Commit Graph

3585 Commits

Author SHA1 Message Date
Ingo Molnar 2e2dcc7631 Merge branch 'x86/paravirt-spinlocks' into x86/for-linus 2008-07-21 16:45:56 +02:00
Ingo Molnar acee709cab Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus 2008-07-21 16:37:17 +02:00
Ingo Molnar e66d90fb4a Merge branch 'linus' into xen-64bit 2008-07-21 15:06:09 +02:00
Ingo Molnar 1c29dd9a9e Merge branch 'linus' into x86/paravirt-spinlocks 2008-07-21 15:05:58 +02:00
Yinghai Lu 7edf8891ad x86: remove extra calling to get ext cpuid level
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-21 13:03:13 +02:00
Yinghai Lu 9175fc06ae x86: use setup_clear_cpu_cap() when disabling the lapic
... so don't need to call clear_cpu_cap again in early_identify_cpu,
and could use cleared_cpu_caps like other places.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-21 13:03:12 +02:00
Ingo Molnar e27772b48d Merge branch 'linus' into x86/urgent 2008-07-21 11:02:45 +02:00
Avi Kivity 722c05f219 KVM: MMU: Fix potential race setting upper shadow ptes on nonpae hosts
The direct mapped shadow code (used for real mode and two dimensional paging)
sets upper-level ptes using direct assignment rather than calling
set_shadow_pte().  A nonpae host will split this into two writes, which opens
up a race if another vcpu accesses the same memory area.

Fix by calling set_shadow_pte() instead of assigning directly.

Noticed by Izik Eidus.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Glauber Costa 2a7c5b8b55 KVM: x86 emulator: emulate clflush
If the guest issues a clflush in a mmio address, the instruction
can trap into the hypervisor. Currently, we do not decode clflush
properly, causing the guest to hang. This patch fixes this emulating
clflush (opcode 0f ae).

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Marcelo Tosatti 376c53c2b3 KVM: MMU: improve invalid shadow root page handling
Harden kvm_mmu_zap_page() against invalid root pages that
had been shadowed from memslots that are gone.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Marcelo Tosatti 34d4cb8fca KVM: MMU: nuke shadowed pgtable pages and ptes on memslot destruction
Flush the shadow mmu before removing regions to avoid stale entries.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Avi Kivity d6e88aec07 KVM: Prefix some x86 low level function with kvm_, to avoid namespace issues
Fixes compilation with CONFIG_VMI enabled.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:39 +03:00
Ben-Ami Yassour c65bbfa1d6 KVM: check injected pic irq within valid pic irqs
Check that an injected pic irq is between 0 and 15.

Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:39 +03:00
Mohammed Gamal 19fdfa0d13 KVM: x86 emulator: Fix HLT instruction
This patch fixes issue encountered with HLT instruction
under FreeDOS's HIMEM XMS Driver.

The HLT instruction jumped directly to the done label and
skips updating the EIP value, therefore causing the guest
to spin endlessly on the same instruction.

The patch changes the instruction so that it writes back
the updated EIP value.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:38 +03:00
Avi Kivity ac9f6dc0db KVM: Apply the kernel sigmask to vcpus blocked due to being uninitialized
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:38 +03:00
Sheng Yang 4e1096d27f KVM: VMX: Add ept_sync_context in flush_tlb
Fix a potention issue caused by kvm_mmu_slot_remove_write_access(). The
old behavior don't sync EPT TLB with modified EPT entry, which result
in inconsistent content of EPT TLB and EPT table.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:38 +03:00
Marcelo Tosatti 5a4c928804 KVM: mmu_shrink: kvm_mmu_zap_page requires slots_lock to be held
kvm_mmu_zap_page() needs slots lock held (rmap_remove->gfn_to_memslot,
for example).

Since kvm_lock spinlock is held in mmu_shrink(), do a non-blocking
down_read_trylock().

Untested.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:38 +03:00
Adrian Bunk 7e37c2998a x86: KVM guest: make kvm_smp_prepare_boot_cpu() static
This patch makes the needlessly global kvm_smp_prepare_boot_cpu() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:37 +03:00
Joerg Roedel 0da1db75a2 KVM: SVM: fix suspend/resume support
On suspend the svm_hardware_disable function is called which frees all svm_data
variables. On resume they are not re-allocated. This patch removes the
deallocation of svm_data from the hardware_disable function to the
hardware_unsetup function which is not called on suspend.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:37 +03:00
Marcelo Tosatti f8b78fa3d4 KVM: move slots_lock acquision down to vapic_exit
There is no need to grab slots_lock if the vapic_page will not
be touched.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:36 +03:00
Chris Lalancette efa67e0d1f KVM: VMX: Fake emulate Intel perfctr MSRs
Older linux guests (in this case, 2.6.9) can attempt to
access the performance counter MSRs without a fixup section, and injecting
a GPF kills the guest.  Work around by allowing the guest to write those MSRs.

Tested by me on RHEL-4 i386 and x86_64 guests, as well as F-9 guests.

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:36 +03:00
Sheng Yang 65267ea1b3 KVM: VMX: Fix a wrong usage of vmcs_config
The function ept_update_paging_mode_cr0() write to
CPU_BASED_VM_EXEC_CONTROL based on vmcs_config.cpu_based_exec_ctrl. That's
wrong because the variable may not consistent with the content in the
CPU_BASE_VM_EXEC_CONTROL MSR.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:36 +03:00
Avi Kivity db475c39ec KVM: MMU: Fix printk format
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:35 +03:00
Avi Kivity 6ada8cca79 KVM: MMU: When debug is enabled, make it a run-time parameter
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:35 +03:00
Avi Kivity 7a5b56dfd3 KVM: x86 emulator: lazily evaluate segment registers
Instead of prefetching all segment bases before emulation, read them at the
last moment.  Since most of them are unneeded, we save some cycles on
Intel machines where this is a bit expensive.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:35 +03:00
Avi Kivity 0adc8675d6 KVM: x86 emulator: avoid segment base adjust for lea
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:34 +03:00
Avi Kivity f5b4edcd52 KVM: x86 emulator: simplify rip relative decoding
rip relative decoding is relative to the instruction pointer of the next
instruction; by moving address adjustment until after decoding is complete,
we remove the need to determine the instruction size.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:34 +03:00
Avi Kivity 84411d85da KVM: x86 emulator: simplify r/m decoding
Consolidate the duplicated code when not in any special case.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity dc71d0f162 KVM: x86 emulator: simplify sib decoding
Instead of using sparse switches, use simpler if/else sequences.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity 8684c0af0b KVM: x86 emulator: handle undecoded rex.b with r/m = 5 in certain cases
x86_64 does not decode rex.b in certain cases, where the r/m field = 5.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Mohammed Gamal b13354f8f0 KVM: x86 emulator: emulate nop and xchg reg, acc (opcodes 0x90 - 0x97)
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity f76c710d75 KVM: Use printk_rlimit() instead of reporting emulation failures just once
Emulation failure reports are useful, so allow more than one per the lifetime
of the module.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Glauber Costa 25be46080f KVM: Do not calculate linear rip in emulation failure report
If we're not gonna do anything (case in which failure is already
reported), we do not need to even bother with calculating the linear rip.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Marcelo Tosatti 622395a9e6 KVM: only abort guest entry if timer count goes from 0->1
Only abort guest entry if the timer count went from 0->1, since for 1->2
or larger the bit will either be set already or a timer irq will have
been injected.

