When cr0.wp=0, we may shadow a gpte having u/s=1 and r/w=0 with an spte
having u/s=0 and r/w=1.  This allows excessive access if the guest sets
cr0.wp=1 and accesses through this spte.

Fix by making cr0.wp part of the base role; we'll have different sptes for
the two cases and the problem disappears.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds logic to kvm/x86 which allows to mark an
injected exception as reinjected. This allows to remove an
ugly hack from svm_complete_interrupts that prevented
exceptions from being reinjected at all in the nested case.
The hack was necessary because an reinjected exception into
the nested guest could cause a nested vmexit emulation. But
reinjected exceptions must not intercept. The downside of
the hack is that a exception that in injected could get
lost.
This patch fixes the problem and puts the code for it into
generic x86 files because. Nested-VMX will likely have the
same problem and could reuse the code.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch adds the get_supported_cpuid callback to
kvm_x86_ops. It will be used in do_cpuid_ent to delegate the
decission about some supported cpuid bits to the
architecture modules.

Cc: stable@kernel.org
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Since commit bf47a760, we no longer handle ptes with the global bit
set specially, so there is no reason to distinguish between shadow pages
created with cr4.gpe set and clear.

Such tracking is expensive when the guest toggles cr4.pge, so drop it.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Define 'multimapped' as 'bool'.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

There is no real distinction between glevels=3 and glevels=4; both have
exactly the same format and the code is treated exactly the same way.  Drop
role.glevels and replace is with role.cr4_pae (which is meaningful).  This
simplifies the code a bit.

As a side effect, it allows sharing shadow page tables between pae and
longmode guest page tables at the same guest page.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When a fault triggers a task switch, the error code, if existent, has to
be pushed on the new task's stack. Implement the missing bits.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Currently both SVM and VMX have their own DR handling code. Move it to
x86.c.
Acked-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

kvm_mmu_page.oos_link is not used, so remove it
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Currently emulation is done outside of emulator so things like doing
ins/outs to/from mmio are broken it also makes it hard (if not impossible)
to implement single stepping in the future. The implementation in this
patch is not efficient since it exits to userspace for each IO while
previous implementation did 'ins' in batches. Further patch that
implements pio in string read ahead address this problem.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

in/out emulation is broken now. The breakage is different depending
on where IO device resides. If it is in userspace emulator reports
emulation failure since it incorrectly interprets kvm_emulate_pio()
return value. If IO device is in the kernel emulation of 'in' will do
nothing since kvm_emulate_pio() stores result directly into vcpu
registers, so emulator will overwrite result of emulation during
commit of shadowed register.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Use (get|set)_cr callback to emulate lmsw inside emulator.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Use this callback instead of directly call kvm function. Also rename
realmode_(set|get)_cr to emulator_(set|get)_cr since function has nothing
to do with real mode.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Mov reg, cr instruction doesn't change flags in any meaningful way, so
no need to update rflags after instruction execution.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Commit fb341f57 removed the pte prefetch on guest invlpg, citing guest races.
However, the SDM is adamant that prefetch is allowed:

  "The processor may create entries in paging-structure caches for
   translations required for prefetches and for accesses that are a
   result of speculative execution that would never actually occur
   in the executed code path."

And, in fact, there was a race in the prefetch code: we picked up the pte
without the mmu lock held, so an older invlpg could install the pte over
a newer invlpg.

Reinstate the prefetch logic, but this time note whether another invlpg has
executed using a counter.  If a race occured, do not install the pte.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch use generic linux function native_store_idt()
instead of kvm_get_idt(), and also removed the useless
function kvm_get_idt().
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

segment_base() is used only by vmx so move it there.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Linux now has native_store_gdt() to do the same. Use it instead of
kvm local version.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Based on Gleb's suggestion: Add a helper kvm_is_linear_rip that matches
a given linear RIP against the current one. Use this for guest
single-stepping, more users will follow.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch removes redundant prototype of load_pdptrs().

I found load_pdptrs() twice in kvm_host.h. Let's remove one.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

x86 arch defines desc_ptr for idt/gdt pointers, no need to define
another structure in kvm code.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add proper error and permission checking. This patch also change task
switching code to load segment selectors before segment descriptors, like
SDM requires, otherwise permission checking during segment descriptor
loading will be incorrect.

Cc: stable@kernel.org (2.6.33, 2.6.32)
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Make emulator check that vcpu is allowed to execute IN, INS, OUT,
OUTS, CLI, STI.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently when x86 emulator needs to access memory, page walk is done with
broadest permission possible, so if emulated instruction was executed
by userspace process it can still access kernel memory. Fix that by
providing correct memory access to page walker during emulation.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NAvi Kivity <avi@redhat.com>

None of the other registers have the shadow_ prefix.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Assume that if the guest executes clts, it knows what it's doing, and load the
guest fpu to prevent an #NM exception.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Enhance mov dr instruction emulation used by SVM so that it properly
handles dr4/5: alias to dr6/7 if cr4.de is cleared. Otherwise return
EMULATE_FAIL which will let our only possible caller in that scenario,
ud_interception, re-inject UD.

We do not need to inject faults, SVM does this for us (exceptions take
precedence over instruction interceptions). For the same reason, the
value overflow checks can be removed.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Implement HYPER-V apic MSRs. Spec defines three MSRs that speed-up
access to EOI/TPR/ICR apic registers for PV guests.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NVadim Rozenfeld <vrozenfe@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Minimum HYPER-V implementation should have GUEST_OS_ID, HYPERCALL and
VP_INDEX MSRs.

[avi: fix build on i386]
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NVadim Rozenfeld <vrozenfe@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Defer fpu deactivation as much as possible - if the guest fpu is loaded, keep
it loaded until the next heavyweight exit (where we are forced to unload it).
This reduces unnecessary exits.

We also defer fpu activation on clts; while clts signals the intent to use the
fpu, we can't be sure the guest will actually use it.
Signed-off-by: NAvi Kivity <avi@redhat.com>

We will use this later to give the guest ownership of cr0.ts.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Then the callback can provide the maximum supported large page level, which
is more flexible.

Also move the gb page support into x86_64 specific.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

With slots_lock converted to rcu, the entire kvm hotpath on modern processors
(with npt or ept) now scales beautifully.  Increase the maximum vcpu count to
64 to reflect this.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Using a similar two-step procedure as for memslots.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Have a pointer to an allocated region inside x86's kvm_arch.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Before enabling, execution of "rdtscp" in guest would result in #UD.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Sometime, we need to adjust some state in order to reflect guest CPUID
setting, e.g. if we don't expose rdtscp to guest, we won't want to enable
it on hardware. cpuid_update() is introduced for this purpose.

Also export kvm_find_cpuid_entry() for later use.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Some bits of cr4 can be owned by the guest on vmx, so when we read them,
we copy them to the vcpu structure.  In preparation for making the set of
guest-owned bits dynamic, use helpers to access these bits so we don't need
to know where the bit resides.

No changes to svm since all bits are host-owned there.
Signed-off-by: NAvi Kivity <avi@redhat.com>

They have no place in common code.
Signed-off-by: NAvi Kivity <avi@redhat.com>

update_transition_efer() masks out some efer bits when deciding whether
to switch the msr during guest entry; for example, NX is emulated using the
mmu so we don't need to disable it, and LMA/LME are handled by the hardware.

However, with shared msrs, the comparison is made against a stale value;
at the time of the guest switch we may be running with another guest's efer.

Fix by deferring the mask/compare to the actual point of guest entry.

Noted by Marcelo.
Signed-off-by: NAvi Kivity <avi@redhat.com>