Commit Graph

481513 Commits

Author SHA1 Message Date
Paolo Bonzini
cb5281a572 KVM: move APIC types to arch/x86/
They are not used anymore by IA64, move them away.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-18 09:39:51 +01:00
Paolo Bonzini
333bce5aac Second round of changes for KVM for arm/arm64 for v3.19; fixes reboot
problems, clarifies VCPU init, and fixes a regression concerning the
 VGIC init flow.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJUjsVhAAoJEEtpOizt6ddy5rIH/1V/YVwhprC55YqdHelU9Qu2
 Muzsx+7F71NxC7xgMGFqPD1YrPR+hxvoPhy+ADOBlvcqlolrkDnV9I+8e3geaYNc
 nZ/yEnoGTtbAggiS1smx7usBv34Z88Sd5txNjmj1cmHBy+VOWlyidWMkGBTsfBRe
 mVc61BDUfyC47udgRHXhwS80sbHLJHElmADisFOVmQNBYwwiHiTdx0hMBMnHcC3Y
 /3T0tKxHdeTISnmA+J+n7TcChtTIM4xqC6kwf3rw3b7XX8gdtTKylDHX2GLAg646
 RdebAG2twmGpIc6SxXZbo38f3oY9OFo1Le5xZGa6iUjD56VDw/e4wg4iA2juo0Y=
 =J2Ut
 -----END PGP SIGNATURE-----

Merge tag 'kvm-arm-for-3.19-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

Second round of changes for KVM for arm/arm64 for v3.19; fixes reboot
problems, clarifies VCPU init, and fixes a regression concerning the
VGIC init flow.

Conflicts:
	arch/ia64/kvm/kvm-ia64.c [deleted in HEAD and modified in kvmarm]
2014-12-15 13:06:40 +01:00
Christoffer Dall
05971120fc arm/arm64: KVM: Require in-kernel vgic for the arch timers
It is curently possible to run a VM with architected timers support
without creating an in-kernel VGIC, which will result in interrupts from
the virtual timer going nowhere.

To address this issue, move the architected timers initialization to the
time when we run a VCPU for the first time, and then only initialize
(and enable) the architected timers if we have a properly created and
initialized in-kernel VGIC.

When injecting interrupts from the virtual timer to the vgic, the
current setup should ensure that this never calls an on-demand init of
the VGIC, which is the only call path that could return an error from
kvm_vgic_inject_irq(), so capture the return value and raise a warning
if there's an error there.

We also change the kvm_timer_init() function from returning an int to be
a void function, since the function always succeeds.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-15 11:50:42 +01:00
Christoffer Dall
ca7d9c829d arm/arm64: KVM: Initialize the vgic on-demand when injecting IRQs
Userspace assumes that it can wire up IRQ injections after having
created all VCPUs and after having created the VGIC, but potentially
before starting the first VCPU.  This can currently lead to lost IRQs
because the state of that IRQ injection is not stored anywhere and we
don't return an error to userspace.

We haven't seen this problem manifest itself yet, presumably because
guests reset the devices on boot, but this could cause issues with
migration and other non-standard startup configurations.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-15 11:36:21 +01:00
Christoffer Dall
716139df25 arm/arm64: KVM: Don't allow creating VCPUs after vgic_initialized
When the vgic initializes its internal state it does so based on the
number of VCPUs available at the time.  If we allow KVM to create more
VCPUs after the VGIC has been initialized, we are likely to error out in
unfortunate ways later, perform buffer overflows etc.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:17:10 +01:00
Christoffer Dall
1f57be2895 arm/arm64: KVM: Add (new) vgic_initialized macro
Some code paths will need to check to see if the internal state of the
vgic has been initialized (such as when creating new VCPUs), so
introduce such a macro that checks the nr_cpus field which is set when
the vgic has been initialized.