Using atomic_inc_and_test() for it also introduces an SMP barrier
to the LAPIC version (thought it was unecessary because of timer
migration, but guest can be scheduled to a different pCPU between exit
and kvm_vcpu_block(), so there is the possibility for a race).

Noticed by Avi.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Laurent Vivier 542472b53e KVM: Add coalesced MMIO support (x86 part)
This patch enables coalesced MMIO for x86 architecture.
It defines KVM_MMIO_PAGE_OFFSET and KVM_CAP_COALESCED_MMIO.
It enables the compilation of coalesced_mmio.c.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:31 +03:00
Laurent Vivier 92760499d0 KVM: kvm_io_device: extend in_range() to manage len and write attribute
Modify member in_range() of structure kvm_io_device to pass length and the type
of the I/O (write or read).

This modification allows to use kvm_io_device with coalesced MMIO.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity 131d82791b KVM: MMU: Avoid page prefetch on SVM
SVM cannot benefit from page prefetching since guest page fault bypass
cannot by made to work there.  Avoid accessing the guest page table in
this case.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity d761a501cf KVM: MMU: Move nonpaging_prefetch_page()
In preparation for next patch. No code change.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity 91ed7a0e15 KVM: x86 emulator: implement 'push imm' (opcode 0x68)
Encountered in FC6 boot sequence, now that we don't force ss.rpl = 0 during
the protected mode transition.  Not really necessary, but nice to have.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:29 +03:00
Avi Kivity 19e43636b5 KVM: x86 emulator: simplify push imm8 emulation
Instead of fetching the data explicitly, use SrcImmByte.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:29 +03:00
Avi Kivity eab9f71feb KVM: MMU: Optimize prefetch_page()
Instead of reading each pte individually, read 256 bytes worth of ptes and
batch process them.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin 38d5bc6d50 KVM: x86 emulator: Add support for mov r, sreg (0x8c) instruction
Add support for mov r, sreg (0x8c) instruction

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin 4257198ae2 KVM: x86 emulator: Add support for mov seg, r (0x8e) instruction
Add support for mov r, sreg (0x8c) instruction.

[avi: drop the sreg decoding table in favor of 1:1 encoding]

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin 615ac12561 KVM: x86 emulator: adds support to mov r,imm (opcode 0xb8) instruction
Add support to mov r, imm (0xb8) instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin 954cd36f76 KVM: x86 emulator: add support for jmp far 0xea
Add support for jmp far (opcode 0xea) instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin 89c696383d KVM: x86 emulator: Update c->dst.bytes in decode instruction
Update c->dst.bytes in decode instruction instead of instruction
itself.  It's needed because if c->dst.bytes is equal to 0, the
instruction is not emulated.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin 3e6e0aab1b KVM: Prefixes segment functions that will be exported with "kvm_"
Prefixes functions that will be exported with kvm_.
We also prefixed set_segment() even if it still static
to be coherent.

signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Avi Kivity 9ba075a664 KVM: MTRR support
Add emulation for the memory type range registers, needed by VMware esx 3.5,
and by pci device assignment.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:26 +03:00
Sheng Yang f08864b42a KVM: VMX: Enable NMI with in-kernel irqchip
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:26 +03:00
Sheng Yang 3419ffc8e4 KVM: IOAPIC/LAPIC: Enable NMI support
[avi: fix ia64 build breakage]

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity 50d40d7fb9 KVM: Remove unnecessary ->decache_regs() call
Since we aren't modifying any register, there's no need to decache
the register state.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity 7cc8883074 KVM: Remove decache_vcpus_on_cpu() and related callbacks
Obsoleted by the vmx-specific per-cpu list.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity 543e424366 KVM: VMX: Add list of potentially locally cached vcpus
VMX hardware can cache the contents of a vcpu's vmcs.  This cache needs
to be flushed when migrating a vcpu to another cpu, or (which is the case
that interests us here) when disabling hardware virtualization on a cpu.

The current implementation of decaching iterates over the list of all vcpus,
picks the ones that are potentially cached on the cpu that is being offlined,
and flushes the cache.  The problem is that it uses mutex_trylock() to gain
exclusive access to the vcpu, which fires off a (benign) warning about using
the mutex in an interrupt context.

To avoid this, and to make things generally nicer, add a new per-cpu list
of potentially cached vcus.  This makes the decaching code much simpler.  The
list is vmx-specific since other hardware doesn't have this issue.

[andrea: fix crash on suspend/resume]

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:24 +03:00
Avi Kivity 4ecac3fd6d KVM: Handle virtualization instruction #UD faults during reboot
KVM turns off hardware virtualization extensions during reboot, in order
to disassociate the memory used by the virtualization extensions from the
processor, and in order to have the system in a consistent state.
Unfortunately virtual machines may still be running while this goes on,
and once virtualization extensions are turned off, any virtulization
instruction will #UD on execution.

Fix by adding an exception handler to virtualization instructions; if we get
an exception during reboot, we simply spin waiting for the reset to complete.
If it's a true exception, BUG() so we can have our stack trace.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:41:43 +03:00
Avi Kivity 1b7fcd3263 KVM: MMU: Fix false flooding when a pte points to page table
The KVM MMU tries to detect when a speculative pte update is not actually
used by demand fault, by checking the accessed bit of the shadow pte.  If
the shadow pte has not been accessed, we deem that page table flooded and
remove the shadow page table, allowing further pte updates to proceed
without emulation.

However, if the pte itself points at a page table and only used for write
operations, the accessed bit will never be set since all access will happen
through the emulator.

This is exactly what happens with kscand on old (2.4.x) HIGHMEM kernels.
The kernel points a kmap_atomic() pte at a page table, and then
proceeds with read-modify-write operations to look at the dirty and accessed
bits.  We get a false flood trigger on the kmap ptes, which results in the
mmu spending all its time setting up and tearing down shadows.

