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The xen_play_dead is an undead function. When the vCPU is told to
offline it ends up calling xen_play_dead wherin it calls the
VCPUOP_down hypercall which offlines the vCPU. However, when the
vCPU is onlined back, it resumes execution right after
VCPUOP_down hypercall.
That was OK (albeit the API for play_dead assumes that the CPU
stays dead and never returns) but with commit 4b0c0f294
(tick: Cleanup NOHZ per cpu data on cpu down) that is no longer safe
as said commit resets the ts->inidle which at the start of the
cpu_idle loop was set.
The net effect is that we get this warn:
Broke affinity for irq 16
installing Xen timer for CPU 1
cpu 1 spinlock event irq 48
------------[ cut here ]------------
WARNING: at /home/konrad/linux-linus/kernel/time/tick-sched.c:935 tick_nohz_idle_exit+0x195/0x1b0()
Modules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.10.0-rc3upstream-00068-gdcdbe33 #1
Hardware name: BIOSTAR Group N61PB-M2S/N61PB-M2S, BIOS 6.00 PG 09/03/2009
ffffffff8193b448 ffff880039da5e60 ffffffff816707c8 ffff880039da5ea0
ffffffff8108ce8b ffff880039da4010 ffff88003fa8e500 ffff880039da4010
0000000000000001 ffff880039da4000 ffff880039da4010 ffff880039da5eb0
Call Trace:
[<ffffffff816707c8>] dump_stack+0x19/0x1b
[<ffffffff8108ce8b>] warn_slowpath_common+0x6b/0xa0
[<ffffffff8108ced5>] warn_slowpath_null+0x15/0x20
[<ffffffff810e4745>] tick_nohz_idle_exit+0x195/0x1b0
[<ffffffff810da755>] cpu_startup_entry+0x205/0x250
[<ffffffff81661070>] cpu_bringup_and_idle+0x13/0x15
---[ end trace 915c8c486004dda1 ]---
b/c ts_inidle is set to zero. Thomas suggested that we just add a workaround
to call tick_nohz_idle_enter before returning from xen_play_dead() - and
that is what this patch does and fixes the issue.
We also add the stable part b/c git commit 4b0c0f294 is on the stable
tree.
CC: stable@vger.kernel.org
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Commit f447d56d36af18c5104ff29dcb1327c0c0ac3634 introduced the
implementation of the PV apic ipi interface. But there were some
odd things (it seems none of which cause really any issue but
maybe they should be cleaned up anyway):
- xen_send_IPI_mask_allbutself (and by that xen_send_IPI_allbutself)
ignore the passed in vector and only use the CALL_FUNCTION_SINGLE
vector. While xen_send_IPI_all and xen_send_IPI_mask use the vector.
- physflat_send_IPI_allbutself is declared unnecessarily. It is never
used.
This patch tries to clean up those things.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
- More fixes in the vCPU PVHVM hotplug path.
- Add more documentation.
- Fix various ARM related issues in the Xen generic drivers.
- Updates in the xen-pciback driver per Bjorn's updates.
- Mask the x2APIC feature for PV guests.
* tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pci: Used cached MSI-X capability offset
xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK
xen: clear IRQ_NOAUTOEN and IRQ_NOREQUEST
xen: mask x2APIC feature in PV
xen: SWIOTLB is only used on x86
xen/spinlock: Fix check from greater than to be also be greater or equal to.
xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_info
xen/vcpu: Document the xen_vcpu_info and xen_vcpu
xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.
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On x2apic enabled pvm, doing sysrq+l, got NULL pointer dereference as below.
SysRq : Show backtrace of all active CPUs
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8125e3cb>] memcpy+0xb/0x120
Call Trace:
[<ffffffff81039633>] ? __x2apic_send_IPI_mask+0x73/0x160
[<ffffffff8103973e>] x2apic_send_IPI_all+0x1e/0x20
[<ffffffff8103498c>] arch_trigger_all_cpu_backtrace+0x6c/0xb0
[<ffffffff81501be4>] ? _raw_spin_lock_irqsave+0x34/0x50
[<ffffffff8131654e>] sysrq_handle_showallcpus+0xe/0x10
[<ffffffff8131616d>] __handle_sysrq+0x7d/0x140
[<ffffffff81316230>] ? __handle_sysrq+0x140/0x140
[<ffffffff81316287>] write_sysrq_trigger+0x57/0x60
[<ffffffff811ca996>] proc_reg_write+0x86/0xc0
[<ffffffff8116dd8e>] vfs_write+0xce/0x190
[<ffffffff8116e3e5>] sys_write+0x55/0x90
[<ffffffff8150a242>] system_call_fastpath+0x16/0x1b
That's because apic points to apic_x2apic_cluster or apic_x2apic_phys
but the basic element like cpumask isn't initialized.
Mask x2APIC feature in pvm to avoid overwrite of apic pointer,
update commit message per Konrad's suggestion.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Tested-by: Tamon Shiose <tamon.shiose@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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During review of git commit cb9c6f15f318aa3aeb62fe525aa5c6dcf6eee159
("xen/spinlock: Check against default value of -1 for IRQ line.")
Stefano pointed out a bug in the patch. Unfortunatly due to vacation
timing the fix was not applied and this patch fixes it up.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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As it will point to some data, but not event channel data (the
shared_info has an array limited to 32).
This means that for PVHVM guests with more than 32 VCPUs without
the usage of VCPUOP_register_info any interrupts to VCPUs
larger than 32 would have gone unnoticed during early bootup.
That is OK, as during early bootup, in smp_init we end up calling
the hotplug mechanism (xen_hvm_cpu_notify) which makes the
VCPUOP_register_vcpu_info call for all VCPUs and we can receive
interrupts on VCPUs 33 and further.
This is just a cleanup.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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They are important structures and it is not clear at first
look what they are for.
