1073154 Commits

Author SHA1 Message Date
Hou Wenlong
ca85f00225 KVM: x86/emulator: Defer not-present segment check in __load_segment_descriptor()
Per Intel's SDM on the "Instruction Set Reference", when
loading segment descriptor, not-present segment check should
be after all type and privilege checks. But the emulator checks
it first, then #NP is triggered instead of #GP if privilege fails
and segment is not present. Put not-present segment check after
type and privilege checks in __load_segment_descriptor().

Fixes: 38ba30ba51a00 (KVM: x86 emulator: Emulate task switch in emulator.c)
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Message-Id: <52573c01d369f506cadcf7233812427cf7db81a7.1644292363.git.houwenlong.hwl@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:49 -05:00
Sean Christopherson
85c68eb429 KVM: selftests: Add test to verify KVM handling of ICR
The main thing that the selftest verifies is that KVM copies x2APIC's
ICR[63:32] to/from ICR2 when userspace accesses the vAPIC page via
KVM_{G,S}ET_LAPIC.  KVM previously split x2APIC ICR to ICR+ICR2 at the
time of write (from the guest), and so KVM must preserve that behavior
for backwards compatibility between different versions of KVM.

It will also test other invariants, e.g. that KVM clears the BUSY
flag on ICR writes, that the reserved bits in ICR2 are dropped on writes
from the guest, etc...

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-12-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:48 -05:00
Sean Christopherson
b9964ee36b KVM: x86: Make kvm_lapic_set_reg() a "private" xAPIC helper
Hide the lapic's "raw" write helper inside lapic.c to force non-APIC code
to go through proper helpers when modification the vAPIC state.  Keep the
read helper visible to outsiders for now, refactoring KVM to hide it too
is possible, it will just take more work to do so.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:48 -05:00
Sean Christopherson
a57a31684d KVM: x86: Treat x2APIC's ICR as a 64-bit register, not two 32-bit regs
Emulate the x2APIC ICR as a single 64-bit register, as opposed to forking
it across ICR and ICR2 as two 32-bit registers.  This mirrors hardware
behavior for Intel's upcoming IPI virtualization support, which does not
split the access.

Previous versions of Intel's SDM and AMD's APM don't explicitly state
exactly how ICR is reflected in the vAPIC page for x2APIC, KVM just
happened to speculate incorrectly.

Handling the upcoming behavior is necessary in order to maintain
backwards compatibility with KVM_{G,S}ET_LAPIC, e.g. failure to shuffle
the 64-bit ICR to ICR+ICR2 and vice versa would break live migration if
IPI virtualization support isn't symmetrical across the source and dest.

Cc: Zeng Guang <guang.zeng@intel.com>
Cc: Chao Gao <chao.gao@intel.com>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:48 -05:00
Sean Christopherson
5429478d03 KVM: x86: Add helpers to handle 64-bit APIC MSR read/writes
Add helpers to handle 64-bit APIC read/writes via MSRs to deduplicate the
x2APIC and Hyper-V code needed to service reads/writes to ICR.  Future
support for IPI virtualization will add yet another path where KVM must
handle 64-bit APIC MSR reads/write (to ICR).

Opportunistically fix the comment in the write path; ICR2 holds the
destination (if there's no shorthand), not the vector.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:47 -05:00
Sean Christopherson
7018005235 KVM: x86: Make kvm_lapic_reg_{read,write}() static
Make the low level read/write lapic helpers static, any accesses to the
local APIC from vendor code or non-APIC code should be routed through
proper helpers.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:47 -05:00
Sean Christopherson
bd17f417c0 KVM: x86: WARN if KVM emulates an IPI without clearing the BUSY flag
WARN if KVM emulates an IPI without clearing the BUSY flag, failure to do
so could hang the guest if it waits for the IPI be sent.

Opportunistically use APIC_ICR_BUSY macro instead of open coding the
magic number, and add a comment to clarify why kvm_recalculate_apic_map()
is unconditionally invoked (it's really, really confusing for IPIs due to
the existence of fast paths that don't trigger a potential recalc).

