Commit Graph

484 Commits

Author SHA1 Message Date
Linus Torvalds 66cdd0ceaf Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Marcelo Tosatti:
 "Considerable KVM/PPC work, x86 kvmclock vsyscall support,
  IA32_TSC_ADJUST MSR emulation, amongst others."

Fix up trivial conflict in kernel/sched/core.c due to cross-cpu
migration notifier added next to rq migration call-back.

* tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (156 commits)
  KVM: emulator: fix real mode segment checks in address linearization
  VMX: remove unneeded enable_unrestricted_guest check
  KVM: VMX: fix DPL during entry to protected mode
  x86/kexec: crash_vmclear_local_vmcss needs __rcu
  kvm: Fix irqfd resampler list walk
  KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump
  x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary
  KVM: MMU: optimize for set_spte
  KVM: PPC: booke: Get/set guest EPCR register using ONE_REG interface
  KVM: PPC: bookehv: Add EPCR support in mtspr/mfspr emulation
  KVM: PPC: bookehv: Add guest computation mode for irq delivery
  KVM: PPC: Make EPCR a valid field for booke64 and bookehv
  KVM: PPC: booke: Extend MAS2 EPN mask for 64-bit
  KVM: PPC: e500: Mask MAS2 EPN high 32-bits in 32/64 tlbwe emulation
  KVM: PPC: Mask ea's high 32-bits in 32/64 instr emulation
  KVM: PPC: e500: Add emulation helper for getting instruction ea
  KVM: PPC: bookehv64: Add support for interrupt handling
  KVM: PPC: bookehv: Remove GET_VCPU macro from exception handler
  KVM: PPC: booke: Fix get_tb() compile error on 64-bit
  KVM: PPC: e500: Silence bogus GCC warning in tlb code
  ...
2012-12-13 15:31:08 -08:00
Gleb Natapov 0b26b588d9 VMX: remove unneeded enable_unrestricted_guest check
If enable_unrestricted_guest is true vmx->rmode.vm86_active will
always be false.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-11 21:00:28 -02:00
Gleb Natapov a4d3326c2d KVM: VMX: fix DPL during entry to protected mode
On CPUs without support for unrestricted guests DPL cannot be smaller
than RPL for data segments during guest entry, but this state can occurs
if a data segment selector changes while vcpu is in real mode to a value
with lowest two bits != 00. Fix that by forcing DPL == RPL on transition
to protected mode.

This is a regression introduced by c865c43de6.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-11 21:00:27 -02:00
Zhang Yanfei 8f536b7697 KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump
The vmclear function will be assigned to the callback function pointer
when loading kvm-intel module. And the bitmap indicates whether we
should do VMCLEAR operation in kdump. The bits in the bitmap are
set/unset according to different conditions.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-06 18:26:57 +02:00
Julian Stecklina 66f7b72e11 KVM: x86: Make register state after reset conform to specification
VMX behaves now as SVM wrt to FPU initialization. Code has been moved to
generic code path. General-purpose registers are now cleared on reset and
INIT.  SVM code properly initializes EDX.

Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-05 18:00:07 +02:00
Zhang Xiantao 2b3c5cbc0d kvm: don't use bit24 for detecting address-specific invalidation capability
Bit24 in VMX_EPT_VPID_CAP_MASI is  not used for address-specific invalidation capability
reporting, so remove it from KVM to avoid conflicts in future.

Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-05 16:35:48 +02:00
Zhang Xiantao 0307b7b8c2 kvm: remove unnecessary bit checking for ept violation
Bit 6 in EPT vmexit's exit qualification is not defined in SDM, so remove it.

Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-05 16:35:21 +02:00
Will Auld ba904635d4 KVM: x86: Emulate IA32_TSC_ADJUST MSR
CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported

Basic design is to emulate the MSR by allowing reads and writes to a guest
vcpu specific location to store the value of the emulated MSR while adding
the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will
be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This
is of course as long as the "use TSC counter offsetting" VM-execution control
is enabled as well as the IA32_TSC_ADJUST control.

However, because hardware will only return the TSC + IA32_TSC_ADJUST +
vmsc tsc_offset for a guest process when it does and rdtsc (with the correct
settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one
of these three locations. The argument against storing it in the actual MSR
is performance. This is likely to be seldom used while the save/restore is
required on every transition. IA32_TSC_ADJUST was created as a way to solve
some issues with writing TSC itself so that is not an option either.