Also set nr_cpus = 0 in kvm_vgic_destroy, because the error path in
vgic_init() will call this function, and code should never errornously
assume the vgic to be properly initialized after an error.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:17:10 +01:00
Christoffer Dall
c52edf5f8c arm/arm64: KVM: Rename vgic_initialized to vgic_ready
The vgic_initialized() macro currently returns the state of the
vgic->ready flag, which indicates if the vgic is ready to be used when
running a VM, not specifically if its internal state has been
initialized.

Rename the macro accordingly in preparation for a more nuanced
initialization flow.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:17:05 +01:00
Peter Maydell
6d3cfbe21b arm/arm64: KVM: vgic: move reset initialization into vgic_init_maps()
VGIC initialization currently happens in three phases:
 (1) kvm_vgic_create() (triggered by userspace GIC creation)
 (2) vgic_init_maps() (triggered by userspace GIC register read/write
     requests, or from kvm_vgic_init() if not already run)
 (3) kvm_vgic_init() (triggered by first VM run)

We were doing initialization of some state to correspond with the
state of a freshly-reset GIC in kvm_vgic_init(); this is too late,
since it will overwrite changes made by userspace using the
register access APIs before the VM is run. Move this initialization
earlier, into the vgic_init_maps() phase.

This fixes a bug where QEMU could successfully restore a saved
VM state snapshot into a VM that had already been run, but could
not restore it "from cold" using the -loadvm command line option
(the symptoms being that the restored VM would run but interrupts
were ignored).

Finally rename vgic_init_maps to vgic_init and renamed kvm_vgic_init to
kvm_vgic_map_resources.

  [ This patch is originally written by Peter Maydell, but I have
    modified it somewhat heavily, renaming various bits and moving code
    around.  If something is broken, I am to be blamed. - Christoffer ]

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:52 +01:00
Christoffer Dall
957db105c9 arm/arm64: KVM: Introduce stage2_unmap_vm
Introduce a new function to unmap user RAM regions in the stage2 page
tables.  This is needed on reboot (or when the guest turns off the MMU)
to ensure we fault in pages again and make the dcache, RAM, and icache
coherent.

Using unmap_stage2_range for the whole guest physical range does not
work, because that unmaps IO regions (such as the GIC) which will not be
recreated or in the best case faulted in on a page-by-page basis.

Call this function on secondary and subsequent calls to the
KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest
Stage-1 MMU is off when faulting in pages and make the caches coherent.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:27 +01:00
Christoffer Dall
cf5d318865 arm/arm64: KVM: Turn off vcpus on PSCI shutdown/reboot
When a vcpu calls SYSTEM_OFF or SYSTEM_RESET with PSCI v0.2, the vcpus
should really be turned off for the VM adhering to the suggestions in
the PSCI spec, and it's the sane thing to do.

Also, clarify the behavior and expectations for exits to user space with
the KVM_EXIT_SYSTEM_EVENT case.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:27 +01:00
Christoffer Dall
f7fa034dc8 arm/arm64: KVM: Clarify KVM_ARM_VCPU_INIT ABI
It is not clear that this ioctl can be called multiple times for a given
vcpu.  Userspace already does this, so clarify the ABI.

Also specify that userspace is expected to always make secondary and
subsequent calls to the ioctl with the same parameters for the VCPU as
the initial call (which userspace also already does).

Add code to check that userspace doesn't violate that ABI in the future,
and move the kvm_vcpu_set_target() function which is currently
duplicated between the 32-bit and 64-bit versions in guest.c to a common
static function in arm.c, shared between both architectures.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:26 +01:00
Christoffer Dall
b856a59141 arm/arm64: KVM: Reset the HCR on each vcpu when resetting the vcpu
When userspace resets the vcpu using KVM_ARM_VCPU_INIT, we should also
reset the HCR, because we now modify the HCR dynamically to
enable/disable trapping of guest accesses to the VM registers.