Fix by setting the shadow accessed bit on emulated accesses.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:50 +03:00
Avi Kivity 7682f2d0dd KVM: VMX: Trivial vmcs_write64() code simplification
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:50 +03:00
Chris Lalancette 14ae51b6c0 KVM: SVM: Fake MSR_K7 performance counters
Attached is a patch that fixes a guest crash when booting older Linux kernels.
The problem stems from the fact that we are currently emulating
MSR_K7_EVNTSEL[0-3], but not emulating MSR_K7_PERFCTR[0-3].  Because of this,
setup_k7_watchdog() in the Linux kernel receives a GPF when it attempts to
write into MSR_K7_PERFCTR, which causes an OOPs.

The patch fixes it by just "fake" emulating the appropriate MSRs, throwing
away the data in the process.  This causes the NMI watchdog to not actually
work, but it's not such a big deal in a virtualized environment.

When we get a write to one of these counters, we printk_ratelimit() a warning.
I decided to print it out for all writes, even if the data is 0; it doesn't
seem to make sense to me to special case when data == 0.

Tested by myself on a RHEL-4 guest, and Joerg Roedel on a Windows XP 64-bit
guest.

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:49 +03:00
Aurelien Jarno f697554515 KVM: PIT: support mode 3
The in-kernel PIT emulation ignores pending timers if operating
under mode 3, which for example Hurd uses.

This mode should output a square wave, high for (N+1)/2 counts and low
for (N-1)/2 counts. As we only care about the resulting interrupts, the
period is N, and mode 3 is the same as mode 2 with regard to
interrupts.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:49 +03:00
Joerg Roedel d2ebb4103f KVM: SVM: add tracing support for TDP page faults
To distinguish between real page faults and nested page faults they should be
traced as different events. This is implemented by this patch.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Joerg Roedel af9ca2d703 KVM: SVM: add missing kvmtrace markers
This patch adds the missing kvmtrace markers to the svm
module of kvm.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Joerg Roedel 54e445ca84 KVM: add missing kvmtrace bits
This patch adds some kvmtrace bits to the generic x86 code
where it is instrumented from SVM.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Joerg Roedel a069805579 KVM: SVM: implement dedicated INTR exit handler
With an exit handler for INTR intercepts its possible to account them using
kvmtrace.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:47 +03:00
Joerg Roedel c47f098d69 KVM: SVM: implement dedicated NMI exit handler
With an exit handler for NMI intercepts its possible to account them using
kvmtrace.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:47 +03:00
Joerg Roedel c7bf23babc KVM: VMX: move APIC_ACCESS trace entry to generic code
This patch moves the trace entry for APIC accesses from the VMX code to the
generic lapic code. This way APIC accesses from SVM will also be traced.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:47 +03:00
Harvey Harrison 8b2cf73cc1 KVM: add statics were possible, function definition in lapic.h
Noticed by sparse:
arch/x86/kvm/vmx.c:1583:6: warning: symbol 'vmx_disable_intercept_for_msr' was not declared. Should it be static?
arch/x86/kvm/x86.c:3406:5: warning: symbol 'kvm_task_switch_16' was not declared. Should it be static?
arch/x86/kvm/x86.c:3429:5: warning: symbol 'kvm_task_switch_32' was not declared. Should it be static?
arch/x86/kvm/mmu.c:1968:6: warning: symbol 'kvm_mmu_remove_one_alloc_mmu_page' was not declared. Should it be static?
arch/x86/kvm/mmu.c:2014:6: warning: symbol 'mmu_destroy_caches' was not declared. Should it be static?
arch/x86/kvm/lapic.c:862:5: warning: symbol 'kvm_lapic_get_base' was not declared. Should it be static?
arch/x86/kvm/i8254.c:94:5: warning: symbol 'pit_get_gate' was not declared. Should it be static?
arch/x86/kvm/i8254.c:196:5: warning: symbol '__pit_timer_fn' was not declared. Should it be static?
arch/x86/kvm/i8254.c:561:6: warning: symbol '__inject_pit_timer_intr' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:46 +03:00
Peter Zijlstra 31656519e1 sched, x86: clean up hrtick implementation
random uvesafb failures were reported against Gentoo:

  http://bugs.gentoo.org/show_bug.cgi?id=222799

and Mihai Moldovan bisected it back to:

> 8f4d37ec07 is first bad commit
> commit 8f4d37ec07
> Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Date:   Fri Jan 25 21:08:29 2008 +0100
>
>    sched: high-res preemption tick

Linus suspected it to be hrtick + vm86 interaction and observed:

> Btw, Peter, Ingo: I think that commit is doing bad things. They aren't
> _incorrect_ per se, but they are definitely bad.
>
> Why?
>
> Using random _TIF_WORK_MASK flags is really impolite for doing
> "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S
> special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of
> vm86 mode unnecessarily.
>
> See the "work_notifysig_v86" label, and how it does that
> "save_v86_state()" thing etc etc.

Right, I never liked having to fiddle with those TIF flags. Initially I
needed it because the hrtimer base lock could not nest in the rq lock.
That however is fixed these days.

Currently the only reason left to fiddle with the TIF flags is remote
wakeups. We cannot program a remote cpu's hrtimer. I've been thinking
about using the new and improved IPI function call stuff to implement
hrtimer_start_on().

However that does require that smp_call_function_single(.wait=0) works
from interrupt context - /me looks at the latest series from Jens - Yes
that does seem to be supported, good.

Here's a stab at cleaning this stuff up ...

Mihai reported test success as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Mihai Moldovan <ionic@ionic.de>
Cc: Michal Januszewski <spock@gentoo.org>
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:37:28 +02:00
Mike Travis c4762aba0b NR_CPUS: Replace NR_CPUS in speedstep-centrino.c
Some cleanups in speedstep-centrino.c for NR_CPUS=4096.

  * Use new CPUMASK_PTR (instead of old CPUMASK_VAR).

  * Replace arrays sized by NR_CPUS with percpu variables.

  * Cleanup some formatting problems (>80 chars per line)
    and other checkpatch complaints.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:21:12 +02:00
Mike Travis 1bd9d6b64e NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genapic_flat_64.c
* nr_cpu_ids should be used to determine if a percpu area is
    available for a given cpu.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:21:10 +02:00
Mike Travis 247bc6ca0f NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genx2apic_uv_x.c
* Replace NR_CPUS loop with for_each_possible_cpu().

  * nr_cpu_ids should be used to determine if a percpu area is
    available for a given cpu.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:21:09 +02:00
Mike Travis f2ad47ffeb NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/proc.c
* Use nr_cpu_ids instead of NR_CPUS to limit traversal of cpu online map.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:21:09 +02:00
Mike Travis 6bca67f951 NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/mcheck/mce_64.c
* nr_cpu_ids should be used to allocate arrays based on the number of
    cpu's present.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:21:08 +02:00
Simon Arlott e3a61b0a8c x86: add unknown_nmi_panic kernel parameter
It's not possible to enable the unknown_nmi_panic sysctl option
until init is run. It's useful to be able to panic the kernel
during boot too, this adds a parameter to enable this option.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:10:31 +02:00
Yinghai Lu 63b5d7af25 x86: add ->pre_time_init to x86_quirks
so NUMAQ can use that to call numaq_pre_time_init()

This allows us to remove a NUMAQ special from arch/x86/kernel/setup.c.

