Commit Graph

2391 Commits

Author SHA1 Message Date
Marcelo Tosatti
42897d866b KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initialization
TSC initialization will soon make use of online_vcpus.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:14 -02:00
Marcelo Tosatti
d828199e84 KVM: x86: implement PVCLOCK_TSC_STABLE_BIT pvclock flag
KVM added a global variable to guarantee monotonicity in the guest.
One of the reasons for that is that the time between

	1. ktime_get_ts(&timespec);
	2. rdtscll(tsc);

Is variable. That is, given a host with stable TSC, suppose that
two VCPUs read the same time via ktime_get_ts() above.

The time required to execute 2. is not the same on those two instances
executing in different VCPUS (cache misses, interrupts...).

If the TSC value that is used by the host to interpolate when
calculating the monotonic time is the same value used to calculate
the tsc_timestamp value stored in the pvclock data structure, and
a single <system_timestamp, tsc_timestamp> tuple is visible to all
vcpus simultaneously, this problem disappears. See comment on top
of pvclock_update_vm_gtod_copy for details.

Monotonicity is then guaranteed by synchronicity of the host TSCs
and guest TSCs.

Set TSC stable pvclock flag in that case, allowing the guest to read
clock from userspace.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:13 -02:00
Marcelo Tosatti
16e8d74d2d KVM: x86: notifier for clocksource changes
Register a notifier for clocksource change event. In case
the host switches to clock other than TSC, disable master
clock usage.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:12 -02:00
Marcelo Tosatti
886b470cb1 KVM: x86: pass host_tsc to read_l1_tsc
Allow the caller to pass host tsc value to kvm_x86_ops->read_l1_tsc().

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:11 -02:00
Marcelo Tosatti
78c0337a38 KVM: x86: retain pvclock guest stopped bit in guest memory
Otherwise its possible for an unrelated KVM_REQ_UPDATE_CLOCK (such as due to CPU
migration) to clear the bit.

Noticed by Paolo Bonzini.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:05 -02:00
Guo Chao
807f12e57c KVM: remove unnecessary return value check
No need to check return value before breaking switch.

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:29 -02:00
Guo Chao
951179ce86 KVM: x86: fix return value of kvm_vm_ioctl_set_tss_addr()
Return value of this function will be that of ioctl().

#include <stdio.h>
#include <linux/kvm.h>

int main () {
	int fd;
	fd = open ("/dev/kvm", 0);
	fd = ioctl (fd, KVM_CREATE_VM, 0);
	ioctl (fd, KVM_SET_TSS_ADDR, 0xfffff000);
	perror ("");
	return 0;
}

Output is "Operation not permitted". That's not what
we want.

Return -EINVAL in this case.

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:29 -02:00
Guo Chao
18595411a7 KVM: do not kfree error pointer
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and
kvm_arch_vcpu_ioctl().

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:28 -02:00
Xiao Guangrong
81c52c56e2 KVM: do not treat noslot pfn as a error pfn
This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn

After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
  when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
  is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-29 20:31:04 -02:00
Marcelo Tosatti
19bf7f8ac3 Merge remote-tracking branch 'master' into queue
Merge reason: development work has dependency on kvm patches merged
upstream.

Conflicts:
	arch/powerpc/include/asm/Kbuild
	arch/powerpc/include/asm/kvm_para.h

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-29 19:15:32 -02:00
Christoffer Dall
8ca40a70a7 KVM: Take kvm instead of vcpu to mmu_notifier_retry
The mmu_notifier_retry is not specific to any vcpu (and never will be)
so only take struct kvm as a parameter.

The motivation is the ARM mmu code that needs to call this from
somewhere where we long let go of the vcpu pointer.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-23 13:35:43 +02:00
Gleb Natapov
7f46ddbd48 KVM: apic: fix LDR calculation in x2apic mode
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Chegu Vinod  <chegu_vinod@hp.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-22 18:03:27 +02:00
Xiao Guangrong
f3ac1a4b66 KVM: MMU: fix release noslot pfn
We can not directly call kvm_release_pfn_clean to release the pfn
since we can meet noslot pfn which is used to cache mmio info into
spte

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-22 18:03:25 +02:00
Borislav Petkov
1f5b77f51a KVM: SVM: Cleanup error statements
Use __func__ instead of the function name in svm_hardware_enable since
those things tend to get out of sync. This also slims down printk line
length in conjunction with using pr_err.

