Commit Graph

196 Commits

Author SHA1 Message Date
Avi Kivity
8684c0af0b KVM: x86 emulator: handle undecoded rex.b with r/m = 5 in certain cases
x86_64 does not decode rex.b in certain cases, where the r/m field = 5.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Mohammed Gamal
b13354f8f0 KVM: x86 emulator: emulate nop and xchg reg, acc (opcodes 0x90 - 0x97)
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity
f76c710d75 KVM: Use printk_rlimit() instead of reporting emulation failures just once
Emulation failure reports are useful, so allow more than one per the lifetime
of the module.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Glauber Costa
25be46080f KVM: Do not calculate linear rip in emulation failure report
If we're not gonna do anything (case in which failure is already
reported), we do not need to even bother with calculating the linear rip.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Marcelo Tosatti
622395a9e6 KVM: only abort guest entry if timer count goes from 0->1
Only abort guest entry if the timer count went from 0->1, since for 1->2
or larger the bit will either be set already or a timer irq will have
been injected.

Using atomic_inc_and_test() for it also introduces an SMP barrier
to the LAPIC version (thought it was unecessary because of timer
migration, but guest can be scheduled to a different pCPU between exit
and kvm_vcpu_block(), so there is the possibility for a race).

Noticed by Avi.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Laurent Vivier
542472b53e KVM: Add coalesced MMIO support (x86 part)
This patch enables coalesced MMIO for x86 architecture.
It defines KVM_MMIO_PAGE_OFFSET and KVM_CAP_COALESCED_MMIO.
It enables the compilation of coalesced_mmio.c.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:31 +03:00
Laurent Vivier
92760499d0 KVM: kvm_io_device: extend in_range() to manage len and write attribute
Modify member in_range() of structure kvm_io_device to pass length and the type
of the I/O (write or read).

This modification allows to use kvm_io_device with coalesced MMIO.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity
131d82791b KVM: MMU: Avoid page prefetch on SVM
SVM cannot benefit from page prefetching since guest page fault bypass
cannot by made to work there.  Avoid accessing the guest page table in
this case.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity
d761a501cf KVM: MMU: Move nonpaging_prefetch_page()
In preparation for next patch. No code change.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity
91ed7a0e15 KVM: x86 emulator: implement 'push imm' (opcode 0x68)
Encountered in FC6 boot sequence, now that we don't force ss.rpl = 0 during
the protected mode transition.  Not really necessary, but nice to have.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:29 +03:00
Avi Kivity
19e43636b5 KVM: x86 emulator: simplify push imm8 emulation
Instead of fetching the data explicitly, use SrcImmByte.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:29 +03:00
Avi Kivity
eab9f71feb KVM: MMU: Optimize prefetch_page()
Instead of reading each pte individually, read 256 bytes worth of ptes and
batch process them.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin
38d5bc6d50 KVM: x86 emulator: Add support for mov r, sreg (0x8c) instruction
Add support for mov r, sreg (0x8c) instruction

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin
4257198ae2 KVM: x86 emulator: Add support for mov seg, r (0x8e) instruction
Add support for mov r, sreg (0x8c) instruction.

[avi: drop the sreg decoding table in favor of 1:1 encoding]

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin
615ac12561 KVM: x86 emulator: adds support to mov r,imm (opcode 0xb8) instruction
Add support to mov r, imm (0xb8) instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin
954cd36f76 KVM: x86 emulator: add support for jmp far 0xea
Add support for jmp far (opcode 0xea) instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin
89c696383d KVM: x86 emulator: Update c->dst.bytes in decode instruction
Update c->dst.bytes in decode instruction instead of instruction
itself.  It's needed because if c->dst.bytes is equal to 0, the
instruction is not emulated.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin
3e6e0aab1b KVM: Prefixes segment functions that will be exported with "kvm_"
Prefixes functions that will be exported with kvm_.
We also prefixed set_segment() even if it still static
to be coherent.

signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Avi Kivity
9ba075a664 KVM: MTRR support
Add emulation for the memory type range registers, needed by VMware esx 3.5,
and by pci device assignment.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:26 +03:00
Sheng Yang
f08864b42a KVM: VMX: Enable NMI with in-kernel irqchip
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:26 +03:00
Sheng Yang
3419ffc8e4 KVM: IOAPIC/LAPIC: Enable NMI support
[avi: fix ia64 build breakage]

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity
50d40d7fb9 KVM: Remove unnecessary ->decache_regs() call
Since we aren't modifying any register, there's no need to decache
the register state.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity
7cc8883074 KVM: Remove decache_vcpus_on_cpu() and related callbacks
Obsoleted by the vmx-specific per-cpu list.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity
543e424366 KVM: VMX: Add list of potentially locally cached vcpus
VMX hardware can cache the contents of a vcpu's vmcs.  This cache needs
to be flushed when migrating a vcpu to another cpu, or (which is the case
that interests us here) when disabling hardware virtualization on a cpu.

The current implementation of decaching iterates over the list of all vcpus,
picks the ones that are potentially cached on the cpu that is being offlined,
and flushes the cache.  The problem is that it uses mutex_trylock() to gain
exclusive access to the vcpu, which fires off a (benign) warning about using
the mutex in an interrupt context.

To avoid this, and to make things generally nicer, add a new per-cpu list
of potentially cached vcus.  This makes the decaching code much simpler.  The
list is vmx-specific since other hardware doesn't have this issue.

[andrea: fix crash on suspend/resume]

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:24 +03:00
Avi Kivity
4ecac3fd6d KVM: Handle virtualization instruction #UD faults during reboot
KVM turns off hardware virtualization extensions during reboot, in order
to disassociate the memory used by the virtualization extensions from the
processor, and in order to have the system in a consistent state.
Unfortunately virtual machines may still be running while this goes on,
and once virtualization extensions are turned off, any virtulization
instruction will #UD on execution.

Fix by adding an exception handler to virtualization instructions; if we get
an exception during reboot, we simply spin waiting for the reset to complete.
If it's a true exception, BUG() so we can have our stack trace.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:41:43 +03:00
Avi Kivity
1b7fcd3263 KVM: MMU: Fix false flooding when a pte points to page table
The KVM MMU tries to detect when a speculative pte update is not actually
used by demand fault, by checking the accessed bit of the shadow pte.  If
the shadow pte has not been accessed, we deem that page table flooded and
remove the shadow page table, allowing further pte updates to proceed
without emulation.

However, if the pte itself points at a page table and only used for write
operations, the accessed bit will never be set since all access will happen
through the emulator.

This is exactly what happens with kscand on old (2.4.x) HIGHMEM kernels.
The kernel points a kmap_atomic() pte at a page table, and then
proceeds with read-modify-write operations to look at the dirty and accessed
bits.  We get a false flood trigger on the kmap ptes, which results in the
mmu spending all its time setting up and tearing down shadows.

Fix by setting the shadow accessed bit on emulated accesses.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:50 +03:00
Avi Kivity
7682f2d0dd KVM: VMX: Trivial vmcs_write64() code simplification
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:50 +03:00
Chris Lalancette
14ae51b6c0 KVM: SVM: Fake MSR_K7 performance counters
Attached is a patch that fixes a guest crash when booting older Linux kernels.
The problem stems from the fact that we are currently emulating
MSR_K7_EVNTSEL[0-3], but not emulating MSR_K7_PERFCTR[0-3].  Because of this,
setup_k7_watchdog() in the Linux kernel receives a GPF when it attempts to
write into MSR_K7_PERFCTR, which causes an OOPs.

The patch fixes it by just "fake" emulating the appropriate MSRs, throwing
away the data in the process.  This causes the NMI watchdog to not actually
work, but it's not such a big deal in a virtualized environment.

When we get a write to one of these counters, we printk_ratelimit() a warning.
I decided to print it out for all writes, even if the data is 0; it doesn't
seem to make sense to me to special case when data == 0.

