Commit Graph

11996 Commits

Author SHA1 Message Date
Peter Zijlstra
3e4d3af501 mm: stack based kmap_atomic()
Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00
Bjorn Helgaas
1af3c2e45e x86: allocate space within a region top-down
Request that allocate_resource() use available space from high addresses
first, rather than the default of using low addresses first.

The most common place this makes a difference is when we move or assign
new PCI device resources.  Low addresses are generally scarce, so it's
better to use high addresses when possible.  This follows Windows practice
for PCI allocation.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228#c42
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:45 -07:00
Bjorn Helgaas
419afdf53c x86: update iomem_resource end based on CPU physical address capabilities
The iomem_resource map reflects the available physical address space.
We statically initialize the end to -1, i.e., 0xffffffff_ffffffff, but
of course we can only use as much as the CPU can address.

This patch updates the end based on the CPU capabilities, so we don't
mistakenly allocate space that isn't usable, as we're likely to do when
allocating from the top-down.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:44 -07:00
Bjorn Helgaas
dc9887dc02 x86/PCI: allocate space from the end of a region, not the beginning
Allocate from the end of a region, not the beginning.

For example, if we need to allocate 0x800 bytes for a device on bus
0000:00 given these resources:

    [mem 0xbff00000-0xdfffffff] PCI Bus 0000:00
      [mem 0xc0000000-0xdfffffff] PCI Bus 0000:02

the available space at [mem 0xbff00000-0xbfffffff] is passed to the
alignment callback (pcibios_align_resource()).  Prior to this patch, we
would put the new 0x800 byte resource at the beginning of that available
space, i.e., at [mem 0xbff00000-0xbff007ff].

With this patch, we put it at the end, at [mem 0xbffff800-0xbfffffff].

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228#c41
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:42 -07:00
Russ Anderson
c8f730b1ab x86, uv: Enable Westmere support on SGI UV
Enable Westmere support on SGI UV.  The UV initialization code is dependent on
the APICID bits.  Westmere-EX uses different APIC bit mapping than Nehalem-EX.
This code reads the apic shift value from a UV MMR to do the proper bit
decoding to determint the pnode.

Signed-off-by: Russ Anderson <rja@sgi.com>
LKML-Reference: <20101026212728.GB15071@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-26 15:15:28 -07:00
Stefano Stabellini
ea5b8f7393 xen: initialize cpu masks for pv guests in xen_smp_init
Pv guests don't have ACPI and need the cpu masks to be set
correctly as early as possible so we call xen_fill_possible_map from
xen_smp_init.
On the other hand the initial domain supports ACPI so in this case we skip
xen_fill_possible_map and rely on it. However Xen might limit the number
of cpus usable by the domain, so we filter those masks during smp
initialization using the VCPUOP_is_up hypercall.
It is important that the filtering is done before
xen_setup_vcpu_info_placement.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-10-26 20:33:15 +01:00
Linus Torvalds
f1ebdd60cc Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (22 commits)
  Add _addr_lsb field to ia64 siginfo
  Fix migration.c compilation on s390
  HWPOISON: Remove retry loop for try_to_unmap
  HWPOISON: Turn addr_valid from bitfield into char
  HWPOISON: Disable DEBUG by default
  HWPOISON: Convert pr_debugs to pr_info
  HWPOISON: Improve comments in memory-failure.c
  x86: HWPOISON: Report correct address granuality for huge hwpoison faults
  Encode huge page size for VM_FAULT_HWPOISON errors
  Fix build error with !CONFIG_MIGRATION
  hugepage: move is_hugepage_on_freelist inside ifdef to avoid warning
  Clean up __page_set_anon_rmap
  HWPOISON, hugetlb: fix unpoison for hugepage
  HWPOISON, hugetlb: soft offlining for hugepage
  HWPOSION, hugetlb: recover from free hugepage error when !MF_COUNT_INCREASED
  hugetlb: move refcounting in hugepage allocation inside hugetlb_lock
  HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page()
  hugetlb: hugepage migration core
  hugetlb: redefine hugepage copy functions
  hugetlb: add allocate function for hugepage migration
  ...
2010-10-26 10:13:10 -07:00
Linus Torvalds
4f6876031e Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ]: x86, cpufreq: Mark longrun_get_policy with __cpuinit.
  [CPUFREQ] add sampling_down_factor tunable to improve ondemand performance
  [CPUFREQ] arch/x86/kernel/cpu/cpufreq: Fix unsigned return type
  [CPUFREQ] drivers/cpufreq: Adjust confusing if indentation
2010-10-26 10:00:04 -07:00
Ian Campbell
45263cb099 xen: include xen/xen.h for definition of xen_initial_domain()
CC      arch/x86/xen/setup.o
        arch/x86/xen/setup.c: In function 'xen_memory_setup':
        arch/x86/xen/setup.c:161: error: implicit declaration of function 'xen_initial_domain'

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-25 16:32:48 -07:00
Borislav Petkov
610470ce80 x86-32, mm: Remove duplicated #include
b40827fa72 added an include
directive which is needless and is taken care of by a previous
one. Remove it.

Caught-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Signed-off-by: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <20101025162523.GA4712@a1.tnic>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-25 19:39:33 +02:00
Ingo Molnar
7d7a48b760 Merge branch 'linus' into x86/urgent
Merge reason: We want to queue up a dependent fix.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-25 19:38:52 +02:00
Ingo Molnar
0b849ee888 Merge branch 'x86' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent 2010-10-25 19:17:32 +02:00
Borislav Petkov
9afd281a15 x86-32, mm: Remove duplicated include
Commit b40827fa72 ("x86-32, mm: Add an initial page table for core
bootstrapping") added an include directive which is needless and is
taken care of by a previous one.  Remove it.