The xen_vcpu is a pointer. By default it points to the shared_info
structure (at the CPU offset location). However if the
VCPUOP_register_vcpu_info hypercall is implemented we can make the
xen_vcpu pointer point to a per-CPU location.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v1: Added comments from Ian Campbell]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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If a user did:
echo 0 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu1/online
we would (this a build with DEBUG enabled) get to:
smpboot: ++++++++++++++++++++=_---CPU UP 1
.. snip..
smpboot: Stack at about ffff880074c0ff44
smpboot: CPU1: has booted.
and hang. The RCU mechanism would kick in an try to IPI the CPU1
but the IPIs (and all other interrupts) would never arrive at the
CPU1. At first glance at least. A bit digging in the hypervisor
trace shows that (using xenanalyze):
[vla] d4v1 vec 243 injecting
0.043163027 --|x d4v1 intr_window vec 243 src 5(vector) intr f3
] 0.043163639 --|x d4v1 vmentry cycles 1468
] 0.043164913 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254
0.043164913 --|x d4v1 inj_virq vec 243 real
[vla] d4v1 vec 243 injecting
0.043164913 --|x d4v1 intr_window vec 243 src 5(vector) intr f3
] 0.043165526 --|x d4v1 vmentry cycles 1472
] 0.043166800 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254
0.043166800 --|x d4v1 inj_virq vec 243 real
[vla] d4v1 vec 243 injecting
there is a pending event (subsequent debugging shows it is the IPI
from the VCPU0 when smpboot.c on VCPU1 has done
"set_cpu_online(smp_processor_id(), true)") and the guest VCPU1 is
interrupted with the callback IPI (0xf3 aka 243) which ends up calling
__xen_evtchn_do_upcall.
The __xen_evtchn_do_upcall seems to do *something* but not acknowledge
the pending events. And the moment the guest does a 'cli' (that is the
ffffffff81673254 in the log above) the hypervisor is invoked again to
inject the IPI (0xf3) to tell the guest it has pending interrupts.
This repeats itself forever.
The culprit was the per_cpu(xen_vcpu, cpu) pointer. At the bootup
we set each per_cpu(xen_vcpu, cpu) to point to the
shared_info->vcpu_info[vcpu] but later on use the VCPUOP_register_vcpu_info
to register per-CPU structures (xen_vcpu_setup).
This is used to allow events for more than 32 VCPUs and for performance
optimizations reasons.
When the user performs the VCPU hotplug we end up calling the
the xen_vcpu_setup once more. We make the hypercall which returns
-EINVAL as it does not allow multiple registration calls (and
already has re-assigned where the events are being set). We pick
the fallback case and set per_cpu(xen_vcpu, cpu) to point to the
shared_info->vcpu_info[vcpu] (which is a good fallback during bootup).
However the hypervisor is still setting events in the register
per-cpu structure (per_cpu(xen_vcpu_info, cpu)).
As such when the events are set by the hypervisor (such as timer one),
and when we iterate in __xen_evtchn_do_upcall we end up reading stale
events from the shared_info->vcpu_info[vcpu] instead of the
per_cpu(xen_vcpu_info, cpu) structures. Hence we never acknowledge the
events that the hypervisor has set and the hypervisor keeps on reminding
us to ack the events which we never do.
The fix is simple. Don't on the second time when xen_vcpu_setup is
called over-write the per_cpu(xen_vcpu, cpu) if it points to
per_cpu(xen_vcpu_info).
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 paravirt update from Ingo Molnar:
"Various paravirtualization related changes - the biggest one makes
guest support optional via CONFIG_HYPERVISOR_GUEST"
* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, wakeup, sleep: Use pvops functions for changing GDT entries
x86, xen, gdt: Remove the pvops variant of store_gdt.
x86-32, gdt: Store/load GDT for ACPI S3 or hibernation/resume path is not needed
x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.
x86: Make Linux guest support optional
x86, Kconfig: Move PARAVIRT_DEBUG into the paravirt menu
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perparatory x86 kasrl changes from Ingo Molnar:
"This contains changes from the ongoing KASLR work, by Kees Cook.
The main changes are the use of a read-only IDT on x86 (which
decouples the userspace visible virtual IDT address from the physical
address), and a rework of ELF relocation support, in preparation of
random, boot-time kernel image relocation."
* 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, relocs: Refactor the relocs tool to merge 32- and 64-bit ELF
x86, relocs: Build separate 32/64-bit tools
x86, relocs: Add 64-bit ELF support to relocs tool
x86, relocs: Consolidate processing logic
x86, relocs: Generalize ELF structure names
x86: Use a read-only IDT alias on all CPUs
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar:
"This is a pretty large, multi-arch series unifying and generalizing
the various disjunct pieces of idle routines that architectures have
historically copied from each other and have grown in random, wildly
inconsistent and sometimes buggy directions:
101 files changed, 455 insertions(+), 1328 deletions(-)
this went through a number of review and test iterations before it was
committed, it was tested on various architectures, was exposed to
linux-next for quite some time - nevertheless it might cause problems
on architectures that don't read the mailing lists and don't regularly
test linux-next.
This cat herding excercise was motivated by the -rt kernel, and was
brought to you by Thomas "the Whip" Gleixner."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
idle: Remove GENERIC_IDLE_LOOP config switch
um: Use generic idle loop
ia64: Make sure interrupts enabled when we "safe_halt()"
sparc: Use generic idle loop
idle: Remove unused ARCH_HAS_DEFAULT_IDLE
bfin: Fix typo in arch_cpu_idle()
xtensa: Use generic idle loop
x86: Use generic idle loop
unicore: Use generic idle loop
tile: Use generic idle loop
tile: Enter idle with preemption disabled
sh: Use generic idle loop
score: Use generic idle loop
s390: Use generic idle loop
powerpc: Use generic idle loop
parisc: Use generic idle loop
openrisc: Use generic idle loop
mn10300: Use generic idle loop
mips: Use generic idle loop
microblaze: Use generic idle loop
...
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git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen updates from Konrad Rzeszutek Wilk:
"Features:
- Populate the boot_params with EDD data.
- Cleanups in the IRQ code.
Bug-fixes:
- CPU hotplug offline/online in PVHVM mode.
- Re-upload processor PM data after ACPI S3 suspend/resume cycle."
And Konrad gets a gold star for sending the pull request early when he
thought he'd be away for the first week of the merge window (but because
of 3.9 dragging out to -rc8 he then re-sent the reminder on the first
day of the merge window anyway)
* tag 'stable/for-linus-3.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: resolve section mismatch warnings in xen-acpi-processor
xen: Re-upload processor PM data to hypervisor after S3 resume (v2)
xen/smp: Unifiy some of the PVs and PVHVM offline CPU path
xen/smp/pvhvm: Don't initialize IRQ_WORKER as we are using the native one.
xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM
xen/spinlock: Check against default value of -1 for IRQ line.
xen/time: Add default value of -1 for IRQ and check for that.
xen/events: Check that IRQ value passed in is valid.
xen/time: Fix kasprintf splat when allocating timer%d IRQ line.
xen/smp/spinlock: Fix leakage of the spinlock interrupt line for every CPU online/offline
xen/smp: Fix leakage of timer interrupt line for every CPU online/offline.
xen kconfig: fix select INPUT_XEN_KBDDEV_FRONTEND
xen: drop tracking of IRQ vector
x86/xen: populate boot_params with EDD data
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The "xen_cpu_die" and "xen_hvm_cpu_die" are very similar.