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:47 -05:00
Sean Christopherson
b51818afdc KVM: SVM: Don't rewrite guest ICR on AVIC IPI virtualization failure
Don't bother rewriting the ICR value into the vAPIC page on an AVIC IPI
virtualization failure, the access is a trap, i.e. the value has already
been written to the vAPIC page.  The one caveat is if hardware left the
BUSY flag set (which appears to happen somewhat arbitrarily), in which
case go through the "nodecode" APIC-write path in order to clear the BUSY
flag.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:46 -05:00
Sean Christopherson
ed60920efe KVM: SVM: Use common kvm_apic_write_nodecode() for AVIC write traps
Use the common kvm_apic_write_nodecode() to handle AVIC/APIC-write traps
instead of open coding the same exact code.  This will allow making the
low level lapic helpers inaccessible outside of lapic.c code.

Opportunistically clean up the params to eliminate a bunch of svm=>vcpu
reflection.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:46 -05:00
Sean Christopherson
b031f10435 KVM: x86: Use "raw" APIC register read for handling APIC-write VM-Exit
Use the "raw" helper to read the vAPIC register after an APIC-write trap
VM-Exit.  Hardware is responsible for vetting the write, and the caller
is responsible for sanitizing the offset.  This is a functional change,
as it means KVM will consume whatever happens to be in the vAPIC page if
the write was dropped by hardware.  But, unless userspace deliberately
wrote garbage into the vAPIC page via KVM_SET_LAPIC, the value should be
zero since it's not writable by the guest.

This aligns common x86 with SVM's AVIC logic, i.e. paves the way for
using the nodecode path to handle APIC-write traps when AVIC is enabled.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:45 -05:00
Sean Christopherson
b5ede3df79 KVM: VMX: Handle APIC-write offset wrangling in VMX code
Move the vAPIC offset adjustments done in the APIC-write trap path from
common x86 to VMX in anticipation of using the nodecode path for SVM's
AVIC.  The adjustment reflects hardware behavior, i.e. it's technically a
property of VMX, no common x86.  SVM's AVIC behavior is identical, so
it's a bit of a moot point, the goal is purely to make it easier to
understand why the adjustment is ok.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:45 -05:00
Paolo Bonzini
d22a81b304 KVM: x86: Do not change ICR on write to APIC_SELF_IPI
Emulating writes to SELF_IPI with a write to ICR has an unwanted side effect:
the value of ICR in vAPIC page gets changed.  The lists SELF_IPI as write-only,
with no associated MMIO offset, so any write should have no visible side
effect in the vAPIC page.

Reported-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:45 -05:00
Zhenzhong Duan
f66af9f222 KVM: x86: Fix emulation in writing cr8
In emulation of writing to cr8, one of the lowest four bits in TPR[3:0]
is kept.

According to Intel SDM 10.8.6.1(baremetal scenario):
"APIC.TPR[bits 7:4] = CR8[bits 3:0], APIC.TPR[bits 3:0] = 0";

and SDM 28.3(use TPR shadow):
"MOV to CR8. The instruction stores bits 3:0 of its source operand into
bits 7:4 of VTPR; the remainder of VTPR (bits 3:0 and bits 31:8) are
cleared.";

and AMD's APM 16.6.4:
"Task Priority Sub-class (TPS)-Bits 3 : 0. The TPS field indicates the
current sub-priority to be used when arbitrating lowest-priority messages.
This field is written with zero when TPR is written using the architectural
CR8 register.";

so in KVM emulated scenario, clear TPR[3:0] to make a consistent behavior
as in other scenarios.

This doesn't impact evaluation and delivery of pending virtual interrupts
because processor does not use the processor-priority sub-class to
determine which interrupts to delivery and which to inhibit.

Sub-class is used by hardware to arbitrate lowest priority interrupts,
but KVM just does a round-robin style delivery.