The remaining option, defined above as our solution has the problem of
returning incorrect vmcs tsc_offset values (unless we intercept and fix, not
done here) as mentioned above. However, more problematic is that storing the
data in vmcs tsc_offset will have a different semantic effect on the system
than does using the actual MSR. This is illustrated in the following example:

The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest
process performs a rdtsc. In this case the guest process will get
TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including
IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics
as seen by the guest do not and hence this will not cause a problem.

Signed-off-by: Will Auld <will.auld@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-30 18:29:30 -02:00
Will Auld 8fe8ab46be KVM: x86: Add code to track call origin for msr assignment
In order to track who initiated the call (host or guest) to modify an msr
value I have changed function call parameters along the call path. The
specific change is to add a struct pointer parameter that points to (index,
data, caller) information rather than having this information passed as
individual parameters.

The initial use for this capability is for updating the IA32_TSC_ADJUST msr
while setting the tsc value. It is anticipated that this capability is
useful for other tasks.

Signed-off-by: Will Auld <will.auld@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-30 18:26:12 -02:00
Xiao Guangrong 5a560f8b5e KVM: VMX: fix memory order between loading vmcs and clearing vmcs
vmcs->cpu indicates whether it exists on the target cpu, -1 means the vmcs
does not exist on any vcpu

If vcpu load vmcs with vmcs.cpu = -1, it can be directly added to cpu's percpu
list. The list can be corrupted if the cpu prefetch the vmcs's list before
reading vmcs->cpu. Meanwhile, we should remove vmcs from the list before
making vmcs->vcpu == -1 be visible

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 21:14:46 -02:00
Xiao Guangrong e6c7d32172 KVM: VMX: fix invalid cpu passed to smp_call_function_single
In loaded_vmcs_clear, loaded_vmcs->cpu is the fist parameter passed to
smp_call_function_single, if the target cpu is downing (doing cpu hot remove),
loaded_vmcs->cpu can become -1 then -1 is passed to smp_call_function_single

It can be triggered when vcpu is being destroyed, loaded_vmcs_clear is called
in the preemptionable context

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-28 22:04:58 -02:00
Marcelo Tosatti 42897d866b KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initialization
TSC initialization will soon make use of online_vcpus.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:14 -02:00
Marcelo Tosatti 886b470cb1 KVM: x86: pass host_tsc to read_l1_tsc
Allow the caller to pass host tsc value to kvm_x86_ops->read_l1_tsc().

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:11 -02:00
Takashi Iwai 29282fde80 KVM: x86: Fix invalid secondary exec controls in vmx_cpuid_update()
The commit [ad756a16: KVM: VMX: Implement PCID/INVPCID for guests with
EPT] introduced the unconditional access to SECONDARY_VM_EXEC_CONTROL,
and this triggers kernel warnings like below on old CPUs:

    vmwrite error: reg 401e value a0568000 (err 12)
    Pid: 13649, comm: qemu-kvm Not tainted 3.7.0-rc4-test2+ #154
    Call Trace:
     [<ffffffffa0558d86>] vmwrite_error+0x27/0x29 [kvm_intel]
     [<ffffffffa054e8cb>] vmcs_writel+0x1b/0x20 [kvm_intel]
     [<ffffffffa054f114>] vmx_cpuid_update+0x74/0x170 [kvm_intel]
     [<ffffffffa03629b6>] kvm_vcpu_ioctl_set_cpuid2+0x76/0x90 [kvm]
     [<ffffffffa0341c67>] kvm_arch_vcpu_ioctl+0xc37/0xed0 [kvm]
     [<ffffffff81143f7c>] ? __vunmap+0x9c/0x110
     [<ffffffffa0551489>] ? vmx_vcpu_load+0x39/0x1a0 [kvm_intel]
     [<ffffffffa0340ee2>] ? kvm_arch_vcpu_load+0x52/0x1a0 [kvm]
     [<ffffffffa032dcd4>] ? vcpu_load+0x74/0xd0 [kvm]
     [<ffffffffa032deb0>] kvm_vcpu_ioctl+0x110/0x5e0 [kvm]
     [<ffffffffa032e93d>] ? kvm_dev_ioctl+0x4d/0x4a0 [kvm]
     [<ffffffff8117dc6f>] do_vfs_ioctl+0x8f/0x530
     [<ffffffff81139d76>] ? remove_vma+0x56/0x60
     [<ffffffff8113b708>] ? do_munmap+0x328/0x400
     [<ffffffff81187c8c>] ? fget_light+0x4c/0x100
     [<ffffffff8117e1a1>] sys_ioctl+0x91/0xb0
     [<ffffffff815a942d>] system_call_fastpath+0x1a/0x1f

This patch adds a check for the availability of secondary exec
control to avoid these warnings.

