This patch makes the cmpxchg_gpte() function aware of the
difference between l1-gfns and l2-gfns when nested
virtualization is in use. This fixes a potential
data-corruption problem in the l1-guest and makes the code
work correct (at least as correct as the hardware which is
emulated in this code) again.
Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
The last_guest_tsc is used in vcpu_load to adjust the
tsc_offset since tsc-scaling is merged. So the
last_guest_tsc needs to be updated in vcpu_put instead of
the the last_host_tsc. This is fixed with this patch.
Reported-by: Jan Kiszka <jan.kiszka@web.de> Tested-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: SVM: Fix nested sel_cr0 intercept path with decode-assists
This patch fixes a bug in the nested-svm path when
decode-assists is available on the machine. After a
selective-cr0 intercept is detected the rip is advanced
unconditionally. This causes the l1-guest to continue
running with an l2-rip.
This bug was with the sel_cr0 unit-test on decode-assists
capable hardware.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Nelson Elhage [Wed, 13 Apr 2011 15:44:13 +0000 (11:44 -0400)]
KVM: x86 emulator: Handle wraparound in (cs_base + offset) when fetching insns
Currently, setting a large (i.e. negative) base address for %cs does not work on
a 64-bit host. The "JOS" teaching operating system, used by MIT and other
universities, relies on such segments while bootstrapping its way to full
virtual memory management.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Jeff Mahoney [Wed, 13 Apr 2011 01:30:17 +0000 (21:30 -0400)]
KVM: Fix off by one in kvm_for_each_vcpu iteration
This patch avoids gcc issuing the following warning when KVM_MAX_VCPUS=1:
warning: array subscript is above array bounds
kvm_for_each_vcpu currently checks to see if the index for the vcpu is
valid /after/ loading it. We don't run into problems because the address
is still inside the enclosing struct kvm and we never deference or write
to it, so this isn't a security issue.
The warning occurs when KVM_MAX_VCPUS=1 because the increment portion of
the loop will *always* cause the loop to load an invalid location since
++idx will always be > 0.
This patch moves the load so that the check occurs before the load and
we don't run into the compiler warning.
Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Avi Kivity <avi@redhat.com>
When doing a soft int, we need to bump eip before pushing it to
the stack. Otherwise we'll do the int a second time.
[apw@canonical.com: merged eip update as per Jan's recommendation.] Signed-off-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: x86 emulator: Make emulate_push() store the value directly
PUSH emulation stores the value by calling writeback() after setting
the dst operand appropriately in emulate_push().
This writeback() using dst is not needed at all because we know the
target is the stack. So this patch makes emulate_push() call, newly
introduced, segmented_write() directly.
By this, many inlined writeback()'s are removed.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
Jan Kiszka [Tue, 12 Apr 2011 23:27:55 +0000 (01:27 +0200)]
KVM: VMX: Ensure that vmx_create_vcpu always returns proper error
In case certain allocations fail, vmx_create_vcpu may return 0 as error
instead of a negative value encoded via ERR_PTR. This causes a NULL
pointer dereferencing later on in kvm_vm_ioctl_vcpu_create.
Gleb Natapov [Thu, 31 Mar 2011 10:06:41 +0000 (12:06 +0200)]
KVM: emulator: do not needlesly sync registers from emulator ctxt to vcpu
Currently we sync registers back and forth before/after exiting
to userspace for IO, but during IO device model shouldn't need to
read/write the registers, so we can as well skip those sync points. The
only exaception is broken vmware backdor interface. The new code sync
registers content during IO only if registers are read from/written to
by userspace in the middle of the IO operation and this almost never
happens in practise.
KVM: SVM: Fix fault-rip on vmsave/vmload emulation
When the emulation of vmload or vmsave fails because the
guest passed an unsupported physical address it gets an #GP
with rip pointing to the instruction after vmsave/vmload.
