1014032 Commits

Author SHA1 Message Date
Jing Zhang
bc9e9e672d KVM: debugfs: Reuse binary stats descriptors
To remove code duplication, use the binary stats descriptors in the
implementation of the debugfs interface for statistics. This unifies
the definition of statistics for the binary and debugfs interfaces.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-8-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 18:00:29 -04:00
Jing Zhang
0b45d58738 KVM: selftests: Add selftest for KVM statistics data binary interface
Add selftest to check KVM stats descriptors validity.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-7-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 18:00:26 -04:00
Jing Zhang
fdc09ddd40 KVM: stats: Add documentation for binary statistics interface
This new API provides a file descriptor for every VM and VCPU to read
KVM statistics data in binary format.
It is meant to provide a lightweight, flexible, scalable and efficient
lock-free solution for user space telemetry applications to pull the
statistics data periodically for large scale systems. The pulling
frequency could be as high as a few times per second.
The statistics descriptors are defined by KVM in kernel and can be
by userspace to discover VM/VCPU statistics during the one-time setup
stage.
The statistics data itself could be read out by userspace telemetry
periodically without any extra parsing or setup effort.
There are a few existed interface protocols and definitions, but no
one can fulfil all the requirements this interface implemented as
below:
1. During high frequency periodic stats reading, there should be no
   extra efforts except the stats data read itself.
2. Support stats annotation, like type (cumulative, instantaneous,
   peak, histogram, etc) and unit (counter, time, size, cycles, etc).
3. The stats data reading should be free of lock/synchronization. We
   don't care about the consistency between all the stats data. All
   stats data can not be read out at exactly the same time. We really
   care about the change or trend of the stats data. The lock-free
   solution is not just for efficiency and scalability, also for the
   stats data accuracy and usability. For example, in the situation
   that all the stats data readings are protected by a global lock,
   if one VCPU died somehow with that lock held, then all stats data
   reading would be blocked, then we have no way from stats data that
   which VCPU has died.
4. The stats data reading workload can be handed over to other
   unprivileged process.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-6-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 18:00:23 -04:00
Jing Zhang
ce55c04945 KVM: stats: Support binary stats retrieval for a VCPU
Add a VCPU ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VCPU stats header,
descriptors and data.
Define VCPU statistics descriptors and header for all architectures.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-5-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 18:00:19 -04:00
Jing Zhang
fcfe1baedd KVM: stats: Support binary stats retrieval for a VM
Add a VM ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VM stats header,
descriptors and data.
Define VM statistics descriptors and header for all architectures.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-4-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 18:00:10 -04:00
Jing Zhang
cb082bfab5 KVM: stats: Add fd-based API to read binary stats data
This commit defines the API for userspace and prepare the common
functionalities to support per VM/VCPU binary stats data readings.

The KVM stats now is only accessible by debugfs, which has some
shortcomings this change series are supposed to fix:
1. The current debugfs stats solution in KVM could be disabled
   when kernel Lockdown mode is enabled, which is a potential
   rick for production.
2. The current debugfs stats solution in KVM is organized as "one
   stats per file", it is good for debugging, but not efficient
   for production.
3. The stats read/clear in current debugfs solution in KVM are
   protected by the global kvm_lock.

Besides that, there are some other benefits with this change:
1. All KVM VM/VCPU stats can be read out in a bulk by one copy
   to userspace.
2. A schema is used to describe KVM statistics. From userspace's
   perspective, the KVM statistics are self-describing.
3. With the fd-based solution, a separate telemetry would be able
   to read KVM stats in a less privileged environment.
4. After the initial setup by reading in stats descriptors, a
   telemetry only needs to read the stats data itself, no more
   parsing or setup is needed.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-3-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:57 -04:00
Jing Zhang
0193cc908b KVM: stats: Separate generic stats from architecture specific ones
Generic KVM stats are those collected in architecture independent code
or those supported by all architectures; put all generic statistics in
a separate structure.  This ensures that they are defined the same way
in the statistics API which is being added, removing duplication among
different architectures in the declaration of the descriptors.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-2-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:56 -04:00
Sean Christopherson
6c6e166b2c KVM: x86/mmu: Don't WARN on a NULL shadow page in TDP MMU check
Treat a NULL shadow page in the "is a TDP MMU" check as valid, non-TDP
root.  KVM uses a "direct" PAE paging MMU when TDP is disabled and the
guest is running with paging disabled.  In that case, root_hpa points at
the pae_root page (of which only 32 bytes are used), not a standard
shadow page, and the WARN fires (a lot).