(and paves the way to remove the NUMAQ subarch)

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 09:25:52 +02:00
Yinghai Lu 64898a8bad x86: extend and use x86_quirks to clean up NUMAQ code
add these new x86_quirks methods:

	int *mpc_record;
	int (*mpc_apic_id)(struct mpc_config_processor *m);
	void (*mpc_oem_bus_info)(struct mpc_config_bus *m, char *name);
	void (*mpc_oem_pci_bus)(struct mpc_config_bus *m);
	void (*smp_read_mpc_oem)(struct mp_config_oemtable *oemtable,
                                    unsigned short oemsize);

... and move NUMAQ related mps table handling to numaq_32.c.

also move the call to smp_read_mpc_oem() to smp_read_mpc() directly.

Should not change functionality, albeit it would be nice to get it
tested on real NUMAQ as well ...

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 09:25:52 +02:00
Yinghai Lu 3c9cb6de1e x86: introduce x86_quirks
introduce x86_quirks array of boot-time quirk methods.

No change in functionality intended.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 09:18:17 +02:00
Yinghai Lu 5f1f2b3d9d x86: improve debug printout: add target bootmem range in early_res_to_bootmem()
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 09:11:07 +02:00
Ingo Molnar d092633bff Subject: devmem, x86: fix rename of CONFIG_NONPROMISC_DEVMEM
From: Arjan van de Ven <arjan@infradead.org>
Date: Sat, 19 Jul 2008 15:47:17 -0700

CONFIG_NONPROMISC_DEVMEM was a rather confusing name - but renaming it
to CONFIG_PROMISC_DEVMEM causes problems on architectures that do not
support this feature; this patch renames it to CONFIG_STRICT_DEVMEM,
so that architectures can opt-in into it.

( the polarity of the option is still the same as it was originally; it
  needs to be for now to not break architectures that don't have the
  infastructure yet to support this feature)

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: "V.Radhakrishnan" <rk@atr-labs.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
2008-07-20 08:35:55 +02:00
Yinghai Lu e5849e71ad x86: remove arch_get_ram_range
no user now

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 17:43:40 -07:00
venkatesh.pallipadi@intel.com fec0962e0b x86: Add a debugfs interface to dump PAT memtype
Add a debugfs interface to list out all the PAT memtype reservations.
Appears at debugfs x86/pat_memtype_list and output format is
type @ <start addr>-<end addr>

We do not hold the lock while printing the entire list. So, the list may not be
a consistent copy in case where regions are getting added or deleted
at the same time.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 17:22:05 -07:00
venkatesh.pallipadi@intel.com ae79cdaacb x86: Add a arch directory for x86 under debugfs
Add a directory for x86 arch under debugfs. Can be used to accumulate all
x86 specific debugfs files.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 17:22:04 -07:00
Jan Beulich 2ddf9b7b3e i386/xen: add proper unwind annotations to xen_sysenter_target
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 16:05:55 -07:00
Jan Beulich 08ad8afaa0 x86: reduce force_mwait visibility
It's not used anywhere outside its single referencing file.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 15:55:09 -07:00
Jan Beulich 08e1a13e7d x86: reduce forbid_dac's visibility
It's not used anywhere outside its declaring file.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 14:39:37 -07:00
Bernhard Walle 91467bdf6e x86: move dma32_reserve_bootmem() after reserve_crashkernel()
On a x86-64 machine (nothing special I could encounter) I had the problem that
crashkernel reservation with the usual "64M@16M" failed. While debugging that,
I encountered that dma32_reserve_bootmem() reserves a memory region which is in
that area.

Because dma32_reserve_bootmem() does not rely on a specific offset but
crashkernel does, it makes sense to move the dma32_reserve_bootmem()
reservation down a bit. I tested that patch and it works without problems. I
don't see any negative effects of that move, but maybe I oversaw something ...

While we strictly don't need that patch in 2.6.27 because we have the
automatic, dynamic offset detection, it makes sense to also include it here
because:

  - it's easier to get it in -stable then,
  - many people are still used to the 'crashkernel=...@16M' syntax,
  - not everybody may be using a reloatable kernel.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: kexec@lists.infradead.org
Cc: vgoyal@redhat.com
Cc: akpm@linux-foundation.org
Cc: Bernhard Walle <bwalle@suse.de>
Cc: yhlu.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 23:35:46 +02:00
Jan Beulich 369c99205f x86: fix two modpost warnings
Even though it's only the difference of the two __initdata symbols
that's being calculated, modpost still doesn't like this. So rather
calculate the size once in an __init function and store it for later
use.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 14:34:08 -07:00
Jan Beulich f2ba93929f x86: check function status in EDD boot code
Without checking the return value of get_edd_info() and adding the
entry only in the success case, 6 devices show up under
/sys/firmware/edd/, no matter how many devices are actually present.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-18 14:33:17 -07:00
Hiroshi Shimamoto 812b121d55 x86_64: ia32_signal.c: remove signal number conversion
This was old code that was needed for iBCS and x86-64 never supported that.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:08:20 +02:00
Mike Travis eb53fac5ca cpumask: Use optimized CPUMASK_ALLOC macros in the centrino_target
* Use the CPUMASK_ALLOC macros in the centrino_target() function.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:03:00 +02:00
Mike Travis c42f4f4c6d cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/ldt.c
* Optimize various places where a pointer to the cpumask_of_cpu value
    will result in reducing stack pressure.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:02:58 +02:00
Mike Travis cb6d2be60d cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/io_apic_64.c
* Optimize various places where a pointer to the cpumask_of_cpu value
    will result in reducing stack pressure.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:02:57 +02:00
Mike Travis 65c0118453 cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr
* This patch replaces the dangerous lvalue version of cpumask_of_cpu
    with new cpumask_of_cpu_ptr macros.  These are patterned after the
    node_to_cpumask_ptr macros.

    In general terms, if there is a cpumask_of_cpu_map[] then a pointer to
    the cpumask_of_cpu_map[cpu] entry is used.  The cpumask_of_cpu_map
    is provided when there is a large NR_CPUS count, reducing
    greatly the amount of code generated and stack space used for
    cpumask_of_cpu().  The pointer to the cpumask_t value is needed for
    calling set_cpus_allowed_ptr() to reduce the amount of stack space
    needed to pass the cpumask_t value.