Caught-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Signed-off-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-25 10:05:13 -07:00
Linus Torvalds
fbaab1dc19 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86: (44 commits)
  eeepc-wmi: Add cpufv sysfs interface
  eeepc-wmi: add additional hotkeys
  panasonic-laptop: Simplify calls to acpi_pcc_retrieve_biosdata
  panasonic-laptop: Handle errors properly if they happen
  intel_pmic_gpio: fix off-by-one value range checking
  IBM Real-Time "SMI Free" mode driver -v7
  Add OLPC XO-1 rfkill driver
  Move hdaps driver to platform/x86
  ideapad-laptop: Fix Makefile
  intel_pmic_gpio: swap the bits and mask args for intel_scu_ipc_update_register
  ideapad: Add param: no_bt_rfkill
  ideapad: Change the driver name to ideapad-laptop
  ideapad: rewrite the sw rfkill set
  ideapad: rewrite the hw rfkill notify
  ideapad: use EC command to control camera
  ideapad: use return value of _CFG to tell if device exist or not
  ideapad: make sure we bind on the correct device
  ideapad: check VPC bit before sync rfkill hw status
  ideapad: add ACPI helpers
  dell-laptop: Add debugfs support
  ...
2010-10-25 08:28:13 -07:00
Robert Richter
4cafc4b8d7 Merge branch 'oprofile/core' into oprofile/x86
Conflicts:
	arch/x86/oprofile/op_model_amd.c

Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-10-25 16:58:34 +02:00
Ingo Molnar
2c78ffeca9 x86/oprofile: Fix uninitialized variable use in debug printk
Stephen Rothwell reported this build warning:

  arch/x86/oprofile/op_model_amd.c: In function 'ibs_eilvt_valid':
  arch/x86/oprofile/op_model_amd.c:289: warning: 'offset' may be used uninitialized in this function

And correctly observed that indeed the variable is used uninitialized in
this function. The result of this bug can be a debug printk with a bogus
value.

Also fix a few more small details that made this function hard to read
and which probably contributed to the bug being introduced to begin with:

 - Use more symmetric error conditions

 - Remove the !0 obfuscation

 - Add newlines to the printk output

 - Remove bogus linebreaks in printk strings and elsewhere

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20101025115736.41d51abe.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-25 08:46:20 +02:00
Len Brown
38add9b4ba Merge branches 'bugzilla-15807', 'bugzilla-15979-v2' and 'bugzilla-19162' into release 2010-10-25 02:12:27 -04:00
Linus Torvalds
229aebb873 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Update broken web addresses in arch directory.
  Update broken web addresses in the kernel.
  Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
  Revert "Fix typo: configuation => configuration" partially
  ida: document IDA_BITMAP_LONGS calculation
  ext2: fix a typo on comment in ext2/inode.c
  drivers/scsi: Remove unnecessary casts of private_data
  drivers/s390: Remove unnecessary casts of private_data
  net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
  drivers/infiniband: Remove unnecessary casts of private_data
  drivers/gpu/drm: Remove unnecessary casts of private_data
  kernel/pm_qos_params.c: Remove unnecessary casts of private_data
  fs/ecryptfs: Remove unnecessary casts of private_data
  fs/seq_file.c: Remove unnecessary casts of private_data
  arm: uengine.c: remove C99 comments
  arm: scoop.c: remove C99 comments
  Fix typo configue => configure in comments
  Fix typo: configuation => configuration
  Fix typo interrest[ing|ed] => interest[ing|ed]
  Fix various typos of valid in comments
  ...

Fix up trivial conflicts in:
	drivers/char/ipmi/ipmi_si_intf.c
	drivers/usb/gadget/rndis.c
	net/irda/irnet/irnet_ppp.c
2010-10-24 13:41:39 -07:00
Linus Torvalds
1765a1fe5d Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits)
  KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
  KVM: Fix signature of kvm_iommu_map_pages stub
  KVM: MCE: Send SRAR SIGBUS directly
  KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
  KVM: fix typo in copyright notice
  KVM: Disable interrupts around get_kernel_ns()
  KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
  KVM: MMU: move access code parsing to FNAME(walk_addr) function
  KVM: MMU: audit: check whether have unsync sps after root sync
  KVM: MMU: audit: introduce audit_printk to cleanup audit code
  KVM: MMU: audit: unregister audit tracepoints before module unloaded
  KVM: MMU: audit: fix vcpu's spte walking
  KVM: MMU: set access bit for direct mapping
  KVM: MMU: cleanup for error mask set while walk guest page table
  KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
  KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
  KVM: x86: Fix constant type in kvm_get_time_scale
  KVM: VMX: Add AX to list of registers clobbered by guest switch
  KVM guest: Move a printk that's using the clock before it's ready
  KVM: x86: TSC catchup mode
  ...
2010-10-24 12:47:25 -07:00
Huang Ying
77db5cbd29 KVM: MCE: Send SRAR SIGBUS directly
Originally, SRAR SIGBUS is sent to QEMU-KVM via touching the poisoned
page. But commit 9605456919 prevents the
signal from being sent. So now the signal is sent via
force_sig_info_fault directly.

[marcelo: use send_sig_info instead]

Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:15 +02:00
Huang Ying
5854dbca9b KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
Now we have MCG_SER_P (and corresponding SRAO/SRAR MCE) support in
kernel and QEMU-KVM, the MCG_SER_P should be added into
KVM_MCE_CAP_SUPPORTED to make all these code really works.

Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:15 +02:00
Nicolas Kaiser
9611c18777 KVM: fix typo in copyright notice
Fix typo in copyright notice.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:14 +02:00
Avi Kivity
395c6b0a9d KVM: Disable interrupts around get_kernel_ns()
get_kernel_ns() wants preemption disabled.  It doesn't make a lot of sense
during the get/set ioctls (no way to make them non-racy) but the callee wants
it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:14 +02:00
Avi Kivity
7ebaf15eef KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:14 +02:00
Xiao Guangrong
3377078027 KVM: MMU: move access code parsing to FNAME(walk_addr) function
Move access code parsing from caller site to FNAME(walk_addr) function

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:14 +02:00
Xiao Guangrong
6903074c36 KVM: MMU: audit: check whether have unsync sps after root sync
After root synced, all unsync sps are synced, this patch add a check to make
sure it's no unsync sps in VCPU's page table

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:14 +02:00
Xiao Guangrong
38904e1287 KVM: MMU: audit: introduce audit_printk to cleanup audit code
Introduce audit_printk, and record audit point instead audit name

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:13 +02:00
Xiao Guangrong
c42fffe3a3 KVM: MMU: audit: unregister audit tracepoints before module unloaded
fix:

Call Trace:
 [<ffffffffa01e46ba>] ? kvm_mmu_pte_write+0x229/0x911 [kvm]
 [<ffffffffa01c6ba9>] ? gfn_to_memslot+0x39/0xa0 [kvm]
 [<ffffffffa01c6c26>] ? mark_page_dirty+0x16/0x2e [kvm]
 [<ffffffffa01c6d6f>] ? kvm_write_guest_page+0x67/0x7f [kvm]
 [<ffffffff81066fbd>] ? local_clock+0x2a/0x3b
 [<ffffffffa01d52ce>] emulator_write_phys+0x46/0x54 [kvm]
 ......
Code:  Bad RIP value.
RIP  [<ffffffffa0172056>] 0xffffffffa0172056
 RSP <ffff880134f69a70>
CR2: ffffffffa0172056

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:13 +02:00
Xiao Guangrong
98224bf1d1 KVM: MMU: audit: fix vcpu's spte walking
After nested nested paging, it may using long mode to shadow 32/PAE paging
guest, so this patch fix it

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:12 +02:00
Xiao Guangrong
33f91edb92 KVM: MMU: set access bit for direct mapping
Set access bit while setup up direct page table if it's nonpaing or npt enabled,
it's good for CPU's speculate access

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:11 +02:00
Xiao Guangrong
20bd40dc64 KVM: MMU: cleanup for error mask set while walk guest page table
Small cleanup for set page fault error code

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:10 +02:00
Xiao Guangrong
6292757fb0 KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
The value of 'vcpu->arch.mmu.pae_root' is not modified, so we can update
'root_hpa' out of the loop.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:09 +02:00
Sheng Yang
7129eecac1 KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
Eliminate:
arch/x86/kvm/emulate.c:801: warning: ‘sv’ may be used uninitialized in this
function

on gcc 4.1.2

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:09 +02:00
Jan Kiszka
50933623e5 KVM: x86: Fix constant type in kvm_get_time_scale
Older gcc versions complain about the improper type (for x86-32), 4.5
seems to fix this silently. However, we should better use the right type
initially.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:08 +02:00
Jan Kiszka
07d6f555d5 KVM: VMX: Add AX to list of registers clobbered by guest switch
By chance this caused no harm so far. We overwrite AX during switch
to/from guest context, so we must declare this.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:07 +02:00
Arjan Koers
19b6a85b78 KVM guest: Move a printk that's using the clock before it's ready
Fix a hang during SMP kernel boot on KVM that showed up
after commit 489fb490db
(2.6.35) and 59aab522154a2f17b25335b63c1cf68a51fb6ae0
(2.6.34.1). The problem only occurs when
CONFIG_PRINTK_TIME is set.

KVM-Stable-Tag.
Signed-off-by: Arjan Koers <0h61vkll2ly8@xutrox.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:06 +02:00
Zachary Amsden
c285545f81 KVM: x86: TSC catchup mode
Negate the effects of AN TYM spell while kvm thread is preempted by tracking
conversion factor to the highest TSC rate and catching the TSC up when it has
fallen behind the kernel view of time.  Note that once triggered, we don't
turn off catchup mode.

A slightly more clever version of this is possible, which only does catchup
when TSC rate drops, and which specifically targets only CPUs with broken
TSC, but since these all are considered unstable_tsc(), this patch covers
all necessary cases.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:05 +02:00
Zachary Amsden
34c238a1d1 KVM: x86: Rename timer function
This just changes some names to better reflect the usage they
will be given.  Separated out to keep confusion to a minimum.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:05 +02:00
Zachary Amsden
5f4e3f8827 KVM: x86: Make math work for other scales
The math in kvm_get_time_scale relies on the fact that
NSEC_PER_SEC < 2^32.  To use the same function to compute
arbitrary time scales, we must extend the first reduction
step to shrink the base rate to a 32-bit value, and
possibly reduce the scaled rate into a 32-bit as well.

Note we must take care to avoid an arithmetic overflow
when scaling up the tps32 value (this could not happen
with the fixed scaled value of NSEC_PER_SEC, but can
happen with scaled rates above 2^31.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:04 +02:00
Avi Kivity
49e9d557f9 KVM: VMX: Respect interrupt window in big real mode
If an interrupt is pending, we need to stop emulation so we
can inject it.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:02 +02:00
Mohammed Gamal
a92601bb70 KVM: VMX: Emulated real mode interrupt injection
Replace the inject-as-software-interrupt hack we currently have with
emulated injection.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:01 +02:00
Mohammed Gamal
63995653ad KVM: Add kvm_inject_realmode_interrupt() wrapper
This adds a wrapper function kvm_inject_realmode_interrupt() around the
emulator function emulate_int_real() to allow real mode interrupt injection.

[avi: initialize operand and address sizes before emulating interrupts]
[avi: initialize rip for real mode interrupt injection]
[avi: clear interrupt pending flag after emulating interrupt injection]

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:01 +02:00
Mohammed Gamal
4ab8e02404 KVM: x86 emulator: Expose emulate_int_real()
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:00 +02:00
Hillf Danton
cb16a7b387 KVM: MMU: fix counting of rmap entries in rmap_add()
It seems that rmap entries are under counted.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:59 +02:00
Gleb Natapov
a0a07cd2c5 KVM: SVM: do not generate "external interrupt exit" if other exit is pending
Nested SVM checks for external interrupt after injecting nested exception.
In case there is external interrupt pending the code generates "external
interrupt exit" and overwrites previous exit info. If previously injected
exception already generated exit it will be lost.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Avi Kivity
f4f5105087 KVM: Convert PIC lock from raw spinlock to ordinary spinlock
The PIC code used to be called from preempt_disable() context, which
wasn't very good for PREEMPT_RT.  That is no longer the case, so move
back from raw_spinlock_t to spinlock_t.

Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Zachary Amsden
28e4639adf KVM: x86: Fix kvmclock bug
If preempted after kvmclock values are updated, but before hardware
virtualization is entered, the last tsc time as read by the guest is
never set.  It underflows the next time kvmclock is updated if there
has not yet been a successful entry / exit into hardware virt.