No functionality change.

Cc: Joerg Roedel <joro@8bytes.org>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-22 16:04:59 +02:00
Xiao Guangrong
bf4ca23ef5 KVM: VMX: report internal error for MMIO #PF due to delivery event
The #PF with PFEC.RSV = 1 indicates that the guest is accessing MMIO, we
can not fix it if it is caused by delivery event. Reporting internal error
for this case

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-18 16:30:32 +02:00
Xiao Guangrong
b9bf6882c1 KVM: VMX: report internal error for the unhandleable event
VM exits during Event Delivery is really unexpected if it is not caused
by Exceptions/EPT-VIOLATION/TASK_SWITCH, we'd better to report an internal
and freeze the guest, the VMM has the chance to check the guest

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-18 16:30:29 +02:00
Gleb Natapov
471842ec49 KVM: do not de-cache cr4 bits needlessly
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-18 14:49:28 +02:00
Xiao Guangrong
bd6360cc0a KVM: MMU: introduce FNAME(prefetch_gpte)
The only difference between FNAME(update_pte) and FNAME(pte_prefetch)
is that the former is allowed to prefetch gfn from dirty logged slot,
so introduce a common function to prefetch spte

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-17 16:39:19 +02:00
Xiao Guangrong
a052b42b0e KVM: MMU: move prefetch_invalid_gpte out of pagaing_tmp.h
The function does not depend on guest mmu mode, move it out from
paging_tmpl.h

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-17 16:39:18 +02:00
Xiao Guangrong
d4878f24e3 KVM: MMU: cleanup FNAME(page_fault)
Let it return emulate state instead of spte like __direct_map

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-17 16:39:16 +02:00
Xiao Guangrong
bd660776da KVM: MMU: remove mmu_is_invalid
Remove mmu_is_invalid and use is_invalid_pfn instead

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-17 16:39:15 +02:00
Jan Kiszka
b6785def83 KVM: x86: Make emulator_fix_hypercall static
No users outside of kvm/x86.c.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-08 14:03:16 -03:00
Jan Kiszka
8b6e4547e0 KVM: x86: Convert kvm_arch_vcpu_reset into private kvm_vcpu_reset
There are no external callers of this function as there is no concept of
resetting a vcpu from generic code.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-08 14:02:35 -03:00
Linus Torvalds
ecefbd94b8 KVM updates for the 3.7 merge window
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Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Avi Kivity:
 "Highlights of the changes for this release include support for vfio
  level triggered interrupts, improved big real mode support on older
  Intels, a streamlines guest page table walker, guest APIC speedups,
  PIO optimizations, better overcommit handling, and read-only memory."

* tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (138 commits)
  KVM: s390: Fix vcpu_load handling in interrupt code
  KVM: x86: Fix guest debug across vcpu INIT reset
  KVM: Add resampling irqfds for level triggered interrupts
  KVM: optimize apic interrupt delivery
  KVM: MMU: Eliminate pointless temporary 'ac'
  KVM: MMU: Avoid access/dirty update loop if all is well
  KVM: MMU: Eliminate eperm temporary
  KVM: MMU: Optimize is_last_gpte()
  KVM: MMU: Simplify walk_addr_generic() loop
  KVM: MMU: Optimize pte permission checks
  KVM: MMU: Update accessed and dirty bits after guest pagetable walk
  KVM: MMU: Move gpte_access() out of paging_tmpl.h
  KVM: MMU: Optimize gpte_access() slightly
  KVM: MMU: Push clean gpte write protection out of gpte_access()
  KVM: clarify kvmclock documentation
  KVM: make processes waiting on vcpu mutex killable
  KVM: SVM: Make use of asm.h
  KVM: VMX: Make use of asm.h
  KVM: VMX: Make lto-friendly
  KVM: x86: lapic: Clean up find_highest_vector() and count_vectors()
  ...

Conflicts:
	arch/s390/include/asm/processor.h
	arch/x86/kvm/i8259.c
2012-10-04 09:30:33 -07:00
Linus Torvalds
ac07f5c3cb Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/fpu update from Ingo Molnar:
 "The biggest change is the addition of the non-lazy (eager) FPU saving
  support model and enabling it on CPUs with optimized xsaveopt/xrstor
  FPU state saving instructions.