    If there isn't a cpumask_of_cpu_map[], then a temporary variable is
    declared and filled in with value from cpumask_of_cpu(cpu) as well as
    a pointer variable pointing to this temporary variable.  Afterwards,
    the pointer is used to reference the cpumask value.  The compiler
    will optimize out the extra dereference through the pointer as well
    as the stack space used for the pointer, resulting in identical code.

    A good example of the orthogonal usages is in net/sunrpc/svc.c:

	case SVC_POOL_PERCPU:
	{
		unsigned int cpu = m->pool_to[pidx];
		cpumask_of_cpu_ptr(cpumask, cpu);

		*oldmask = current->cpus_allowed;
		set_cpus_allowed_ptr(current, cpumask);
		return 1;
	}
	case SVC_POOL_PERNODE:
	{
		unsigned int node = m->pool_to[pidx];
		node_to_cpumask_ptr(nodecpumask, node);

		*oldmask = current->cpus_allowed;
		set_cpus_allowed_ptr(current, nodecpumask);
		return 1;
	}

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:02:57 +02:00
Ingo Molnar bb2c018b09 Merge branch 'linus' into cpus4096
Conflicts:

	drivers/acpi/processor_throttling.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:00:54 +02:00
Ingo Molnar f6dc8ccaab Merge branch 'linus' into core/generic-dma-coherent
Conflicts:

	kernel/Makefile

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 21:13:20 +02:00
Ingo Molnar 9b610fda0d Merge branch 'linus' into timers/nohz 2008-07-18 19:53:16 +02:00
Alexander Beregalov fa10c51a04 arch/x86/kernel/cpu/common_64.c: remove double inclusions
x86: remove double inclusions in arch/x86/kernel/cpu/common_64.c

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Cc: yhlu.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 19:25:28 +02:00
Hiroshi Shimamoto 1181f8b5f0 x86_32: remove redundant KERN_INFO
This printk has a KERN_ facility level in the format string.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 19:01:04 +02:00
Jaswinder Singh 6ac8d51f01 x86: introducing asm-x86/traps.h
Declaring x86 traps under one hood.
Declaring x86 do_traps before defining them.

Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 18:51:57 +02:00
Joerg Roedel 5ff4789d04 AMD IOMMU: set iommu for device from ACPI code too
The device<->iommu relationship has to be set from the information in the ACPI
table too. This patch adds this logic to the driver.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 18:43:32 +02:00
Ingo Molnar f1b0c8d3d3 Merge branch 'linus' into x86/amd-iommu 2008-07-18 18:43:08 +02:00
Thomas Petazzoni 9781f39fd2 x86: consolidate the definition of the force_mwait variable
The force_mwait variable iss defined either in
arch/x86/kernel/cpu/amd.c or in arch/x86/kernel/setup_64.c, but it is
only initialized and used in arch/x86/kernel/process.c. This patch
moves the declaration to arch/x86/kernel/process.c.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: michael@free-electrons.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 18:39:19 +02:00
Alexander Beregalov 4712965422 x86 setup.c: cleanup includes
x86: remove double includes in setup.c

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Cc: yhlu.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 18:21:17 +02:00
Thomas Gleixner b8f8c3cf0a nohz: prevent tick stop outside of the idle loop
Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:

	scheduler switch to idle task
	enable interrupts

Window starts here

	----> interrupt happens (does not set NEED_RESCHED)
	      	irq_exit() stops the tick

	----> interrupt happens (does set NEED_RESCHED)

	return from schedule()
	
	cpu_idle(): preempt_disable();

Window ends here

The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.

The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.

Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.

cpu_idle()
{
	preempt_disable();

	while(1) {
		 tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
		 			          are in the idle loop

		 while (!need_resched())
		       halt();

		 tick_nohz_restart_sched_tick(); <- disables NOHZ mode
		 preempt_enable_no_resched();
		 schedule();
		 preempt_disable();
	}
}

In hindsight we should have done this forever, but ... 

/me grabs a large brown paperbag.

Debugged-by: Jack Ren <jack.ren@marvell.com>, 
Debugged-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-18 18:10:28 +02:00
Akinobu Mita 8b2b9c1af0 x86, intel_cacheinfo: fix use-after-free cache_kobject
This avoids calling kobject_uevent() with cache_kobject that has
already been deallocated in an error path.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 17:49:33 +02:00
Ingo Molnar 3f9b5cc018 x86: re-enable OPTIMIZE_INLINING
re-enable OPTIMIZE_INLINING more widely. Jeff Dike fixed the remaining
outstanding issue in this commit:

| commit 4f81c5350b
| Author: Jeff Dike <jdike@addtoit.com>
| Date:   Mon Jul 7 13:36:56 2008 -0400
|
|     [UML] fix gcc ICEs and unresolved externs
[...]
|    This patch reintroduces unit-at-a-time for gcc >= 4.0, bringing back the
|    possibility of Uli's crash.  If that happens, we'll debug it.

it's still default-off and thus opt-in.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:30:05 +02:00
Alexander van Heukelum 7dedcee394 x86: traps_xx: modify x86_64 to use _log_lvl variants
i386 has show_trace_log_lvl and show_stack_log_lvl, allowing
traces to be emitted with log-level annotations. This patch
introduces them to x86_64, but log_lvl is only ever set to
an empty string. Output of traces is unchanged.

i386-chunk is whitespace-only.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:21:17 +02:00
Alexander van Heukelum 78cbac65fd x86: traps_xx: refactor die() like in x86_64
Make the diff between the traps_32.c and traps_64.c a bit smaller.

Change traps_32.c to look more like traps_64.c:
 - move lock information to file scope
 - split out oops_begin() and oops_end() from die()
 - increment nest counter in oops_begin

Only whitespace change in traps_64.c

No functional changes intended.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:21:17 +02:00
Russ Anderson 7019cc2dd6 x86 BIOS interface for RTC on SGI UV
Real-time code needs to know the number of cycles per second
on SGI UV.  The information is provided via a run time BIOS
call.  This patch provides the linux side of that interface.
This is the first of several run time BIOS calls to be defined
in uv/bios.h and bios_uv.c.

Note that BIOS_CALL() is just a stub for now.  The bios
side is being worked on.

Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:35:14 +02:00
Maciej W. Rozycki 49a66a0bce x86: I/O APIC: Always report how the timer has been set up
Following recent (and less so) issues with the 8254 timer when routed
through the I/O or local APIC, always report which configurations have
been tried and which one has been set up eventually.  This is so that logs
posted by people for some other reason can be used as a cross-reference
when investigating any possible future problems.

The change unifies messages printed on 32-bit and 64-bit platforms and
adds trailing newlines (removes leading ones), so that proper log level
annotation can be used and any possible interspersed output will not cause
a mess.