Cc: <stable@vger.kernel.org> [v3.6+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-16 20:25:18 -02:00
Xiao Guangrong bf4ca23ef5 KVM: VMX: report internal error for MMIO #PF due to delivery event
The #PF with PFEC.RSV = 1 indicates that the guest is accessing MMIO, we
can not fix it if it is caused by delivery event. Reporting internal error
for this case

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

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-18 16:30:29 +02:00
Linus Torvalds ecefbd94b8 KVM updates for the 3.7 merge window
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Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

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

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

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

  There are also various Sparse fixes"

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

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, kvm: fix kvm's usage of kernel_fpu_begin/end()
  x86, fpu: remove cpu_has_xmm check in the fx_finit()
  x86, fpu: make eagerfpu= boot param tri-state
  x86, fpu: enable eagerfpu by default for xsaveopt
  x86, fpu: decouple non-lazy/eager fpu restore from xsave
  x86, fpu: use non-lazy fpu restore for processors supporting xsave
  lguest, x86: handle guest TS bit for lazy/non-lazy fpu host models
  x86, fpu: always use kernel_fpu_begin/end() for in-kernel FPU usage
  x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
  x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig()
  x86, fpu: drop_fpu() before restoring new state from sigframe
  x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels
  x86, fpu: Consolidate inline asm routines for saving/restoring fpu state
  x86, signal: Cleanup ifdefs and is_ia32, is_x32
2012-10-01 11:10:52 -07:00
Jan Kiszka c863901075 KVM: x86: Fix guest debug across vcpu INIT reset
If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.

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

Found while trying to stop on start_secondary.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-23 15:00:07 +02:00
Suresh Siddha b1a74bf821 x86, kvm: fix kvm's usage of kernel_fpu_begin/end()
Preemption is disabled between kernel_fpu_begin/end() and as such
it is not a good idea to use these routines in kvm_load/put_guest_fpu()
which can be very far apart.

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

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

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

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-09-21 16:59:04 -07:00
Peter Senna Tschudin 4b8073e467 arch/x86: Remove unecessary semicolons
Found by http://coccinelle.lip6.fr/

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: avi@redhat.com
Cc: mtosatti@redhat.com
Cc: a.p.zijlstra@chello.nl
Cc: rusty@rustcorp.com.au
Cc: masami.hiramatsu.pt@hitachi.com
Cc: suresh.b.siddha@intel.com
Cc: joerg.roedel@amd.com
Cc: agordeev@redhat.com
Cc: yinghai@kernel.org
Cc: bhelgaas@google.com
Cc: liuj97@gmail.com
Link: http://lkml.kernel.org/r/1347986174-30287-7-git-send-email-peter.senna@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-19 17:32:48 +02:00
Avi Kivity b188c81f2e KVM: VMX: Make use of asm.h
Use macros for bitness-insensitive register names, instead of
rolling our own.

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

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 10:38:03 -03:00
Xiao Guangrong 4484141a94 KVM: fix error paths for failed gfn_to_page() calls
This bug was triggered:
[ 4220.198458] BUG: unable to handle kernel paging request at fffffffffffffffe
[ 4220.203907] IP: [<ffffffff81104d85>] put_page+0xf/0x34
......
[ 4220.237326] Call Trace:
[ 4220.237361]  [<ffffffffa03830d0>] kvm_arch_destroy_vm+0xf9/0x101 [kvm]
[ 4220.237382]  [<ffffffffa036fe53>] kvm_put_kvm+0xcc/0x127 [kvm]
[ 4220.237401]  [<ffffffffa03702bc>] kvm_vcpu_release+0x18/0x1c [kvm]
[ 4220.237407]  [<ffffffff81145425>] __fput+0x111/0x1ed
[ 4220.237411]  [<ffffffff8114550f>] ____fput+0xe/0x10
[ 4220.237418]  [<ffffffff81063511>] task_work_run+0x5d/0x88
[ 4220.237424]  [<ffffffff8104c3f7>] do_exit+0x2bf/0x7ca

The test case:

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

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

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

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

	return vm_fd;
}

static int create_vcpu(int vm_fd)
{
	int vcpu_fd;

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

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

	create_vcpu(vm_fd);
	return NULL;
}

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

	(void)argc;
	(void)argv;

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

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

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

Fixed by checking the page before it is used

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-10 11:34:11 +03:00
Ren, Yongjie 4f97704555 KVM: x86: Check INVPCID feature bit in EBX of leaf 7
Checks and operations on the INVPCID feature bit should use EBX
of CPUID leaf 7 instead of ECX.

Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Signed-off-by: Yongjie Ren <yongjien.ren@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-09 17:34:01 +03:00
Mathias Krause 772e031899 KVM: VMX: constify lookup tables
We use vmcs_field_to_offset_table[], kvm_vmx_segment_fields[] and
kvm_vmx_exit_handlers[] as lookup tables only -- make them r/o.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05 12:42:09 +03:00
Avi Kivity a81aba14dc KVM: VMX: Ignore segment G and D bits when considering whether we can virtualize
We will enter the guest with G and D cleared; as real hardware ignores D in
real mode, and G is taken care of by the limit test, we allow more code to
run in vm86 mode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:21 -03:00
Avi Kivity ce56680347 KVM: VMX: Save all segment data in real mode
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:21 -03:00
Avi Kivity 1390a28b27 KVM: VMX: Preserve segment limit and access rights in real mode
While this is undocumented, real processors do not reload the segment
limit and access rights when loading a segment register in real mode.
Real programs rely on it so we need to comply with this behaviour.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:21 -03:00
Avi Kivity 7263642028 KVM: VMX: Return real real-mode segment data even if emulate_invalid_guest_state=1
emulate_invalid_guest_state=1 doesn't mean we don't munge the segments in the
vmcs; we do.  So we need to return the real ones (maintained by vmx_set_segment).

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:21 -03:00
Avi Kivity e2a610d7fc KVM: VMX: Allow vm86 virtualization of big real mode
Usually, big real mode uses large (4GB) segments.  Currently we don't
virtualize this; if any segment has a limit other than 0xffff, we emulate.
But if we set the vmx-visible limit to 0xffff, we can use vm86 to virtualize
real mode; if an access overruns the segment limit, the guest will #GP, which
we will trap and forward to the emulator.  This results in significantly
faster execution, and less risk of hitting an unemulated instruction.

If the limit is less than 0xffff, we retain the existing behaviour.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:20 -03:00
Avi Kivity 495e116684 KVM: VMX: Allow real mode emulation using vm86 with dpl=0
Real mode is always entered from protected mode with dpl=0.  Since
the dpl doesn't affect execution, and we already override it to 3
in the vmcs (as vmx requires), we can allow execution in that state.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:20 -03:00
Avi Kivity c865c43de6 KVM: VMX: Retain limit and attributes when entering protected mode
Real processors don't change segment limits and attributes while in
real mode.  Mimic that behaviour.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:20 -03:00
Avi Kivity f5f7b2fe3b KVM: VMX: Use kvm_segment to save protected-mode segments when entering realmode
Instead of using struct kvm_save_segment, use struct kvm_segment, which is what
the other APIs use.  This leads to some simplification.

We replace save_rmode_seg() with a call to vmx_save_segment().  Since this depends
on rmode.vm86_active, we move the call to before setting the flag.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:19 -03:00
Avi Kivity 72fbefec26 KVM: VMX: Fix incorrect lookup of segment S flag in fix_pmode_dataseg()
fix_pmode_dataseg() looks up S in ->base instead of ->ar_bytes.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:19 -03:00
Avi Kivity baa7e81e32 KVM: VMX: Separate saving pre-realmode state from setting segments
Commit b246dd5df1 ("KVM: VMX: Fix KVM_SET_SREGS with big real mode
segments") moved fix_rmode_seg() to vmx_set_segment(), so that it is
applied not just on transitions to real mode, but also on KVM_SET_SREGS
(migration).  However fix_rmode_seg() not only munges the vmcs segments,
it also sets up the save area for us to restore when returning to
protected mode or to return in vmx_get_segment().

Move saving the segment into a new function, save_rmode_seg(), and
call it just during the transition.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 20:02:19 -03:00
Avi Kivity dbcb4e7980 KVM: VMX: Advertize RDTSC exiting to nested guests
All processors that support VMX have that feature, and guests (Xen) depend on
it.  As we already implement it, advertize it to the guest.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-13 19:08:28 -03:00
Gleb Natapov 2a7921b7a0 KVM: VMX: restore MSR_IA32_DEBUGCTLMSR after VMEXIT
MSR_IA32_DEBUGCTLMSR is zeroed on VMEXIT. Restore it to the correct
value.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-13 19:07:58 -03:00
Xiao Guangrong 32cad84f44 KVM: do not release the error page
After commit a2766325cf, the error page is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:58 +03:00
Avi Kivity fe56097b23 Merge remote-tracking branch 'upstream' into next
- bring back critical fixes (esp. aa67f6096c)
 - provide an updated base for development