Tested by myself on a RHEL-4 guest, and Joerg Roedel on a Windows XP 64-bit
guest.

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:49 +03:00
Aurelien Jarno
f697554515 KVM: PIT: support mode 3
The in-kernel PIT emulation ignores pending timers if operating
under mode 3, which for example Hurd uses.

This mode should output a square wave, high for (N+1)/2 counts and low
for (N-1)/2 counts. As we only care about the resulting interrupts, the
period is N, and mode 3 is the same as mode 2 with regard to
interrupts.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:49 +03:00
Joerg Roedel
d2ebb4103f KVM: SVM: add tracing support for TDP page faults
To distinguish between real page faults and nested page faults they should be
traced as different events. This is implemented by this patch.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Joerg Roedel
af9ca2d703 KVM: SVM: add missing kvmtrace markers
This patch adds the missing kvmtrace markers to the svm
module of kvm.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Joerg Roedel
54e445ca84 KVM: add missing kvmtrace bits
This patch adds some kvmtrace bits to the generic x86 code
where it is instrumented from SVM.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Joerg Roedel
a069805579 KVM: SVM: implement dedicated INTR exit handler
With an exit handler for INTR intercepts its possible to account them using
kvmtrace.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:47 +03:00
Joerg Roedel
c47f098d69 KVM: SVM: implement dedicated NMI exit handler
With an exit handler for NMI intercepts its possible to account them using
kvmtrace.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:47 +03:00
Joerg Roedel
c7bf23babc KVM: VMX: move APIC_ACCESS trace entry to generic code
This patch moves the trace entry for APIC accesses from the VMX code to the
generic lapic code. This way APIC accesses from SVM will also be traced.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:47 +03:00
Harvey Harrison
8b2cf73cc1 KVM: add statics were possible, function definition in lapic.h
Noticed by sparse:
arch/x86/kvm/vmx.c:1583:6: warning: symbol 'vmx_disable_intercept_for_msr' was not declared. Should it be static?
arch/x86/kvm/x86.c:3406:5: warning: symbol 'kvm_task_switch_16' was not declared. Should it be static?
arch/x86/kvm/x86.c:3429:5: warning: symbol 'kvm_task_switch_32' was not declared. Should it be static?
arch/x86/kvm/mmu.c:1968:6: warning: symbol 'kvm_mmu_remove_one_alloc_mmu_page' was not declared. Should it be static?
arch/x86/kvm/mmu.c:2014:6: warning: symbol 'mmu_destroy_caches' was not declared. Should it be static?
arch/x86/kvm/lapic.c:862:5: warning: symbol 'kvm_lapic_get_base' was not declared. Should it be static?
arch/x86/kvm/i8254.c:94:5: warning: symbol 'pit_get_gate' was not declared. Should it be static?
arch/x86/kvm/i8254.c:196:5: warning: symbol '__pit_timer_fn' was not declared. Should it be static?
arch/x86/kvm/i8254.c:561:6: warning: symbol '__inject_pit_timer_intr' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:46 +03:00
Jens Axboe
15c8b6c1aa on_each_cpu(): kill unused 'retry' parameter
It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26 11:24:38 +02:00
Jens Axboe
8691e5a8f6 smp_call_function: get rid of the unused nonatomic/retry argument
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26 11:24:35 +02:00
Gerd Hoffmann
50d0a0f987 KVM: Make kvm host use the paravirt clocksource structs
This patch updates the kvm host code to use the pvclock structs.
It also makes the paravirt clock compatible with Xen.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 21:02:32 +03:00
Avi Kivity
a9b21b6229 KVM: VMX: Fix host msr corruption with preemption enabled
Switching msrs can occur either synchronously as a result of calls to
the msr management functions (usually in response to the guest touching
virtualized msrs), or asynchronously when preempting a kvm thread that has
guest state loaded.  If we're unlucky enough to have the two at the same
time, host msrs are corrupted and the machine goes kaput on the next syscall.