Fix this by simply setting last_tsc to the newly read tsc value so
that any computed nsec advance of kvmclock is nulled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Joerg Roedel
0959ffacf3 KVM: MMU: Don't track nested fault info in error-code
This patch moves the detection whether a page-fault was
nested or not out of the error code and moves it into a
separate variable in the fault struct.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:55 +02:00
Avi Kivity
625831a3f4 KVM: VMX: Move fixup_rmode_irq() to avoid forward declaration
No code changes.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:54 +02:00
Avi Kivity
b463a6f744 KVM: Non-atomic interrupt injection
Change the interrupt injection code to work from preemptible, interrupts
enabled context.  This works by adding a ->cancel_injection() operation
that undoes an injection in case we were not able to actually enter the guest
(this condition could never happen with atomic injection).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:54 +02:00
Avi Kivity
83422e17c1 KVM: VMX: Parameterize vmx_complete_interrupts() for both exit and entry
Currently vmx_complete_interrupts() can decode event information from vmx
exit fields into the generic kvm event queues.  Make it able to decode
the information from the entry fields as well by parametrizing it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:52 +02:00
Avi Kivity
537b37e267 KVM: VMX: Move real-mode interrupt injection fixup to vmx_complete_interrupts()
This allows reuse of vmx_complete_interrupts() for cancelling injections.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:51 +02:00
Avi Kivity
51aa01d13d KVM: VMX: Split up vmx_complete_interrupts()
vmx_complete_interrupts() does too much, split it up:
 - vmx_vcpu_run() gets the "cache important vmcs fields" part
 - a new vmx_complete_atomic_exit() gets the parts that must be done atomically
 - a new vmx_recover_nmi_blocking() does what its name says
 - vmx_complete_interrupts() retains the event injection recovery code

This helps in reducing the work done in atomic context.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:51 +02:00
Avi Kivity
3842d135ff KVM: Check for pending events before attempting injection
Instead of blindly attempting to inject an event before each guest entry,
check for a possible event first in vcpu->requests.  Sites that can trigger
event injection are modified to set KVM_REQ_EVENT:

- interrupt, nmi window opening
- ppr updates
- i8259 output changes
- local apic irr changes
- rflags updates
- gif flag set
- event set on exit

This improves non-injecting entry performance, and sets the stage for
non-atomic injection.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:50 +02:00
Avi Kivity
b0bc3ee2b5 KVM: MMU: Fix regression with ept memory types merged into non-ept page tables
Commit "KVM: MMU: Make tdp_enabled a mmu-context parameter" made real-mode
set ->direct_map, and changed the code that merges in the memory type depend
on direct_map instead of tdp_enabled.  However, in this case what really
matters is tdp, not direct_map, since tdp changes the pte format regardless
of whether the mapping is direct or not.

As a result, real-mode shadow mappings got corrupted with ept memory types.
The result was a huge slowdown, likely due to the cache being disabled.

Change it back as the simplest fix for the regression (real fix is to move
all that to vmx code, and not use tdp_enabled as a synonym for ept).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:49 +02:00
Joerg Roedel
4c62a2dc92 KVM: X86: Report SVM bit to userspace only when supported
This patch fixes a bug in KVM where it _always_ reports the
support of the SVM feature to userspace. But KVM only
supports SVM on AMD hardware and only when it is enabled in
the kernel module. This patch fixes the wrong reporting.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:48 +02:00
Joerg Roedel
3d4aeaad8b KVM: SVM: Report Nested Paging support to userspace
This patch implements the reporting of the nested paging
feature support to userspace.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:47 +02:00
Joerg Roedel
55c5e464fc KVM: SVM: Expect two more candiates for exit_int_info
This patch adds INTR and NMI intercepts to the list of
expected intercepts with an exit_int_info set. While this
can't happen on bare metal it is architectural legal and may
happen with KVMs SVM emulation.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:46 +02:00
Joerg Roedel
4b16184c1c KVM: SVM: Initialize Nested Nested MMU context on VMRUN
This patch adds code to initialize the Nested Nested Paging
MMU context when the L1 guest executes a VMRUN instruction
and has nested paging enabled in its VMCB.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:46 +02:00
Joerg Roedel
5bd2edc341 KVM: SVM: Implement MMU helper functions for Nested Nested Paging
This patch adds the helper functions which will be used in
the mmu context for handling nested nested page faults.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:45 +02:00
Joerg Roedel
2d48a985c7 KVM: MMU: Track NX state in struct kvm_mmu
With Nested Paging emulation the NX state between the two
MMU contexts may differ. To make sure that always the right
fault error code is recorded this patch moves the NX state
into struct kvm_mmu so that the code can distinguish between
L1 and L2 NX state.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:44 +02:00
Joerg Roedel
81407ca553 KVM: MMU: Allow long mode shadows for legacy page tables
Currently the KVM softmmu implementation can not shadow a 32
bit legacy or PAE page table with a long mode page table.
This is a required feature for nested paging emulation
because the nested page table must alway be in host format.
So this patch implements the missing pieces to allow long
mode page tables for page table types.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:43 +02:00
Joerg Roedel
651dd37a9c KVM: MMU: Refactor mmu_alloc_roots function
This patch factors out the direct-mapping paths of the
mmu_alloc_roots function into a seperate function. This
makes it a lot easier to avoid all the unnecessary checks
done in the shadow path which may break when running direct.
In fact, this patch already fixes a problem when running PAE
guests on a PAE shadow page table.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:42 +02:00
Joerg Roedel
d41d1895eb KVM: MMU: Introduce kvm_pdptr_read_mmu
This function is implemented to load the pdptr pointers of
the currently running guest (l1 or l2 guest). Therefore it
takes care about the current paging mode and can read pdptrs
out of l2 guest physical memory.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:42 +02:00
Joerg Roedel
ff03a073e7 KVM: MMU: Add kvm_mmu parameter to load_pdptrs function
This function need to be able to load the pdptrs from any
mmu context currently in use. So change this function to
take an kvm_mmu parameter to fit these needs.
As a side effect this patch also moves the cached pdptrs
from vcpu_arch into the kvm_mmu struct.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:41 +02:00
Joerg Roedel
d47f00a62b KVM: X86: Propagate fetch faults
KVM currently ignores fetch faults in the instruction
emulator. With nested-npt we could have such faults. This
patch adds the code to handle these.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:41 +02:00
Joerg Roedel
d4f8cf664e KVM: MMU: Propagate the right fault back to the guest after gva_to_gpa
This patch implements logic to make sure that either a
page-fault/page-fault-vmexit or a nested-page-fault-vmexit
is propagated back to the guest.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:40 +02:00
Joerg Roedel
02f59dc9f1 KVM: MMU: Introduce init_kvm_nested_mmu()
This patch introduces the init_kvm_nested_mmu() function
which is used to re-initialize the nested mmu when the l2
guest changes its paging mode.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:39 +02:00
Joerg Roedel
3d06b8bfd4 KVM: MMU: Introduce kvm_read_nested_guest_page()
This patch introduces the kvm_read_guest_page_x86 function
which reads from the physical memory of the guest. If the
guest is running in guest-mode itself with nested paging
enabled it will read from the guest's guest physical memory
instead.
The patch also changes changes the code to use this function
where it is necessary.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:38 +02:00
Joerg Roedel
2329d46d21 KVM: MMU: Make walk_addr_generic capable for two-level walking
This patch uses kvm_read_guest_page_tdp to make the
walk_addr_generic functions suitable for two-level page
table walking.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:38 +02:00
Joerg Roedel
ec92fe44e7 KVM: X86: Add kvm_read_guest_page_mmu function
This patch adds a function which can read from the guests
physical memory or from the guest's guest physical memory.
This will be used in the two-dimensional page table walker.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:37 +02:00
Joerg Roedel
6539e738f6 KVM: MMU: Implement nested gva_to_gpa functions
This patch adds the functions to do a nested l2_gva to
l1_gpa page table walk.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:36 +02:00
Joerg Roedel
14dfe855f9 KVM: X86: Introduce pointer to mmu context used for gva_to_gpa
This patch introduces the walk_mmu pointer which points to
the mmu-context currently used for gva_to_gpa translations.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:35 +02:00
Joerg Roedel
c30a358d33 KVM: MMU: Add infrastructure for two-level page walker
This patch introduces a mmu-callback to translate gpa
addresses in the walk_addr code. This is later used to
translate l2_gpa addresses into l1_gpa addresses.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:34 +02:00
Joerg Roedel
1e301feb07 KVM: MMU: Introduce generic walk_addr function
This is the first patch in the series towards a generic
walk_addr implementation which could walk two-dimensional
page tables in the end. In this first step the walk_addr
function is renamed into walk_addr_generic which takes a
mmu context as an additional parameter.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:33 +02:00
Joerg Roedel
8df25a328a KVM: MMU: Track page fault data in struct vcpu
This patch introduces a struct with two new fields in
vcpu_arch for x86:

	* fault.address
	* fault.error_code

This will be used to correctly propagate page faults back
into the guest when we could have either an ordinary page
fault or a nested page fault. In the case of a nested page
fault the fault-address is different from the original
address that should be walked. So we need to keep track
about the real fault-address.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:33 +02:00
Joerg Roedel
3241f22da8 KVM: MMU: Let is_rsvd_bits_set take mmu context instead of vcpu
This patch changes is_rsvd_bits_set() function prototype to
take only a kvm_mmu context instead of a full vcpu.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:32 +02:00
Joerg Roedel
52fde8df7d KVM: MMU: Introduce kvm_init_shadow_mmu helper function
Some logic of the init_kvm_softmmu function is required to
build the Nested Nested Paging context. So factor the
required logic into a seperate function and export it.
Also make the whole init path suitable for more than one mmu
context.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:32 +02:00
Joerg Roedel
cb659db8a7 KVM: MMU: Introduce inject_page_fault function pointer
This patch introduces an inject_page_fault function pointer
into struct kvm_mmu which will be used to inject a page
fault. This will be used later when Nested Nested Paging is
implemented.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:31 +02:00
Joerg Roedel
5777ed340d KVM: MMU: Introduce get_cr3 function pointer
This function pointer in the MMU context is required to
implement Nested Nested Paging.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:31 +02:00
Joerg Roedel
1c97f0a04c KVM: X86: Introduce a tdp_set_cr3 function
This patch introduces a special set_tdp_cr3 function pointer
in kvm_x86_ops which is only used for tpd enabled mmu
contexts. This allows to remove some hacks from svm code.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:30 +02:00
Joerg Roedel
f43addd461 KVM: MMU: Make set_cr3 a function pointer in kvm_mmu
This is necessary to implement Nested Nested Paging. As a
side effect this allows some cleanups in the SVM nested
paging code.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:29 +02:00
Joerg Roedel
c5a78f2b64 KVM: MMU: Make tdp_enabled a mmu-context parameter
This patch changes the tdp_enabled flag from its global
meaning to the mmu-context and renames it to direct_map
there. This is necessary for Nested SVM with emulation of
Nested Paging where we need an extra MMU context to shadow
the Nested Nested Page Table.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:28 +02:00
Joerg Roedel
957446afce KVM: MMU: Check for root_level instead of long mode
The walk_addr function checks for !is_long_mode in its 64
bit version. But what is meant here is a check for pae
paging. Change the condition to really check for pae paging
so that it also works with nested nested paging.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:27 +02:00
Jes Sorensen
7b91409822 KVM: x86: Emulate MSR_EBC_FREQUENCY_ID
Some operating systems store data about the host processor at the
time of installation, and when booted on a more uptodate cpu tries
to read MSR_EBC_FREQUENCY_ID. This has been found with XP.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:27 +02:00
Jes Sorensen
b9a52c4b78 x86: Define MSR_EBC_FREQUENCY_ID
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:26 +02:00
Roedel, Joerg
b75f4eb341 KVM: SVM: Clean up rip handling in vmrun emulation
This patch changes the rip handling in the vmrun emulation
path from using next_rip to the generic kvm register access
functions.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:25 +02:00
Joerg Roedel
cda0008299 KVM: SVM: Restore correct registers after sel_cr0 intercept emulation
This patch implements restoring of the correct rip, rsp, and
rax after the svm emulation in KVM injected a selective_cr0
write intercept into the guest hypervisor. The problem was
that the vmexit is emulated in the instruction emulation
which later commits the registers right after the write-cr0
instruction. So the l1 guest will continue to run with the
l2 rip, rsp and rax resulting in unpredictable behavior.