Fixes: b93463aa59d6 ("KVM: Accelerated apic support")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220210094506.20181-1-zhenzhong.duan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:44 -05:00
Paolo Bonzini
b5f61c035d KVM: x86: flush TLB separately from MMU reset
For both CR0 and CR4, disassociate the TLB flush logic from the
MMU role logic.  Instead  of relying on kvm_mmu_reset_context() being
a superset of various TLB flushes (which is not necessarily going to
be the case in the future), always call it if the role changes
but also set the various TLB flush requests according to what is
in the manual.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01 08:50:42 -05:00
Paolo Bonzini
6d58f275e6 KVM: x86/mmu: clear MMIO cache when unloading the MMU
For cleanliness, do not leave a stale GVA in the cache after all the roots are
cleared.  In practice, kvm_mmu_load will go through kvm_mmu_sync_roots if
paging is on, and will not use vcpu_match_mmio_gva at all if paging is off.
However, leaving data in the cache might cause bugs in the future.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:19 -05:00
Paolo Bonzini
d2e5f33341 KVM: x86/mmu: Always use current mmu's role when loading new PGD
Since the guest PGD is now loaded after the MMU has been set up
completely, the desired role for a cache hit is simply the current
mmu_role.  There is no need to compute it again, so __kvm_mmu_new_pgd
can be folded in kvm_mmu_new_pgd.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:18 -05:00
Paolo Bonzini
3cffc89d9d KVM: x86/mmu: load new PGD after the shadow MMU is initialized
Now that __kvm_mmu_new_pgd does not look at the MMU's root_level and
shadow_root_level anymore, pull the PGD load after the initialization of
the shadow MMUs.

Besides being more intuitive, this enables future simplifications
and optimizations because it's not necessary anymore to compute the
role outside kvm_init_mmu.  In particular, kvm_mmu_reset_context was not
attempting to use a cached PGD to avoid having to figure out the new role.
With this change, it could follow what nested_{vmx,svm}_load_cr3 are doing,
and avoid unloading all the cached roots.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:18 -05:00
Paolo Bonzini
5499ea73e7 KVM: x86/mmu: look for a cached PGD when going from 32-bit to 64-bit
Right now, PGD caching avoids placing a PAE root in the cache by using the
old value of mmu->root_level and mmu->shadow_root_level; it does not look
for a cached PGD if the old root is a PAE one, and then frees it using
kvm_mmu_free_roots.

Change the logic instead to free the uncacheable root early.
This way, __kvm_new_mmu_pgd is able to look up the cache when going from
32-bit to 64-bit (if there is a hit, the invalid root becomes the least
recently used).  An example of this is nested virtualization with shadow
paging, when a 64-bit L1 runs a 32-bit L2.

As a side effect (which is actually the reason why this patch was
written), PGD caching does not use the old value of mmu->root_level
and mmu->shadow_root_level anymore.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:18 -05:00
Paolo Bonzini
0c1c92f15f KVM: x86/mmu: do not pass vcpu to root freeing functions
These functions only operate on a given MMU, of which there is more
than one in a vCPU (we care about two, because the third does not have
any roots and is only used to walk guest page tables).  They do need a
struct kvm in order to lock the mmu_lock, but they do not needed anything
else in the struct kvm_vcpu.  So, pass the vcpu->kvm directly to them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:17 -05:00
Paolo Bonzini
594bef7931 KVM: x86/mmu: do not consult levels when freeing roots
Right now, PGD caching requires a complicated dance of first computing
the MMU role and passing it to __kvm_mmu_new_pgd(), and then separately calling
kvm_init_mmu().

Part of this is due to kvm_mmu_free_roots using mmu->root_level and
mmu->shadow_root_level to distinguish whether the page table uses a single
root or 4 PAE roots.  Because kvm_init_mmu() can overwrite mmu->root_level,
kvm_mmu_free_roots() must be called before kvm_init_mmu().

However, even after kvm_init_mmu() there is a way to detect whether the
page table may hold PAE roots, as root.hpa isn't backed by a shadow when
it points at PAE roots.  Using this method results in simpler code, and
is one less obstacle in moving all calls to __kvm_mmu_new_pgd() after the
MMU has been initialized.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:17 -05:00
Paolo Bonzini
b9e5603c2a KVM: x86: use struct kvm_mmu_root_info for mmu->root
The root_hpa and root_pgd fields form essentially a struct kvm_mmu_root_info.
Use the struct to have more consistency between mmu->root and
mmu->prev_roots.