  There are also various Sparse fixes"

Fix up trivial add-add conflict in arch/x86/kernel/traps.c

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, kvm: fix kvm's usage of kernel_fpu_begin/end()
  x86, fpu: remove cpu_has_xmm check in the fx_finit()
  x86, fpu: make eagerfpu= boot param tri-state
  x86, fpu: enable eagerfpu by default for xsaveopt
  x86, fpu: decouple non-lazy/eager fpu restore from xsave
  x86, fpu: use non-lazy fpu restore for processors supporting xsave
  lguest, x86: handle guest TS bit for lazy/non-lazy fpu host models
  x86, fpu: always use kernel_fpu_begin/end() for in-kernel FPU usage
  x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
  x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig()
  x86, fpu: drop_fpu() before restoring new state from sigframe
  x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels
  x86, fpu: Consolidate inline asm routines for saving/restoring fpu state
  x86, signal: Cleanup ifdefs and is_ia32, is_x32
2012-10-01 11:10:52 -07:00
Linus Torvalds
08815bc267 Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/cleanups from Ingo Molnar:
 "Smaller cleanups"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch/x86: Remove unecessary semicolons
  x86, boot: Remove obsolete and unused constant RAMDISK
2012-10-01 10:47:45 -07:00
Linus Torvalds
7e92daaefa Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf update from Ingo Molnar:
 "Lots of changes in this cycle as well, with hundreds of commits from
  over 30 contributors.  Most of the activity was on the tooling side.

  Higher level changes:

   - New 'perf kvm' analysis tool, from Xiao Guangrong.

   - New 'perf trace' system-wide tracing tool

   - uprobes fixes + cleanups from Oleg Nesterov.

   - Lots of patches to make perf build on Android out of box, from
     Irina Tirdea

   - Extend ftrace function tracing utility to be more dynamic for its
     users.  It allows for data passing to the callback functions, as
     well as reading regs as if a breakpoint were to trigger at function
     entry.

     The main goal of this patch series was to allow kprobes to use
     ftrace as an optimized probe point when a probe is placed on an
     ftrace nop.  With lots of help from Masami Hiramatsu, and going
     through lots of iterations, we finally came up with a good
     solution.

   - Add cpumask for uncore pmu, use it in 'stat', from Yan, Zheng.

   - Various tracing updates from Steve Rostedt

   - Clean up and improve 'perf sched' performance by elliminating lots
     of needless calls to libtraceevent.

   - Event group parsing support, from Jiri Olsa

   - UI/gtk refactorings and improvements from Namhyung Kim

   - Add support for non-tracepoint events in perf script python, from
     Feng Tang

   - Add --symbols to 'script', similar to the one in 'report', from
     Feng Tang.

  Infrastructure enhancements and fixes:

   - Convert the trace builtins to use the growing evsel/evlist
     tracepoint infrastructure, removing several open coded constructs
     like switch like series of strcmp to dispatch events, etc.
     Basically what had already been showcased in 'perf sched'.

   - Add evsel constructor for tracepoints, that uses libtraceevent just
     to parse the /format events file, use it in a new 'perf test' to
     make sure the libtraceevent format parsing regressions can be more
     readily caught.

   - Some strange errors were happening in some builds, but not on the
     next, reported by several people, problem was some parser related
     files, generated during the build, didn't had proper make deps, fix
     from Eric Sandeen.

   - Introduce struct and cache information about the environment where
     a perf.data file was captured, from Namhyung Kim.

   - Fix handling of unresolved samples when --symbols is used in
     'report', from Feng Tang.

   - Add union member access support to 'probe', from Hyeoncheol Lee.

   - Fixups to die() removal, from Namhyung Kim.

   - Render fixes for the TUI, from Namhyung Kim.

   - Don't enable annotation in non symbolic view, from Namhyung Kim.

   - Fix pipe mode in 'report', from Namhyung Kim.

   - Move related stats code from stat to util/, will be used by the
     'stat' kvm tool, from Xiao Guangrong.

   - Remove die()/exit() calls from several tools.

