In KVM, specially for nested guests, there is a dominant pattern of:

	=> map guest memory -> do_something -> unmap guest memory

In addition to all this unnecessarily noise in the code due to boiler plate
code, most of the time the mapping function does not properly handle memory
that is not backed by "struct page". This new guest mapping API encapsulate
most of this boiler plate code and also handles guest memory that is not
backed by "struct page".

The current implementation of this API is using memremap for memory that is
not backed by a "struct page" which would lead to a huge slow-down if it
was used for high-frequency mapping operations. The API does not have any
effect on current setups where guest memory is backed by a "struct page".
Further patches are going to also introduce a pfn-cache which would
significantly improve the performance of the memremap case.
Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

cmpxchg_gpte() calls get_user_pages_fast() to retrieve the number of
pages and the respective struct page to map in the kernel virtual
address space.
This doesn't work if get_user_pages_fast() is invoked with a userspace
virtual address that's backed by PFNs outside of kernel reach (e.g., when
limiting the kernel memory with mem= in the command line and using
/dev/mem to map memory).

If get_user_pages_fast() fails, look up the VMA that back the userspace
virtual address, compute the PFN and the physical address, and map it in
the kernel virtual address space with memremap().
Signed-off-by: NFilippo Sironi <sironi@amazon.de>
Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Update the PML table without mapping and unmapping the page. This also
avoids using kvm_vcpu_gpa_to_page(..) which assumes that there is a "struct
page" for guest memory.

As a side-effect of using kvm_write_guest_page the page is also properly
marked as dirty.
Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Read the data directly from guest memory instead of the map->read->unmap
sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which
assumes that there is a "struct page" for guest memory.
Suggested-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The hardware configuration register has some useful bits which can be
used by guests. Implement McStatusWrEn which can be used by guests when
injecting MCEs with the in-kernel mce-inject module.

For that, we need to set bit 18 - McStatusWrEn - first, before writing
the MCi_STATUS registers (otherwise we #GP).

Add the required machinery to do so.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: KVM <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The capabilities header depends on asm/vmx.h but doesn't explicitly
include said file.  This currently doesn't cause problems as all users
of capbilities.h first include asm/vmx.h, but the issue often results in
build errors if someone starts moving things around the VMX files.

Fixes: 3077c191 ("KVM: VMX: Move capabilities structs and helpers to dedicated file")
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Smatch complains about this:

    arch/x86/kvm/vmx/vmx.c:5730 dump_vmcs()
    warn: KERN_* level not at start of string

The code should be using pr_cont() instead of pr_err().

Fixes: 9d609649 ("KVM: vmx: print more APICv fields in dump_vmcs")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

is_dirty has been renamed to flush, but the comment for it is
outdated. And the description about @flush parameter for
kvm_clear_dirty_log_protect() is missing, add it in this patch
as well.
Signed-off-by: NJiang Biao <benbjiang@tencent.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If a memory slot's size is not a multiple of 64 pages (256K), then
the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages
either requires the requested page range to go beyond memslot->npages,
or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect
requires log->num_pages to be both in range and aligned.

To allow this case, allow log->num_pages not to be a multiple of 64 if
it ends exactly on the last page of the slot.
Reported-by: NPeter Xu <peterx@redhat.com>
Fixes: 98938aa8 ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02)
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Ten percent of nothin' is... let me do the math here.  Nothin' into
nothin', carry the nothin'...

Cc: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Checking for a pending non-periodic interrupt in start_hv_timer() leads
to restart_apic_timer() making an unnecessary call to start_sw_timer()
due to start_hv_timer() returning false.

Alternatively, start_hv_timer() could return %true when there is a
pending non-periodic interrupt, but that approach is less intuitive,
i.e. would require a beefy comment to explain an otherwise simple check.

Cc: Liran Alon <liran.alon@oracle.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Suggested-by: NLiran Alon <liran.alon@oracle.com>
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Refactor kvm_x86_ops->set_hv_timer to use an explicit parameter for
stating that the timer has expired.  Overloading the return value is
unnecessarily clever, e.g. can lead to confusion over the proper return
value from start_hv_timer() when r==1.

Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Explicitly call cancel_hv_timer() instead of returning %false to coerce
restart_apic_timer() into canceling it by way of start_sw_timer().

Functionally, the existing code is correct in the sense that it doesn't
doing anything visibily wrong, e.g. generate spurious interrupts or miss
an interrupt.  But it's extremely confusing and inefficient, e.g. there
are multiple extraneous calls to apic_timer_expired() that effectively
get dropped due to @timer_pending being %true.

Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

...now that VMX's preemption timer, i.e. the hv_timer, also adjusts its
programmed time based on lapic_timer_advance_ns.  Without the delay, a
guest can see a timer interrupt arrive before the requested time when
KVM is using the hv_timer to emulate the guest's interrupt.