The patch is entirely search and replace except for cached_root_available,
which does not need a temporary struct kvm_mmu_root_info anymore.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:16 -05:00
Paolo Bonzini
9191b8f074 KVM: x86/mmu: avoid NULL-pointer dereference on page freeing bugs
WARN and bail if KVM attempts to free a root that isn't backed by a shadow
page.  KVM allocates a bare page for "special" roots, e.g. when using PAE
paging or shadowing 2/3/4-level page tables with 4/5-level, and so root_hpa
will be valid but won't be backed by a shadow page.  It's all too easy to
blindly call mmu_free_root_page() on root_hpa, be nice and WARN instead of
crashing KVM and possibly the kernel.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:16 -05:00
Paolo Bonzini
57cb3bb0dc KVM: x86: do not deliver asynchronous page faults if CR0.PG=0
Enabling async page faults is nonsensical if paging is disabled, but
it is allowed because CR0.PG=0 does not clear the async page fault
MSR.  Just ignore them and only use the artificial halt state,
similar to what happens in guest mode if async #PF vmexits are disabled.

Given the increasingly complex logic, and the nicer code if the new
"if" is placed last, opportunistically change the "||" into a chain
of "if (...) return false" statements.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:16 -05:00
Paolo Bonzini
d617429936 KVM: x86: Reinitialize context if host userspace toggles EFER.LME
While the guest runs, EFER.LME cannot change unless CR0.PG is clear, and
therefore EFER.NX is the only bit that can affect the MMU role.  However,
set_efer accepts a host-initiated change to EFER.LME even with CR0.PG=1.
In that case, the MMU has to be reset.

Fixes: 11988499e62b ("KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes")
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:15 -05:00
David Dunn
20e416720e KVM: selftests: Verify disabling PMU virtualization via KVM_CAP_CONFIG_PMU
On a VM with PMU disabled via KVM_CAP_PMU_CONFIG, the PMU should not be
usable by the guest.

Signed-off-by: David Dunn <daviddunn@google.com>
Message-Id: <20220223225743.2703915-4-daviddunn@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:15 -05:00
David Dunn
f49b8138e6 KVM: selftests: Carve out helper to create "default" VM without vCPUs
Carve out portion of vm_create_default so that selftests can modify
a "default" VM prior to creating vcpus.

Signed-off-by: David Dunn <daviddunn@google.com>
Message-Id: <20220223225743.2703915-3-daviddunn@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:15 -05:00
David Dunn
ba7bb663f5 KVM: x86: Provide per VM capability for disabling PMU virtualization
Add a new capability, KVM_CAP_PMU_CAPABILITY, that takes a bitmask of
settings/features to allow userspace to configure PMU virtualization on
a per-VM basis.  For now, support a single flag, KVM_PMU_CAP_DISABLE,
to allow disabling PMU virtualization for a VM even when KVM is configured
with enable_pmu=true a module level.

To keep KVM simple, disallow changing VM's PMU configuration after vCPUs
have been created.

Signed-off-by: David Dunn <daviddunn@google.com>
Message-Id: <20220223225743.2703915-2-daviddunn@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:14 -05:00
Sean Christopherson
925088781e KVM: x86: Fix pointer mistmatch warning when patching RET0 static calls
Cast kvm_x86_ops.func to 'void *' when updating KVM static calls that are
conditionally patched to __static_call_return0().  clang complains about
using mismatching pointers in the ternary operator, which breaks the
build when compiling with CONFIG_KVM_WERROR=y.

  >> arch/x86/include/asm/kvm-x86-ops.h:82:1: warning: pointer type mismatch
  ('bool (*)(struct kvm_vcpu *)' and 'void *') [-Wpointer-type-mismatch]

Fixes: 5be2226f417d ("KVM: x86: allow defining return-0 static calls")
Reported-by: Like Xu <like.xu.linux@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: David Dunn <daviddunn@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Message-Id: <20220223162355.3174907-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:14 -05:00
Vipin Sharma
e45cce30ea KVM: Move VM's worker kthreads back to the original cgroup before exiting.
VM worker kthreads can linger in the VM process's cgroup for sometime
after KVM terminates the VM process.