Fixes: 0b873fd7fb53 ("KVM: x86/mmu: Remove redundant is_tdp_mmu_enabled check")
Cc: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622072454.3449146-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:56 -04:00
Sean Christopherson
ef6a74b2e5 KVM: sefltests: Add x86-64 test to verify MMU reacts to CPUID updates
Add an x86-only test to verify that x86's MMU reacts to CPUID updates
that impact the MMU.  KVM has had multiple bugs where it fails to
reconfigure the MMU after the guest's vCPU model changes.

Sadly, this test is effectively limited to shadow paging because the
hardware page walk handler doesn't support software disabling of GBPAGES
support, and KVM doesn't manually walk the GVA->GPA on faults for
performance reasons (doing so would large defeat the benefits of TDP).

Don't require !TDP for the tests as there is still value in running the
tests with TDP, even though the tests will fail (barring KVM hacks).
E.g. KVM should not completely explode if MAXPHYADDR results in KVM using
4-level vs. 5-level paging for the guest.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-20-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:56 -04:00
Sean Christopherson
ad5f16e422 KVM: selftests: Add hugepage support for x86-64
Add x86-64 hugepage support in the form of a x86-only variant of
virt_pg_map() that takes an explicit page size.  To keep things simple,
follow the existing logic for 4k pages and disallow creating a hugepage
if the upper-level entry is present, even if the desired pfn matches.

Opportunistically fix a double "beyond beyond" reported by checkpatch.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-19-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:55 -04:00
Sean Christopherson
b007e904b3 KVM: selftests: Genericize upper level page table entry struct
In preparation for adding hugepage support, replace "pageMapL4Entry",
"pageDirectoryPointerEntry", and "pageDirectoryEntry" with a common
"pageUpperEntry", and add a helper to create an upper level entry. All
upper level entries have the same layout, using unique structs provides
minimal value and requires a non-trivial amount of code duplication.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-18-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:55 -04:00
Sean Christopherson
f681d6861b KVM: selftests: Add PTE helper for x86-64 in preparation for hugepages
Add a helper to retrieve a PTE pointer given a PFN, address, and level
in preparation for adding hugepage support.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-17-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:49 -04:00
Sean Christopherson
6d96ca6a60 KVM: selftests: Rename x86's page table "address" to "pfn"
Rename the "address" field to "pfn" in x86's page table structs to match
reality.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:49 -04:00
Sean Christopherson
cce0c23dd9 KVM: selftests: Add wrapper to allocate page table page
Add a helper to allocate a page for use in constructing the guest's page
tables.  All architectures have identical address and memslot
requirements (which appear to be arbitrary anyways).

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-15-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:49 -04:00
Sean Christopherson
444d084b46 KVM: selftests: Unconditionally allocate EPT tables in memslot 0
Drop the EPTP memslot param from all EPT helpers and shove the hardcoded
'0' down to the vm_phy_page_alloc() calls.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:48 -04:00
Sean Christopherson
4307af730b KVM: selftests: Unconditionally use memslot '0' for page table allocations
Drop the memslot param from virt_pg_map() and virt_map() and shove the
hardcoded '0' down to the vm_phy_page_alloc() calls.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-13-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:48 -04:00
Sean Christopherson
a75a895e64 KVM: selftests: Unconditionally use memslot 0 for vaddr allocations
Drop the memslot param(s) from vm_vaddr_alloc() now that all callers
directly specific '0' as the memslot.  Drop the memslot param from
virt_pgd_alloc() as well since vm_vaddr_alloc() is its only user.
I.e. shove the hardcoded '0' down to the vm_phy_pages_alloc() calls.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:42 -04:00
Sean Christopherson
408633c326 KVM: selftests: Use "standard" min virtual address for CPUID test alloc
Use KVM_UTIL_MIN_ADDR as the minimum for x86-64's CPUID array.  The
system page size was likely used as the minimum because _something_ had
to be provided.  Increasing the min from 0x1000 to 0x2000 should have no
meaningful impact on the test, and will allow changing vm_vaddr_alloc()
to use KVM_UTIL_MIN_VADDR as the default.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:19 -04:00
Sean Christopherson
233446c1e6 KVM: selftests: Use alloc page helper for xAPIC IPI test
Use the common page allocation helper for the xAPIC IPI test, effectively
raising the minimum virtual address from 0x1000 to 0x2000.  Presumably
the test won't explode if it can't get a page at address 0x1000...