Fixes: c5ce8235 ("KVM: VMX: Optimize tscdeadline timer latency")
Cc: <stable@vger.kernel.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Since commits 668fffa3 ("kvm: better MWAIT emulation for guestsâ€)
and 4d5422ce ("KVM: X86: Provide a capability to disable MWAIT interceptsâ€),
KVM was modified to allow an admin to configure certain guests to execute
MONITOR/MWAIT inside guest without being intercepted by host.

This is useful in case admin wishes to allocate a dedicated logical
processor for each vCPU thread. Thus, making it safe for guest to
completely control the power-state of the logical processor.

The ability to use this new KVM capability was introduced to QEMU by
commits 6f131f13e68d ("kvm: support -overcommit cpu-pm=on|offâ€) and
2266d4431132 ("i386/cpu: make -cpu host support monitor/mwaitâ€).

However, exposing MONITOR/MWAIT to a Linux guest may cause it's intel_idle
kernel module to execute c1e_promotion_disable() which will attempt to
RDMSR/WRMSR from/to MSR_IA32_POWER_CTL to manipulate the "C1E Enable"
bit. This behaviour was introduced by commit
32e95180 ("intel_idle: export both C1 and C1Eâ€).

Becuase KVM doesn't emulate this MSR, running KVM with ignore_msrs=0
will cause the above guest behaviour to raise a #GP which will cause
guest to kernel panic.

Therefore, add support for nop emulation of MSR_IA32_POWER_CTL to
avoid #GP in guest in this scenario.

Future commits can optimise emulation further by reflecting guest
MSR changes to host MSR to provide guest with the ability to
fine-tune the dedicated logical processor power-state.
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Let guests clear the Intel PT ToPA PMI status (bit 55 of
MSR_CORE_PERF_GLOBAL_OVF_CTRL).
Signed-off-by: NLuwei Kang <luwei.kang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Inject a PMI for KVM guest when Intel PT working
in Host-Guest mode and Guest ToPA entry memory buffer
was completely filled.
Signed-off-by: NLuwei Kang <luwei.kang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This reverts commit 919f6cd8.

The patch was applied twice.
The first commit is eca6be56.
Reported-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Merge tag 'kvm-s390-next-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Features and fixes for 5.2

- VSIE crypto fixes
- new guest features for gen15
- disable halt polling for nested virtualization with overcommit

Let's use the correct validity number.

Fixes: 56019f9a ("KVM: s390: vsie: Allow CRYCB FORMAT-2")
Signed-off-by: NPierre Morel <pmorel@linux.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <1556269201-22918-1-git-send-email-pmorel@linux.ibm.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

When the guest do not have AP instructions nor Key management
we should return without shadowing the CRYCB.

We did not check correctly in the past.

Fixes: b10bd9a2 ("s390: vsie: Use effective CRYCBD.31 to check CRYCBD validity")
Fixes: 6ee74098 ("KVM: s390: vsie: allow CRYCB FORMAT-0")
Signed-off-by: NPierre Morel <pmorel@linux.ibm.com>
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <1556269010-22258-1-git-send-email-pmorel@linux.ibm.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

We do track the current steal time of the host CPUs. Let us use
this value to disable halt polling if the steal time goes beyond
a configured value.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

There are cases where halt polling is unwanted. For example when running
KVM on an over committed LPAR we rather want to give back the CPU to
neighbour LPARs instead of polling. Let us provide a callback that
allows architectures to disable polling.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Instead of adding a new machine option to disable/enable the keywrapping
options of pckmo (like for AES and DEA) we can now use the CPU model to
decide. As ECC is also wrapped with the AES key we need that to be
enabled.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

This enables stfle.151 and adds the subfunctions for DFLTCC. Bit 151 is
added to the list of facilities that will be enabled when there is no
cpu model involved as DFLTCC requires no additional handling from
userspace, e.g. for migration.

Please note that a cpu model enabled user space can and will have the
final decision on the facility bits for a guests.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCollin Walling <walling@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

This enables stfle.150 and adds the subfunctions for SORTL. Bit 150 is
added to the list of facilities that will be enabled when there is no
cpu model involved as sortl requires no additional handling from
userspace, e.g. for migration.

Please note that a cpu model enabled user space can and will have the
final decision on the facility bits for a guests.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCollin Walling <walling@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

Some of the new features have a 32byte response for the query function.
Provide a new wrapper similar to __cpacf_query. We might want to factor
this out if other users come up, as of today there is none. So let us
keep the function within KVM.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCollin Walling <walling@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

This enables stfle.155 and adds the subfunctions for KDSA. Bit 155 is
added to the list of facilities that will be enabled when there is no
cpu model involved as MSA9 requires no additional handling from
userspace, e.g. for migration.

Please note that a cpu model enabled user space can and will have the
final decision on the facility bits for a guests.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: NCollin Walling <walling@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

If vector support is enabled, the vector BCD enhancements facility
might also be enabled.
We can directly forward this facility to the guest if available
and VX is requested by user space.