This is crucial for reboot of VMs working since otherwise we will not be
doing the necessary cache maintenance operations when faulting in pages
with the guest MMU off.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:26 +01:00
Christoffer Dall
3ad8b3de52 arm/arm64: KVM: Correct KVM_ARM_VCPU_INIT power off option
The implementation of KVM_ARM_VCPU_INIT is currently not doing what
userspace expects, namely making sure that a vcpu which may have been
turned off using PSCI is returned to its initial state, which would be
powered on if userspace does not set the KVM_ARM_VCPU_POWER_OFF flag.

Implement the expected functionality and clarify the ABI.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:25 +01:00
Christoffer Dall
03f1d4c17e arm/arm64: KVM: Don't clear the VCPU_POWER_OFF flag
If a VCPU was originally started with power off (typically to be brought
up by PSCI in SMP configurations), there is no need to clear the
POWER_OFF flag in the kernel, as this flag is only tested during the
init ioctl itself.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:25 +01:00
Nadav Amit
ab646f54f4 KVM: x86: em_ret_far overrides cpl
commit d50eaa1803 ("KVM: x86: Perform limit checks when assigning EIP")
mistakenly used zero as cpl on em_ret_far. Use the actual one.

Fixes: d50eaa1803
Cc: stable@vger.kernel.org
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-11 12:27:32 +01:00
Bandan Das
78051e3b7e KVM: nVMX: Disable unrestricted mode if ept=0
If L0 has disabled EPT, don't advertise unrestricted
mode at all since it depends on EPT to run real mode code.

Fixes: 92fbc7b195
Cc: stable@vger.kernel.org
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-11 12:26:15 +01:00
Nadav Amit
64a38292ed KVM: x86: Emulate should check #UD before #GP
Intel SDM table 6-2 ("Priority Among Simultaneous Exceptions and Interrupts")
shows that faults from decoding the next instruction got higher priority than
general protection.  Moving the protected-mode check before the CPL check to
avoid wrong exception on vm86 mode.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10 12:53:37 +01:00
Nadav Amit
bc397a6c91 KVM: x86: Do not push eflags.vm on pushf
The pushf instruction does not push eflags.VM, so emulation should not do so as
well.  Although eflags.RF should not be pushed as well, it is already cleared
by the time pushf is executed.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10 12:51:28 +01:00
Nadav Amit
53bb4f789a KVM: x86: Remove prefix flag when GP macro is used
The macro GP already sets the flag Prefix. Remove the redundant flag for
0f_38_f0 and 0f_38_f1 opcodes.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10 12:51:13 +01:00
Andy Lutomirski
29fa682546 x86, kvm: Clear paravirt_enabled on KVM guests for espfix32's benefit
paravirt_enabled has the following effects:

 - Disables the F00F bug workaround warning.  There is no F00F bug
   workaround any more because Linux's standard IDT handling already
   works around the F00F bug, but the warning still exists.  This
   is only cosmetic, and, in any event, there is no such thing as
   KVM on a CPU with the F00F bug.

 - Disables 32-bit APM BIOS detection.  On a KVM paravirt system,
   there should be no APM BIOS anyway.

 - Disables tboot.  I think that the tboot code should check the
   CPUID hypervisor bit directly if it matters.

 - paravirt_enabled disables espfix32.  espfix32 should *not* be
   disabled under KVM paravirt.

The last point is the purpose of this patch.  It fixes a leak of the
high 16 bits of the kernel stack address on 32-bit KVM paravirt
guests.  Fixes CVE-2014-8134.

Cc: stable@vger.kernel.org
Suggested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10 12:49:39 +01:00
Radim Krčmář
e08e833616 KVM: cpuid: recompute CPUID 0xD.0:EBX,ECX
We reused host EBX and ECX, but KVM might not support all features;
emulated XSAVE size should be smaller.

EBX depends on unknown XCR0, so we default to ECX.

SDM CPUID (EAX = 0DH, ECX = 0):
 EBX Bits 31-00: Maximum size (bytes, from the beginning of the
     XSAVE/XRSTOR save area) required by enabled features in XCR0. May
     be different than ECX if some features at the end of the XSAVE save
     area are not enabled.