Lets coalesce them.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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There is no need to use the PV version of the IRQ_WORKER mechanism
as under PVHVM we are using the native version. The native
version is using the SMP API.
They just sit around unused:
69: 0 0 xen-percpu-ipi irqwork0
83: 0 0 xen-percpu-ipi irqwork1
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23
(xen: disable PV spinlocks on HVM) for details.
But we did not disable it everywhere - which means that when
we boot as PVHVM we end up allocating per-CPU irq line for
spinlock. This fixes that.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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The default (uninitialized) value of the IRQ line is -1.
Check if we already have allocated an spinlock interrupt line
and if somebody is trying to do it again. Also set it to -1
when we offline the CPU.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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If the timer interrupt has been de-init or is just now being
initialized, the default value of -1 should be preset as
interrupt line. Check for that and if something is odd
WARN us.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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When we online the CPU, we get this splat:
smpboot: Booting Node 0 Processor 1 APIC 0x2
installing Xen timer for CPU 1
BUG: sleeping function called from invalid context at /home/konrad/ssd/konrad/linux/mm/slab.c:3179
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
Pid: 0, comm: swapper/1 Not tainted 3.9.0-rc6upstream-00001-g3884fad #1
Call Trace:
[<ffffffff810c1fea>] __might_sleep+0xda/0x100
[<ffffffff81194617>] __kmalloc_track_caller+0x1e7/0x2c0
[<ffffffff81303758>] ? kasprintf+0x38/0x40
[<ffffffff813036eb>] kvasprintf+0x5b/0x90
[<ffffffff81303758>] kasprintf+0x38/0x40
[<ffffffff81044510>] xen_setup_timer+0x30/0xb0
[<ffffffff810445af>] xen_hvm_setup_cpu_clockevents+0x1f/0x30
[<ffffffff81666d0a>] start_secondary+0x19c/0x1a8
The solution to that is use kasprintf in the CPU hotplug path
that 'online's the CPU. That is, do it in in xen_hvm_cpu_notify,
and remove the call to in xen_hvm_setup_cpu_clockevents.
Unfortunatly the later is not a good idea as the bootup path
does not use xen_hvm_cpu_notify so we would end up never allocating
timer%d interrupt lines when booting. As such add the check for
atomic() to continue.
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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online/offline
While we don't use the spinlock interrupt line (see for details
commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 -
xen: disable PV spinlocks on HVM) - we should still do the proper
init / deinit sequence. We did not do that correctly and for the
CPU init for PVHVM guest we would allocate an interrupt line - but
failed to deallocate the old interrupt line.
This resulted in leakage of an irq_desc but more importantly this splat
as we online an offlined CPU:
genirq: Flags mismatch irq 71. 0002cc20 (spinlock1) vs. 0002cc20 (spinlock1)
Pid: 2542, comm: init.late Not tainted 3.9.0-rc6upstream #1
Call Trace:
[<ffffffff811156de>] __setup_irq+0x23e/0x4a0
[<ffffffff81194191>] ? kmem_cache_alloc_trace+0x221/0x250
[<ffffffff811161bb>] request_threaded_irq+0xfb/0x160
[<ffffffff8104c6f0>] ? xen_spin_trylock+0x20/0x20
[<ffffffff813a8423>] bind_ipi_to_irqhandler+0xa3/0x160
[<ffffffff81303758>] ? kasprintf+0x38/0x40
[<ffffffff8104c6f0>] ? xen_spin_trylock+0x20/0x20
[<ffffffff810cad35>] ? update_max_interval+0x15/0x40
[<ffffffff816605db>] xen_init_lock_cpu+0x3c/0x78
[<ffffffff81660029>] xen_hvm_cpu_notify+0x29/0x33
[<ffffffff81676bdd>] notifier_call_chain+0x4d/0x70
[<ffffffff810bb2a9>] __raw_notifier_call_chain+0x9/0x10
[<ffffffff8109402b>] __cpu_notify+0x1b/0x30
[<ffffffff8166834a>] _cpu_up+0xa0/0x14b
[<ffffffff816684ce>] cpu_up+0xd9/0xec
[<ffffffff8165f754>] store_online+0x94/0xd0
[<ffffffff8141d15b>] dev_attr_store+0x1b/0x20
[<ffffffff81218f44>] sysfs_write_file+0xf4/0x170
[<ffffffff811a2864>] vfs_write+0xb4/0x130
[<ffffffff811a302a>] sys_write+0x5a/0xa0
[<ffffffff8167ada9>] system_call_fastpath+0x16/0x1b
cpu 1 spinlock event irq -16
smpboot: Booting Node 0 Processor 1 APIC 0x2
And if one looks at the /proc/interrupts right after
offlining (CPU1):
70: 0 0 xen-percpu-ipi spinlock0
71: 0 0 xen-percpu-ipi spinlock1
77: 0 0 xen-percpu-ipi spinlock2
There is the oddity of the 'spinlock1' still being present.
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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In the PVHVM path when we do CPU online/offline path we would
leak the timer%d IRQ line everytime we do a offline event. The
online path (xen_hvm_setup_cpu_clockevents via
x86_cpuinit.setup_percpu_clockev) would allocate a new interrupt
line for the timer%d.
But we would still use the old interrupt line leading to:
kernel BUG at /home/konrad/ssd/konrad/linux/kernel/hrtimer.c:1261!
invalid opcode: 0000 [#1] SMP
RIP: 0010:[<ffffffff810b9e21>] [<ffffffff810b9e21>] hrtimer_interrupt+0x261/0x270
.. snip..
