioapic: Use apic_ack_irq() irq_remapping: Use apic_ack_irq() x86/apic: Provide apic_ack_irq() genirq/migration: Avoid out of line call if pending is not set genirq/generic_pending: Do not lose pending affinity update x86/apic/vector: Prevent hlist corruption and leaks x86/vector: Fix the args of vector_alloc tracepoint x86/idt: Simplify the idt_setup_apic_and_irq_gates() x86/platform/uv: Remove extra parentheses x86/mm: Decouple dynamic __PHYSICAL_MASK from AMD SME x86: Mark native_set_p4d() as __always_inline x86/microcode: Make the late update update_lock a raw lock for RT x86/mtrr: Convert to use strncpy_from_user() helper x86/mtrr: Convert to use match_string() helper x86/vdso: Remove unused file x86/i8237: Register device based on FADT legacy boot flag

x86/intel_rdt: Enable CMT and MBM on new Skylake stepping

2018-06-09T14:04:34Z

New stepping of Skylake has fixes for cache occupancy and memory bandwidth monitoring. Update the code to enable these by default on newer steppings. Signed-off-by: Tony Luck Signed-off-by: Thomas Gleixner Cc: Fenghua Yu Cc: stable@vger.kernel.org # v4.14 Cc: Vikas Shivappa Link: https://lkml.kernel.org/r/20180608160732.9842-1-tony.luck@intel.com

x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth

2018-05-19T11:16:44Z

mba_sc is a feedback loop where we periodically read MBM counters and try to restrict the bandwidth below a max value so the below is always true: "current bandwidth(cur_bw) < user specified bandwidth(user_bw)" The frequency of these checks is currently 1s and we just tag along the MBM overflow timer to do the updates. Doing it once in a second also makes the calculation of bandwidth easy. The steps of increase or decrease of bandwidth is the minimum granularity specified by the hardware. Although the MBA's goal is to restrict the bandwidth below a maximum, there may be a need to even increase the bandwidth. Since MBA controls the L2 external bandwidth where as MBM measures the L3 external bandwidth, we may end up restricting some rdtgroups unnecessarily. This may happen in the sequence where rdtgroup (set of jobs) had high "L3 <-> memory traffic" in initial phases -> mba_sc kicks in and reduced bandwidth percentage values -> but after some it has mostly "L2 <-> L3" traffic. In this scenario mba_sc increases the bandwidth percentage when there is lesser memory traffic. Signed-off-by: Vikas Shivappa Signed-off-by: Thomas Gleixner Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1524263781-14267-7-git-send-email-vikas.shivappa@linux.intel.com

x86/intel_rdt/mba_sc: Add schemata support

2018-05-19T11:16:44Z

Currently when user updates the "schemata" with new MBA percentage values, kernel writes the corresponding bandwidth percentage values to the IA32_MBA_THRTL_MSR. When MBA is expressed in MBps, the schemata format is changed to have the per package memory bandwidth in MBps instead of being specified in percentage. Do not write the IA32_MBA_THRTL_MSRs when the schemata is updated as that is handled separately. Signed-off-by: Vikas Shivappa Signed-off-by: Thomas Gleixner Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1524263781-14267-5-git-send-email-vikas.shivappa@linux.intel.com

x86/intel_rdt/mba_sc: Add initialization support

2018-05-19T11:16:43Z

When MBA software controller is enabled, a per domain storage is required for user specified bandwidth in "MBps" and the "percentage" values which are programmed into the IA32_MBA_THRTL_MSR. Add support for these data structures and initialization. The MBA percentage values have a default max value of 100 but however the max value in MBps is not available from the hardware so it's set to U32_MAX. This simply says that the control group can use all bandwidth by default but does not say what is the actual max bandwidth available. The actual bandwidth that is available may depend on lot of factors like QPI link, number of memory channels, memory channel frequency, its width and memory speed, how many channels are configured and also if memory interleaving is enabled. So there is no way to determine the maximum at runtime reliably. Signed-off-by: Vikas Shivappa Signed-off-by: Thomas Gleixner Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1524263781-14267-4-git-send-email-vikas.shivappa@linux.intel.com

x86/intel_rdt/mba_sc: Enable/disable MBA software controller

2018-05-19T11:16:43Z

Currently user does memory bandwidth allocation(MBA) by specifying the bandwidth in percentage via the resctrl schemata file: "/sys/fs/resctrl/schemata" Add a new mount option "mba_MBps" to enable the user to specify MBA in MBps: $mount -t resctrl resctrl [-o cdp[,cdpl2][mba_MBps]] /sys/fs/resctrl Signed-off-by: Vikas Shivappa Signed-off-by: Thomas Gleixner Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1524263781-14267-3-git-send-email-vikas.shivappa@linux.intel.com