* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, mce: Clean up thermal init by introducing intel_thermal_supported()
x86, mce: Thermal monitoring depends on APIC being enabled
x86: Gart: fix breakage due to IOMMU initialization cleanup
x86: Move swiotlb initialization before dma32_free_bootmem
x86: Fix build warning in arch/x86/mm/mmio-mod.c
x86: Remove usedac in feature-removal-schedule.txt
x86: Fix duplicated UV BAU interrupt vector
nvram: Fix write beyond end condition; prove to gcc copy is safe
mm: Adjust do_pages_stat() so gcc can see copy_from_user() is safe
x86: Limit the number of processor bootup messages
x86: Remove enabling x2apic message for every CPU
doc: Add documentation for bootloader_{type,version}
x86, msr: Add support for non-contiguous cpumasks
x86: Use find_e820() instead of hard coded trampoline address
x86, AMD: Fix stale cpuid4_info shared_map data in shared_cpu_map cpumasks
Trivial percpu-naming-introduced conflicts in arch/x86/kernel/cpu/intel_cacheinfo.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
m68k: rename global variable vmalloc_end to m68k_vmalloc_end
percpu: add missing per_cpu_ptr_to_phys() definition for UP
percpu: Fix kdump failure if booted with percpu_alloc=page
percpu: make misc percpu symbols unique
percpu: make percpu symbols in ia64 unique
percpu: make percpu symbols in powerpc unique
percpu: make percpu symbols in x86 unique
percpu: make percpu symbols in xen unique
percpu: make percpu symbols in cpufreq unique
percpu: make percpu symbols in oprofile unique
percpu: make percpu symbols in tracer unique
percpu: make percpu symbols under kernel/ and mm/ unique
percpu: remove some sparse warnings
percpu: make alloc_percpu() handle array types
vmalloc: fix use of non-existent percpu variable in put_cpu_var()
this_cpu: Use this_cpu_xx in trace_functions_graph.c
this_cpu: Use this_cpu_xx for ftrace
this_cpu: Use this_cpu_xx in nmi handling
this_cpu: Use this_cpu operations in RCU
this_cpu: Use this_cpu ops for VM statistics
...
Fix up trivial (famous last words) global per-cpu naming conflicts in
arch/x86/kvm/svm.c
mm/slab.c
Interrupt vector 0xec has been doubly defined in irq_vectors.h
It seems arbitrary whether LOCAL_PENDING_VECTOR or
UV_BAU_MESSAGE is the higher number. As long as they are
unique. If they are not unique we'll hit a BUG in
alloc_system_vector().
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
LKML-Reference: <E1NJ9Pe-0004P7-0Q@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/amd-iommu: Fix PCI hotplug with passthrough mode
x86/amd-iommu: Fix passthrough mode
x86: mmio-mod.c: Use pr_fmt
x86: kmmio.c: Add and use pr_fmt(fmt)
x86: i8254.c: Add pr_fmt(fmt)
x86: setup_percpu.c: Use pr_<level> and add pr_fmt(fmt)
x86: es7000_32.c: Use pr_<level> and add pr_fmt(fmt)
x86: Print DMI_BOARD_NAME as well as DMI_PRODUCT_NAME from __show_regs()
x86: Factor duplicated code out of __show_regs() into show_regs_common()
arch/x86/kernel/microcode*: Use pr_fmt() and remove duplicated KERN_ERR prefix
x86, mce: fix confusion between bank attributes and mce attributes
x86/mce: Set up timer unconditionally
x86: Fix bogus warning in apic_noop.apic_write()
x86: Fix typo in arch/x86/mm/kmmio.c
x86: ASUS P4S800 reboot=bios quirk
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/mmap:
Add missing alignment check in arch/score sys_mmap()
fix broken aliasing checks for MAP_FIXED on sparc32, mips, arm and sh
Get rid of open-coding in ia64_brk()
sparc_brk() is not needed anymore
switch do_brk() to get_unmapped_area()
Take arch_mmap_check() into get_unmapped_area()
fix a struct file leak in do_mmap_pgoff()
Unify sys_mmap*
Cut hugetlb case early for 32bit on ia64
arch_mmap_check() on mn10300
Kill ancient crap in s390 compat mmap
arm: add arch_mmap_check(), get rid of sys_arm_mremap()
file ->get_unmapped_area() shouldn't duplicate work of get_unmapped_area()
kill useless checks in sparc mremap variants
fix pgoff in "have to relocate" case of mremap()
fix the arch checks in MREMAP_FIXED case
fix checks for expand-in-place mremap
do_mremap() untangling, part 3
do_mremap() untangling, part 2
untangling do_mremap(), part 1
The current rd/wrmsr_on_cpus helpers assume that the supplied
cpumasks are contiguous. However, there are machines out there
like some K8 multinode Opterons which have a non-contiguous core
enumeration on each node (e.g. cores 0,2 on node 0 instead of 0,1), see
http://www.gossamer-threads.com/lists/linux/kernel/1160268.