 ECX Bit 31-00: Maximum size (bytes, from the beginning of the
     XSAVE/XRSTOR save area) of the XSAVE/XRSTOR save area required by
     all supported features in the processor, i.e all the valid bit
     fields in XCR0.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:49 +01:00
Wanpeng Li
81dc01f749 kvm: vmx: add nested virtualization support for xsaves
Add nested virtualization support for xsaves.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:44 +01:00
Wanpeng Li
203000993d kvm: vmx: add MSR logic for XSAVES
Add logic to get/set the XSS model-specific register.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:39 +01:00
Wanpeng Li
f53cd63c2d kvm: x86: handle XSAVES vmcs and vmexit
Initialize the XSS exit bitmap.  It is zero so there should be no XSAVES
or XRSTORS exits.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:33 +01:00
Paolo Bonzini
404e0a19e1 KVM: cpuid: mask more bits in leaf 0xd and subleaves
- EAX=0Dh, ECX=1: output registers EBX/ECX/EDX are reserved.

- EAX=0Dh, ECX>1: output register ECX bit 0 is clear for all the CPUID
leaves we support, because variable "supported" comes from XCR0 and not
XSS.  Bits above 0 are reserved, so ECX is overall zero.  Output register
EDX is reserved.

Source: Intel Architecture Instruction Set Extensions Programming
Reference, ref. number 319433-022

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:17 +01:00
Paolo Bonzini
412a3c411e KVM: cpuid: set CPUID(EAX=0xd,ECX=1).EBX correctly
This is the size of the XSAVES area.  This starts providing guest support
for XSAVES (with no support yet for supervisor states, i.e. XSS == 0
always in guests for now).

Wanpeng Li suggested testing XSAVEC as well as XSAVES, since in practice
no real processor exists that only has one of them, and there is no
other way for userspace programs to compute the area of the XSAVEC
save area.  CPUID(EAX=0xd,ECX=1).EBX provides an upper bound.

Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:17 +01:00
Wanpeng Li
55412b2eda kvm: x86: Add kvm_x86_ops hook that enables XSAVES for guest
Expose the XSAVES feature to the guest if the kvm_x86_ops say it is
available.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:16 +01:00
Paolo Bonzini
5c404cabd1 KVM: x86: use F() macro throughout cpuid.c
For code that deals with cpuid, this makes things a bit more readable.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:15 +01:00
Paolo Bonzini
df1daba7d1 KVM: x86: support XSAVES usage in the host
Userspace is expecting non-compacted format for KVM_GET_XSAVE, but
struct xsave_struct might be using the compacted format.  Convert
in order to preserve userspace ABI.

Likewise, userspace is passing non-compacted format for KVM_SET_XSAVE
but the kernel will pass it to XRSTORS, and we need to convert back.

Fixes: f31a9f7c71
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: stable@vger.kernel.org
Cc: H. Peter Anvin <hpa@linux.intel.com>
Tested-by: Nadav Amit <namit@cs.technion.ac.il>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:05 +01:00
Paolo Bonzini
ba7b39203a x86: export get_xsave_addr
get_xsave_addr is the API to access XSAVE states, and KVM would
like to use it.  Export it.

Cc: stable@vger.kernel.org
Cc: x86@kernel.org
Cc: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:55:44 +01:00
Paolo Bonzini
28145be0a7 KVM: s390: Fixups for kvm/next (3.19)
Here we have two fixups of the latest interrupt rework and
 one architectural fixup.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.14 (GNU/Linux)
 