Cc: Peter Shier <pshier@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:19 -04:00
Sean Christopherson
5ae4d8706f KVM: selftests: Use alloc_page helper for x86-64's GDT/IDT/TSS allocations
Switch to the vm_vaddr_alloc_page() helper for x86-64's "kernel"
allocations now that the helper uses the same min virtual address as the
open coded versions.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:18 -04:00
Sean Christopherson
106a2e766e KVM: selftests: Lower the min virtual address for misc page allocations
Reduce the minimum virtual address of page allocations from 0x10000 to
KVM_UTIL_MIN_VADDR (0x2000).  Both values appear to be completely
arbitrary, and reducing the min to KVM_UTIL_MIN_VADDR will allow for
additional consolidation of code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:18 -04:00
Sean Christopherson
a9db9609c0 KVM: selftests: Add helpers to allocate N pages of virtual memory
Add wrappers to allocate 1 and N pages of memory using de facto standard
values as the defaults for minimum virtual address, data memslot, and
page table memslot.  Convert all compatible users.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:18 -04:00
Sean Christopherson
95be3709ff KVM: selftests: Use "standard" min virtual address for Hyper-V pages
Use the de facto standard minimum virtual address for Hyper-V's hcall
params page.  It's the allocator's job to not double-allocate memory,
i.e. there's no reason to force different regions for the params vs.
hcall page.  This will allow adding a page allocation helper with a
"standard" minimum address.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:18 -04:00
Sean Christopherson
1dcd1c58ae KVM: selftests: Unconditionally use memslot 0 for x86's GDT/TSS setup
Refactor x86's GDT/TSS allocations to for memslot '0' at its
vm_addr_alloc() call sites instead of passing in '0' from on high.  This
is a step toward using a common helper for allocating pages.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:17 -04:00
Sean Christopherson
7a4f1a75b7 KVM: selftests: Unconditionally use memslot 0 when loading elf binary
Use memslot '0' for all vm_vaddr_alloc() calls when loading the test
binary.  This is the first step toward adding a helper to handle page
allocations with a default value for the target memslot.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:17 -04:00
Sean Christopherson
96d41cfd1b KVM: selftests: Zero out the correct page in the Hyper-V features test
Fix an apparent copy-paste goof in hyperv_features where hcall_page
(which is two pages, so technically just the first page) gets zeroed
twice, and hcall_params gets zeroed none times.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:17 -04:00
Sean Christopherson
ecc3a92c6f KVM: selftests: Remove errant asm/barrier.h include to fix arm64 build
Drop an unnecessary include of asm/barrier.h from dirty_log_test.c to
allow the test to build on arm64.  arm64, s390, and x86 all build cleanly
without the include (PPC and MIPS aren't supported in KVM's selftests).

arm64's barrier.h includes linux/kasan-checks.h, which is not copied
into tools/.

  In file included from ../../../../tools/include/asm/barrier.h:8,
                   from dirty_log_test.c:19:
     .../arm64/include/asm/barrier.h:12:10: fatal error: linux/kasan-checks.h: No such file or directory
     12 | #include <linux/kasan-checks.h>
        |          ^~~~~~~~~~~~~~~~~~~~~~
  compilation terminated.

Fixes: 84292e565951 ("KVM: selftests: Add dirty ring buffer test")
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:17 -04:00
Sean Christopherson
b33bb78a1f KVM: nVMX: Handle split-lock #AC exceptions that happen in L2
Mark #ACs that won't be reinjected to the guest as wanted by L0 so that
KVM handles split-lock #AC from L2 instead of forwarding the exception to
L1.  Split-lock #AC isn't yet virtualized, i.e. L1 will treat it like a
regular #AC and do the wrong thing, e.g. reinject it into L2.