* upstream: (4334 commits)
  missed mnt_drop_write() in do_dentry_open()
  UBIFS: nuke pdflush from comments
  gfs2: nuke pdflush from comments
  drbd: nuke pdflush from comments
  nilfs2: nuke write_super from comments
  hfs: nuke write_super from comments
  vfs: nuke pdflush from comments
  jbd/jbd2: nuke write_super from comments
  btrfs: nuke pdflush from comments
  btrfs: nuke write_super from comments
  ext4: nuke pdflush from comments
  ext4: nuke write_super from comments
  ext3: nuke write_super from comments
  Documentation: fix the VM knobs descritpion WRT pdflush
  Documentation: get rid of write_super
  vfs: kill write_super and sync_supers
  ACPI processor: Fix tick_broadcast_mask online/offline regression
  ACPI: Only count valid srat memory structures
  ACPI: Untangle a return statement for better readability
  Linux 3.6-rc1
  ...

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-05 13:25:10 +03:00
Avi Kivity aa67f6096c KVM: VMX: Fix ds/es corruption on i386 with preemption
Commit b2da15ac26 ("KVM: VMX: Optimize %ds, %es reload") broke i386
in the following scenario:

  vcpu_load
  ...
  vmx_save_host_state
  vmx_vcpu_run
  (ds.rpl, es.rpl cleared by hardware)

  interrupt
    push ds, es  # pushes bad ds, es
    schedule
      vmx_vcpu_put
        vmx_load_host_state
          reload ds, es (with __USER_DS)
    pop ds, es  # of other thread's stack
    iret
  # other thread runs
  interrupt
    push ds, es
    schedule  # back in vcpu thread
    pop ds, es  # now with rpl=0
    iret
  ...
  vcpu_put
  resume_userspace
  iret  # clears ds, es due to mismatched rpl

(instead of resume_userspace, we might return with SYSEXIT and then
take an exception; when the exception IRETs we end up with cleared
ds, es)

Fix by avoiding the optimization on i386 and reloading ds, es on the
lightweight exit path.

Reported-by: Chris Clayron <chris2553@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01 20:23:57 -03:00
Guo Chao 0fa0607147 KVM: VMX: Fix typos
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-20 15:19:04 -03:00
Mao, Junjie ad756a1603 KVM: VMX: Implement PCID/INVPCID for guests with EPT
This patch handles PCID/INVPCID for guests.

Process-context identifiers (PCIDs) are a facility by which a logical processor
may cache information for multiple linear-address spaces so that the processor
may retain cached information when software switches to a different linear
address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual
Volume 3A for details.

For guests with EPT, the PCID feature is enabled and INVPCID behaves as running
natively.
For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD.

Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-12 13:07:34 +03:00
Xiao Guangrong 4f5982a56a KVM: VMX: export PFEC.P bit on ept
Export the present bit of page fault error code, the later patch
will use it

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-11 16:51:17 +03:00
Avi Kivity a27685c33a KVM: VMX: Emulate invalid guest state by default
Our emulation should be complete enough that we can emulate guests
while they are in big real mode, or in a mode transition that is not
virtualizable without unrestricted guest support.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:05 +03:00
Avi Kivity de5f70e0c6 KVM: VMX: Improve error reporting during invalid guest state emulation
If instruction emulation fails, report it properly to userspace.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:04 +03:00
Avi Kivity de87dcddc7 KVM: VMX: Stop invalid guest state emulation on pending event
Process the event, possibly injecting an interrupt, before continuing.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:04 +03:00
Avi Kivity 7c068e4558 KVM: VMX: Continue emulating after batch exhausted
If we return early from an invalid guest state emulation loop, make
sure we return to it later if the guest state is still invalid.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:03 +03:00
Avi Kivity bdea48e305 KVM: VMX: Fix interrupt exit condition during emulation
Checking EFLAGS.IF is incorrect as we might be in interrupt shadow.  If
that is the case, the main loop will notice that and not inject the interrupt,
causing an endless loop.

Fix by using vmx_interrupt_allowed() to check if we can inject an interrupt
instead.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:02 +03:00
Avi Kivity b8405c184b KVM: VMX: Limit iterations with emulator_invalid_guest_state
Otherwise, if the guest ends up looping, we never exit the srcu critical
section, which causes synchronize_srcu() to hang.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:01 +03:00