Most easily triggered by Windows Server 2008, as it does a lot of msr
switching during bootup.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:26:17 +03:00
Avi Kivity
6bf6a9532f KVM: MMU: Fix oops on guest userspace access to guest pagetable
KVM has a heuristic to unshadow guest pagetables when userspace accesses
them, on the assumption that most guests do not allow userspace to access
pagetables directly. Unfortunately, in addition to unshadowing the pagetables,
it also oopses.

This never triggers on ordinary guests since sane OSes will clear the
pagetables before assigning them to userspace, which will trigger the flood
heuristic, unshadowing the pagetables before the first userspace access. One
particular guest, though (Xenner) will run the kernel in userspace, triggering
the oops.  Since the heuristic is incorrect in this case, we can simply
remove it.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:20:12 +03:00
Marcelo Tosatti
3094538739 KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend)
kvm_mmu_pte_write() does not handle 32-bit non-PAE large page backed
guests properly. It will instantiate two 2MB sptes pointing to the same
physical 2MB page when a guest large pte update is trapped.

Instead of duplicating code to handle this, disallow directory level
updates to happen through kvm_mmu_pte_write(), so the two 2MB sptes
emulating one guest 4MB pte can be correctly created by the page fault
handling path.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:18:18 +03:00
Marcelo Tosatti
6597ca09e6 KVM: MMU: Fix rmap_write_protect() hugepage iteration bug
rmap_next() does not work correctly after rmap_remove(), as it expects
the rmap chains not to change during iteration.  Fix (for now) by restarting
iteration from the beginning.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:17:10 +03:00
Marcelo Tosatti
06e0564566 KVM: close timer injection race window in __vcpu_run
If a timer fires after kvm_inject_pending_timer_irqs() but before
local_irq_disable() the code will enter guest mode and only inject such
timer interrupt the next time an unrelated event causes an exit.

It would be simpler if the timer->pending irq conversion could be done
with IRQ's disabled, so that the above problem cannot happen.

For now introduce a new vcpu requests bit to cancel guest entry.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:16:59 +03:00
Marcelo Tosatti
d4acf7e7ab KVM: Fix race between timer migration and vcpu migration
A guest vcpu instance can be scheduled to a different physical CPU
between the test for KVM_REQ_MIGRATE_TIMER and local_irq_disable().

If that happens, the timer will only be migrated to the current pCPU on
the next exit, meaning that guest LAPIC timer event can be delayed until
a host interrupt is triggered.

Fix it by cancelling guest entry if any vcpu request is pending.  This
has the side effect of nicely consolidating vcpu->requests checks.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:16:52 +03:00
Avi Kivity
3c9155106d KVM: MMU: Fix is_empty_shadow_page() check
The check is only looking at one of two possible empty ptes.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:36:33 +03:00
Avi Kivity
ebb0e6264c KVM: MMU: Fix printk() format string
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:36:20 +03:00
Avi Kivity
8d2d73b9a5 KVM: MMU: reschedule during shadow teardown
Shadows for large guests can take a long time to tear down, so reschedule
occasionally to avoid softlockup warnings.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:32:20 +03:00
Eli Collins
e693d71b46 KVM: VMX: Clear CR4.VMXE in hardware_disable
Clear CR4.VMXE in hardware_disable. There's no reason to leave it set
after doing a VMXOFF.

VMware Workstation 6.5 checks CR4.VMXE as a proxy for whether the CPU is
in VMX mode, so leaving VMXE set means we'll refuse to power on. With this
change the user can power on after unloading the kvm-intel module. I
tested on kvm-67 and kvm-69.

Signed-off-by: Eli Collins <ecollins@vmware.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:30:20 +03:00
Marcelo Tosatti
2f5997140f KVM: migrate PIT timer
Migrate the PIT timer to the physical CPU which vcpu0 is scheduled on,
similarly to what is done for the LAPIC timers, otherwise PIT interrupts
will be delayed until an unrelated event causes an exit.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:25:51 +03:00