kvm_mmu initialization is mostly filling in function pointers, there is
no way for it to fail.  Clean up unused return values.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

They do the same thing, and destroy_kvm_mmu can be confused with
kvm_mmu_destroy.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

The new_cr3 MMU callback has been a wrapper for mmu_free_roots since commit
e676505a (KVM: MMU: Force cr3 reload with two dimensional paging on mov
cr3 emulation, 2012-07-08).

The commit message mentioned that "mmu_free_roots() is somewhat of an overkill,
but fixing that is more complicated and will be done after this minimal fix".
One year has passed, and no one really felt the need to do a different fix.
Wrap the call with a kvm_mmu_new_cr3 function for clarity, but remove the
callback.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

The free MMU callback has been a wrapper for mmu_free_roots since mmu_free_roots
itself was introduced (commit 17ac10ad, [PATCH] KVM: MU: Special treatment
for shadow pae root pages, 2007-01-05), and has always been the same for all
MMU cases.  Remove the indirection as it is useless.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

This makes the interface more deterministic for userspace, which can expect
(after configuring only the features it supports) to get exactly the same
state from the kernel, independent of the host CPU and kernel version.
Suggested-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

A guest can still attempt to save and restore XSAVE states even if they
have been masked in CPUID leaf 0Dh.  This usually is not visible to
the guest, but is still wrong: "Any attempt to set a reserved bit (as
determined by the contents of EAX and EDX after executing CPUID with
EAX=0DH, ECX= 0H) in XCR0 for a given processor will result in a #GP
exception".

The patch also performs the same checks as __kvm_set_xcr in KVM_SET_XSAVE.
This catches migration from newer to older kernel/processor before the
guest starts running.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

XSAVE entries that KVM does not support are reported by
KVM_GET_SUPPORTED_CPUID for leaf 0Dh index 0 if the host supports them;
they should be left out unless there is also hypervisor support for them.

Sub-leafs are correctly handled in supported_xcr0_bit, fix index 0
to match.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

In commit e935b837 ("KVM: Convert kvm_lock to raw_spinlock"),
the kvm_lock was made a raw lock.  However, the kvm mmu_shrink()
function tries to grab the (non-raw) mmu_lock within the scope of
the raw locked kvm_lock being held.  This leads to the following:

BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0
Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm]

Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt
Call Trace:
 [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160
 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50
 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm]
 [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0
 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260
 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730
 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0
 [<ffffffff811185bf>] kswapd+0x18f/0x490
 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50
 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50
 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730
 [<ffffffff81060d2b>] kthread+0xdb/0xe0
 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100
 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10
 [<ffffffff81060c50>] ? __init_kthread_worker+0x

After the previous patch, kvm_lock need not be a raw spinlock anymore,
so change it back.
Reported-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If #PF happens during delivery of an exception into L2 and L1 also do
not have the page mapped in its shadow page table then L0 needs to
generate vmexit to L2 with original event in IDT_VECTORING_INFO, but
current code combines both exception and generates #DF instead. Fix that
by providing nVMX specific function to handle page faults during page
table walk that handles this case correctly.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

All exceptions should be checked for intercept during delivery to L2,
but we check only #PF currently. Drop nested_run_pending while we are
at it since exception cannot be injected during vmentry anyway.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
[Renamed the nested_vmx_check_exception function. - Paolo]
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If an exception causes vmexit directly it should not be reported in
IDT_VECTORING_INFO during the exit. For that we need to be able to
distinguish between exception that is injected into nested VM and one that
is reinjected because its delivery failed. Fortunately we already have
mechanism to do so for nested SVM, so here we just use correct function
to requeue exceptions and make sure that reinjected exception is not
moved to IDT_VECTORING_INFO during vmexit emulation and not re-checked
for interception during delivery.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

EXIT_REASON_VMLAUNCH/EXIT_REASON_VMRESUME exit does not mean that nested
VM will actually run during next entry. Move setting nested_run_pending
closer to vmentry emulation code and move its clearing close to vmexit to
minimize amount of code that will erroneously run with nested_run_pending
set.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Now that we provide EPT support, there is no reason to torture our
guests by hiding the relieving unrestricted guest mode feature. We just
need to relax CR0 checks for always-on bits as PE and PG can now be
switched off.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Implement and advertise VM_EXIT_SAVE_IA32_EFER. L0 traps EFER writes
unconditionally, so we always find the current L2 value in the
architectural state.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Fiddling with CR3 for L2 is L1's job. It may set its own, different
identity map or simple leave it alone if unrestricted guest mode is
enabled. This also fixes reading back the current CR3 on L2 exits for
reporting it to L1.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

kvm_set_cr0 performs checks on the state transition that may prevent
loading L1's cr0. For now we rely on the hardware to catch invalid
states loaded by L1 into its VMCS. Still, consistency checks on the host
state part of the VMCS on guest entry will have to be improved later on.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Set "blocked by NMI" flag if EPT violation happens during IRET from NMI
otherwise NMI can be called recursively causing stack corruption.
Signed-off-by: NGleb Natapov <gleb@redhat.com>

After nested vmentry stale cache can be used to reload L2 PDPTR pointers
which will cause L2 guest to fail. Fix it by invalidating cache on nested
vmentry emulation.

https://bugzilla.kernel.org/show_bug.cgi?id=60830Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Page tables in a read-only memory slot will currently cause a triple
fault because the page walker uses gfn_to_hva and it fails on such a slot.