Fixes: e6f8b6c12f03 ("KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest")
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622172244.3561540-1-seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:16 -04:00
Colin Ian King
31c6565700 KVM: x86/mmu: Fix uninitialized boolean variable flush
In the case where kvm_memslots_have_rmaps(kvm) is false the boolean
variable flush is not set and is uninitialized.  If is_tdp_mmu_enabled(kvm)
is true then the call to kvm_tdp_mmu_zap_collapsible_sptes passes the
uninitialized value of flush into the call. Fix this by initializing
flush to false.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: e2209710ccc5 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622150912.23429-1-colin.king@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:16 -04:00
Hou Wenlong
e5830fb13b KVM: selftests: fix triple fault if ept=0 in dirty_log_test
Commit 22f232d134e1 ("KVM: selftests: x86: Set supported CPUIDs on
default VM") moved vcpu_set_cpuid into vm_create_with_vcpus, but
dirty_log_test doesn't use it to create vm. So vcpu's CPUIDs is
not set, the guest's pa_bits in kvm would be smaller than the
value queried by userspace.

However, the dirty track memory slot is in the highest GPA, the
reserved bits in gpte would be set with wrong pa_bits.
For shadow paging, page fault would fail in permission_fault and
be injected into guest. Since guest doesn't have idt, it finally
leads to vm_exit for triple fault.

Move vcpu_set_cpuid into vm_vcpu_add_default to set supported
CPUIDs on default vcpu, since almost all tests need it.

Fixes: 22f232d134e1 ("KVM: selftests: x86: Set supported CPUIDs on default VM")
Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com>
Message-Id: <411ea2173f89abce56fc1fca5af913ed9c5a89c9.1624351343.git.houwenlong93@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:16 -04:00
Jim Mattson
18f63b15b0 KVM: x86: Print CPU of last attempted VM-entry when dumping VMCS/VMCB
Failed VM-entry is often due to a faulty core. To help identify bad
cores, print the id of the last logical processor that attempted
VM-entry whenever dumping a VMCS or VMCB.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210621221648.1833148-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 04:31:13 -04:00
Paolo Bonzini
c3ab0e28a4 Merge branch 'topic/ppc-kvm' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux into HEAD
- Support for the H_RPT_INVALIDATE hypercall

- Conversion of Book3S entry/exit to C

- Bug fixes
2021-06-23 07:30:41 -04:00
Nathan Chancellor
51696f39cb KVM: PPC: Book3S HV: Workaround high stack usage with clang
LLVM does not emit optimal byteswap assembly, which results in high
stack usage in kvmhv_enter_nested_guest() due to the inlining of
byteswap_pt_regs(). With LLVM 12.0.0:

arch/powerpc/kvm/book3s_hv_nested.c:289:6: error: stack frame size of
2512 bytes in function 'kvmhv_enter_nested_guest' [-Werror,-Wframe-larger-than=]
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
     ^
1 error generated.

While this gets fixed in LLVM, mark byteswap_pt_regs() as
noinline_for_stack so that it does not get inlined and break the build
due to -Werror by default in arch/powerpc/. Not inlining saves
approximately 800 bytes with LLVM 12.0.0:

arch/powerpc/kvm/book3s_hv_nested.c:290:6: warning: stack frame size of
1728 bytes in function 'kvmhv_enter_nested_guest' [-Wframe-larger-than=]
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
     ^
1 warning generated.

Cc: stable@vger.kernel.org # v4.20+
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1292
Link: https://bugs.llvm.org/show_bug.cgi?id=49610
Link: https://lore.kernel.org/r/202104031853.vDT0Qjqj-lkp@intel.com/
Link: https://gist.github.com/ba710e3703bf45043a31e2806c843ffd
Link: https://lore.kernel.org/r/20210621182440.990242-1-nathan@kernel.org
2021-06-23 00:18:30 +10:00
Bharata B Rao
81468083f3 KVM: PPC: Book3S HV: Use H_RPT_INVALIDATE in nested KVM
In the nested KVM case, replace H_TLB_INVALIDATE by the new hcall
H_RPT_INVALIDATE if available. The availability of this hcall
is determined from "hcall-rpt-invalidate" string in ibm,hypertas-functions
DT property.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-7-bharata@linux.ibm.com
2021-06-22 23:38:28 +10:00
Bharata B Rao
b87cc116c7 KVM: PPC: Book3S HV: Add KVM_CAP_PPC_RPT_INVALIDATE capability
Now that we have H_RPT_INVALIDATE fully implemented, enable
support for the same via KVM_CAP_PPC_RPT_INVALIDATE KVM capability