   - Resolve vdso callchains, from Jiri Olsa

   - Don't pass const char pointers to basename, so that we can
     unconditionally use libgen.h and thus avoid ifdef BIONIC lines,
     from David Ahern

   - Refactor hist formatting so that it can be reused with the GTK
     browser, From Namhyung Kim

   - Fix build for another rbtree.c change, from Adrian Hunter.

   - Make 'perf diff' command work with evsel hists, from Jiri Olsa.

   - Use the only field_sep var that is set up: symbol_conf.field_sep,
     fix from Jiri Olsa.

   - .gitignore compiled python binaries, from Namhyung Kim.

   - Get rid of die() in more libtraceevent places, from Namhyung Kim.

   - Rename libtraceevent 'private' struct member to 'priv' so that it
     works in C++, from Steven Rostedt

   - Remove lots of exit()/die() calls from tools so that the main perf
     exit routine can take place, from David Ahern

   - Fix x86 build on x86-64, from David Ahern.

   - {int,str,rb}list fixes from Suzuki K Poulose

   - perf.data header fixes from Namhyung Kim

   - Allow user to indicate objdump path, needed in cross environments,
     from Maciek Borzecki

   - Fix hardware cache event name generation, fix from Jiri Olsa

   - Add round trip test for sw, hw and cache event names, catching the
     problem Jiri fixed, after Jiri's patch, the test passes
     successfully.

   - Clean target should do clean for lib/traceevent too, fix from David
     Ahern

   - Check the right variable for allocation failure, fix from Namhyung
     Kim

   - Set up evsel->tp_format regardless of evsel->name being set
     already, fix from Namhyung Kim

   - Oprofile fixes from Robert Richter.

   - Remove perf_event_attr needless version inflation, from Jiri Olsa

   - Introduce libtraceevent strerror like error reporting facility,
     from Namhyung Kim

   - Add pmu mappings to perf.data header and use event names from cmd
     line, from Robert Richter

   - Fix include order for bison/flex-generated C files, from Ben
     Hutchings

   - Build fixes and documentation corrections from David Ahern

   - Assorted cleanups from Robert Richter

   - Let O= makes handle relative paths, from Steven Rostedt

   - perf script python fixes, from Feng Tang.

   - Initial bash completion support, from Frederic Weisbecker

   - Allow building without libelf, from Namhyung Kim.

   - Support DWARF CFI based unwind to have callchains when %bp based
     unwinding is not possible, from Jiri Olsa.

   - Symbol resolution fixes, while fixing support PPC64 files with an
     .opt ELF section was the end goal, several fixes for code that
     handles all architectures and cleanups are included, from Cody
     Schafer.

   - Assorted fixes for Documentation and build in 32 bit, from Robert
     Richter

   - Cache the libtraceevent event_format associated to each evsel
     early, so that we avoid relookups, i.e.  calling pevent_find_event
     repeatedly when processing tracepoint events.

     [ This is to reduce the surface contact with libtraceevents and
        make clear what is that the perf tools needs from that lib: so
        far parsing the common and per event fields.  ]

   - Don't stop the build if the audit libraries are not installed, fix
     from Namhyung Kim.

   - Fix bfd.h/libbfd detection with recent binutils, from Markus
     Trippelsdorf.

   - Improve warning message when libunwind devel packages not present,
     from Jiri Olsa"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (282 commits)
  perf trace: Add aliases for some syscalls
  perf probe: Print an enum type variable in "enum variable-name" format when showing accessible variables
  perf tools: Check libaudit availability for perf-trace builtin
  perf hists: Add missing period_* fields when collapsing a hist entry
  perf trace: New tool
  perf evsel: Export the event_format constructor
  perf evsel: Introduce rawptr() method
  perf tools: Use perf_evsel__newtp in the event parser
  perf evsel: The tracepoint constructor should store sys:name
  perf evlist: Introduce set_filter() method
  perf evlist: Renane set_filters method to apply_filters
  perf test: Add test to check we correctly parse and match syscall open parms
  perf evsel: Handle endianity in intval method
  perf evsel: Know if byte swap is needed
  perf tools: Allow handling a NULL cpu_map as meaning "all cpus"
  perf evsel: Improve tracepoint constructor setup
  tools lib traceevent: Fix error path on pevent_parse_event
  perf test: Fix build failure
  trace: Move trace event enable from fs_initcall to core_initcall
  tracing: Add an option for disabling markers
  ...
2012-10-01 10:28:49 -07:00
Jan Kiszka
c863901075 KVM: x86: Fix guest debug across vcpu INIT reset
If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.