OVMF uses such a page table; however, real hardware seems to be fine with
that as long as the accessed/dirty bits are set.  Save whether the slot
is readonly, and later check it when updating the accessed and dirty bits.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Opcode CA

This gets used by a DOS based NetWare guest.
Signed-off-by: NBruce Rogers <brogers@suse.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Convert the remaining couple of random shrinkers in the tree to the new
API.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NGlauber Costa <glommer@openvz.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

vcpu in page_fault_can_be_fast() is not used so remove it
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

The offset to add to the hosts monotonic time, kvmclock_offset, is
calculated against the monotonic time at KVM_SET_CLOCK ioctl time.

Request a master clock update at this time, to reduce a potentially
unbounded difference between the values of the masterclock and
the clock value used to calculate kvmclock_offset.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Support for single-step in the emulator (new in 3.12) does not work for
MMIO or PIO writes, because they are completed without returning to
the emulator.  This is not worse than what we had in 3.11; still, add
comments so that the issue is not forgotten.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

These will happen due to MMIO.
Suggested-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Note that we are using APIC_DM_REMRD which has reserved usage.
In future if APIC_DM_REMRD usage is standardized, then we should
find some other way or go back to old method.
Suggested-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

kvm_hc_kick_cpu allows the calling vcpu to kick another vcpu out of halt state.
the presence of these hypercalls is indicated to guest via
kvm_feature_pv_unhalt.

Fold pv_unhalt flag into GET_MP_STATE ioctl to aid migration
During migration, any vcpu that got kicked but did not become runnable
(still in halted state) should be runnable after migration.
Signed-off-by: NSrivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: NSuzuki Poulose <suzuki@in.ibm.com>
[Raghu: Apic related changes, folding pvunhalted into vcpu_runnable
 Added flags for future use (suggested by Gleb)]
[ Raghu: fold pv_unhalt flag as suggested by Eric Northup]
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Advertise VM_EXIT_SAVE_IA32_PAT and VM_EXIT_LOAD_IA32_PAT.
Signed-off-by: NArthur Chunqi Li <yzt356@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Do not report that we can enter the guest in 64-bit mode if the host is
32-bit only. This is not supported by KVM.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

At least WB must be possible.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When asking vmx to load the PAT MSR for us while switching from L1 to L2
or vice versa, we have to update arch.pat as well as it may later be
used again to load or read out the MSR content.
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Tested-by: NArthur Chunqi Li <yzt356@gmail.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Some trivial code cleanups not really related to nested EPT.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NNadav Har'El <nyh@il.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Some additional comments to preexisting code:
Explain who (L0 or L1) handles EPT violation and misconfiguration exits.
Don't mention "shadow on either EPT or shadow" as the only two options.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NNadav Har'El <nyh@il.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This is the last patch of the basic Nested EPT feature, so as to allow
bisection through this patch series: The guest will not see EPT support until
this last patch, and will not attempt to use the half-applied feature.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NNadav Har'El <nyh@il.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If we let L1 use EPT, we should probably also support the INVEPT instruction.

In our current nested EPT implementation, when L1 changes its EPT table
for L2 (i.e., EPT12), L0 modifies the shadow EPT table (EPT02), and in
the course of this modification already calls INVEPT. But if last level
of shadow page is unsync not all L1's changes to EPT12 are intercepted,
which means roots need to be synced when L1 calls INVEPT. Global INVEPT
should not be different since roots are synced by kvm_mmu_load() each
time EPTP02 changes.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NNadav Har'El <nyh@il.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

KVM's existing shadow MMU code already supports nested TDP. To use it, we
need to set up a new "MMU context" for nested EPT, and create a few callbacks
for it (nested_ept_*()). This context should also use the EPT versions of
the page table access functions (defined in the previous patch).
Then, we need to switch back and forth between this nested context and the
regular MMU context when switching between L1 and L2 (when L1 runs this L2
with EPT).
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NNadav Har'El <nyh@il.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Inject nEPT fault to L1 guest. This patch is original from Xinhao.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

need_remote_flush() assumes that shadow page is in PT64 format, but
with addition of nested EPT this is no longer always true. Fix it by
bits definitions that depend on host shadow page type.
Reported-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Since nEPT doesn't support A/D bit, so we should not set those bit
when build shadow page table.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This is the first patch in a series which adds nested EPT support to KVM's
nested VMX. Nested EPT means emulating EPT for an L1 guest so that L1 can use
EPT when running a nested guest L2. When L1 uses EPT, it allows the L2 guest
to set its own cr3 and take its own page faults without either of L0 or L1
getting involved. This often significanlty improves L2's performance over the
previous two alternatives (shadow page tables over EPT, and shadow page
tables over shadow page tables).

This patch adds EPT support to paging_tmpl.h.

paging_tmpl.h contains the code for reading and writing page tables. The code
for 32-bit and 64-bit tables is very similar, but not identical, so
paging_tmpl.h is #include'd twice in mmu.c, once with PTTTYPE=32 and once
with PTTYPE=64, and this generates the two sets of similar functions.

There are subtle but important differences between the format of EPT tables
and that of ordinary x86 64-bit page tables, so for nested EPT we need a
third set of functions to read the guest EPT table and to write the shadow
EPT table.

So this patch adds third PTTYPE, PTTYPE_EPT, which creates functions (prefixed
with "EPT") which correctly read and write EPT tables.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NNadav Har'El <nyh@il.ibm.com>
Signed-off-by: NJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: NXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>