 iQIcBAABAgAGBQJUgIO9AAoJEBF7vIC1phx8U5YQALKPvkoyVaGOexDCQQJrz04+
 9W5ZQuvg020jj1EmRPlv9yekhtYBTYA/OVT+FsDG3eq+xCS4Y04vlvUfk2Lq0YAB
 Bk+cU7plNP8f1Ml/kRTC/yfWcPe8iCVI1WA7zqA2wwEbaEZCz+9+i76wyriDWtJM
 FJEKXqVmLZH/H+GAw4GQG0YrO4uZ70Sk5F5YVtceGN5mDlqCATXa2xADm4ciAiIW
 L6w+G3KjIuv/Opds6DFMfJgYQeAF+0MFFWpD2rUfVLwIvdtBTtnxVwQZfpoXH7rF
 SeNU6n7CILS0csW/ZMcuTE8UrYgW1kkj1iVgc6fT7nkTWWZ5+iGRbAKQG5WPKibn
 84f9cn7kJ22ZobayaLskNfe041o1a+zMUCswHdFYTgF29WefeqkikoPx0B80g4p6
 O1jZqSZXKiTtlmIqiISikJhDVx0/kC+ftlu4MJLKq7O8RgcaYmAJp7gSGz50sMPB
 AybcfNkoYsg5J85sinT16TA/Vmcd3ZBWRqaokiRFD/uuqh5cKnyZOTpPwph8Welq
 QxBtqpG36cBLRJRMzlSJNXg1LKvb8WAxWYxGjiSL/8y/V3intnSFYdLjhNpx3yj8
 WCxaG3m2Gf68RQOVSdqlvgH//xBeSz0l9grX+BzJNvBY7aZMmTbXHwIt/lSCiBZd
 radGCMmVN4YEq4OoTgyr
 =ZZSq
 -----END PGP SIGNATURE-----

Merge tag 'kvm-s390-next-20141204' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Fixups for kvm/next (3.19)

Here we have two fixups of the latest interrupt rework and
one architectural fixup.
2014-12-05 13:55:40 +01:00
Jens Freimann
99e20009ae KVM: s390: clean up return code handling in irq delivery code
Instead of returning a possibly random or'ed together value, let's
always return -EFAULT if rc is set.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-12-04 16:39:00 +01:00
Jens Freimann
9185124e87 KVM: s390: use atomic bitops to access pending_irqs bitmap
Currently we use a mixture of atomic/non-atomic bitops
and the local_int spin lock to protect the pending_irqs bitmap
and interrupt payload data.

We need to use atomic bitops for the pending_irqs bitmap everywhere
and in addition acquire the local_int lock where interrupt data needs
to be protected.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-12-04 16:38:57 +01:00
David Hildenbrand
467fc29892 KVM: s390: some ext irqs have to clear the ext cpu addr
The cpu address of a source cpu (responsible for an external irq) is only to
be stored if bit 6 of the ext irq code is set.

If bit 6 is not set, it is to be zeroed out.

The special external irq code used for virtio and pfault uses the cpu addr as a
parameter field. As bit 6 is set, this implementation is correct.

Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-12-04 16:38:38 +01:00
Christian Borntraeger
7a72f7a140 KVM: track pid for VCPU only on KVM_RUN ioctl
We currently track the pid of the task that runs the VCPU in vcpu_load.
If a yield to that VCPU is triggered while the PID of the wrong thread
is active, the wrong thread might receive a yield, but this will most
likely not help the executing thread at all.  Instead, if we only track
the pid on the KVM_RUN ioctl, there are two possibilities:

1) the thread that did a non-KVM_RUN ioctl is holding a mutex that
the VCPU thread is waiting for.  In this case, the VCPU thread is not
runnable, but we also do not do a wrong yield.

2) the thread that did a non-KVM_RUN ioctl is sleeping, or doing
something that does not block the VCPU thread.  In this case, the
VCPU thread can receive the directed yield correctly.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Rik van Riel <riel@redhat.com>
CC: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
CC: Michael Mueller <mimu@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:13 +01:00
David Hildenbrand
eed6e79d73 KVM: don't check for PF_VCPU when yielding
kvm_enter_guest() has to be called with preemption disabled and will
set PF_VCPU.  Current code takes PF_VCPU as a hint that the VCPU thread
is running and therefore needs no yield.