This patch is not the final word, it is just an easy patch
to fix the issue. The real fix will be done when the
instruction emulator is made aware of nested virtualization.
Until this is done this patch fixes the issue and provides
an easy way to fix this in -stable too.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:24 +02:00
Joerg Roedel
f87f928882 KVM: MMU: Fix 32 bit legacy paging with NPT
This patch fixes 32 bit legacy paging with NPT enabled. The
mmu_check_root call on the top-level of the loop causes
root_gfn to take values (in the tdp_enabled path) which are
outside of guest memory. So the mmu_check_root call fails at
some point in the loop interation causing the guest to
tiple-fault.
This patch changes the mmu_check_root calls to the places
where they are really necessary. As a side-effect it
introduces a check for the root of a pae page table too.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:23 +02:00
Xiao Guangrong
30644b902c KVM: MMU: lower the aduit frequency
The audit is very high overhead, so we need lower the frequency to assure
the guest is running.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:59 +02:00
Xiao Guangrong
eb2591865a KVM: MMU: improve spte audit
Both audit_mappings() and audit_sptes_have_rmaps() need to walk vcpu's page
table, so we can do these checking in a spte walking

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:58 +02:00
Xiao Guangrong
49edf87806 KVM: MMU: improve active sp audit
Both audit_rmap() and audit_write_protection() need to walk all active sp, so
we can do these checking in a sp walking

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:57 +02:00
Xiao Guangrong
2f4f337248 KVM: MMU: move audit to a separate file
Move the audit code from arch/x86/kvm/mmu.c to arch/x86/kvm/mmu_audit.c

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:57 +02:00
Xiao Guangrong
8b1fe17cc7 KVM: MMU: support disable/enable mmu audit dynamicly
Add a r/w module parameter named 'mmu_audit', it can control audit
enable/disable:

enable:
  echo 1 > /sys/module/kvm/parameters/mmu_audit

disable:
  echo 0 > /sys/module/kvm/parameters/mmu_audit

This patch not change the logic

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:56 +02:00
Jes Sorensen
84e0cefa8d KVM: Fix guest kernel crash on MSR_K7_CLK_CTL
MSR_K7_CLK_CTL is a no longer documented MSR, which is only relevant
on said old AMD CPU models. This change returns the expected value,
which the Linux kernel is expecting to avoid writing back the MSR,
plus it ignores all writes to the MSR.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:55 +02:00
Avi Kivity
9ed049c3b6 KVM: i8259: Make ICW1 conform to spec
ICW is not a full reset, instead it resets a limited number of registers
in the PIC.  Change ICW1 emulation to only reset those registers.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:54 +02:00
Avi Kivity
7d9ddaedd8 KVM: x86 emulator: clean up control flow in x86_emulate_insn()
x86_emulate_insn() is full of things like

    if (rc != X86EMUL_CONTINUE)
        goto done;
    break;

consolidate all of those at the end of the switch statement.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:54 +02:00
Avi Kivity
a4d4a7c188 KVM: x86 emulator: fix group 11 decoding for reg != 0
These are all undefined.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:53 +02:00
Avi Kivity
b9eac5f4d1 KVM: x86 emulator: use single stage decoding for mov instructions
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:52 +02:00
Avi Kivity
e90aa41e6c KVM: Don't save/restore MSR_IA32_PERF_STATUS
It is read/only; restoring it only results in annoying messages.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:51 +02:00
Marcelo Tosatti
eaa48512ba KVM: SVM: init_vmcb should reset vcpu->efer
Otherwise EFER_LMA bit is retained across a SIPI reset.

Fixes guest cpu onlining.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:51 +02:00
Marcelo Tosatti
678041ad9d KVM: SVM: reset mmu context in init_vmcb
Since commit aad827034e no mmu reinitialization is performed
via init_vmcb.

Zero vcpu->arch.cr0 and pass the reset value as a parameter to
kvm_set_cr0.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:50 +02:00
Avi Kivity
c41a15dd46 KVM: Fix pio trace direction
out = write, in = read, not the other way round.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:49 +02:00
Xiao Guangrong
8e0e8afa82 KVM: MMU: remove count_rmaps()
Nothing is checked in count_rmaps(), so remove it

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:49 +02:00
Xiao Guangrong
365fb3fdf6 KVM: MMU: rewrite audit_mappings_page() function
There is a bugs in this function, we call gfn_to_pfn() and kvm_mmu_gva_to_gpa_read() in
atomic context(kvm_mmu_audit() is called under the spinlock(mmu_lock)'s protection).

This patch fix it by:
- introduce gfn_to_pfn_atomic instead of gfn_to_pfn
- get the mapping gfn from kvm_mmu_page_get_gfn()

And it adds 'notrap' ptes check in unsync/direct sps

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:48 +02:00
Xiao Guangrong
bc32ce2152 KVM: MMU: fix wrong not write protected sp report
The audit code reports some sp not write protected in current code, it's just the
bug in audit_write_protection(), since:

- the invalid sp not need write protected
- using uninitialize local variable('gfn')
- call kvm_mmu_audit() out of mmu_lock's protection

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:47 +02:00
Xiao Guangrong
0beb8d6604 KVM: MMU: check rmap for every spte
The read-only spte also has reverse mapping, so fix the code to check them,
also modify the function name to fit its doing

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:46 +02:00
Xiao Guangrong
9ad17b1001 KVM: MMU: fix compile warning in audit code
fix:

arch/x86/kvm/mmu.c: In function ‘kvm_mmu_unprotect_page’:
arch/x86/kvm/mmu.c:1741: warning: format ‘%lx’ expects type ‘long unsigned int’, but argument 3 has type ‘gfn_t’
arch/x86/kvm/mmu.c:1745: warning: format ‘%lx’ expects type ‘long unsigned int’, but argument 3 has type ‘gfn_t’
arch/x86/kvm/mmu.c: In function ‘mmu_unshadow’:
arch/x86/kvm/mmu.c:1761: warning: format ‘%lx’ expects type ‘long unsigned int’, but argument 3 has type ‘gfn_t’
arch/x86/kvm/mmu.c: In function ‘set_spte’:
arch/x86/kvm/mmu.c:2005: warning: format ‘%lx’ expects type ‘long unsigned int’, but argument 3 has type ‘gfn_t’
arch/x86/kvm/mmu.c: In function ‘mmu_set_spte’:
arch/x86/kvm/mmu.c:2033: warning: format ‘%lx’ expects type ‘long unsigned int’, but argument 7 has type ‘gfn_t’

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:46 +02:00
Jason Wang
23e7a7944f KVM: pit: Do not check pending pit timer in vcpu thread
Pit interrupt injection was done by workqueue, so no need to check
pending pit timer in vcpu thread which could lead unnecessary
unblocking of vcpu.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:45 +02:00
Avi Kivity
6230f7fc04 KVM: x86 emulator: simplify ALU opcode block decode further
The ALU opcode block is very regular; introduce D6ALU() to define decode
flags for 6 instructions at a time.