This patch fixes out-of-bounds writes (see URL above) by adding per-CPU
msr structs which are used on the respective cores.
Additionally, two helpers, msrs_{alloc,free}, are provided for use by
the callers of the MSR accessors.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20091211171440.GD31998@aftab>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
New helper - sys_mmap_pgoff(); switch syscalls to using it.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Jens found the following crash/regression:
[ 0.000000] found SMP MP-table at [ffff8800000fdd80] fdd80
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 0-fff BIOS data page
and
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 6000-7fff TRAMPOLINE
and bisected it to b24c2a9 ("x86: Move find_smp_config()
earlier and avoid bootmem usage").
It turns out the BIOS is using the first 64k for mptable,
without reserving it.
So try to find good range for the real-mode trampoline instead of
hard coding it, in case some bios tries to use that range for sth.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4B21630A.6000308@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The device change notifier is initialized in the dma_ops
initialization path. But this path is never executed for
iommu=pt. Move the notifier initialization to IOMMU hardware
init code to fix this.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
The data structure changes to use dev->archdata.iommu field
broke the iommu=pt mode because in this case the
dev->archdata.iommu was left uninitialized. This moves the
inititalization of the devices into the main init function
and fixes the problem.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Unify x86_32 and x86_64 implementations of __show_regs() header,
standardizing on the x86_64 format string in the process. Also,
32-bit will now call print_modules.
Signed-off-by: Andy Isaacson <adi@hexapodia.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Robert Hancock <hancockrwd@gmail.com>
Cc: Richard Zidlicky <rz@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20091208082942.GA27174@hexapodia.org>
[ v2: resolved conflict ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'timers-for-linus-hpet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: hpet: Make WARN_ON understandable
x86: arch specific support for remapping HPET MSIs
intr-remap: generic support for remapping HPET MSIs
x86, hpet: Simplify the HPET code
x86, hpet: Disable per-cpu hpet timer if ARAT is supported
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
hwrng: core - Prevent too-small buffer sizes
hwrng: virtio-rng - Convert to new API
hwrng: core - Replace u32 in driver API with byte array
crypto: ansi_cprng - Move FIPS functions under CONFIG_CRYPTO_FIPS
crypto: testmgr - Add ghash algorithm test before provide to users
crypto: ghash-clmulni-intel - Put proper .data section in place
crypto: ghash-clmulni-intel - Use gas macro for PCLMULQDQ-NI and PSHUFB
crypto: aesni-intel - Use gas macro for AES-NI instructions
x86: Generate .byte code for some new instructions via gas macro
crypto: ghash-intel - Fix irq_fpu_usable usage
crypto: ghash-intel - Add PSHUFB macros
crypto: ghash-intel - Hard-code pshufb
crypto: ghash-intel - Fix building failure on x86_32
crypto: testmgr - Fix warning
crypto: ansi_cprng - Fix test in get_prng_bytes
crypto: hash - Remove cra_u.{digest,hash}
crypto: api - Remove digest case from procfs show handler
crypto: hash - Remove legacy hash/digest code
crypto: ansi_cprng - Add FIPS wrapper
crypto: ghash - Add PCLMULQDQ accelerated implementation
* 'x86-process-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64: merge the standard and compat start_thread() functions
x86-64: make compat_start_thread() match start_thread()
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (36 commits)
x86, mm: Correct the implementation of is_untracked_pat_range()
x86/pat: Trivial: don't create debugfs for memtype if pat is disabled
x86, mtrr: Fix sorting of mtrr after subtracting
x86: Move find_smp_config() earlier and avoid bootmem usage
x86, platform: Change is_untracked_pat_range() to bool; cleanup init
x86: Change is_ISA_range() into an inline function
x86, mm: is_untracked_pat_range() takes a normal semiclosed range
x86, mm: Call is_untracked_pat_range() rather than is_ISA_range()
x86: UV SGI: Don't track GRU space in PAT
x86: SGI UV: Fix BAU initialization
x86, numa: Use near(er) online node instead of roundrobin for NUMA
x86, numa, bootmem: Only free bootmem on NUMA failure path
x86: Change crash kernel to reserve via reserve_early()
x86: Eliminate redundant/contradicting cache line size config options
x86: When cleaning MTRRs, do not fold WP into UC
x86: remove "extern" from function prototypes in <asm/proto.h>
x86, mm: Report state of NX protections during boot
x86, mm: Clean up and simplify NX enablement
x86, pageattr: Make set_memory_(x|nx) aware of NX support
x86, sleep: Always save the value of EFER
...