However, the check on PF_VCPU is wrong on s390, where preemption has
to stay enabled in order to correctly process page faults.  Thus,
s390 reenables preemption and starts to execute the guest.  The thread
might be scheduled out between kvm_enter_guest() and kvm_exit_guest(),
resulting in PF_VCPU being set but not being run.  When this happens,
the opportunity for directed yield is missed.

However, this check is done already in kvm_vcpu_on_spin before calling
kvm_vcpu_yield_loop:

        if (!ACCESS_ONCE(vcpu->preempted))
                continue;

so the check on PF_VCPU is superfluous in general, and this patch
removes it.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:12 +01:00
Igor Mammedov
9c1a5d3878 kvm: optimize GFN to memslot lookup with large slots amount
Current linear search doesn't scale well when
large amount of memslots is used and looked up slot
is not in the beginning memslots array.
Taking in account that memslots don't overlap, it's
possible to switch sorting order of memslots array from
'npages' to 'base_gfn' and use binary search for
memslot lookup by GFN.

As result of switching to binary search lookup times
are reduced with large amount of memslots.

Following is a table of search_memslot() cycles
during WS2008R2 guest boot.

                         boot,          boot + ~10 min
                         mostly same    of using it,
                         slot lookup    randomized lookup
                max      average        average
                cycles   cycles         cycles

13 slots      : 1450       28           30

13 slots      : 1400       30           40
binary search

117 slots     : 13000      30           460

117 slots     : 2000       35           180
binary search

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:11 +01:00
Igor Mammedov
0e60b0799f kvm: change memslot sorting rule from size to GFN
it will allow to use binary search for GFN -> memslot
lookups, reducing lookup cost with large slots amount.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:11 +01:00
Igor Mammedov
d4ae84a02b kvm: search_memslots: add simple LRU memslot caching
In typical guest boot workload only 2-3 memslots are used
extensively, and at that it's mostly the same memslot
lookup operation.

Adding LRU cache improves average lookup time from
46 to 28 cycles (~40%) for this workload.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:10 +01:00
Igor Mammedov
7f379cff11 kvm: update_memslots: drop not needed check for the same slot
UP/DOWN shift loops will shift array in needed
direction and stop at place where new slot should
be placed regardless of old slot size.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:09 +01:00
Igor Mammedov
5a38b6e6b4 kvm: update_memslots: drop not needed check for the same number of pages
if number of pages haven't changed sorting algorithm
will do nothing, so there is no need to do extra check
to avoid entering sorting logic.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:09 +01:00
Radim Krčmář
45c3094a64 KVM: x86: allow 256 logical x2APICs again
While fixing an x2apic bug,
 17d68b7 KVM: x86: fix guest-initiated crash with x2apic (CVE-2013-6376)
we've made only one cluster available.  This means that the amount of
logically addressible x2APICs was reduced to 16 and VCPUs kept
overwriting themselves in that region, so even the first cluster wasn't
set up correctly.

This patch extends x2APIC support back to the logical_map's limit, and
keeps the CVE fixed as messages for non-present APICs are dropped.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:08 +01:00
Radim Krčmář
25995e5b4a KVM: x86: check bounds of APIC maps
They can't be violated now, but play it safe for the future.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:08 +01:00
Radim Krčmář
fa834e9197 KVM: x86: fix APIC physical destination wrapping
x2apic allows destinations > 0xff and we don't want them delivered to
lower APICs.  They are correctly handled by doing nothing.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:07 +01:00
Radim Krčmář
085563fb04 KVM: x86: deliver phys lowest-prio
Physical mode can't address more than one APIC, but lowest-prio is
allowed, so we just reuse our paths.

SDM 10.6.2.1 Physical Destination:
  Also, for any non-broadcast IPI or I/O subsystem initiated interrupt
  with lowest priority delivery mode, software must ensure that APICs
  defined in the interrupt address are present and enabled to receive
  interrupts.