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-6-bharata@linux.ibm.com
2021-06-22 23:38:28 +10:00
Bharata B Rao
53324b51c5 KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE
Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped invalidations for any level of nested guests
are handled by implementing H_RPT_INVALIDATE handler in the
nested guest exit path in L0.

Partition-scoped invalidation requests are forwarded to the
right nested guest, handled there and passed down to L0
for eventual handling.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
[aneesh: Nested guest partition-scoped invalidation changes]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Squash in fixup patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-5-bharata@linux.ibm.com
2021-06-22 23:35:37 +10:00
Sean Christopherson
ba1f82456b KVM: nVMX: Dynamically compute max VMCS index for vmcs12
Calculate the max VMCS index for vmcs12 by walking the array to find the
actual max index.  Hardcoding the index is prone to bitrot, and the
calculation is only done on KVM bringup (albeit on every CPU, but there
aren't _that_ many null entries in the array).

Fixes: 3c0f99366e34 ("KVM: nVMX: Add a TSC multiplier field in VMCS12")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210618214658.2700765-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-21 12:58:55 -04:00
Jim Mattson
5140bc7d6b KVM: VMX: Skip #PF(RSVD) intercepts when emulating smaller maxphyaddr
As part of smaller maxphyaddr emulation, kvm needs to intercept
present page faults to see if it needs to add the RSVD flag (bit 3) to
the error code. However, there is no need to intercept page faults
that already have the RSVD flag set. When setting up the page fault
intercept, add the RSVD flag into the #PF error code mask field (but
not the #PF error code match field) to skip the intercept when the
RSVD flag is already set.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210618235941.1041604-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-21 12:58:55 -04:00
Bharata B Rao
f0c6fbbb90 KVM: PPC: Book3S HV: Add support for H_RPT_INVALIDATE
H_RPT_INVALIDATE does two types of TLB invalidations:

1. Process-scoped invalidations for guests when LPCR[GTSE]=0.
   This is currently not used in KVM as GTSE is not usually
   disabled in KVM.
2. Partition-scoped invalidations that an L1 hypervisor does on
   behalf of an L2 guest. This is currently handled
   by H_TLB_INVALIDATE hcall and this new replaces the old that.

This commit enables process-scoped invalidations for L1 guests.
Support for process-scoped and partition-scoped invalidations
from/for nested guests will be added separately.

Process scoped tlbie invalidations from L1 and nested guests
need RS register for TLBIE instruction to contain both PID and
LPID.  This patch introduces primitives that execute tlbie
instruction with both PID and LPID set in prepartion for
H_RPT_INVALIDATE hcall.

A description of H_RPT_INVALIDATE follows:

int64   /* H_Success: Return code on successful completion */
        /* H_Busy - repeat the call with the same */
        /* H_Parameter, H_P2, H_P3, H_P4, H_P5 : Invalid
	   parameters */
hcall(const uint64 H_RPT_INVALIDATE, /* Invalidate RPT
					translation
					lookaside information */
      uint64 id,        /* PID/LPID to invalidate */
      uint64 target,    /* Invalidation target */
      uint64 type,      /* Type of lookaside information */
      uint64 pg_sizes,  /* Page sizes */
      uint64 start,     /* Start of Effective Address (EA)
			   range (inclusive) */
      uint64 end)       /* End of EA range (exclusive) */

Invalidation targets (target)
-----------------------------
Core MMU        0x01 /* All virtual processors in the
			partition */
Core local MMU  0x02 /* Current virtual processor */
Nest MMU        0x04 /* All nest/accelerator agents
			in use by the partition */

A combination of the above can be specified,
except core and core local.