KVM terminates the worker kthreads by calling kthread_stop() which waits
on the 'exited' completion, triggered by exit_mm(), via mm_release(), in
do_exit() during the kthread's exit.  However, these kthreads are
removed from the cgroup using the cgroup_exit() which happens after the
exit_mm(). Therefore, A VM process can terminate in between the
exit_mm() and cgroup_exit() calls, leaving only worker kthreads in the
cgroup.

Moving worker kthreads back to the original cgroup (kthreadd_task's
cgroup) makes sure that the cgroup is empty as soon as the main VM
process is terminated.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220222054848.563321-1-vipinsh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:14 -05:00
Peng Hao
0b8934d3a9 KVM: VMX: Remove scratch 'cpu' variable that shadows an identical scratch var
From: Peng Hao <flyingpeng@tencent.com>

 Remove a redundant 'cpu' declaration from inside an if-statement that
 that shadows an identical declaration at function scope.  Both variables
 are used as scratch variables in for_each_*_cpu() loops, thus there's no
 harm in sharing a variable.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <20220222103954.70062-1-flyingpeng@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:13 -05:00
Peng Hao
105e0c441a kvm: vmx: Fix typos comment in __loaded_vmcs_clear()
Fix a comment documenting the memory barrier related to clearing a
loaded_vmcs; loaded_vmcs tracks the host CPU the VMCS is loaded on via
the field 'cpu', it doesn't have a 'vcpu' field.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <20220222104029.70129-1-flyingpeng@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:13 -05:00
Peng Hao
fbc2dfe53a KVM: nVMX: Make setup/unsetup under the same conditions
Make sure nested_vmx_hardware_setup/unsetup() are called in pairs under
the same conditions.  Calling nested_vmx_hardware_unsetup() when nested
is false "works" right now because it only calls free_page() on zero-
initialized pointers, but it's possible that more code will be added to
nested_vmx_hardware_unsetup() in the future.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <20220222104054.70286-1-flyingpeng@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 08:20:13 -05:00
Paolo Bonzini
c0f1eaeb9e Merge branch 'kvm-hv-xmm-hypercall-fixes' into HEAD
The fixes for 5.17 conflict with cleanups made in the same area
earlier in the 5.18 development cycle.
2022-02-25 08:20:08 -05:00
Vitaly Kuznetsov
47d3e5cdfe KVM: x86: hyper-v: HVCALL_SEND_IPI_EX is an XMM fast hypercall
It has been proven on practice that at least Windows Server 2019 tries
using HVCALL_SEND_IPI_EX in 'XMM fast' mode when it has more than 64 vCPUs
and it needs to send an IPI to a vCPU > 63. Similarly to other XMM Fast
hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}{,_EX}), this
information is missing in TLFS as of 6.0b. Currently, KVM returns an error
(HV_STATUS_INVALID_HYPERCALL_INPUT) and Windows crashes.

Note, HVCALL_SEND_IPI is a 'standard' fast hypercall (not 'XMM fast') as
all its parameters fit into RDX:R8 and this is handled by KVM correctly.

Cc: stable@vger.kernel.org # 5.14.x: 3244867af8c0: KVM: x86: Ignore sparse banks size for an "all CPUs", non-sparse IPI req
Cc: stable@vger.kernel.org # 5.14.x
Fixes: d8f5537a8816 ("KVM: hyper-v: Advertise support for fast XMM hypercalls")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220222154642.684285-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 05:52:22 -05:00
Vitaly Kuznetsov
7321f47ead KVM: x86: hyper-v: Fix the maximum number of sparse banks for XMM fast TLB flush hypercalls
When TLB flush hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX are
issued in 'XMM fast' mode, the maximum number of allowed sparse_banks is
not 'HV_HYPERCALL_MAX_XMM_REGISTERS - 1' (5) but twice as many (10) as each
XMM register is 128 bit long and can hold two 64 bit long banks.