I have chosen to use apic_printk(APIC_QUIET, ...) rather than printk(...)
so that the distinction of these messages is maintained making possible
future decisions about changes in this area easier.  A change posted
separately making apic_verbosity unsigned removes any extra code that
would otherwise be generated as a result of this design decision.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:27:47 +02:00
Maciej W. Rozycki baa1318841 x86: APIC: Make apic_verbosity unsigned
As a microoptimisation, make apic_verbosity unsigned.  This will make
apic_printk(APIC_QUIET, ...) expand into just printk(...) with the
surrounding condition and a reference to apic_verbosity removed.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:27:43 +02:00
Maciej W. Rozycki 17c44697f2 x86: I/O APIC: Include <asm/i8259.h> required by some code
Include <asm/i8259.h> for i8259A_lock used in print_PIC() -- #if-0-ed out
by default.  The 32-bit version gets it right already.

The plan is to enable this code with "apic=debug" eventually.  This will
aid with debugging strange problems without the need to ask people to
apply patches.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:27:38 +02:00
Cyrill Gorcunov 836c129de9 x86: apic_32 - introduce calibrate_APIC_clock
Introduce calibrate_APIC_clock so it could help in further 32/64bit
apic code merging.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: macro@linux-mips.org
Cc: yhlu.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:17:30 +02:00
Cyrill Gorcunov 89b3b1f41b x86: apic_64 - make calibrate_APIC_clock to return error code
Make calibration_result to return error and check calibration_result
to be sufficient inside calibrate_APIC_clock.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: macro@linux-mips.org
Cc: yhlu.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:17:29 +02:00
Yinghai Lu caadbdce24 x86: enable memory tester support on 32-bit
only supports memory below max_low_pfn.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:11:58 +02:00
Yinghai Lu 1f067167a8 x86: seperate memtest from init_64.c
it's separate functionality that deserves its own file.

This also prepares 32-bit memtest support.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 14:10:27 +02:00
Hiroshi Shimamoto fbdb7da91b x86_64: ia32_signal.c: use macro instead of immediate
Make and use macro FIX_EFLAGS, instead of immediate value 0x40DD5 in
ia32_restore_sigcontext().

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 13:54:08 +02:00
Ingo Molnar cdbfc557c4 Merge branch 'linus' into x86/cleanups 2008-07-18 13:53:16 +02:00
Jeremy Fitzhardinge 95c7c23b06 xen: report hypervisor version
Various versions of the hypervisor have differences in what ABIs and
features they support.  Print some details into the boot log to help
with remote debugging.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 13:50:42 +02:00
Ingo Molnar 2fb5e1e101 Merge branch 'linus' into x86/paravirt-spinlocks
Conflicts:

	arch/x86/kernel/Makefile

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 13:41:27 +02:00
Maciej W. Rozycki 593f4a788e x86: APIC: remove apic_write_around(); use alternatives
Use alternatives to select the workaround for the 11AP Pentium erratum
for the affected steppings on the fly rather than build time.  Remove the
X86_GOOD_APIC configuration option and replace all the calls to
apic_write_around() with plain apic_write(), protecting accesses to the
ESR as appropriate due to the 3AP Pentium erratum.  Remove
apic_read_around() and all its invocations altogether as not needed.
Remove apic_write_atomic() and all its implementing backends.  The use of
ASM_OUTPUT2() is not strictly needed for input constraints, but I have
used it for readability's sake.

I had the feeling no one else was brave enough to do it, so I went ahead
and here it is.  Verified by checking the generated assembly and tested
with both a 32-bit and a 64-bit configuration, also with the 11AP
"feature" forced on and verified with gdb on /proc/kcore to work as
expected (as an 11AP machines are quite hard to get hands on these days).
Some script complained about the use of "volatile", but apic_write() needs
it for the same reason and is effectively a replacement for writel(), so I
have disregarded it.

I am not sure what the policy wrt defconfig files is, they are generated
and there is risk of a conflict resulting from an unrelated change, so I
have left changes to them out.  The option will get removed from them at
the next run.

Some testing with machines other than mine will be needed to avoid some
stupid mistake, but despite its volume, the change is not really that
intrusive, so I am fairly confident that because it works for me, it will
everywhere.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 12:51:21 +02:00
Yinghai Lu 29cbeb0e17 x86: use cpu_clear in remove_cpu_from_maps
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 12:20:28 +02:00
Ingo Molnar cd569ef5d6 Merge branch 'linus' into x86/urgent 2008-07-18 12:20:23 +02:00
Ingo Molnar 48ae744434 Merge branch 'linus' into x86/step 2008-07-18 10:14:56 +02:00
Ingo Molnar 6879827f4e x86: remove arch/x86/kernel/smpcommon_32.c
Yinghai Lu noticed that arch/x86/kernel/smpcommon_32.c got
renamed to arch/x86/kernel/smpcommon.c but the old almost-empty
file stayed around. Zap it.

Reported-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 01:21:53 +02:00
Ingo Molnar 64d206d896 x86: rename CONFIG_NONPROMISC_DEVMEM to CONFIG_PROMISC_DEVMEM
Linus observed:

> The real bug is that we shouldn't have "double negatives", and
> certainly not negative config options. Making that "promiscuous
> /dev/mem" option a negated thing as a config option was bad.

right ... lets rename this option. There should never be a negation
in config options.

[ that reminds me of CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER, but that
  is for another commit ;-) ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 00:28:57 +02:00
Ingo Molnar 393d81aa02 Merge branch 'linus' into xen-64bit 2008-07-17 23:57:20 +02:00
H. Peter Anvin 4fdf08b5bf x86: unify and correct the GDT_ENTRY() macro
Merge the GDT_ENTRY() macro between arch/x86/boot/pm.c and
arch/x86/kernel/acpi/sleep.c and put the new one in
<asm-x86/segment.h>.