This is a bug and fixed by this patch.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Joerg Roedel [Fri, 25 Mar 2011 08:44:51 +0000 (09:44 +0100)]
KVM: X86: Implement userspace interface to set virtual_tsc_khz
This patch implements two new vm-ioctls to get and set the
virtual_tsc_khz if the machine supports tsc-scaling. Setting
the tsc-frequency is only possible before userspace creates
any vcpu.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Joerg Roedel [Fri, 25 Mar 2011 08:44:50 +0000 (09:44 +0100)]
KVM: X86: Delegate tsc-offset calculation to architecture code
With TSC scaling in SVM the tsc-offset needs to be
calculated differently. This patch propagates this
calculation into the architecture specific modules so that
this complexity can be handled there.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Joerg Roedel [Fri, 25 Mar 2011 08:44:49 +0000 (09:44 +0100)]
KVM: X86: Implement call-back to propagate virtual_tsc_khz
This patch implements a call-back into the architecture code
to allow the propagation of changes to the virtual tsc_khz
of the vcpu.
On SVM it updates the tsc_ratio variable, on VMX it does
nothing.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Joerg Roedel [Fri, 25 Mar 2011 08:44:48 +0000 (09:44 +0100)]
KVM: X86: Make tsc_delta calculation a function of guest tsc
The calculation of the tsc_delta value to ensure a
forward-going tsc for the guest is a function of the
host-tsc. This works as long as the guests tsc_khz is equal
to the hosts tsc_khz. With tsc-scaling hardware support this
is not longer true and the tsc_delta needs to be calculated
using guest_tsc values.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Tue, 5 Apr 2011 13:21:58 +0000 (16:21 +0300)]
KVM: x86 emulator: Re-add VendorSpecific tag to VMMCALL insn
VMMCALL needs the VendorSpecific tag so that #UD emulation
(called if a guest running on AMD was migrated to an Intel host)
is allowed to process the instruction.
The vcpu->mutex is used by kvm_ioctl_* (KVM_RUN etc) and same was
used when clearing the stats (in kvmppc_init_timing_stats()). What happens
is that when the guest is idle then it held the vcpu->mutx. While the
exiting timing process waits for guest to release the vcpu->mutex and
a hang state is reached.
Now using seprate lock for exit timing stats.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
This patch removes all the old code which handled the nested
selective cr0 write intercepts. This code was only in place
as a work-around until the instruction emulator is capable
of doing the same. This is the case with this patch-set and
so the code can be removed.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: SVM: Add intercept checks for SVM instructions
This patch adds the necessary code changes in the
instruction emulator and the extensions to svm.c to
implement intercept checks for the svm instructions.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a check_perm callback for each opcode into
the instruction emulator. This will be used to do all
necessary permission checks on instructions before checking
whether they are intercepted or not.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Mon, 4 Apr 2011 10:39:22 +0000 (12:39 +0200)]
KVM: x86 emulator: add framework for instruction intercepts
When running in guest mode, certain instructions can be intercepted by
hardware. This also holds for nested guests running on emulated
virtualization hardware, in particular instructions emulated by kvm
itself.
This patch adds a framework for intercepting instructions. If an
instruction is marked for interception, and if we're running in guest
mode, a callback is called to check whether an intercept is needed or
not. The callback is called at three points in time: immediately after
beginning execution, after checking privilge exceptions, and after
checking memory exception. This suits the different interception points
defined for different instructions and for the various virtualization
instruction sets.
In addition, a new X86EMUL_INTERCEPT is defined, which any callback or
memory access may define, allowing the more complicated intercepts to be
implemented in existing callbacks.
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Tue, 29 Mar 2011 09:34:38 +0000 (11:34 +0200)]
KVM: x86 emulator: Specialize decoding for insns with 66/f2/f3 prefixes
Most SIMD instructions use the 66/f2/f3 prefixes to distinguish between
different variants of the same instruction. Usually the encoding is quite
regular, but in some cases (including non-SIMD instructions) the prefixes
generate very different instructions. Examples include XCHG/PAUSE,
MOVQ/MOVDQA/MOVDQU, and MOVBE/CRC32.
Allow the emulator to handle these special cases by splitting such opcodes
into groups, with different decode flags and execution functions for different
prefixes.
