Avi Kivity [Mon, 8 Jun 2009 12:52:39 +0000 (15:52 +0300)]
KVM: Disable large pages on misaligned memory slots
If a slots guest physical address and host virtual address unequal (mod
large page size), then we would erronously try to back guest large pages
with host large pages. Detect this misalignment and diable large page
support for the trouble slot.
Cc: stable@kernel.org Signed-off-by: Avi Kivity <avi@redhat.com>
Andi Kleen [Mon, 8 Jun 2009 09:37:09 +0000 (17:37 +0800)]
KVM: Add VT-x machine check support
VT-x needs an explicit MC vector intercept to handle machine checks in the
hyper visor.
It also has a special option to catch machine checks that happen
during VT entry.
Do these interceptions and forward them to the Linux machine check
handler. Make it always look like user space is interrupted because
the machine check handler treats kernel/user space differently.
Gleb Natapov [Mon, 11 May 2009 10:35:53 +0000 (13:35 +0300)]
KVM: Do not migrate pending software interrupts.
INTn will be re-executed after migration. If we wanted to migrate
pending software interrupt we would need to migrate interrupt type
and instruction length too, but we do not have all required info on
SVM, so SVM->VMX migration would need to re-execute INTn anyway. To
make it simple never migrate pending soft interrupt.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 11 May 2009 10:35:52 +0000 (13:35 +0300)]
KVM: inject NMI after IRET from a previous NMI, not before.
If NMI is received during handling of another NMI it should be injected
immediately after IRET from previous NMI handler, but SVM intercept IRET
before instruction execution so we can't inject pending NMI at this
point and there is not way to request exit when NMI window opens. This
patch fix SVM code to open NMI window after IRET by single stepping over
IRET instruction.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 11 May 2009 10:35:48 +0000 (13:35 +0300)]
KVM: Remove irq_pending bitmap
Only one interrupt vector can be injected from userspace irqchip at
any given time so no need to store it in a bitmap. Put it into interrupt
queue directly.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Carsten Otte [Tue, 12 May 2009 15:21:53 +0000 (17:21 +0200)]
KVM: s390: Verify memory in kvm run
This check verifies that the guest we're trying to run in KVM_RUN
has some memory assigned to it. It enters an endless exception
loop if this is not the case.
Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Carsten Otte [Tue, 12 May 2009 15:21:52 +0000 (17:21 +0200)]
KVM: s390: Sanity check on validity intercept
This patch adds a sanity check for the content of the guest
prefix register content before faulting in the cpu lowcore
that it refers to. The guest might end up in an endless loop
where SIE complains about missing lowcore with incorrect
content of the prefix register without this fix.
Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Carsten Otte [Tue, 12 May 2009 15:21:51 +0000 (17:21 +0200)]
KVM: s390: Unlink vcpu on destroy - v2
This patch makes sure we do unlink a vcpu's sie control block
from the system control area in kvm_arch_vcpu_destroy. This
prevents illegal accesses to the sie control block from other
virtual cpus after free.
Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: s390: optimize float int lock: spin_lock_bh --> spin_lock
The floating interrupt lock is only taken in process context. We can
replace all spin_lock_bh with standard spin_lock calls.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: s390: use hrtimer for clock wakeup from idle - v2
This patch reworks the s390 clock comparator wakeup to hrtimer. The clock
comparator is a per-cpu value that is compared against the TOD clock. If
ckc <= TOD an external interrupt 1004 is triggered. Since the clock comparator
and the TOD clock have a much higher resolution than jiffies we should use
hrtimers to trigger the wakeup. This speeds up guest nanosleep for small
values.
Since hrtimers callbacks run in hard-irq context, I added a tasklet to do
the actual work with enabled interrupts.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Carsten Otte [Tue, 12 May 2009 15:21:48 +0000 (17:21 +0200)]
KVM: s390: Fix memory slot versus run - v3
This patch fixes an incorrectness in the kvm backend for s390.
In case virtual cpus are being created before the corresponding
memory slot is being registered, we need to update the sie
control blocks for the virtual cpus.
*updates in v3*
In consideration of the s390 memslot constraints locking was changed
to trylock. These locks should never be held, as vcpu's can't run without
the single memslot we just assign when running this code. To ensure this
never deadlocks in case other code changes the code uses trylocks and bail
out if it can't get all locks.
Additionally most of the discussed special conditions for s390 like
only one memslot and no user_alloc are now checked for validity in
kvm_arch_set_memory_region.
Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Robert P. J. Day [Tue, 12 May 2009 20:44:06 +0000 (13:44 -0700)]
KVM: Expand on "help" info to specify kvm intel and amd module names
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Avi Kivity <avi@redhat.com>
Glauber Costa [Tue, 12 May 2009 20:21:06 +0000 (16:21 -0400)]
KVM: Deal with interrupt shadow state for emulated instructions
We currently unblock shadow interrupt state when we skip an instruction,
but failing to do so when we actually emulate one. This blocks interrupts
in key instruction blocks, in particular sti; hlt; sequences
If the instruction emulated is an sti, we have to block shadow interrupts.