We could warn on top of that.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:06 +01:00
Radim Krčmář
698f9755d9 KVM: x86: don't retry hopeless APIC delivery
False from kvm_irq_delivery_to_apic_fast() means that we don't handle it
in the fast path, but we still return false in cases that were perfectly
handled, fix that.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:06 +01:00
Radim Krčmář
decdc28382 KVM: x86: use MSR_ICR instead of a number
0x830 MSR is 0x300 xAPIC MMIO, which is MSR_ICR.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:05 +01:00
Nadav Amit
c69d3d9bc1 KVM: x86: Fix reserved x2apic registers
x2APIC has no registers for DFR and ICR2 (see Intel SDM 10.12.1.2 "x2APIC
Register Address Space"). KVM needs to cause #GP on such accesses.

Fix it (DFR and ICR2 on read, ICR2 on write, DFR already handled on writes).

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:05 +01:00
Nadav Amit
39f062ff51 KVM: x86: Generate #UD when memory operand is required
Certain x86 instructions that use modrm operands only allow memory operand
(i.e., mod012), and cause a #UD exception otherwise. KVM ignores this fact.
Currently, the instructions that are such and are emulated by KVM are MOVBE,
MOVNTPS, MOVNTPD and MOVNTI.  MOVBE is the most blunt example, since it may be
emulated by the host regardless of MMIO.

The fix introduces a new group for handling such instructions, marking mod3 as
illegal instruction.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04 15:29:04 +01:00
Paolo Bonzini
be06b6bece KVM: s390: Several fixes,cleanups and reworks
Here is a bunch of fixes that deal mostly with architectural compliance:
 - interrupt priorities
 - interrupt handling
 - intruction exit handling
 
 We also provide a helper function for getting the guest visible storage key.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.14 (GNU/Linux)
 
 iQIcBAABAgAGBQJUeHKOAAoJEBF7vIC1phx8fS8P/2i1zXvsB+Mp9FafU6FO3Ci6
 yM/ZBLFEsX2jmU0TGR2szZCP4xuHqomJm441+2CX9bXzjf8vnA2hGiDYX0bnBraK
 1/klx6Li1fQxsiSHXIgBXr0wh5ftNUdFVZiJoifY9dEdrhVI+YEiptIl7lADCFXi
 SdGtjEAzrVEe8H0g6OuBXeEfPzHvxAzNJ31yHuiCKl7vbFVnXNVPeZhq3dJZwmWC
 iIdlSqGIjbcHNMLXvrScLDAScBe6WruBLhPSy5aTIA2eBU6f4qkOedSFABJkIAq+
 V6v5pXWbrVBIqfLXE7Vp7jxhP7+viBGzu/gPkfT8HV1pQZDa94WojF8hGU0DLGLd
 vgZuFDV8cMOZMUS/onXOwnIXN5VPvP8V2v3y8gTiap3MykRiyTGEzq2auU9p0K5n
 /8W6Cn1P/WBS8MOFYg726DGmMAWkzpEVz9rxpCLaTpzz7QVyLuSLq/n3SXyQNQIl
 zhox/KzwUQD0t1062USoK3w4suYNvnX0BuFOwxXvS7f4bsb+6V/t0GyIBnVAL/OF
 DZzJSIyzP/Ur/9krxJQxML3kEELU1CjwSLOrzDUnZA3ytaKvsLrHkTb9nK6fREDK
 14AGRnp94B3EMPR6T+7T6gvwK2Y/QIo8Y/EFAa2BwXY4Q/BQPSVU3x3RK6L9+7jY
 VaG9sgn4OC2ZPzxjqMTc
 =MQUy
 -----END PGP SIGNATURE-----

Merge tag 'kvm-s390-next-20141128' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Several fixes,cleanups and reworks

Here is a bunch of fixes that deal mostly with architectural compliance:
- interrupt priorities
- interrupt handling
- intruction exit handling

We also provide a helper function for getting the guest visible storage key.
2014-12-03 15:20:11 +01:00