Fix up conflicts (added both iommu_shutdown and is_untracked_pat_range)
to 'struct x86_platform_ops') in
arch/x86/include/asm/x86_init.h
arch/x86/kernel/x86_init.c
* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: ucode-amd: Move family check to microcde_amd.c's init function
x86, ucode-amd: Ensure ucode update on suspend/resume after CPU off/online cycle
x86: ucode-amd: Convert printk(KERN_*...) to pr_*(...)
x86: ucode-amd: Don't warn when no ucode is available for a CPU revision
x86: ucode-amd: Load ucode-patches once and not separately of each CPU
x86, amd-ucode: Remove needless log messages
* 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block: (113 commits)
cfq-iosched: Do not access cfqq after freeing it
block: include linux/err.h to use ERR_PTR
cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit
blkio: Allow CFQ group IO scheduling even when CFQ is a module
blkio: Implement dynamic io controlling policy registration
blkio: Export some symbols from blkio as its user CFQ can be a module
block: Fix io_context leak after failure of clone with CLONE_IO
block: Fix io_context leak after clone with CLONE_IO
cfq-iosched: make nonrot check logic consistent
io controller: quick fix for blk-cgroup and modular CFQ
cfq-iosched: move IO controller declerations to a header file
cfq-iosched: fix compile problem with !CONFIG_CGROUP
blkio: Documentation
blkio: Wait on sync-noidle queue even if rq_noidle = 1
blkio: Implement group_isolation tunable
blkio: Determine async workload length based on total number of queues
blkio: Wait for cfq queue to get backlogged if group is empty
blkio: Propagate cgroup weight updation to cfq groups
blkio: Drop the reference to queue once the task changes cgroup
blkio: Provide some isolation between groups
...
* 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (84 commits)
KVM: VMX: Fix comparison of guest efer with stale host value
KVM: s390: Fix prefix register checking in arch/s390/kvm/sigp.c
KVM: Drop user return notifier when disabling virtualization on a cpu
KVM: VMX: Disable unrestricted guest when EPT disabled
KVM: x86 emulator: limit instructions to 15 bytes
KVM: s390: Make psw available on all exits, not just a subset
KVM: x86: Add KVM_GET/SET_VCPU_EVENTS
KVM: VMX: Report unexpected simultaneous exceptions as internal errors
KVM: Allow internal errors reported to userspace to carry extra data
KVM: Reorder IOCTLs in main kvm.h
KVM: x86: Polish exception injection via KVM_SET_GUEST_DEBUG
KVM: only clear irq_source_id if irqchip is present
KVM: x86: disallow KVM_{SET,GET}_LAPIC without allocated in-kernel lapic
KVM: x86: disallow multiple KVM_CREATE_IRQCHIP
KVM: VMX: Remove vmx->msr_offset_efer
KVM: MMU: update invlpg handler comment
KVM: VMX: move CR3/PDPTR update to vmx_set_cr3
KVM: remove duplicated task_switch check
KVM: powerpc: Fix BUILD_BUG_ON condition
KVM: VMX: Use shared msr infrastructure
...