While we're at it, correct the bitmasks for the limit and flags.  The
new version relies on using ULL constants in order to cause type
promotion rather than explicit casts; this avoids having to include
<linux/types.h> in <asm-x86/segments.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-07-17 11:29:24 -07:00
Linus Torvalds 2b04be7e8a Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: fix asm/e820.h for userspace inclusion
  x86: fix numaq_tsc_disable
  x86: fix kernel_physical_mapping_init() for large x86 systems
2008-07-17 10:38:59 -07:00
Linus Torvalds bdec6cace4 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: do not trace library functions
  ftrace: do not trace scheduler functions
  ftrace: fix lockup with MAXSMP
  ftrace: fix merge buglet
2008-07-17 10:37:10 -07:00
Yinghai Lu 9354094a95 x86: fix numaq_tsc_disable
fix:

 arch/x86/kernel/numaq_32.c: In function ‘numaq_tsc_disable’:
 arch/x86/kernel/numaq_32.c:99: warning: ‘return’ with a value, in function returning void

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-17 19:27:08 +02:00
Jeremy Fitzhardinge 93a0886e23 x86, xen, power: fix up config dependencies on PM
Xen save/restore needs bits of code enabled by PM_SLEEP, and PM_SLEEP
depends on PM.  So make XEN_SAVE_RESTORE depend on PM and PM_SLEEP
depend on XEN_SAVE_RESTORE.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-17 19:25:20 +02:00
Ingo Molnar fab3b58d3b x86 reboot quirks: add Dell Precision WorkStation T5400
as reported in:

  "reboot=bios is mandatory on Dell T5400 server."
  http://bugzilla.kernel.org/show_bug.cgi?id=11108

add a DMI reboot quirk.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
2008-07-17 13:56:15 +02:00
Ingo Molnar 8e9509c827 ftrace: fix merge buglet
-tip testing found a bootup hang here:

  initcall anon_inode_init+0x0/0x130 returned 0 after 0 msecs
  calling  acpi_event_init+0x0/0x57

the bootup should have continued with:

  initcall acpi_event_init+0x0/0x57 returned 0 after 45 msecs

but it hung hard there instead.

bisection led to this commit:

| commit 5806b81ac1
| Merge: d14c8a6... 6712e29...
| Author: Ingo Molnar <mingo@elte.hu>
| Date:   Mon Jul 14 16:11:52 2008 +0200
|     Merge branch 'auto-ftrace-next' into tracing/for-linus

turns out that i made this mistake in the merge:

  ifdef CONFIG_FTRACE
  # Do not profile debug utilities
  CFLAGS_REMOVE_tsc_64.o = -pg
  CFLAGS_REMOVE_tsc_32.o = -pg

those two files got unified meanwhile - so the dont-profile annotation
got lost. The proper rule is:

  CFLAGS_REMOVE_tsc.o = -pg

i guess this could have been caught sooner if the CFLAGS_REMOVE* kbuild
rule aborted the build if it met a target that does not exist anymore?

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-17 13:26:50 +02:00
Linus Torvalds dc7c65db28 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (72 commits)
  Revert "x86/PCI: ACPI based PCI gap calculation"
  PCI: remove unnecessary volatile in PCIe hotplug struct controller
  x86/PCI: ACPI based PCI gap calculation
  PCI: include linux/pm_wakeup.h for device_set_wakeup_capable
  PCI PM: Fix pci_prepare_to_sleep
  x86/PCI: Fix PCI config space for domains > 0
  Fix acpi_pm_device_sleep_wake() by providing a stub for CONFIG_PM_SLEEP=n
  PCI: Simplify PCI device PM code
  PCI PM: Introduce pci_prepare_to_sleep and pci_back_from_sleep
  PCI ACPI: Rework PCI handling of wake-up
  ACPI: Introduce new device wakeup flag 'prepared'
  ACPI: Introduce acpi_device_sleep_wake function
  PCI: rework pci_set_power_state function to call platform first
  PCI: Introduce platform_pci_power_manageable function
  ACPI: Introduce acpi_bus_power_manageable function
  PCI: make pci_name use dev_name
  PCI: handle pci_name() being const
  PCI: add stub for pci_set_consistent_dma_mask()
  PCI: remove unused arch pcibios_update_resource() functions
  PCI: fix pci_setup_device()'s sprinting into a const buffer
  ...

Fixed up conflicts in various files (arch/x86/kernel/setup_64.c,
arch/x86/pci/irq.c, arch/x86/pci/pci.h, drivers/acpi/sleep/main.c,
drivers/pci/pci.c, drivers/pci/pci.h, include/acpi/acpi_bus.h) from x86
and ACPI updates manually.
2008-07-16 17:25:46 -07:00
Jesse Barnes 58b6e55384 Revert "x86/PCI: ACPI based PCI gap calculation"
This reverts commit 809d9a8f93.

This one isn't quite ready for prime time.  It needs more testing and
additional feedback from the ACPI guys.
2008-07-16 16:21:47 -07:00
Zhao Yakui da5e09a1b3 ACPI : Create "idle=nomwait" bootparam
"idle=nomwait" disables the use of the MWAIT
instruction from both C1 (C1_FFH) and deeper (C2C3_FFH)
C-states.

When MWAIT is unavailable, the BIOS and OS generally
negotiate to use the HALT instruction for C1,
and use IO accesses for deeper C-states.

This option is useful for power and performance
comparisons, and also to work around BIOS bugs
where broken MWAIT support is advertised.

http://bugzilla.kernel.org/show_bug.cgi?id=10807
http://bugzilla.kernel.org/show_bug.cgi?id=10914

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2008-07-16 23:27:05 +02:00
Zhao Yakui c1e3b377ad ACPI: Create "idle=halt" bootparam
"idle=halt" limits the idle loop to using
the halt instruction.  No MWAIT, no IO accesses,
no C-states deeper than C1.

If something is broken in the idle code,
"idle=halt" is a less severe workaround
than "idle=poll" which disables all power savings.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2008-07-16 23:27:05 +02:00
Zhao Yakui 5b53496a5a ACPI: Disable the C2C3_FFH access mode HW has no MWAIT support
991528d734
(ACPI: Processor native C-states using MWAIT)
started passing C2C3_FFH to _PDC to tell the BIOS
that Linux supports MWAIT for deep C-states.

However, we should first double check with the hardware
that it actually supports MWAIT before potentially exposing
a BIOS bug of an MWAIT _CST on HW that doesn't support MWAIT.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2008-07-16 23:27:04 +02:00
Bob Moore 19d0cfe9dd ACPICA: Update DMAR and SRAT table definitions
Synchronized tables with current specifications.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2008-07-16 23:27:04 +02:00
Roland McGrath 380fdd7585 x86 ptrace: user-sets-TF nits
This closes some arcane holes in single-step handling that can arise
only when user programs set TF directly (via popf or sigreturn) and
then use vDSO (syscall/sysenter) system call entry.  In those entry
paths, the clear_TF_reenable case hits and we must check TIF_SINGLESTEP
to be sure our bookkeeping stays correct wrt the user's view of TF.

Signed-off-by: Roland McGrath <roland@redhat.com>
2008-07-16 12:15:17 -07:00
Roland McGrath d4d6715016 x86 ptrace: unify syscall tracing
This unifies and cleans up the syscall tracing code on i386 and x86_64.

Using a single function for entry and exit tracing on 32-bit made the
do_syscall_trace() into some terrible spaghetti.  The logic is clear and
simple using separate syscall_trace_enter() and syscall_trace_leave()
functions as on 64-bit.

The unification adds PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP support
on x86_64, for 32-bit ptrace() callers and for 64-bit ptrace() callers
tracing either 32-bit or 64-bit tasks.  It behaves just like 32-bit.