<IRQ>
[<ffffffff810445ef>] xen_timer_interrupt+0x2f/0x1b0
[<ffffffff81104825>] ? stop_machine_cpu_stop+0xb5/0xf0
[<ffffffff8111434c>] handle_irq_event_percpu+0x7c/0x240
[<ffffffff811175b9>] handle_percpu_irq+0x49/0x70
[<ffffffff813a74a3>] __xen_evtchn_do_upcall+0x1c3/0x2f0
[<ffffffff813a760a>] xen_evtchn_do_upcall+0x2a/0x40
[<ffffffff8167c26d>] xen_hvm_callback_vector+0x6d/0x80
<EOI>
[<ffffffff81666d01>] ? start_secondary+0x193/0x1a8
[<ffffffff81666cfd>] ? start_secondary+0x18f/0x1a8
There is also the oddity (timer1) in the /proc/interrupts after
offlining CPU1:
64: 1121 0 xen-percpu-virq timer0
78: 0 0 xen-percpu-virq timer1
84: 0 2483 xen-percpu-virq timer2
This patch fixes it.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: stable@vger.kernel.org
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During early setup of a dom0 kernel, populate boot_params with the
Enhanced Disk Drive (EDD) and MBR signature data. This makes
information on the BIOS boot device available in /sys/firmware/edd/.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Flush lazy MMU when DEBUG_PAGEALLOC is set
x86/mm/cpa/selftest: Fix false positive in CPA self test
x86/mm/cpa: Convert noop to functional fix
x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal
x86, mm, paravirt: Fix vmalloc_fault oops during lazy MMU updates
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The two use-cases where we needed to store the GDT were during ACPI S3 suspend
and resume. As the patches:
x86/gdt/i386: store/load GDT for ACPI S3 or hibernation/resume path is not needed
x86/gdt/64-bit: store/load GDT for ACPI S3 or hibernate/resume path is not needed.
have demonstrated - there are other mechanism by which the GDT is
saved and reloaded during early resume path.
Hence we do not need to worry about the pvops call-chain for saving the
GDT and can and can eliminate it. The other areas where the store_gdt is
used are never going to be hit when running under the pvops platforms.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1365194544-14648-4-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
Make a copy of the IDT (as seen via the "sidt" instruction) read-only.
This primarily removes the IDT from being a target for arbitrary memory
write attacks, and has the added benefit of also not leaking the kernel
base offset, if it has been relocated.
We already did this on vendor == Intel and family == 5 because of the
F0 0F bug -- regardless of if a particular CPU had the F0 0F bug or
not. Since the workaround was so cheap, there simply was no reason to
be very specific. This patch extends the readonly alias to all CPUs,
but does not activate the #PF to #UD conversion code needed to deliver
the proper exception in the F0 0F case except on Intel family 5
processors.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130410192422.GA17344@www.outflux.net
Cc: Eric Northup <digitaleric@google.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
Invoking arch_flush_lazy_mmu_mode() results in calls to
preempt_enable()/disable() which may have performance impact.
Since lazy MMU is not used on bare metal we can patch away
arch_flush_lazy_mmu_mode() so that it is never called in such
environment.
[ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU
updates" may cause a minor performance regression on
bare metal. This patch resolves that performance regression. It is
somewhat unclear to me if this is a good -stable candidate. ]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.com
Tested-by: Josh Boyer <jwboyer@redhat.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> SEE NOTE ABOVE
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130321215235.486594473@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
|
|
provided pagetables.
Occassionaly on a DL380 G4 the guest would crash quite early with this:
(XEN) d244:v0: unhandled page fault (ec=0003)
(XEN) Pagetable walk from ffffffff84dc7000:
(XEN) L4[0x1ff] = 00000000c3f18067 0000000000001789
(XEN) L3[0x1fe] = 00000000c3f14067 000000000000178d
(XEN) L2[0x026] = 00000000dc8b2067 0000000000004def
(XEN) L1[0x1c7] = 00100000dc8da067 0000000000004dc7
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 244 (vcpu#0) crashed on cpu#3:
(XEN) ----[ Xen-4.1.3OVM x86_64 debug=n Not tainted ]----
(XEN) CPU: 3
(XEN) RIP: e033:[<ffffffff81263f22>]
(XEN) RFLAGS: 0000000000000216 EM: 1 CONTEXT: pv guest
(XEN) rax: 0000000000000000 rbx: ffffffff81785f88 rcx: 000000000000003f
(XEN) rdx: 0000000000000000 rsi: 00000000dc8da063 rdi: ffffffff84dc7000
The offending code shows it to be a loop writting the value zero
(%rax) in the %rdi (the L4 provided by Xen) register:
0: 44 00 00 add %r8b,(%rax)
3: 31 c0 xor %eax,%eax
5: b9 40 00 00 00 mov $0x40,%ecx
a: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1)
11: 00 00
13: ff c9 dec %ecx
15:* 48 89 07 mov %rax,(%rdi) <-- trapping instruction
18: 48 89 47 08 mov %rax,0x8(%rdi)
1c: 48 89 47 10 mov %rax,0x10(%rdi)
which fails. xen_setup_kernel_pagetable recycles some of the Xen's
page-table entries when it has switched over to its Linux page-tables.
Right before try to clear the page, we make a hypercall to change
it from _RO to _RW and that works (otherwise we would hit an BUG()).
And the _RW flag is set for that page:
(XEN) L1[0x1c7] = 001000004885f067 0000000000004dc7
The error code is 3, so PFEC_page_present and PFEC_write_access, so page is
present (correct), and we tried to write to the page, but a violation
occurred. The one theory is that the the page entries in hardware
(which are cached) are not up to date with what we just set. Especially
as we have just done an CR3 write and flushed the multicalls.
This patch does solve the problem by flusing out the TLB page
entry after changing it from _RO to _RW and we don't hit this
issue anymore.
Fixed-Oracle-Bug: 16243091 [ON OCCASIONS VM START GOES INTO
'CRASH' STATE: CLEAR_PAGE+0X12 ON HP DL380 G4]
Reported-and-Tested-by: Saar Maoz <Saar.Maoz@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
|
We move the setting of write_cr3 from the early bootup variant
(see git commit 0cc9129d75ef8993702d97ab0e49542c15ac6ab9
"x86-64, xen, mmu: Provide an early version of write_cr3.")
to a more appropiate location.
This new location sets all of the other non-early variants
of pvops calls - and most importantly is before the
alternative_asm mechanism kicks in.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
|
Put all config options needed to run Linux as a guest behind a
CONFIG_HYPERVISOR_GUEST menu so that they don't get built-in by default
but be selectable by the user. Also, make all units which depend on
x86_hyper, depend on this new symbol so that compilation doesn't fail
when CONFIG_HYPERVISOR_GUEST is disabled but those units assume its
presence.
Sort options in the new HYPERVISOR_GUEST menu, adapt config text and
drop redundant select.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1362428421-9244-3-git-send-email-bp@alien8.de
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
The git commit 8eaffa67b43e99ae581622c5133e20b0f48bcef1
(xen/pat: Disable PAT support for now) explains in details why
we want to disable PAT for right now. However that
change was not enough and we should have also disabled
the pat_enabled value. Otherwise we end up with:
mmap-example:3481 map pfn expected mapping type write-back for
[mem 0x00010000-0x00010fff], got uncached-minus
------------[ cut here ]------------
WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774 untrack_pfn+0xb8/0xd0()
mem 0x00010000-0x00010fff], got uncached-minus
------------[ cut here ]------------
WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774
untrack_pfn+0xb8/0xd0()
...