Trivial conflicts due to new Kconfig options in arch/Kconfig and kernel/Makefile
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1815 commits)
mac80211: fix reorder buffer release
iwmc3200wifi: Enable wimax core through module parameter
iwmc3200wifi: Add wifi-wimax coexistence mode as a module parameter
iwmc3200wifi: Coex table command does not expect a response
iwmc3200wifi: Update wiwi priority table
iwlwifi: driver version track kernel version
iwlwifi: indicate uCode type when fail dump error/event log
iwl3945: remove duplicated event logging code
b43: fix two warnings
ipw2100: fix rebooting hang with driver loaded
cfg80211: indent regulatory messages with spaces
iwmc3200wifi: fix NULL pointer dereference in pmkid update
mac80211: Fix TX status reporting for injected data frames
ath9k: enable 2GHz band only if the device supports it
airo: Fix integer overflow warning
rt2x00: Fix padding bug on L2PAD devices.
WE: Fix set events not propagated
b43legacy: avoid PPC fault during resume
b43: avoid PPC fault during resume
tcp: fix a timewait refcnt race
...
Fix up conflicts due to sysctl cleanups (dead sysctl_check code and
CTL_UNNUMBERED removed) in
kernel/sysctl_check.c
net/ipv4/sysctl_net_ipv4.c
net/ipv6/addrconf.c
net/sctp/sysctl.c
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits)
security/tomoyo: Remove now unnecessary handling of security_sysctl.
security/tomoyo: Add a special case to handle accesses through the internal proc mount.
sysctl: Drop & in front of every proc_handler.
sysctl: Remove CTL_NONE and CTL_UNNUMBERED
sysctl: kill dead ctl_handler definitions.
sysctl: Remove the last of the generic binary sysctl support
sysctl net: Remove unused binary sysctl code
sysctl security/tomoyo: Don't look at ctl_name
sysctl arm: Remove binary sysctl support
sysctl x86: Remove dead binary sysctl support
sysctl sh: Remove dead binary sysctl support
sysctl powerpc: Remove dead binary sysctl support
sysctl ia64: Remove dead binary sysctl support
sysctl s390: Remove dead sysctl binary support
sysctl frv: Remove dead binary sysctl support
sysctl mips/lasat: Remove dead binary sysctl support
sysctl drivers: Remove dead binary sysctl support
sysctl crypto: Remove dead binary sysctl support
sysctl security/keys: Remove dead binary sysctl support
sysctl kernel: Remove binary sysctl logic
...
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, msr, cpumask: Use struct cpumask rather than the deprecated cpumask_t
x86, cpuid: Simplify the code in cpuid_open
x86, cpuid: Remove the bkl from cpuid_open()
x86, msr: Remove the bkl from msr_open()
x86: AMD Geode LX optimizations
x86, msr: Unify rdmsr_on_cpus/wrmsr_on_cpus
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
include/linux/compiler-gcc4.h: Fix build bug - gcc-4.0.2 doesn't understand __builtin_object_size
x86/alternatives: No need for alternatives-asm.h to re-invent stuff already in asm.h
x86/alternatives: Check replacementlen <= instrlen at build time
x86, 64-bit: Set data segments to null after switching to 64-bit mode
x86: Clean up the loadsegment() macro
x86: Optimize loadsegment()
x86: Add missing might_fault() checks to copy_{to,from}_user()
x86-64: __copy_from_user_inatomic() adjustments
x86: Remove unused thread_return label from switch_to()
x86, 64-bit: Fix bstep_iret jump
x86: Don't use the strict copy checks when branch profiling is in use
x86, 64-bit: Move K8 B step iret fixup to fault entry asm
x86: Generate cmpxchg build failures
x86: Add a Kconfig option to turn the copy_from_user warnings into errors
x86: Turn the copy_from_user check into an (optional) compile time warning
x86: Use __builtin_memset and __builtin_memcpy for memset/memcpy
x86: Use __builtin_object_size() to validate the buffer size for copy_from_user()
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
x86, apic: Enable lapic nmi watchdog on AMD Family 11h
x86: Remove unnecessary mdelay() from cpu_disable_common()
x86, ioapic: Document another case when level irq is seen as an edge
x86, ioapic: Fix the EOI register detection mechanism
x86, io-apic: Move the effort of clearing remoteIRR explicitly before migrating the irq
x86: SGI UV: Map low MMR ranges
x86: apic: Print out SRAT table APIC id in hex
x86: Re-get cfg_new in case reuse/move irq_desc
x86: apic: Remove not needed #ifdef
x86: io-apic: IO-APIC MMIO should not fail on resource insertion
x86: Remove asm/apicnum.h
x86: apic: Do not use stacked physid_mask_t
x86, apic: Get rid of apicid_to_cpu_present assign on 64-bit
x86, ioapic: Use snrpintf while set names for IO-APIC resourses
x86, apic: Use PAGE_SIZE instead of numbers
x86: Remove local_irq_enable()/local_irq_disable() in fixup_irqs()
x86: Use EOI register in io-apic on intel platforms
x86: Force irq complete move during cpu offline
x86: Remove move_cleanup_count from irq_cfg
x86, intr-remap: Avoid irq_chip mask/unmask in fixup_irqs() for intr-remapping
...