Suggested by Paolo Bonzini.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:43 +02:00
Avi Kivity
217fc9cfca KVM: Fix build error due to 64-bit division in nsec_to_cycles()
Use do_div() instead.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:43 +02:00
Avi Kivity
34d1f4905e KVM: x86 emulator: trap and propagate #DE from DIV and IDIV
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:42 +02:00
Avi Kivity
f6b3597bde KVM: x86 emulator: add macros for executing instructions that may trap
Like DIV and IDIV.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:41 +02:00
Avi Kivity
739ae40606 KVM: x86 emulator: simplify instruction decode flags for opcodes 0F 00-FF
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:41 +02:00
Avi Kivity
d269e3961a KVM: x86 emulator: simplify instruction decode flags for opcodes E0-FF
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:40 +02:00
Avi Kivity
d2c6c7adb1 KVM: x86 emulator: simplify instruction decode flags for opcodes C0-DF
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:39 +02:00
Avi Kivity
50748613d1 KVM: x86 emulator: simplify instruction decode flags for opcodes A0-AF
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:38 +02:00
Avi Kivity
76e8e68d44 KVM: x86 emulator: simplify instruction decode flags for opcodes 80-8F
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:38 +02:00
Avi Kivity
48fe67b5f7 KVM: x86 emulator: simplify string instruction decode flags
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:37 +02:00
Avi Kivity
5315fbb223 KVM: x86 emulator: simplify ALU block (opcodes 00-3F) decode flags
Use the new byte/word dual opcode decode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:36 +02:00
Avi Kivity
8d8f4e9f66 KVM: x86 emulator: support byte/word opcode pairs
Many x86 instructions come in byte and word variants distinguished with bit
0 of the opcode.  Add macros to aid in defining them.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:35 +02:00
Avi Kivity
081bca0e6b KVM: x86 emulator: refuse SrcMemFAddr (e.g. LDS) with register operand
SrcMemFAddr is not defined with the modrm operand designating a register
instead of a memory address.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:35 +02:00
Gleb Natapov
d2ddd1c483 KVM: x86 emulator: get rid of "restart" in emulation context.
x86_emulate_insn() will return 1 if instruction can be restarted
without re-entering a guest.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:34 +02:00
Gleb Natapov
3e2f65d57a KVM: x86 emulator: move string instruction completion check into separate function
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:33 +02:00
Gleb Natapov
6e2fb2cadd KVM: x86 emulator: Rename variable that shadows another local variable.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:32 +02:00
Wei Yongjun
cc4feed57f KVM: x86 emulator: add CALL FAR instruction emulation (opcode 9a)
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:31 +02:00
Xiao Guangrong
189be38db3 KVM: MMU: combine guest pte read between fetch and pte prefetch
Combine guest pte read between guest pte check in the fetch path and pte prefetch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:28 +02:00
Xiao Guangrong
957ed9effd KVM: MMU: prefetch ptes when intercepted guest #PF
Support prefetch ptes when intercept guest #PF, avoid to #PF by later
access

If we meet any failure in the prefetch path, we will exit it and
not try other ptes to avoid become heavy path

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:27 +02:00
Zachary Amsden
1d5f066e0b KVM: x86: Fix a possible backwards warp of kvmclock
Kernel time, which advances in discrete steps may progress much slower
than TSC.  As a result, when kvmclock is adjusted to a new base, the
apparent time to the guest, which runs at a much higher, nsec scaled
rate based on the current TSC, may have already been observed to have
a larger value (kernel_ns + scaled tsc) than the value to which we are
setting it (kernel_ns + 0).

We must instead compute the clock as potentially observed by the guest
for kernel_ns to make sure it does not go backwards.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:24 +02:00
Zachary Amsden
347bb4448c x86: pvclock: Move scale_delta into common header
The scale_delta function for shift / multiply with 31-bit
precision moves to a common header so it can be used by both
kernel and kvm module.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:24 +02:00
Zachary Amsden
ca84d1a24c KVM: x86: Add clock sync request to hardware enable
If there are active VCPUs which are marked as belonging to
a particular hardware CPU, request a clock sync for them when
enabling hardware; the TSC could be desynchronized on a newly
arriving CPU, and we need to recompute guests system time
relative to boot after a suspend event.

This covers both cases.

Note that it is acceptable to take the spinlock, as either
no other tasks will be running and no locks held (BSP after
resume), or other tasks will be guaranteed to drop the lock
relatively quickly (AP on CPU_STARTING).

Noting we now get clock synchronization requests for VCPUs
which are starting up (or restarting), it is tempting to
attempt to remove the arch/x86/kvm/x86.c CPU hot-notifiers
at this time, however it is not correct to do so; they are
required for systems with non-constant TSC as the frequency
may not be known immediately after the processor has started
until the cpufreq driver has had a chance to run and query
the chipset.

Updated: implement better locking semantics for hardware_enable

Removed the hack of dropping and retaking the lock by adding the
semantic that we always hold kvm_lock when hardware_enable is
called.  The one place that doesn't need to worry about it is
resume, as resuming a frozen CPU, the spinlock won't be taken.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:24 +02:00
Zachary Amsden
46543ba45f KVM: x86: Robust TSC compensation
Make the match of TSC find TSC writes that are close to each other
instead of perfectly identical; this allows the compensator to also
work in migration / suspend scenarios.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
759379dd68 KVM: x86: Add helper functions for time computation
Add a helper function to compute the kernel time and convert nanoseconds
back to CPU specific cycles.  Note that these must not be called in preemptible
context, as that would mean the kernel could enter software suspend state,
which would cause non-atomic operation.

Also, convert the KVM_SET_CLOCK / KVM_GET_CLOCK ioctls to use the kernel
time helper, these should be bootbased as well.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
48434c20e1 KVM: x86: Fix deep C-state TSC desynchronization
When CPUs with unstable TSCs enter deep C-state, TSC may stop
running.  This causes us to require resynchronization.  Since
we can't tell when this may potentially happen, we assume the
worst by forcing re-compensation for it at every point the VCPU
task is descheduled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
e48672fa25 KVM: x86: Unify TSC logic
Move the TSC control logic from the vendor backends into x86.c
by adding adjust_tsc_offset to x86 ops.  Now all TSC decisions
can be done in one place.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:23 +02:00
Zachary Amsden
6755bae8e6 KVM: x86: Warn about unstable TSC
If creating an SMP guest with unstable host TSC, issue a warning

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
8cfdc00085 KVM: x86: Make cpu_tsc_khz updates use local CPU
This simplifies much of the init code; we can now simply always
call tsc_khz_changed, optionally passing it a new value, or letting
it figure out the existing value (while interrupts are disabled, and
thus, by inference from the rule, not raceful against CPU hotplug or
frequency updates, which will issue IPIs to the local CPU to perform
this very same task).