Pid: 3481, comm: mmap-example Tainted: GF 3.8.0-6-generic #13-Ubuntu
Call Trace:
[<ffffffff8105879f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff810587fa>] warn_slowpath_null+0x1a/0x20
[<ffffffff8104bcc8>] untrack_pfn+0xb8/0xd0
[<ffffffff81156c1c>] unmap_single_vma+0xac/0x100
[<ffffffff81157459>] unmap_vmas+0x49/0x90
[<ffffffff8115f808>] exit_mmap+0x98/0x170
[<ffffffff810559a4>] mmput+0x64/0x100
[<ffffffff810560f5>] dup_mm+0x445/0x660
[<ffffffff81056d9f>] copy_process.part.22+0xa5f/0x1510
[<ffffffff81057931>] do_fork+0x91/0x350
[<ffffffff81057c76>] sys_clone+0x16/0x20
[<ffffffff816ccbf9>] stub_clone+0x69/0x90
[<ffffffff816cc89d>] ? system_call_fastpath+0x1a/0x1f
---[ end trace 4918cdd0a4c9fea4 ]---
(a similar message shows up if you end up launching 'mcelog')
The call chain is (as analyzed by Liu, Jinsong):
do_fork
--> copy_process
--> dup_mm
--> dup_mmap
--> copy_page_range
--> track_pfn_copy
--> reserve_pfn_range
--> line 624: flags != want_flags
It comes from different memory types of page table (_PAGE_CACHE_WB) and MTRR
(_PAGE_CACHE_UC_MINUS).
Stefan Bader dug in this deep and found out that:
"That makes it clearer as this will do
reserve_memtype(...)
--> pat_x_mtrr_type
--> mtrr_type_lookup
--> __mtrr_type_lookup
And that can return -1/0xff in case of MTRR not being enabled/initialized. Which
is not the case (given there are no messages for it in dmesg). This is not equal
to MTRR_TYPE_WRBACK and thus becomes _PAGE_CACHE_UC_MINUS.
It looks like the problem starts early in reserve_memtype:
if (!pat_enabled) {
/* This is identical to page table setting without PAT */
if (new_type) {
if (req_type == _PAGE_CACHE_WC)
*new_type = _PAGE_CACHE_UC_MINUS;
else
*new_type = req_type & _PAGE_CACHE_MASK;
}
return 0;
}
This would be what we want, that is clearing the PWT and PCD flags from the
supported flags - if pat_enabled is disabled."
This patch does that - disabling PAT.
CC: stable@vger.kernel.org # 3.3 and further
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reported-and-Tested-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen update from Konrad Rzeszutek Wilk:
"This has two new ACPI drivers for Xen - a physical CPU offline/online
and a memory hotplug. The way this works is that ACPI kicks the
drivers and they make the appropiate hypercall to the hypervisor to
tell it that there is a new CPU or memory. There also some changes to
the Xen ARM ABIs and couple of fixes. One particularly nasty bug in
the Xen PV spinlock code was fixed by Stefan Bader - and has been
there since the 2.6.32!
Features:
- Xen ACPI memory and CPU hotplug drivers - allowing Xen hypervisor
to be aware of new CPU and new DIMMs
- Cleanups
Bug-fixes:
- Fixes a long-standing bug in the PV spinlock wherein we did not
kick VCPUs that were in a tight loop.
- Fixes in the error paths for the event channel machinery"
Fix up a few semantic conflicts with the ACPI interface changes in
drivers/xen/xen-acpi-{cpu,mem}hotplug.c.
* tag 'stable/for-linus-3.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: event channel arrays are xen_ulong_t and not unsigned long
xen: Send spinlock IPI to all waiters
xen: introduce xen_remap, use it instead of ioremap
xen: close evtchn port if binding to irq fails
xen-evtchn: correct comment and error output
xen/tmem: Add missing %s in the printk statement.
xen/acpi: move xen_acpi_get_pxm under CONFIG_XEN_DOM0
xen/acpi: ACPI cpu hotplug
xen/acpi: Move xen_acpi_get_pxm to Xen's acpi.h
xen/stub: driver for CPU hotplug
xen/acpi: ACPI memory hotplug
xen/stub: driver for memory hotplug
xen: implement updated XENMEM_add_to_physmap_range ABI
xen/smp: Move the common CPU init code a bit to prep for PVH patch.
|
|
With commit 8170e6bed465 ("x86, 64bit: Use a #PF handler to materialize
early mappings on demand") we started hitting an early bootup crash
where the Xen hypervisor would inform us that:
(XEN) d7:v0: unhandled page fault (ec=0000)
(XEN) Pagetable walk from ffffea000005b2d0:
(XEN) L4[0x1d4] = 0000000000000000 ffffffffffffffff
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 7 (vcpu#0) crashed on cpu#3:
(XEN) ----[ Xen-4.2.0 x86_64 debug=n Not tainted ]----
.. that Xen was unable to context switch back to dom0.
Looking at the calling stack we find:
[<ffffffff8103feba>] xen_get_user_pgd+0x5a <--
[<ffffffff8103feba>] xen_get_user_pgd+0x5a
[<ffffffff81042d27>] xen_write_cr3+0x77
[<ffffffff81ad2d21>] init_mem_mapping+0x1f9
[<ffffffff81ac293f>] setup_arch+0x742
[<ffffffff81666d71>] printk+0x48
We are trying to figure out whether we need to up-date the user PGD as
well. Please keep in mind that under 64-bit PV guests we have a limited
amount of rings: 0 for the Hypervisor, and 1 for both the Linux kernel
and user-space. As such the Linux pvops'fied version of write_cr3
checks if it has to update the user-space cr3 as well.
That clearly is not needed during early bootup. The recent changes (see
above git commit) streamline the x86 page table allocation to be much
simpler (And also incidentally the #PF handler ends up in spirit being
similar to how the Xen toolstack sets up the initial page-tables).
The fix is to have an early-bootup version of cr3 that just loads the
kernel %cr3. The later version - which also handles user-page
modifications will be used after the initial page tables have been
setup.
[ hpa: removed a redundant #ifdef and made the new function __init.
Also note that x86-32 already has such an early xen_write_cr3. ]
Tested-by: "H. Peter Anvin" <hpa@zytor.com>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1361579812-23709-1-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm changes from Peter Anvin:
"This is a huge set of several partly interrelated (and concurrently
developed) changes, which is why the branch history is messier than
one would like.