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (63 commits)
x86, Calgary IOMMU quirk: Find nearest matching Calgary while walking up the PCI tree
x86/amd-iommu: Remove amd_iommu_pd_table
x86/amd-iommu: Move reset_iommu_command_buffer out of locked code
x86/amd-iommu: Cleanup DTE flushing code
x86/amd-iommu: Introduce iommu_flush_device() function
x86/amd-iommu: Cleanup attach/detach_device code
x86/amd-iommu: Keep devices per domain in a list
x86/amd-iommu: Add device bind reference counting
x86/amd-iommu: Use dev->arch->iommu to store iommu related information
x86/amd-iommu: Remove support for domain sharing
x86/amd-iommu: Rearrange dma_ops related functions
x86/amd-iommu: Move some pte allocation functions in the right section
x86/amd-iommu: Remove iommu parameter from dma_ops_domain_alloc
x86/amd-iommu: Use get_device_id and check_device where appropriate
x86/amd-iommu: Move find_protection_domain to helper functions
x86/amd-iommu: Simplify get_device_resources()
x86/amd-iommu: Let domain_for_device handle aliases
x86/amd-iommu: Remove iommu specific handling from dma_ops path
x86/amd-iommu: Remove iommu parameter from __(un)map_single
x86/amd-iommu: Make alloc_new_range aware of multiple IOMMUs
...
Use the new unreachable() macro instead of for(;;);. When
allyesconfig is built with a GCC-4.5 snapshot on i686 the size of the
text segment is reduced by 3987 bytes (from 6827019 to 6823032).
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: x86@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"Definition" is misspelled "defintion" in several comments; this
patch fixes them. No code changes.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
update_transition_efer() masks out some efer bits when deciding whether
to switch the msr during guest entry; for example, NX is emulated using the
mmu so we don't need to disable it, and LMA/LME are handled by the hardware.
However, with shared msrs, the comparison is made against a stale value;
at the time of the guest switch we may be running with another guest's efer.
Fix by deferring the mask/compare to the actual point of guest entry.
Noted by Marcelo.
Signed-off-by: Avi Kivity <avi@redhat.com>
While we are never normally passed an instruction that exceeds 15 bytes,
smp games can cause us to attempt to interpret one, which will cause
large latencies in non-preempt hosts.
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
This new IOCTL exports all yet user-invisible states related to
exceptions, interrupts, and NMIs. Together with appropriate user space
changes, this fixes sporadic problems of vmsave/restore, live migration
and system reset.
[avi: future-proof abi by adding a flags field]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The various syscall-related MSRs are fairly expensive to switch. Currently
we switch them on every vcpu preemption, which is far too often:
- if we're switching to a kernel thread (idle task, threaded interrupt,
kernel-mode virtio server (vhost-net), for example) and back, then
there's no need to switch those MSRs since kernel threasd won't
be exiting to userspace.
- if we're switching to another guest running an identical OS, most likely
those MSRs will have the same value, so there's little point in reloading
them.
- if we're running the same OS on the guest and host, the MSRs will have
identical values and reloading is unnecessary.
This patch uses the new user return notifiers to implement last-minute
switching, and checks the msr values to avoid unnecessary reloading.
Signed-off-by: Avi Kivity <avi@redhat.com>
When we migrate a kvm guest that uses pvclock between two hosts, we may
suffer a large skew. This is because there can be significant differences
between the monotonic clock of the hosts involved. When a new host with
a much larger monotonic time starts running the guest, the view of time
will be significantly impacted.
Situation is much worse when we do the opposite, and migrate to a host with
a smaller monotonic clock.