The same goes for mov ss. pop ss also needs it, but we don't currently
emulate it.
Without this patch, I cannot boot gpxe option roms at vmx machines.
This is described at https://bugzilla.redhat.com/show_bug.cgi?id=494469
Signed-off-by: Glauber Costa <glommer@redhat.com> CC: H. Peter Anvin <hpa@zytor.com> CC: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Glauber Costa [Tue, 12 May 2009 20:21:05 +0000 (16:21 -0400)]
KVM: Replace ->drop_interrupt_shadow() by ->set_interrupt_shadow()
This patch replaces drop_interrupt_shadow with the more
general set_interrupt_shadow, that can either drop or raise
it, depending on its parameter. It also adds ->get_interrupt_shadow()
for future use.
Signed-off-by: Glauber Costa <glommer@redhat.com> CC: H. Peter Anvin <hpa@zytor.com> CC: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Marcelo Tosatti [Thu, 7 May 2009 20:55:13 +0000 (17:55 -0300)]
KVM: protect assigned dev workqueue, int handler and irq acker
kvm_assigned_dev_ack_irq is vulnerable to a race condition with the
interrupt handler function. It does:
if (dev->host_irq_disabled) {
enable_irq(dev->host_irq);
dev->host_irq_disabled = false;
}
If an interrupt triggers before the host->dev_irq_disabled assignment,
it will disable the interrupt and set dev->host_irq_disabled to true.
On return to kvm_assigned_dev_ack_irq, dev->host_irq_disabled is set to
false, and the next kvm_assigned_dev_ack_irq call will fail to reenable
it.
Other than that, having the interrupt handler and work handlers run in
parallel sounds like asking for trouble (could not spot any obvious
problem, but better not have to, its fragile).
CC: sheng.yang@intel.com Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Marcelo Tosatti [Thu, 7 May 2009 20:55:12 +0000 (17:55 -0300)]
KVM: use smp_send_reschedule in kvm_vcpu_kick
KVM uses a function call IPI to cause the exit of a guest running on a
physical cpu. For virtual interrupt notification there is no need to
wait on IPI receival, or to execute any function.
This is exactly what the reschedule IPI does, without the overhead
of function IPI. So use it instead of smp_call_function_single in
kvm_vcpu_kick.
Also change the "guest_mode" variable to a bit in vcpu->requests, and
use that to collapse multiple IPI's that would be issued between the
first one and zeroing of guest mode.
This allows kvm_vcpu_kick to called with interrupts disabled.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Sun, 10 May 2009 08:41:39 +0000 (11:41 +0300)]
KVM: Fix cpuid feature misreporting
MTRR, PAT, MCE, and MCA are all supported (to some extent) but not reported.
Vista requires these features, so if userspace relies on kernel cpuid
reporting, it loses support for Vista.
On AMD CPUs sometimes the DB bit in the stack segment
descriptor is left as 1, although the whole segment has
been made unusable. Clear it here to pass an Intel VMX
entry check when cross vendor migrating.
Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Sheng Yang [Mon, 27 Apr 2009 12:35:43 +0000 (20:35 +0800)]
KVM: Enable snooping control for supported hardware
Memory aliases with different memory type is a problem for guest. For the guest
without assigned device, the memory type of guest memory would always been the
same as host(WB); but for the assigned device, some part of memory may be used
as DMA and then set to uncacheable memory type(UC/WC), which would be a conflict of
host memory type then be a potential issue.
Snooping control can guarantee the cache correctness of memory go through the
DMA engine of VT-d.
[avi: fix build on ia64]
Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Start to use interrupt/exception queues like VMX does.
This also fix the bug that if exit was caused by a guest
internal exception access to IDT the exception was not
reinjected.
Use EVENTINJ to inject interrupts. Use VINT only for detecting when IRQ
windows is open again. EVENTINJ ensures
the interrupt is injected immediately and not delayed.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: ia64: restore irq state before calling kvm_vcpu_init
Make sure to restore the psr after calling kvm_insert_vmm_mapping()
which calls ia64_itr_entry() as it disables local interrupts and
kvm_vcpu_init() may sleep.
KVM: x86: check for cr3 validity in ioctl_set_sregs
Matt T. Yourst notes that kvm_arch_vcpu_ioctl_set_sregs lacks validity
checking for the new cr3 value:
"Userspace callers of KVM_SET_SREGS can pass a bogus value of cr3 to
the kernel. This will trigger a NULL pointer access in gfn_to_rmap()
when userspace next tries to call KVM_RUN on the affected VCPU and kvm
attempts to activate the new non-existent page table root.