Avi Kivity [Wed, 20 Jan 2010 14:00:35 +0000 (16:00 +0200)]
KVM: x86 emulator: do not munge rep prefix
Currently we store a rep prefix as 1 or 2 depending on whether it is a REPE or
REPNE. Since sse instructions depend on the prefix value, store it as the
original opcode to simplify things further on.
Avi Kivity [Wed, 20 Jan 2010 10:01:20 +0000 (12:01 +0200)]
KVM: 16-byte mmio support
Since sse instructions can issue 16-byte mmios, we need to support them. We
can't increase the kvm_run mmio buffer size to 16 bytes without breaking
compatibility, so instead we break the large mmios into two smaller 8-byte
ones. Since the bus is 64-bit we aren't breaking any atomicity guarantees.
Glauber Costa [Wed, 23 Mar 2011 16:40:42 +0000 (13:40 -0300)]
KVM: expose async pf through our standard mechanism
As Avi recently mentioned, the new standard mechanism for exposing features
is KVM_GET_SUPPORTED_CPUID, not spamming CAPs. For some reason async pf
missed that.
So expose async_pf here.
Signed-off-by: Glauber Costa <glommer@redhat.com> CC: Gleb Natapov <gleb@redhat.com> CC: Avi Kivity <avi@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Wed, 23 Mar 2011 13:02:47 +0000 (15:02 +0200)]
KVM: VMX: simplify NMI mask management
Use vmx_set_nmi_mask() instead of open-coding management of
the hardware bit and the software hint (nmi_known_unmasked).
There's a slight change of behaviour when running without
hardware virtual NMI support - we now clear the NMI mask if
NMI delivery faulted in that case as well. This improves
emulation accuracy.
Avi Kivity [Mon, 7 Mar 2011 14:52:07 +0000 (16:52 +0200)]
KVM: VMX: Avoid vmx_recover_nmi_blocking() when unneeded
When we haven't injected an interrupt, we don't need to recover
the nmi blocking state (since the guest can't set it by itself).
This allows us to avoid a VMREAD later on.
Avi Kivity [Mon, 7 Mar 2011 13:26:44 +0000 (15:26 +0200)]
KVM: VMX: Cache cpl
We may read the cpl quite often in the same vmexit (instruction privilege
check, memory access checks for instruction and operands), so we gain
a bit if we cache the value.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (27 commits)
slcan: fix ldisc->open retval
net/usb: mark LG VL600 LTE modem ethernet interface as WWAN
xfrm: Don't allow esn with disabled anti replay detection
xfrm: Assign the inner mode output function to the dst entry
net: dev_close() should check IFF_UP
vlan: fix GVRP at dismantle time
netfilter: revert a2361c8735e07322023aedc36e4938b35af31eb0
netfilter: IPv6: fix DSCP mangle code
netfilter: IPv6: initialize TOS field in REJECT target module
IPVS: init and cleanup restructuring
IPVS: Change of socket usage to enable name space exit.
netfilter: ebtables: only call xt_compat_add_offset once per rule
netfilter: fix ebtables compat support
netfilter: ctnetlink: fix timestamp support for new conntracks
pch_gbe: support ML7223 IOH
PCH_GbE : Fixed the issue of checksum judgment
PCH_GbE : Fixed the issue of collision detection
NET: slip, fix ldisc->open retval
be2net: Fixed bugs related to PVID.
ehea: fix wrongly reported speed and port
...
David Rientjes [Wed, 11 May 2011 00:08:54 +0000 (17:08 -0700)]
slub: Revert "[PARISC] slub: fix panic with DISCONTIGMEM"
This reverts commit 4a5fa3590f09, which did not allow SLUB to be used
on architectures that use DISCONTIGMEM without compiling NUMA support
without CONFIG_BROKEN also set.
The slub panic that it was intended to prevent is addressed by d9b41e0b54fd ("[PARISC] set memory ranges in N_NORMAL_MEMORY when
onlined") on parisc so there is no further slub issues with such a
configuration.
The reverts allows SLUB now to be used on such architectures since
there haven't been any reports of additional errors.
Cc: James Bottomley <James.Bottomley@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>