The *really* big items are two humonguous patchsets mostly developed
by Yinghai Lu at my request, which completely revamps the way we
create initial page tables. In particular, rather than estimating how
much memory we will need for page tables and then build them into that
memory -- a calculation that has shown to be incredibly fragile -- we
now build them (on 64 bits) with the aid of a "pseudo-linear mode" --
a #PF handler which creates temporary page tables on demand.
This has several advantages:
1. It makes it much easier to support things that need access to data
very early (a followon patchset uses this to load microcode way
early in the kernel startup).
2. It allows the kernel and all the kernel data objects to be invoked
from above the 4 GB limit. This allows kdump to work on very large
systems.
3. It greatly reduces the difference between Xen and native (Xen's
equivalent of the #PF handler are the temporary page tables created
by the domain builder), eliminating a bunch of fragile hooks.
The patch series also gets us a bit closer to W^X.
Additional work in this pull is the 64-bit get_user() work which you
were also involved with, and a bunch of cleanups/speedups to
__phys_addr()/__pa()."
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits)
x86, mm: Move reserving low memory later in initialization
x86, doc: Clarify the use of asm("%edx") in uaccess.h
x86, mm: Redesign get_user with a __builtin_choose_expr hack
x86: Be consistent with data size in getuser.S
x86, mm: Use a bitfield to mask nuisance get_user() warnings
x86/kvm: Fix compile warning in kvm_register_steal_time()
x86-32: Add support for 64bit get_user()
x86-32, mm: Remove reference to alloc_remap()
x86-32, mm: Remove reference to resume_map_numa_kva()
x86-32, mm: Rip out x86_32 NUMA remapping code
x86/numa: Use __pa_nodebug() instead
x86: Don't panic if can not alloc buffer for swiotlb
mm: Add alloc_bootmem_low_pages_nopanic()
x86, 64bit, mm: hibernate use generic mapping_init
x86, 64bit, mm: Mark data/bss/brk to nx
x86: Merge early kernel reserve for 32bit and 64bit
x86: Add Crash kernel low reservation
x86, kdump: Remove crashkernel range find limit for 64bit
memblock: Add memblock_mem_size()
x86, boot: Not need to check setup_header version for setup_data
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
- Rework of the ACPI namespace scanning code from Rafael J. Wysocki
with contributions from Bjorn Helgaas, Jiang Liu, Mika Westerberg,
Toshi Kani, and Yinghai Lu.
- ACPI power resources handling and ACPI device PM update from Rafael
J Wysocki.
- ACPICA update to version 20130117 from Bob Moore and Lv Zheng with
contributions from Aaron Lu, Chao Guan, Jesper Juhl, and Tim Gardner.
- Support for Intel Lynxpoint LPSS from Mika Westerberg.
- cpuidle update from Len Brown including Intel Haswell support, C1
state for intel_idle, removal of global pm_idle.
- cpuidle fixes and cleanups from Daniel Lezcano.
- cpufreq fixes and cleanups from Viresh Kumar and Fabio Baltieri with
contributions from Stratos Karafotis and Rickard Andersson.
- Intel P-states driver for Sandy Bridge processors from Dirk
Brandewie.
- cpufreq driver for Marvell Kirkwood SoCs from Andrew Lunn.
- cpufreq fixes related to ordering issues between acpi-cpufreq and
powernow-k8 from Borislav Petkov and Matthew Garrett.
- cpufreq support for Calxeda Highbank processors from Mark Langsdorf
and Rob Herring.
- cpufreq driver for the Freescale i.MX6Q SoC and cpufreq-cpu0 update
from Shawn Guo.
- cpufreq Exynos fixes and cleanups from Jonghwan Choi, Sachin Kamat,
and Inderpal Singh.
- Support for "lightweight suspend" from Zhang Rui.
- Removal of the deprecated power trace API from Paul Gortmaker.
- Assorted updates from Andreas Fleig, Colin Ian King, Davidlohr Bueso,
Joseph Salisbury, Kees Cook, Li Fei, Nishanth Menon, ShuoX Liu,
Srinivas Pandruvada, Tejun Heo, Thomas Renninger, and Yasuaki
Ishimatsu.
* tag 'pm+acpi-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (267 commits)
PM idle: remove global declaration of pm_idle
unicore32 idle: delete stray pm_idle comment
openrisc idle: delete pm_idle
mn10300 idle: delete pm_idle
microblaze idle: delete pm_idle
m32r idle: delete pm_idle, and other dead idle code
ia64 idle: delete pm_idle
cris idle: delete idle and pm_idle
ARM64 idle: delete pm_idle
ARM idle: delete pm_idle
blackfin idle: delete pm_idle
sparc idle: rename pm_idle to sparc_idle
sh idle: rename global pm_idle to static sh_idle
x86 idle: rename global pm_idle to static x86_idle
APM idle: register apm_cpu_idle via cpuidle
cpufreq / intel_pstate: Add kernel command line option disable intel_pstate.
cpufreq / intel_pstate: Change to disallow module build
tools/power turbostat: display SMI count by default
intel_idle: export both C1 and C1E
ACPI / hotplug: Fix concurrency issues and memory leaks
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/apic changes from Ingo Molnar:
"Main changes:
- Multiple MSI support added to the APIC, PCI and AHCI code - acked
by all relevant maintainers, by Alexander Gordeev.
The advantage is that multiple AHCI ports can have multiple MSI
irqs assigned, and can thus spread to multiple CPUs.
[ Drivers can make use of this new facility via the
pci_enable_msi_block_auto() method ]
- x86 IOAPIC code from interrupt remapping cleanups from Joerg
Roedel:
These patches move all interrupt remapping specific checks out of
the x86 core code and replaces the respective call-sites with
function pointers. As a result the interrupt remapping code is
better abstraced from x86 core interrupt handling code.
- Various smaller improvements, fixes and cleanups."