This happens since kvm only validates that cr3 points to a valid guest
physical memory page when code *inside* the guest sets cr3. However, kvm
currently trusts the userspace caller (e.g. QEMU) on the host machine to
always supply a valid page table root, rather than properly validating
it along with the rest of the reloaded guest state."
nathan binkert [Sat, 28 Mar 2009 04:53:05 +0000 (21:53 -0700)]
KVM: Make kvm header C++ friendly
Two things needed fixing: 1) g++ does not allow a named structure type
within an anonymous union and 2) Avoid name clash between two padding
fields within the same struct by giving them different names as is
done elsewhere in the header.
Signed-off-by: Nathan Binkert <nate@binkert.org> Signed-off-by: Avi Kivity <avi@redhat.com>
Assuming that PIT counter reads should return 0 for an expired timer
is wrong: when it is active, the counter never stops (see comment on
__kpit_elapsed).
Also arm a one shot timer for mode 0.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Sheng Yang [Thu, 2 Apr 2009 02:28:37 +0000 (10:28 +0800)]
KVM: MMU: Discard reserved bits checking on PDE bit 7-8
1. It's related to a Linux kernel bug which fixed by Ingo on 07a66d7c53a538e1a9759954a82bb6c07365eff9. The original code exists for quite a
long time, and it would convert a PDE for large page into a normal PDE. But it
fail to fit normal PDE well. With the code before Ingo's fix, the kernel would
fall reserved bit checking with bit 8 - the remaining global bit of PTE. So the
kernel would receive a double-fault.
2. After discussion, we decide to discard PDE bit 7-8 reserved checking for now.
For this marked as reserved in SDM, but didn't checked by the processor in
fact...
Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 30 Mar 2009 13:03:29 +0000 (16:03 +0300)]
KVM: Fix unneeded instruction skipping during task switching.
There is no need to skip instruction if the reason for a task switch
is a task gate in IDT and access to it is caused by an external even.
The problem is currently solved only for VMX since there is no reliable
way to skip an instruction in SVM. We should emulate it instead.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 30 Mar 2009 13:03:18 +0000 (16:03 +0300)]
KVM: VMX: Do not zero idt_vectoring_info in vmx_complete_interrupts().
We will need it later in task_switch().
Code in handle_exception() is dead. is_external_interrupt(vect_info)
will always be false since idt_vectoring_info is zeroed in
vmx_complete_interrupts().
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 30 Mar 2009 13:03:13 +0000 (16:03 +0300)]
KVM: VMX: Rewrite vmx_complete_interrupt()'s twisted maze of if() statements
...with a more straightforward switch().
Also fix a bug when NMI could be dropped on exit. Although this should
never happen in practice, since NMIs can only be injected, never triggered
internally by the guest like exceptions.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 30 Mar 2009 13:03:08 +0000 (16:03 +0300)]
KVM: VMX: Fix handling of a fault during NMI unblocked due to IRET
Bit 12 is undefined in any of the following cases:
If the VM exit sets the valid bit in the IDT-vectoring information field.
If the VM exit is due to a double fault.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Tue, 31 Mar 2009 08:31:54 +0000 (11:31 +0300)]
KVM: MMU: Use different shadows when EFER.NXE changes
A pte that is shadowed when the guest EFER.NXE=1 is not valid when
EFER.NXE=0; if bit 63 is set, the pte should cause a fault, and since the
shadow EFER always has NX enabled, this won't happen.
Fix by using a different shadow page table for different EFER.NXE bits. This
allows vcpus to run correctly with different values of EFER.NXE, and for
transitions on this bit to be handled correctly without requiring a full
flush.
Dong, Eddie [Mon, 30 Mar 2009 08:21:08 +0000 (16:21 +0800)]
KVM: MMU: Emulate #PF error code of reserved bits violation
Detect, indicate, and propagate page faults where reserved bits are set.
Take care to handle the different paging modes, each of which has different
sets of reserved bits.
[avi: fix pte reserved bits for efer.nxe=0]
Signed-off-by: Eddie Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Yang Zhang [Mon, 23 Mar 2009 07:31:04 +0000 (03:31 -0400)]
KVM: ia64: enable external interrupt in vmm
Currently, the interrupt enable bit is cleared when in
the vmm. This patch sets the bit and the external interrupts can
be dealt with when in the vmm. This improves the I/O performance.
Signed-off-by: Yang Zhang <yang.zhang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Gleb Natapov [Mon, 23 Mar 2009 13:11:44 +0000 (15:11 +0200)]
KVM: Timer event should not unconditionally unhalt vcpu.
Currently timer events are processed before entering guest mode. Move it
to main vcpu event loop since timer events should be processed even while
vcpu is halted. Timer may cause interrupt/nmi to be injected and only then
vcpu will be unhalted.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>