Fix this by saving the dr7 used for guest debugging and calculating the
effective register value as well as switch_db_regs on any potential
change. This will change to focus of the set_guest_debug vendor op to
update_dp_bp_intercept.

Found while trying to stop on start_secondary.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-23 15:00:07 +02:00
Alex Williamson
7a84428af7 KVM: Add resampling irqfds for level triggered interrupts
To emulate level triggered interrupts, add a resample option to
KVM_IRQFD.  When specified, a new resamplefd is provided that notifies
the user when the irqchip has been resampled by the VM.  This may, for
instance, indicate an EOI.  Also in this mode, posting of an interrupt
through an irqfd only asserts the interrupt.  On resampling, the
interrupt is automatically de-asserted prior to user notification.
This enables level triggered interrupts to be posted and re-enabled
from vfio with no userspace intervention.

All resampling irqfds can make use of a single irq source ID, so we
reserve a new one for this interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-23 13:50:15 +02:00
Suresh Siddha
b1a74bf821 x86, kvm: fix kvm's usage of kernel_fpu_begin/end()
Preemption is disabled between kernel_fpu_begin/end() and as such
it is not a good idea to use these routines in kvm_load/put_guest_fpu()
which can be very far apart.

kvm_load/put_guest_fpu() routines are already called with
preemption disabled and KVM already uses the preempt notifier to save
the guest fpu state using kvm_put_guest_fpu().

So introduce __kernel_fpu_begin/end() routines which don't touch
preemption and use them instead of kernel_fpu_begin/end()
for KVM's use model of saving/restoring guest FPU state.

Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit
state in the case of VMX. For eagerFPU case, host cr0.TS is always clear.
So no need to worry about it. For the traditional lazyFPU restore case,
change the cr0.TS bit for the host state during vm-exit to be always clear
and cr0.TS bit is set in the __vmx_load_host_state() when the FPU
(guest FPU or the host task's FPU) state is not active. This ensures
that the host/guest FPU state is properly saved, restored
during context-switch and with interrupts (using irq_fpu_usable()) not
stomping on the active FPU state.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-09-21 16:59:04 -07:00
Xiao Guangrong
26bf264e87 KVM: x86: Export svm/vmx exit code and vector code to userspace
Exporting KVM exit information to userspace to be consumed by perf.

Signed-off-by: Dong Hao <haodong@linux.vnet.ibm.com>
[ Dong Hao <haodong@linux.vnet.ibm.com>: rebase it on acme's git tree ]
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1347870675-31495-2-git-send-email-haodong@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-09-21 12:48:09 -03:00
Gleb Natapov
1e08ec4a13 KVM: optimize apic interrupt delivery
Most interrupt are delivered to only one vcpu. Use pre-build tables to
find interrupt destination instead of looping through all vcpus. In case
of logical mode loop only through vcpus in a logical cluster irq is sent
to.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 15:05:26 +03:00
Avi Kivity
c5421519f3 KVM: MMU: Eliminate pointless temporary 'ac'
'ac' essentially reconstructs the 'access' variable we already
have, except for the PFERR_PRESENT_MASK and PFERR_RSVD_MASK.  As
these are not used by callees, just use 'access' directly.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:10 +03:00
Avi Kivity
b514c30f77 KVM: MMU: Avoid access/dirty update loop if all is well
Keep track of accessed/dirty bits; if they are all set, do not
enter the accessed/dirty update loop.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:09 +03:00
Avi Kivity
71331a1da1 KVM: MMU: Eliminate eperm temporary
'eperm' is no longer used in the walker loop, so we can eliminate it.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:09 +03:00
Avi Kivity
6fd01b711b KVM: MMU: Optimize is_last_gpte()
Instead of branchy code depending on level, gpte.ps, and mmu configuration,
prepare everything in a bitmap during mode changes and look it up during
runtime.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:09 +03:00
Avi Kivity
13d22b6aeb KVM: MMU: Simplify walk_addr_generic() loop
The page table walk is coded as an infinite loop, with a special
case on the last pte.