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess
x86, kvm: Fix intialization warnings in kvm.c
x86, irq: Move irq_remapped out of x86 core code
x86, io_apic: Introduce eoi_ioapic_pin call-back
x86, msi: Introduce x86_msi.compose_msi_msg call-back
x86, irq: Introduce setup_remapped_irq()
x86, irq: Move irq_remapped() check into free_remapped_irq
x86, io-apic: Remove !irq_remapped() check from __target_IO_APIC_irq()
x86, io-apic: Move CONFIG_IRQ_REMAP code out of x86 core
x86, irq: Add data structure to keep AMD specific irq remapping information
x86, irq: Move irq_remapping_enabled declaration to iommu code
x86, io_apic: Remove irq_remapping_enabled check in setup_timer_IRQ0_pin
x86, io_apic: Move irq_remapping_enabled checks out of check_timer()
x86, io_apic: Convert setup_ioapic_entry to function pointer
x86, io_apic: Introduce set_affinity function pointer
x86, msi: Use IRQ remapping specific setup_msi_irqs routine
x86, hpet: Introduce x86_msi_ops.setup_hpet_msi
x86, io_apic: Introduce x86_io_apic_ops.print_entries for debugging
x86, io_apic: Introduce x86_io_apic_ops.disable()
x86, apic: Mask IO-APIC and PIC unconditionally on LAPIC resume
...
|
|
There is a loophole between Xen's current implementation of
pv-spinlocks and the scheduler. This was triggerable through
a testcase until v3.6 changed the TLB flushing code. The
problem potentially is still there just not observable in the
same way.
What could happen was (is):
1. CPU n tries to schedule task x away and goes into a slow
wait for the runq lock of CPU n-# (must be one with a lower
number).
2. CPU n-#, while processing softirqs, tries to balance domains
and goes into a slow wait for its own runq lock (for updating
some records). Since this is a spin_lock_irqsave in softirq
context, interrupts will be re-enabled for the duration of
the poll_irq hypercall used by Xen.
3. Before the runq lock of CPU n-# is unlocked, CPU n-1 receives
an interrupt (e.g. endio) and when processing the interrupt,
tries to wake up task x. But that is in schedule and still
on_cpu, so try_to_wake_up goes into a tight loop.
4. The runq lock of CPU n-# gets unlocked, but the message only
gets sent to the first waiter, which is CPU n-# and that is
busily stuck.
5. CPU n-# never returns from the nested interruption to take and
release the lock because the scheduler uses a busy wait.
And CPU n never finishes the task migration because the unlock
notification only went to CPU n-#.
To avoid this and since the unlocking code has no real sense of
which waiter is best suited to grab the lock, just send the IPI
to all of them. This causes the waiters to return from the hyper-
call (those not interrupted at least) and do active spinlocking.
BugLink: http://bugs.launchpad.net/bugs/1011792
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
|
The PV and PVH code CPU init code share some functionality. The
PVH code ("xen/pvh: Extend vcpu_guest_context, p2m, event, and XenBus")
sets some of these up, but not all. To make it easier to read, this
patch removes the PV specific out of the generic way.
No functional change - just code movement.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v2: Fixed compile errors noticed by Fengguang Wu build system]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull xen fixes from Konrad Rzeszutek Wilk:
"Two fixes:
- A simple bug-fix for redundant NULL check.
- CVE-2013-0228/XSA-42: x86/xen: don't assume %ds is usable in
xen_iret for 32-bit PVOPS
and two reverts:
- Revert the PVonHVM kexec. The patch introduces a regression with
older hypervisor stacks, such as Xen 4.1."
* tag 'stable/for-linus-3.8-rc7-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
Revert "xen PVonHVM: use E820_Reserved area for shared_info"
Revert "xen/PVonHVM: fix compile warning in init_hvm_pv_info"
xen: remove redundant NULL check before unregister_and_remove_pcpu().
x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS.
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This reverts commit 9d02b43dee0d7fb18dfb13a00915550b1a3daa9f.
We are doing this b/c on 32-bit PVonHVM with older hypervisors
(Xen 4.1) it ends up bothing up the start_info. This is bad b/c
we use it for the time keeping, and the timekeeping code loops
forever - as the version field never changes. Olaf says to
revert it, so lets do that.
Acked-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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This reverts commit a7be94ac8d69c037d08f0fd94b45a593f1d45176.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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This fixes CVE-2013-0228 / XSA-42
Drew Jones while working on CVE-2013-0190 found that that unprivileged guest user
in 32bit PV guest can use to crash the > guest with the panic like this:
-------------
general protection fault: 0000 [#1] SMP
last sysfs file: /sys/devices/vbd-51712/block/xvda/dev
Modules linked in: sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4
iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6
xt_state nf_conntrack ip6table_filter ip6_tables ipv6 xen_netfront ext4
mbcache jbd2 xen_blkfront dm_mirror dm_region_hash dm_log dm_mod [last
unloaded: scsi_wait_scan]
Pid: 1250, comm: r Not tainted 2.6.32-356.el6.i686 #1
EIP: 0061:[<c0407462>] EFLAGS: 00010086 CPU: 0
EIP is at xen_iret+0x12/0x2b
EAX: eb8d0000 EBX: 00000001 ECX: 08049860 EDX: 00000010
ESI: 00000000 EDI: 003d0f00 EBP: b77f8388 ESP: eb8d1fe0
DS: 0000 ES: 007b FS: 0000 GS: 00e0 SS: 0069
Process r (pid: 1250, ti=eb8d0000 task=c2953550 task.ti=eb8d0000)
Stack:
00000000 0027f416 00000073 00000206 b77f8364 0000007b 00000000 00000000
Call Trace:
Code: c3 8b 44 24 18 81 4c 24 38 00 02 00 00 8d 64 24 30 e9 03 00 00 00
8d 76 00 f7 44 24 08 00 00 02 80 75 33 50 b8 00 e0 ff ff 21 e0 <8b> 40
10 8b 04 85 a0 f6 ab c0 8b 80 0c b0 b3 c0 f6 44 24 0d 02
EIP: [<c0407462>] xen_iret+0x12/0x2b SS:ESP 0069:eb8d1fe0
general protection fault: 0000 [#2]
---[ end trace ab0d29a492dcd330 ]---
Kernel panic - not syncing: Fatal exception
Pid: 1250, comm: r Tainted: G D ---------------
2.6.32-356.el6.i686 #1
Call Trace:
[<c08476df>] ? panic+0x6e/0x122
[<c084b63c>] ? oops_end+0xbc/0xd0
[<c084b260>] ? do_general_protection+0x0/0x210
[<c084a9b7>] ? error_code+0x73/
-------------
Petr says: "
I've analysed the bug and I think that xen_iret() cannot cope with
mangled DS, in this case zeroed out (null selector/descriptor) by either
xen_failsafe_callback() or RESTORE_REGS because the corresponding LDT
entry was invalidated by the reproducer. "
Jan took a look at the preliminary patch and came up a fix that solves
this problem:
"This code gets called after all registers other than those handled by
IRET got already restored, hence a null selector in %ds or a non-null
one that got loaded from a code or read-only data descriptor would
cause a kernel mode fault (with the potential of crashing the kernel
as a whole, if panic_on_oops is set)."