Type of translation to invalidate (type)
---------------------------------------
NESTED       0x0001  /* invalidate nested guest partition-scope */
TLB          0x0002  /* Invalidate TLB */
PWC          0x0004  /* Invalidate Page Walk Cache */
PRT          0x0008  /* Invalidate caching of Process Table
			Entries if NESTED is clear */
PAT          0x0008  /* Invalidate caching of Partition Table
			Entries if NESTED is set */

A combination of the above can be specified.

Page size mask (pages)
----------------------
4K              0x01
64K             0x02
2M              0x04
1G              0x08
All sizes       (-1UL)

A combination of the above can be specified.
All page sizes can be selected with -1.

Semantics: Invalidate radix tree lookaside information
           matching the parameters given.
* Return H_P2, H_P3 or H_P4 if target, type, or pageSizes parameters
  are different from the defined values.
* Return H_PARAMETER if NESTED is set and pid is not a valid nested
  LPID allocated to this partition
* Return H_P5 if (start, end) doesn't form a valid range. Start and
  end should be a valid Quadrant address and  end > start.
* Return H_NotSupported if the partition is not in running in radix
  translation mode.
* May invalidate more translation information than requested.
* If start = 0 and end = -1, set the range to cover all valid
  addresses. Else start and end should be aligned to 4kB (lower 11
  bits clear).
* If NESTED is clear, then invalidate process scoped lookaside
  information. Else pid specifies a nested LPID, and the invalidation
  is performed   on nested guest partition table and nested guest
  partition scope real addresses.
* If pid = 0 and NESTED is clear, then valid addresses are quadrant 3
  and quadrant 0 spaces, Else valid addresses are quadrant 0.
* Pages which are fully covered by the range are to be invalidated.
  Those which are partially covered are considered outside
  invalidation range, which allows a caller to optimally invalidate
  ranges that may   contain mixed page sizes.
* Return H_SUCCESS on success.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-4-bharata@linux.ibm.com
2021-06-21 22:54:27 +10:00
Bharata B Rao
d6265cb33b powerpc/book3s64/radix: Add H_RPT_INVALIDATE pgsize encodings to mmu_psize_def
Add a field to mmu_psize_def to store the page size encodings
of H_RPT_INVALIDATE hcall. Initialize this while scanning the radix
AP encodings. This will be used when invalidating with required
page size encoding in the hcall.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-3-bharata@linux.ibm.com
2021-06-21 22:48:18 +10:00
Aneesh Kumar K.V
f09216a190 KVM: PPC: Book3S HV: Fix comments of H_RPT_INVALIDATE arguments
The type values H_RPTI_TYPE_PRT and H_RPTI_TYPE_PAT indicate
invalidating the caching of process and partition scoped entries
respectively.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-2-bharata@linux.ibm.com
2021-06-21 22:48:18 +10:00
Suraj Jitindar Singh
77bbbc0cf8 KVM: PPC: Book3S HV: Fix TLB management on SMT8 POWER9 and POWER10 processors
The POWER9 vCPU TLB management code assumes all threads in a core share
a TLB, and that TLBIEL execued by one thread will invalidate TLBs for
all threads. This is not the case for SMT8 capable POWER9 and POWER10
(big core) processors, where the TLB is split between groups of threads.
This results in TLB multi-hits, random data corruption, etc.

Fix this by introducing cpu_first_tlb_thread_sibling etc., to determine
which siblings share TLBs, and use that in the guest TLB flushing code.

[npiggin@gmail.com: add changelog and comment]

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210602040441.3984352-1-npiggin@gmail.com
2021-06-21 09:22:34 +10:00
David Matlack
0485cf8dbe KVM: x86/mmu: Remove redundant root_hpa checks
The root_hpa checks below the top-level check in kvm_mmu_page_fault are
theoretically redundant since there is no longer a way for the root_hpa
to be reset during a page fault. The details of why are described in
commit ddce6208217c ("KVM: x86/mmu: Move root_hpa validity checks to top
of page fault handler")