Please note that user space can and will have the final decision
on the facility bits for a guests.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: NCollin Walling <walling@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

If vector support is enabled, the vector enhancements facility 2
might also be enabled.
We can directly forward this facility to the guest if available
and VX is requested by user space.

Please note that user space can and will have the final decision
on the facility bits for a guests.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: NCollin Walling <walling@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

Fix some warnings from smatch:

arch/s390/kvm/interrupt.c:2310 get_io_adapter() warn: potential spectre issue 'kvm->arch.adapters' [r] (local cap)
arch/s390/kvm/interrupt.c:2341 register_io_adapter() warn: potential spectre issue 'dev->kvm->arch.adapters' [w]
Signed-off-by: NEric Farman <farman@linux.ibm.com>
Message-Id: <20190417005414.47801-1-farman@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

All architectures except MIPS were defining it in the same way,
and memory slots are handled entirely by common code so there
is no point in keeping the definition per-architecture.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

EFER.LME and EFER.NX are considered reserved if their respective feature
bits are not advertised to the guest.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

KVM allows userspace to violate consistency checks related to the
guest's CPUID model to some degree.  Generally speaking, userspace has
carte blanche when it comes to guest state so long as jamming invalid
state won't negatively affect the host.

Currently this is seems to be a non-issue as most of the interesting
EFER checks are missing, e.g. NX and LME, but those will be added
shortly.  Proactively exempt userspace from the CPUID checks so as not
to break userspace.

Note, the efer_reserved_bits check still applies to userspace writes as
that mask reflects the host's capabilities, e.g. KVM shouldn't allow a
guest to run with NX=1 if it has been disabled in the host.

Fixes: d8017474 ("KVM: SVM: Only allow setting of EFER_SVME when CPUID SVM is set")
Cc: stable@vger.kernel.org
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Most, but not all, helpers that are related to emulating consistency
checks for nested VM-Entry return -EINVAL when a check fails.  Convert
the holdouts to have consistency throughout and to make it clear that
the functions are signaling pass/fail as opposed to "resume guest" vs.
"exit to userspace".

Opportunistically fix bad indentation in nested_vmx_check_guest_state().
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Convert all top-level nested VM-Enter consistency check functions to
return 0/-EINVAL instead of failure codes, since now they can only
ever return one failure code.

This also does not give the false impression that failure information is
always consumed and/or relevant, e.g. vmx_set_nested_state() only
cares whether or not the checks were successful.

nested_check_host_control_regs() can also now be inlined into its caller,
nested_vmx_check_host_state, since the two have effectively become the
same function.

Based on a patch by Sean Christopherson.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Rename the top-level consistency check functions to (loosely) align with
the SDM.  Historically, KVM has used the terms "prereq" and "postreq" to
differentiate between consistency checks that lead to VM-Fail and those
that lead to VM-Exit.  The terms are vague and potentially misleading,
e.g. "postreq" might be interpreted as occurring after VM-Entry.

Note, while the SDM lumps controls and host state into a single section,
"Checks on VMX Controls and Host-State Area", split them into separate
top-level functions as the two categories of checks result in different
VM instruction errors.  This split will allow for additional cleanup.

Note #2, "vmentry" is intentionally dropped from the new function names
to avoid confusion with nested_check_vm_entry_controls(), and to keep
the length of the functions names somewhat manageable.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Per Intel's SDM, volume 3, section Checking and Loading Guest State:

  Because the checking and the loading occur concurrently, a failure may
  be discovered only after some state has been loaded. For this reason,
  the logical processor responds to such failures by loading state from
  the host-state area, as it would for a VM exit.

In other words, a failed non-register state consistency check results in
a VM-Exit, not VM-Fail.  Moving the non-reg state checks also paves the
way for renaming nested_vmx_check_vmentry_postreqs() to align with the
SDM, i.e. nested_vmx_check_vmentry_guest_state().

Fixes: 26539bd0 ("KVM: nVMX: check vmcs12 for valid activity state")
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

According to section "Checking and Loading Guest State" in Intel SDM vol
3C, the following check is performed on vmentry:

    If the "load IA32_PAT" VM-entry control is 1, the value of the field
    for the IA32_PAT MSR must be one that could be written by WRMSR
    without fault at CPL 0. Specifically, each of the 8 bytes in the
    field must have one of the values 0 (UC), 1 (WC), 4 (WT), 5 (WP),
    6 (WB), or 7 (UC-).
Signed-off-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: NKarl Heubaum <karl.heubaum@oracle.com>
Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

According to section "Checks on Host Control Registers and MSRs" in Intel
SDM vol 3C, the following check is performed on vmentry:

    If the "load IA32_PAT" VM-exit control is 1, the value of the field
    for the IA32_PAT MSR must be one that could be written by WRMSR
    without fault at CPL 0. Specifically, each of the 8 bytes in the
    field must have one of the values 0 (UC), 1 (WC), 4 (WT), 5 (WP),
    6 (WB), or 7 (UC-).
Signed-off-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: NKarl Heubaum <karl.heubaum@oracle.com>
Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>