The way to fix this is to realize that the we can only relay on the
registers that IRET restores. The two that are guaranteed are the
%cs and %ss as they are always fixed GDT selectors. Also they are
inaccessible from user mode - so they cannot be altered. This is
the approach taken in this patch.
Another alternative option suggested by Jan would be to relay on
the subtle realization that using the %ebp or %esp relative references uses
the %ss segment. In which case we could switch from using %eax to %ebp and
would not need the %ss over-rides. That would also require one extra
instruction to compensate for the one place where the register is used
as scaled index. However Andrew pointed out that is too subtle and if
further work was to be done in this code-path it could escape folks attention
and lead to accidents.
Reviewed-by: Petr Matousek <pmatouse@redhat.com>
Reported-by: Petr Matousek <pmatouse@redhat.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Remove 32-bit x86 a cmdline param "no-hlt",
and the cpuinfo_x86.hlt_works_ok that it sets.
If a user wants to avoid HLT, then "idle=poll"
is much more useful, as it avoids invocation of HLT
in idle, while "no-hlt" failed to do so.
Indeed, hlt_works_ok was consulted in only 3 places.
First, in /proc/cpuinfo where "hlt_bug yes"
would be printed if and only if the user booted
the system with "no-hlt" -- as there was no other code
to set that flag.
Second, check_hlt() would not invoke halt() if "no-hlt"
were on the cmdline.
Third, it was consulted in stop_this_cpu(), which is invoked
by native_machine_halt()/reboot_interrupt()/smp_stop_nmi_callback() --
all cases where the machine is being shutdown/reset.
The flag was not consulted in the more frequently invoked
play_dead()/hlt_play_dead() used in processor offline and suspend.
Since Linux-3.0 there has been a run-time notice upon "no-hlt" invocations
indicating that it would be removed in 2012.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
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This macro is only invoked by Xen,
so make its definition specific to Xen.
> set_pm_idle_to_default()
< xen_set_default_idle()
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: xen-devel@lists.xensource.com
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Coming patches to x86/mm2 require the changes and advanced baseline in
x86/boot.
Resolved Conflicts:
arch/x86/kernel/setup.c
mm/nobootmem.c
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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This patch updates x2apic initializaition code to allow x2apic
on VMware platform even without interrupt remapping support.
The hypervisor_x2apic_available hook was added in x2apic
initialization code and used by KVM and XEN, before this.
I have also cleaned up that code to export this hook through the
hypervisor_x86 structure.
Compile tested for KVM and XEN configs, this patch doesn't have
any functional effect on those two platforms.
On VMware platform, verified that x2apic is used in physical
mode on products that support this.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Reviewed-by: Doug Covelli <dcovelli@vmware.com>
Reviewed-by: Dan Hecht <dhecht@vmware.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Avi Kivity <avi@redhat.com>
Link: http://lkml.kernel.org/r/1358466282.423.60.camel@akataria-dtop.eng.vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen fixes from Konrad Rzeszutek Wilk:
- CVE-2013-0190/XSA-40 (or stack corruption for 32-bit PV kernels)
- Fix racy vma access spotted by Al Viro
- Fix mmap batch ioctl potentially resulting in large O(n) page allcations.
- Fix vcpu online/offline BUG:scheduling while atomic..
- Fix unbound buffer scanning for more than 32 vCPUs.
- Fix grant table being incorrectly initialized
- Fix incorrect check in pciback
- Allow privcmd in backend domains.
Fix up whitespace conflict due to ugly merge resolution in Xen tree in
arch/arm/xen/enlighten.c
* tag 'stable/for-linus-3.8-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: Fix stack corruption in xen_failsafe_callback for 32bit PVOPS guests.
Revert "xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic."
xen/gntdev: remove erronous use of copy_to_user
xen/gntdev: correctly unmap unlinked maps in mmu notifier
xen/gntdev: fix unsafe vma access
xen/privcmd: Fix mmap batch ioctl.
Xen: properly bound buffer access when parsing cpu/*/availability
xen/grant-table: correctly initialize grant table version 1
x86/xen : Fix the wrong check in pciback
xen/privcmd: Relax access control in privcmd_ioctl_mmap
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while atomic."
This reverts commit 41bd956de3dfdc3a43708fe2e0c8096c69064a1e.
The fix is incorrect and not appropiate for the latest kernels.
In fact it _causes_ the BUG: scheduling while atomic while
doing vCPU hotplug.
Suggested-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Linux 3.7
* tag 'v3.7': (833 commits)
Linux 3.7
Input: matrix-keymap - provide proper module license
Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage
ipv4: ip_check_defrag must not modify skb before unsharing
Revert "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended"
inet_diag: validate port comparison byte code to prevent unsafe reads
inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run()
inet_diag: validate byte code to prevent oops in inet_diag_bc_run()
inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state
mm: vmscan: fix inappropriate zone congestion clearing
vfs: fix O_DIRECT read past end of block device
net: gro: fix possible panic in skb_gro_receive()
tcp: bug fix Fast Open client retransmission
tmpfs: fix shared mempolicy leak
mm: vmscan: do not keep kswapd looping forever due to individual uncompactable zones
mm: compaction: validate pfn range passed to isolate_freepages_block
mmc: sh-mmcif: avoid oops on spurious interrupts (second try)
Revert misapplied "mmc: sh-mmcif: avoid oops on spurious interrupts"
mmc: sdhci-s3c: fix missing clock for gpio card-detect
lib/Makefile: Fix oid_registry build dependency
...
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Conflicts:
arch/arm/xen/enlighten.c
drivers/xen/Makefile
[We need to have the v3.7 base as the 'for-3.8' was based off v3.7-rc3
and there are some patches in v3.7-rc6 that we to have in our branch]
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git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen bugfixes from Konrad Rzeszutek Wilk:
"Two fixes. One of them is caused by the recent change introduced by
the 'x86-bsp-hotplug-for-linus' tip tree that inhibited bootup (old
function does not do what it used to do). The other one is just a
vanilla bug.
- Fix to bootup regression introduced by 'x86-bsp-hotplug-for-linus'
tip branch.
- Fix to vcpu hotplug code."
* tag 'stable/for-linus-3.8-rc0-bugfix-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/vcpu: Fix vcpu restore path.
xen: Add EVTCHNOP_reset in Xen interface header files.
xen/smp: Use smp_store_boot_cpu_info() to store cpu info for BSP during boot time.
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The runstate of vcpu should be restored for all possible cpus, as well as the
vcpu info placement.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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