We never change those, make them r/o.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We never change emulate_ops[] at runtime so it should be r/o.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The opcode tables never change at runtime, therefor mark them const.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

As the the compiler ensures that the memory operand is always aligned
to a 16 byte memory location, use the aligned variant of MOVDQ for
read_sse_reg() and write_sse_reg().
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Some fields can be constified and/or made static to reduce code and data
size.

Numbers for a 32 bit build:

        text    data     bss     dec     hex filename
before: 3351      80       0    3431     d67 cpuid.o
 after: 3391       0       0    3391     d3f cpuid.o
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

kvm_pic_reset() is not used anywhere. Move reset logic from
pic_ioport_write() there.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

We want the segment selector, nor segment number.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Segment limits are verified in real mode, not just protected mode.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When loading a segment in real mode, only the base and selector must
be modified.  The limit needs to be left alone, otherwise big real mode
users will hit a #GP due to limit checking (currently this is suppressed
because we don't check limits in real mode).
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Real processors don't change segment limits and attributes while in
real mode.  Mimic that behaviour.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

fix_pmode_dataseg() looks up S in ->base instead of ->ar_bytes.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Commit b246dd5d ("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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Instead of populating the entire register file, read in registers
as they are accessed, and write back only the modified ones.  This
saves a VMREAD and VMWRITE on Intel (for rsp, since it is not usually
used during emulation), and a two 128-byte copies for the registers.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The sub-register used to access the stack (sp, esp, or rsp) is not
determined by the address size attribute like other memory references,
but by the stack segment's B bit (if not in x86_64 mode).

Fix by using the existing stack_mask() to figure out the correct mask.

This long-existing bug was exposed by a combination of a27685c3
(emulate invalid guest state by default), which causes many more
instructions to be emulated, and a seabios change (possibly a bug) which
causes the high 16 bits of esp to become polluted across calls to real
mode software interrupts.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Although the possible race described in

  commit 85b70591
  KVM: MMU: fix shrinking page from the empty mmu

was correct, the real cause of that issue was a more trivial bug of
mmu_shrink() introduced by

  commit 19526396
  KVM: MMU: do not iterate over all VMs in mmu_shrink()

Here is the bug:

	if (kvm->arch.n_used_mmu_pages > 0) {
		if (!nr_to_scan--)
			break;
		continue;
	}

We skip VMs whose n_used_mmu_pages is not zero and try to shrink others:
in other words we try to shrink empty ones by mistake.

This patch reverses the logic so that mmu_shrink() can free pages from
the first VM whose n_used_mmu_pages is not zero.  Note that we also add
comments explaining the role of nr_to_scan which is not practically
important now, hoping this will be improved in the future.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

In current code, if we map a readonly memory space from host to guest
and the page is not currently mapped in the host, we will get a fault
pfn and async is not allowed, then the vm will crash

We introduce readonly memory region to map ROM/ROMD to the guest, read access
is happy for readonly memslot, write access on readonly memslot will cause
KVM_EXIT_MMIO exit
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

It can instead of hva_to_pfn_atomic
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently, we reexecute all unhandleable instructions if they do not
access on the mmio, however, it can not work if host map the readonly
memory to guest. If the instruction try to write this kind of memory,
it will fault again when guest retry it, then we will goto a infinite
loop: retry instruction -> write #PF -> emulation fail ->
retry instruction -> ...

Fix it by retrying the instruction only when it faults on the writable
memory
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We validate irq pin number when routing is setup, so
code handling illegal irq # in pic and ioapic on each injection
is never called.
Drop it, replace with BUG_ON to catch out of bounds access bugs.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

MSR_IA32_DEBUGCTLMSR is zeroed on VMEXIT. Restore it to the correct
value.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

kvm_guest_time_update unconditionally clears hv_clock.flags field,
so the notification never reaches the guest.

Fix it by allowing PVCLOCK_GUEST_STOPPED to passthrough.
Reviewed-by: NEric B Munson <emunson@mgebm.net>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

For apic_set_spiv() to track APIC SW state correctly it needs to see
previous and next values of the spurious vector register, but currently
memset() overwrite the old value before apic_set_spiv() get a chance to
do tracking. Fix it by calling apic_set_spiv() before overwriting old
value.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Those functions are used during interrupt injection. When inlined they
become nops on the fast path.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Usually all vcpus have local apic pointer initialized, so the check may
be completely skipped.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Usually all APICs are SW enabled so the check can be optimized out.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Usually all APICs are HW enabled so the check can be optimized out.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

According to SDM apic is enabled on start up.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Do not change apic_base directly. Use kvm_lapic_set_base() instead.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

kvm_get_apic_base() needlessly checks irqchip_in_kernel although it does
the same no matter what result of the check is. kvm_set_apic_base() also
checks for irqchip_in_kernel, but kvm_lapic_set_base() can handle this
case.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

After commit a2766325, 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: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

After commit a2766325, the error pfn is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>