This proposed ioctl will allow userspace to inform us what is the monotonic
clock value in the source host, so we can keep the time skew short, and
more importantly, never goes backwards. Userspace may also need to trigger
the current data, since from the first migration onwards, it won't be
reflected by a simple call to clock_gettime() anymore.
[marcelo: future-proof abi with a flags field]
[jan: fix KVM_GET_CLOCK by clearing flags field instead of checking it]
Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit 705c5323 opened the doors of hell by unconditionally injecting
single-step flags as long as guest_debug signaled this. This doesn't
work when the guest branches into some interrupt or exception handler
and triggers a vmexit with flag reloading.
Fix it by saving cs:rip when user space requests single-stepping and
restricting the trace flag injection to this guest code position.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Support for Xen PV-on-HVM guests can be implemented almost entirely in
userspace, except for handling one annoying MSR that maps a Xen
hypercall blob into guest address space.
A generic mechanism to delegate MSR writes to userspace seems overkill
and risks encouraging similar MSR abuse in the future. Thus this patch
adds special support for the Xen HVM MSR.
I implemented a new ioctl, KVM_XEN_HVM_CONFIG, that lets userspace tell
KVM which MSR the guest will write to, as well as the starting address
and size of the hypercall blobs (one each for 32-bit and 64-bit) that
userspace has loaded from files. When the guest writes to the MSR, KVM
copies one page of the blob from userspace to the guest.
I've tested this patch with a hacked-up version of Gerd's userspace
code, booting a number of guests (CentOS 5.3 i386 and x86_64, and
FreeBSD 8.0-RC1 amd64) and exercising PV network and block devices.
[jan: fix i386 build warning]
[avi: future proof abi with a flags field]
Signed-off-by: Ed Swierk <eswierk@aristanetworks.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
New AMD processors (Family 0x10 models 8+) support the Pause
Filter Feature. This feature creates a new field in the VMCB
called Pause Filter Count. If Pause Filter Count is greater
than 0 and intercepting PAUSEs is enabled, the processor will
increment an internal counter when a PAUSE instruction occurs
instead of intercepting. When the internal counter reaches the
Pause Filter Count value, a PAUSE intercept will occur.
This feature can be used to detect contended spinlocks,
especially when the lock holding VCPU is not scheduled.
Rescheduling another VCPU prevents the VCPU seeking the
lock from wasting its quantum by spinning idly.
Experimental results show that most spinlocks are held
for less than 1000 PAUSE cycles or more than a few
thousand. Default the Pause Filter Counter to 3000 to
detect the contended spinlocks.
Processor support for this feature is indicated by a CPUID
bit.
On a 24 core system running 4 guests each with 16 VCPUs,
this patch improved overall performance of each guest's
32 job kernbench by approximately 3-5% when combined
with a scheduler algorithm thati caused the VCPU to
sleep for a brief period. Further performance improvement
may be possible with a more sophisticated yield algorithm.
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
New NHM processors will support Pause-Loop Exiting by adding 2 VM-execution
control fields:
PLE_Gap - upper bound on the amount of time between two successive
executions of PAUSE in a loop.
PLE_Window - upper bound on the amount of time a guest is allowed to execute in
a PAUSE loop
If the time, between this execution of PAUSE and previous one, exceeds the
PLE_Gap, processor consider this PAUSE belongs to a new loop.
Otherwise, processor determins the the total execution time of this loop(since
1st PAUSE in this loop), and triggers a VM exit if total time exceeds the
PLE_Window.
* Refer SDM volume 3b section 21.6.13 & 22.1.3.
Pause-Loop Exiting can be used to detect Lock-Holder Preemption, where one VP
is sched-out after hold a spinlock, then other VPs for same lock are sched-in
to waste the CPU time.
Our tests indicate that most spinlocks are held for less than 212 cycles.
Performance tests show that with 2X LP over-commitment we can get +2% perf
improvement for kernel build(Even more perf gain with more LPs).
Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Push TF and RF injection and filtering on guest single-stepping into the
vender get/set_rflags callbacks. This makes the whole mechanism more
robust wrt user space IOCTL order and instruction emulations.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Much of so far vendor-specific code for setting up guest debug can
actually be handled by the generic code. This also fixes a minor deficit
in the SVM part /wrt processing KVM_GUESTDBG_ENABLE.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).
Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.
To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.
So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