Code it as an ordinary loop with a termination condition on the last
pte (large page or walk length exhausted), and put the last pte handling
code after the loop where it belongs.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:08 +03:00
Avi Kivity
97d64b7881 KVM: MMU: Optimize pte permission checks
walk_addr_generic() permission checks are a maze of branchy code, which is
performed four times per lookup.  It depends on the type of access, efer.nxe,
cr0.wp, cr4.smep, and in the near future, cr4.smap.

Optimize this away by precalculating all variants and storing them in a
bitmap.  The bitmap is recalculated when rarely-changing variables change
(cr0, cr4) and is indexed by the often-changing variables (page fault error
code, pte access permissions).

The permission check is moved to the end of the loop, otherwise an SMEP
fault could be reported as a false positive, when PDE.U=1 but PTE.U=0.
Noted by Xiao Guangrong.

The result is short, branch-free code.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:08 +03:00
Avi Kivity
8cbc70696f KVM: MMU: Update accessed and dirty bits after guest pagetable walk
While unspecified, the behaviour of Intel processors is to first
perform the page table walk, then, if the walk was successful, to
atomically update the accessed and dirty bits of walked paging elements.

While we are not required to follow this exactly, doing so will allow us
to perform the access permissions check after the walk is complete, rather
than after each walk step.

(the tricky case is SMEP: a zero in any pte's U bit makes the referenced
page a supervisor page, so we can't fault on a one bit during the walk
itself).

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:08 +03:00
Avi Kivity
3d34adec70 KVM: MMU: Move gpte_access() out of paging_tmpl.h
We no longer rely on paging_tmpl.h defines; so we can move the function
to mmu.c.

Rely on zero extension to 64 bits to get the correct nx behaviour.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:08 +03:00
Avi Kivity
edc2ae84eb KVM: MMU: Optimize gpte_access() slightly
If nx is disabled, then is gpte[63] is set we will hit a reserved
bit set fault before checking permissions; so we can ignore the
setting of efer.nxe.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:07 +03:00
Avi Kivity
8ea667f259 KVM: MMU: Push clean gpte write protection out of gpte_access()
gpte_access() computes the access permissions of a guest pte and also
write-protects clean gptes.  This is wrong when we are servicing a
write fault (since we'll be setting the dirty bit momentarily) but
correct when instantiating a speculative spte, or when servicing a
read fault (since we'll want to trap a following write in order to
set the dirty bit).

It doesn't seem to hurt in practice, but in order to make the code
readable, push the write protection out of gpte_access() and into
a new protect_clean_gpte() which is called explicitly when needed.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 13:00:07 +03:00
Peter Senna Tschudin
4b8073e467 arch/x86: Remove unecessary semicolons
Found by http://coccinelle.lip6.fr/

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: avi@redhat.com
Cc: mtosatti@redhat.com
Cc: a.p.zijlstra@chello.nl
Cc: rusty@rustcorp.com.au
Cc: masami.hiramatsu.pt@hitachi.com
Cc: suresh.b.siddha@intel.com
Cc: joerg.roedel@amd.com
Cc: agordeev@redhat.com
Cc: yinghai@kernel.org
Cc: bhelgaas@google.com
Cc: liuj97@gmail.com
Link: http://lkml.kernel.org/r/1347986174-30287-7-git-send-email-peter.senna@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-19 17:32:48 +02:00
Suresh Siddha
9c1c3fac53 x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
kvm's guest fpu save/restore should be wrapped around
kernel_fpu_begin/end(). This will avoid for example taking a DNA
in kvm_load_guest_fpu() when it tries to load the fpu immediately
after doing unlazy_fpu() on the host side.

More importantly this will prevent the host process fpu from being
corrupted.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-09-18 15:52:07 -07:00
Michael S. Tsirkin
9fc77441e5 KVM: make processes waiting on vcpu mutex killable
vcpu mutex can be held for unlimited time so
taking it with mutex_lock on an ioctl is wrong:
one process could be passed a vcpu fd and
call this ioctl on the vcpu used by another process,
it will then be unkillable until the owner exits.

Call mutex_lock_killable instead and return status.
Note: mutex_lock_interruptible would be even nicer,
but I am not sure all users are prepared to handle EINTR
from these ioctls. They might misinterpret it as an error.