Cc: stable@vger.kernel.org # 5.14.x
Fixes: 5974565bc26d ("KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220222154642.684285-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 05:52:12 -05:00
Vitaly Kuznetsov
82c1ead0d6 KVM: x86: hyper-v: Drop redundant 'ex' parameter from kvm_hv_flush_tlb()
'struct kvm_hv_hcall' has all the required information already,
there's no need to pass 'ex' additionally.

No functional change intended.

Cc: stable@vger.kernel.org # 5.14.x
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220222154642.684285-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 05:52:04 -05:00
Vitaly Kuznetsov
50e523dd79 KVM: x86: hyper-v: Drop redundant 'ex' parameter from kvm_hv_send_ipi()
'struct kvm_hv_hcall' has all the required information already,
there's no need to pass 'ex' additionally.

No functional change intended.

Cc: stable@vger.kernel.org # 5.14.x
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220222154642.684285-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25 05:51:53 -05:00
Paolo Bonzini
4dfc4ec2b7 Merge branch 'kvm-ppc-cap-210' into kvm-next-5.18 2022-02-24 08:49:56 -05:00
Paolo Bonzini
0828824158 KVM: s390: Changes for 5.18 part1
- add Claudio as Maintainer
 - first step to do proper storage key checking
 - testcase for missing memop check
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Merge tag 'kvm-s390-next-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Changes for 5.18 part1

- add Claudio as Maintainer
- first step to do proper storage key checking
- testcase for missing memop check
2022-02-22 13:07:28 -05:00
Nicholas Piggin
93b71801a8 KVM: PPC: reserve capability 210 for KVM_CAP_PPC_AIL_MODE_3
Add KVM_CAP_PPC_AIL_MODE_3 to advertise the capability to set the AIL
resource mode to 3 with the H_SET_MODE hypercall. This capability
differs between processor types and KVM types (PR, HV, Nested HV), and
affects guest-visible behaviour.

QEMU will implement a cap-ail-mode-3 to control this behaviour[1], and
use the KVM CAP if available to determine KVM support[2].

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-22 09:06:54 -05:00
Janis Schoetterl-Glausch
3d9042f8b9 KVM: s390: Add missing vm MEM_OP size check
Check that size is not zero, preventing the following warning:

WARNING: CPU: 0 PID: 9692 at mm/vmalloc.c:3059 __vmalloc_node_range+0x528/0x648
Modules linked in:
CPU: 0 PID: 9692 Comm: memop Not tainted 5.17.0-rc3-e4+ #80
Hardware name: IBM 8561 T01 701 (LPAR)
Krnl PSW : 0704c00180000000 0000000082dc584c (__vmalloc_node_range+0x52c/0x648)
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000083 ffffffffffffffff 0000000000000000 0000000000000001
           0000038000000000 000003ff80000000 0000000000000cc0 000000008ebb8000
           0000000087a8a700 000000004040aeb1 000003ffd9f7dec8 000000008ebb8000
           000000009d9b8000 000000000102a1b4 00000380035afb68 00000380035afaa8
Krnl Code: 0000000082dc583e: d028a7f4ff80        trtr    2036(41,%r10),3968(%r15)
           0000000082dc5844: af000000            mc      0,0
          #0000000082dc5848: af000000            mc      0,0
          >0000000082dc584c: a7d90000            lghi    %r13,0
           0000000082dc5850: b904002d            lgr     %r2,%r13
           0000000082dc5854: eb6ff1080004        lmg     %r6,%r15,264(%r15)
           0000000082dc585a: 07fe                bcr     15,%r14
           0000000082dc585c: 47000700            bc      0,1792
Call Trace:
 [<0000000082dc584c>] __vmalloc_node_range+0x52c/0x648
 [<0000000082dc5b62>] vmalloc+0x5a/0x68
 [<000003ff8067f4ca>] kvm_arch_vm_ioctl+0x2da/0x2a30 [kvm]
 [<000003ff806705bc>] kvm_vm_ioctl+0x4ec/0x978 [kvm]
 [<0000000082e562fe>] __s390x_sys_ioctl+0xbe/0x100
 [<000000008360a9bc>] __do_syscall+0x1d4/0x200
 [<0000000083618bd2>] system_call+0x82/0xb0
Last Breaking-Event-Address:
 [<0000000082dc5348>] __vmalloc_node_range+0x28/0x648

Other than the warning, there is no ill effect from the missing check,
the condition is detected by subsequent code and causes a return
with ENOMEM.