Changing syscall_trace_enter() to return the syscall number shortens
all the assembly paths, while adding the SYSEMU feature in a simple way.

Signed-off-by: Roland McGrath <roland@redhat.com>
2008-07-16 12:15:17 -07:00
Roland McGrath 64f0973319 x86 ptrace: unify TIF_SINGLESTEP
This unifies the treatment of TIF_SINGLESTEP on i386 and x86_64.
The bit is now excluded from _TIF_WORK_MASK on i386 as it has been
on x86_64.  This means the do_notify_resume() path using it is never
used, so TIF_SINGLESTEP is not cleared on returning to user mode.

Both now leave TIF_SINGLESTEP set when returning to user, so that
it's already set on an int $0x80 system call entry.  This removes
the need for testing TF on the system_call path.  Doing it this way
fixes the regression for PTRACE_SINGLESTEP into a sigreturn syscall,
introduced by commit 1e2e99f0e4.

The clear_TF_reenable case that sets TIF_SINGLESTEP can only happen
on a non-exception kernel entry, i.e. sysenter/syscall instruction.
That will always get to the syscall exit tracing path.

Signed-off-by: Roland McGrath <roland@redhat.com>
2008-07-16 12:15:16 -07:00
Roland McGrath 6718d0d6da x86 ptrace: block-step fix
The enable_single_step() logic bails out early if TF is already set.
That skips some of the bookkeeping that keeps things straight.
This makes PTRACE_SINGLEBLOCK break the behavior of a user task
that was already setting TF itself in user mode.

Fix the bookkeeping to notice the old TF setting as it should.

Test case at: http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/step-jump-cont-strict.c?cvsroot=systemtap

Signed-off-by: Roland McGrath <roland@redhat.com>
2008-07-16 12:15:16 -07:00
Jack Steiner e22146e610 x86: fix kernel_physical_mapping_init() for large x86 systems
Fix bug in kernel_physical_mapping_init() that causes kernel
page table to be built incorrectly for systems with greater
than 512GB of memory.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 18:27:36 +02:00
Ingo Molnar 77e442461c Merge branch 'linus' into x86/kprobes 2008-07-16 13:11:29 +02:00
Ingo Molnar 34646bca47 x86, paravirt-spinlocks: fix boot hang
the paravirt-spinlock patches caused a boot hang with this config:

 http://redhat.com/~mingo/misc/config-Wed_Jul__9_14_47_04_CEST_2008.bad

i have bisected it down to:

|  commit e17b58c2e85bc2ad2afc07fb8d898017c2b75ed1
|  Author: Jeremy Fitzhardinge <jeremy@goop.org>
|  Date:   Mon Jul 7 12:07:53 2008 -0700
|
|      xen: implement Xen-specific spinlocks

i.e. applying that patch alone causes the hang. The hang happens in the
ftrace self-test:

  initcall utsname_sysctl_init+0x0/0x19 returned 0 after 0 msecs
  calling  init_sched_switch_trace+0x0/0x4c
  Testing tracer sched_switch: PASSED
  initcall init_sched_switch_trace+0x0/0x4c returned 0 after 167 msecs
  calling  init_function_trace+0x0/0x12
  Testing tracer ftrace:
  [hard hang]

it should have continued like this:

  Testing tracer ftrace: PASSED
  initcall init_function_trace+0x0/0x12 returned 0 after 198 msecs
  calling  init_irqsoff_tracer+0x0/0x14
  Testing tracer irqsoff: PASSED
  initcall init_irqsoff_tracer+0x0/0x14 returned 0 after 3 msecs
  calling  init_mmio_trace+0x0/0x12
  initcall init_mmio_trace+0x0/0x12 returned 0 after 0 msecs

the problem is that such lowlevel primitives as spinlocks should never
be built with -pg (which ftrace does). Marking paravirt.o as non-pg and
marking all spinlock ops as always-inline solve the hang.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00
Ingo Molnar 9af98578d6 x86: paravirt spinlocks, modular build fix
fix:

  MODPOST 408 modules
ERROR: "pv_lock_ops" [net/dccp/dccp.ko] undefined!
ERROR: "pv_lock_ops" [fs/jbd2/jbd2.ko] undefined!
ERROR: "pv_lock_ops" [drivers/media/common/saa7146_vv.ko] undefined!

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00
Ingo Molnar 4bb689eee1 x86: paravirt spinlocks, !CONFIG_SMP build fixes
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00
Jeremy Fitzhardinge 2d9e1e2f58 xen: implement Xen-specific spinlocks
The standard ticket spinlocks are very expensive in a virtual
environment, because their performance depends on Xen's scheduler
giving vcpus time in the order that they're supposed to take the
spinlock.

This implements a Xen-specific spinlock, which should be much more
efficient.

The fast-path is essentially the old Linux-x86 locks, using a single
lock byte.  The locker decrements the byte; if the result is 0, then
they have the lock.  If the lock is negative, then locker must spin
until the lock is positive again.

When there's contention, the locker spin for 2^16[*] iterations waiting
to get the lock.  If it fails to get the lock in that time, it adds
itself to the contention count in the lock and blocks on a per-cpu
event channel.

When unlocking the spinlock, the locker looks to see if there's anyone
blocked waiting for the lock by checking for a non-zero waiter count.
If there's a waiter, it traverses the per-cpu "lock_spinners"
variable, which contains which lock each CPU is waiting on.  It picks
one CPU waiting on the lock and sends it an event to wake it up.

This allows efficient fast-path spinlock operation, while allowing
spinning vcpus to give up their processor time while waiting for a
contended lock.

[*] 2^16 iterations is threshold at which 98% locks have been taken
according to Thomas Friebel's Xen Summit talk "Preventing Guests from
Spinning Around".  Therefore, we'd expect the lock and unlock slow
paths will only be entered 2% of the time.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00
Jeremy Fitzhardinge 56397f8dad xen: use lock-byte spinlock implementation
Switch to using the lock-byte spinlock implementation, to avoid the
worst of the performance hit from ticket locks.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00
Jeremy Fitzhardinge 8efcbab674 paravirt: introduce a "lock-byte" spinlock implementation
Implement a version of the old spinlock algorithm, in which everyone
spins waiting for a lock byte.  In order to be compatible with the
ticket-lock's use of a zero initializer, this uses the convention of
'0' for unlocked and '1' for locked.

This algorithm is much better than ticket locks in a virtual
envionment, because it doesn't interact badly with the vcpu scheduler.
If there are multiple vcpus spinning on a lock and the lock is
released, the next vcpu to be scheduled will take the lock, rather
than cycling around until the next ticketed vcpu gets it.

To use this, you must call paravirt_use_bytelocks() very early, before
any spinlocks have been taken.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00