Cleanup paths expect a vcpu that can't be used by
any userspace so this will always succeed - catch bugs
by calling BUG_ON.

Catch callers that don't check return state by adding
__must_check.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 13:46:32 -03:00
Avi Kivity
7454766f7b KVM: SVM: Make use of asm.h
Use macros for bitness-insensitive register names, instead of
rolling our own.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 10:38:05 -03:00
Avi Kivity
b188c81f2e KVM: VMX: Make use of asm.h
Use macros for bitness-insensitive register names, instead of
rolling our own.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 10:38:04 -03:00
Avi Kivity
83287ea420 KVM: VMX: Make lto-friendly
LTO (link-time optimization) doesn't like local labels to be referred to
from a different function, since the two functions may be built in separate
compilation units.  Use an external variable instead.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 10:38:03 -03:00
Takuya Yoshikawa
ecba9a52ac KVM: x86: lapic: Clean up find_highest_vector() and count_vectors()
find_highest_vector() and count_vectors():
 - Instead of using magic values, define and use proper macros.

find_highest_vector():
 - Remove likely() which is there only for historical reasons and not
   doing correct branch predictions anymore.  Using such heuristics
   to optimize this function is not worth it now.  Let CPUs predict
   things instead.

 - Stop checking word[0] separately.  This was only needed for doing
   likely() optimization.

 - Use for loop, not while, to iterate over the register array to make
   the code clearer.

Note that we actually confirmed that the likely() did wrong predictions
by inserting debug code.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-12 13:38:23 -03:00
Xiao Guangrong
4484141a94 KVM: fix error paths for failed gfn_to_page() calls
This bug was triggered:
[ 4220.198458] BUG: unable to handle kernel paging request at fffffffffffffffe
[ 4220.203907] IP: [<ffffffff81104d85>] put_page+0xf/0x34
......
[ 4220.237326] Call Trace:
[ 4220.237361]  [<ffffffffa03830d0>] kvm_arch_destroy_vm+0xf9/0x101 [kvm]
[ 4220.237382]  [<ffffffffa036fe53>] kvm_put_kvm+0xcc/0x127 [kvm]
[ 4220.237401]  [<ffffffffa03702bc>] kvm_vcpu_release+0x18/0x1c [kvm]
[ 4220.237407]  [<ffffffff81145425>] __fput+0x111/0x1ed
[ 4220.237411]  [<ffffffff8114550f>] ____fput+0xe/0x10
[ 4220.237418]  [<ffffffff81063511>] task_work_run+0x5d/0x88
[ 4220.237424]  [<ffffffff8104c3f7>] do_exit+0x2bf/0x7ca

The test case:

	printf(fmt, ##args);		\
	exit(-1);} while (0)

static int create_vm(void)
{
	int sys_fd, vm_fd;

	sys_fd = open("/dev/kvm", O_RDWR);
	if (sys_fd < 0)
		die("open /dev/kvm fail.\n");

	vm_fd = ioctl(sys_fd, KVM_CREATE_VM, 0);
	if (vm_fd < 0)
		die("KVM_CREATE_VM fail.\n");

	return vm_fd;
}

static int create_vcpu(int vm_fd)
{
	int vcpu_fd;

	vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);
	if (vcpu_fd < 0)
		die("KVM_CREATE_VCPU ioctl.\n");
	printf("Create vcpu.\n");
	return vcpu_fd;
}

static void *vcpu_thread(void *arg)
{
	int vm_fd = (int)(long)arg;

	create_vcpu(vm_fd);
	return NULL;
}

int main(int argc, char *argv[])
{
	pthread_t thread;
	int vm_fd;

	(void)argc;
	(void)argv;

	vm_fd = create_vm();
	pthread_create(&thread, NULL, vcpu_thread, (void *)(long)vm_fd);
	printf("Exit.\n");
	return 0;
}

It caused by release kvm->arch.ept_identity_map_addr which is the
error page.

The parent thread can send KILL signal to the vcpu thread when it was
exiting which stops faulting pages and potentially allocating memory.
So gfn_to_pfn/gfn_to_page may fail at this time

Fixed by checking the page before it is used

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-10 11:34:11 +03:00