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
f38e098ff3 KVM: x86: TSC reset compensation
Attempt to synchronize TSCs which are reset to the same value.  In the
case of a reliable hardware TSC, we can just re-use the same offset, but
on non-reliable hardware, we can get closer by adjusting the offset to
match the elapsed time.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
99e3e30aee KVM: x86: Move TSC offset writes to common code
Also, ensure that the storing of the offset and the reading of the TSC
are never preempted by taking a spinlock.  While the lock is overkill
now, it is useful later in this patch series.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
f4e1b3c8bd KVM: x86: Convert TSC writes to TSC offset writes
Change svm / vmx to be the same internally and write TSC offset
instead of bare TSC in helper functions.  Isolated as a single
patch to contain code movement.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:22 +02:00
Zachary Amsden
ae38436b78 KVM: x86: Drop vm_init_tsc
This is used only by the VMX code, and is not done properly;
if the TSC is indeed backwards, it is out of sync, and will
need proper handling in the logic at each and every CPU change.
For now, drop this test during init as misguided.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:21 +02:00
Wei Yongjun
45bf21a8ce KVM: MMU: fix missing percpu counter destroy
commit ad05c88266b4cce1c820928ce8a0fb7690912ba1
(KVM: create aggregate kvm_total_used_mmu_pages value)
introduce percpu counter kvm_total_used_mmu_pages but never
destroy it, this may cause oops when rmmod & modprobe.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:21 +02:00
Xiaotian Feng
80b63faf02 KVM: MMU: fix regression from rework mmu_shrink() code
Latest kvm mmu_shrink code rework makes kernel changes kvm->arch.n_used_mmu_pages/
kvm->arch.n_max_mmu_pages at kvm_mmu_free_page/kvm_mmu_alloc_page, which is called
by kvm_mmu_commit_zap_page. So the kvm->arch.n_used_mmu_pages or
kvm_mmu_available_pages(vcpu->kvm) is unchanged after kvm_mmu_prepare_zap_page(),
This caused kvm_mmu_change_mmu_pages/__kvm_mmu_free_some_pages loops forever.
Moving kvm_mmu_commit_zap_page would make the while loop performs as normal.

Reported-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Tested-by: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:21 +02:00
Wei Yongjun
e4abac67b7 KVM: x86 emulator: add JrCXZ instruction emulation
Add JrCXZ instruction emulation (opcode 0xe3)
Used by FreeBSD boot loader.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:20 +02:00
Wei Yongjun
09b5f4d3c4 KVM: x86 emulator: add LDS/LES/LFS/LGS/LSS instruction emulation
Add LDS/LES/LFS/LGS/LSS instruction emulation.
(opcode 0xc4, 0xc5, 0x0f 0xb2, 0x0f 0xb4~0xb5)

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:20 +02:00
Dave Hansen
45221ab668 KVM: create aggregate kvm_total_used_mmu_pages value
Of slab shrinkers, the VM code says:

 * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
 * querying the cache size, so a fastpath for that case is appropriate.

and it *means* it.  Look at how it calls the shrinkers:

    nr_before = (*shrinker->shrink)(0, gfp_mask);
    shrink_ret = (*shrinker->shrink)(this_scan, gfp_mask);

So, if you do anything stupid in your shrinker, the VM will doubly
punish you.

The mmu_shrink() function takes the global kvm_lock, then acquires
every VM's kvm->mmu_lock in sequence.  If we have 100 VMs, then
we're going to take 101 locks.  We do it twice, so each call takes
202 locks.  If we're under memory pressure, we can have each cpu
trying to do this.  It can get really hairy, and we've seen lock
spinning in mmu_shrink() be the dominant entry in profiles.

This is guaranteed to optimize at least half of those lock
aquisitions away.  It removes the need to take any of the locks
when simply trying to count objects.

A 'percpu_counter' can be a large object, but we only have one
of these for the entire system.  There are not any better
alternatives at the moment, especially ones that handle CPU
hotplug.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:19 +02:00
Dave Hansen
49d5ca2663 KVM: replace x86 kvm n_free_mmu_pages with n_used_mmu_pages
Doing this makes the code much more readable.  That's
borne out by the fact that this patch removes code.  "used"
also happens to be the number that we need to return back to
the slab code when our shrinker gets called.  Keeping this
value as opposed to free makes the next patch simpler.

So, 'struct kvm' is kzalloc()'d.  'struct kvm_arch' is a
structure member (and not a pointer) of 'struct kvm'.  That
means they start out zeroed.  I _think_ they get initialized
properly by kvm_mmu_change_mmu_pages().  But, that only happens
via kvm ioctls.

Another benefit of storing 'used' intead of 'free' is
that the values are consistent from the moment the structure is
allocated: no negative "used" value.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:18 +02:00
Dave Hansen
39de71ec53 KVM: rename x86 kvm->arch.n_alloc_mmu_pages
arch.n_alloc_mmu_pages is a poor choice of name. This value truly
means, "the number of pages which _may_ be allocated".  But,
reading the name, "n_alloc_mmu_pages" implies "the number of allocated
mmu pages", which is dead wrong.

It's really the high watermark, so let's give it a name to match:
nr_max_mmu_pages.  This change will make the next few patches
much more obvious and easy to read.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:18 +02:00
Dave Hansen
e0df7b9f6c KVM: abstract kvm x86 mmu->n_free_mmu_pages
"free" is a poor name for this value.  In this context, it means,
"the number of mmu pages which this kvm instance should be able to
allocate."  But "free" implies much more that the objects are there
and ready for use.  "available" is a much better description, especially
when you see how it is calculated.

In this patch, we abstract its use into a function.  We'll soon
replace the function's contents by calculating the value in a
different way.

All of the reads of n_free_mmu_pages are taken care of in this
patch.  The modification sites will be handled in a patch
later in the series.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:17 +02:00
Avi Kivity
6142914280 KVM: x86 emulator: implement CWD (opcode 99)
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:16 +02:00