__direct_map, kvm_tdp_mmu_map, and get_mmio_spte are all only reachable
through kvm_mmu_page_fault, therefore their root_hpa checks are
redundant.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20210617231948.2591431-5-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:45:47 -04:00
David Matlack
63c0cac938 KVM: x86/mmu: Refactor is_tdp_mmu_root into is_tdp_mmu
This change simplifies the call sites slightly and also abstracts away
the implementation detail of looking at root_hpa as the mechanism for
determining if the mmu is the TDP MMU.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20210617231948.2591431-4-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:45:46 -04:00
David Matlack
0b873fd7fb KVM: x86/mmu: Remove redundant is_tdp_mmu_enabled check
This check is redundant because the root shadow page will only be a TDP
MMU page if is_tdp_mmu_enabled() returns true, and is_tdp_mmu_enabled()
never changes for the lifetime of a VM.

It's possible that this check was added for performance reasons but it
is unlikely that it is useful in practice since to_shadow_page() is
cheap. That being said, this patch also caches the return value of
is_tdp_mmu_root() in direct_page_fault() since there's no reason to
duplicate the call so many times, so performance is not a concern.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20210617231948.2591431-3-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:45:46 -04:00
David Matlack
aa23c0ad14 KVM: x86/mmu: Remove redundant is_tdp_mmu_root check
The check for is_tdp_mmu_root in kvm_tdp_mmu_map is redundant because
kvm_tdp_mmu_map's only caller (direct_page_fault) already checks
is_tdp_mmu_root.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20210617231948.2591431-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:45:46 -04:00
Paolo Bonzini
c62efff28b KVM: x86: Stub out is_tdp_mmu_root on 32-bit hosts
If is_tdp_mmu_root is not inlined, the elimination of TDP MMU calls as dead
code might not work out.  To avoid this, explicitly declare the stubbed
is_tdp_mmu_root on 32-bit hosts.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:45:46 -04:00
Sean Christopherson
8bbed95d2c KVM: x86: WARN and reject loading KVM if NX is supported but not enabled
WARN if NX is reported as supported but not enabled in EFER.  All flavors
of the kernel, including non-PAE 32-bit kernels, set EFER.NX=1 if NX is
supported, even if NX usage is disable via kernel command line.  KVM relies
on NX being enabled if it's supported, e.g. KVM will generate illegal NPT
entries if nx_huge_pages is enabled and NX is supported but not enabled.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210615164535.2146172-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:24:50 -04:00
Sean Christopherson
b26a71a1a5 KVM: SVM: Refuse to load kvm_amd if NX support is not available
Refuse to load KVM if NX support is not available.  Shadow paging has
assumed NX support since commit 9167ab799362 ("KVM: vmx, svm: always run
with EFER.NXE=1 when shadow paging is active"), and NPT has assumed NX
support since commit b8e8c8303ff2 ("kvm: mmu: ITLB_MULTIHIT mitigation").
While the NX huge pages mitigation should not be enabled by default for
AMD CPUs, it can be turned on by userspace at will.

Unlike Intel CPUs, AMD does not provide a way for firmware to disable NX
support, and Linux always sets EFER.NX=1 if it is supported.  Given that
it's extremely unlikely that a CPU supports NPT but not NX, making NX a
formal requirement is far simpler than adding requirements to the
mitigation flow.

Fixes: 9167ab799362 ("KVM: vmx, svm: always run with EFER.NXE=1 when shadow paging is active")
Fixes: b8e8c8303ff2 ("kvm: mmu: ITLB_MULTIHIT mitigation")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210615164535.2146172-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:24:49 -04:00
Sean Christopherson
23f079c249 KVM: VMX: Refuse to load kvm_intel if EPT and NX are disabled
Refuse to load KVM if NX support is not available and EPT is not enabled.
Shadow paging has assumed NX support since commit 9167ab799362 ("KVM:
vmx, svm: always run with EFER.NXE=1 when shadow paging is active"), so
for all intents and purposes this has been a de facto requirement for
over a year.

Do not require NX support if EPT is enabled purely because Intel CPUs let
firmware disable NX support via MSR_IA32_MISC_ENABLES.  If not for that,
VMX (and KVM as a whole) could require NX support with minimal risk to
breaking userspace.

Fixes: 9167ab799362 ("KVM: vmx, svm: always run with EFER.NXE=1 when shadow paging is active")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210615164535.2146172-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-18 06:24:49 -04:00