Fixes: ef11c9463ae0 (KVM: s390: Add vm IOCTL for key checked guest absolute memory access)
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Link: https://lore.kernel.org/r/20220221163237.4122868-1-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2022-02-22 09:16:18 +01:00
Janis Schoetterl-Glausch
cbf9b8109d KVM: s390: Clarify key argument for MEM_OP in api docs
Clarify that the key argument represents the access key, not the whole
storage key.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Link: https://lore.kernel.org/r/20220221143657.3712481-1-scgl@linux.ibm.com
Fixes: 5e35d0eb472b ("KVM: s390: Update api documentation for memop ioctl")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2022-02-22 09:16:18 +01:00
Sean Christopherson
1bbc60d0c7 KVM: x86/mmu: Remove MMU auditing
Remove mmu_audit.c and all its collateral, the auditing code has suffered
severe bitrot, ironically partly due to shadow paging being more stable
and thus not benefiting as much from auditing, but mostly due to TDP
supplanting shadow paging for non-nested guests and shadowing of nested
TDP not heavily stressing the logic that is being audited.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 13:46:23 -05:00
Paolo Bonzini
5be2226f41 KVM: x86: allow defining return-0 static calls
A few vendor callbacks are only used by VMX, but they return an integer
or bool value.  Introduce KVM_X86_OP_OPTIONAL_RET0 for them: if a func is
NULL in struct kvm_x86_ops, it will be changed to __static_call_return0
when updating static calls.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 12:44:22 -05:00
Paolo Bonzini
abb6d479e2 KVM: x86: make several APIC virtualization callbacks optional
All their invocations are conditional on vcpu->arch.apicv_active,
meaning that they need not be implemented by vendor code: even
though at the moment both vendors implement APIC virtualization,
all of them can be optional.  In fact SVM does not need many of
them, and their implementation can be deleted now.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 12:41:23 -05:00
Paolo Bonzini
dd2319c618 KVM: x86: warn on incorrectly NULL members of kvm_x86_ops
Use the newly corrected KVM_X86_OP annotations to warn about possible
NULL pointer dereferences as soon as the vendor module is loaded.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 12:31:43 -05:00
Paolo Bonzini
e4fc23bad8 KVM: x86: remove KVM_X86_OP_NULL and mark optional kvm_x86_ops
The original use of KVM_X86_OP_NULL, which was to mark calls
that do not follow a specific naming convention, is not in use
anymore.  Instead, let's mark calls that are optional because
they are always invoked within conditionals or with static_call_cond.
Those that are _not_, i.e. those that are defined with KVM_X86_OP,
must be defined by both vendor modules or some kind of NULL pointer
dereference is bound to happen at runtime.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 12:31:27 -05:00
Paolo Bonzini
2a89061451 KVM: x86: use static_call_cond for optional callbacks
SVM implements neither update_emulated_instruction nor
set_apic_access_page_addr.  Remove an "if" by calling them
with static_call_cond().

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 12:31:17 -05:00
Paolo Bonzini
8a2897853c KVM: x86: return 1 unconditionally for availability of KVM_CAP_VAPIC
The two ioctls used to implement userspace-accelerated TPR,
KVM_TPR_ACCESS_REPORTING and KVM_SET_VAPIC_ADDR, are available
even if hardware-accelerated TPR can be used.  So there is
no reason not to report KVM_CAP_VAPIC.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 12:30:56 -05:00
Paolo Bonzini
1e8ff29fbb selftests: KVM: allow sev_migrate_tests on machines without SEV-ES
I managed to get hold of a machine that has SEV but not SEV-ES, and
sev_migrate_tests fails because sev_vm_create(true) returns ENOTTY.
Fix this, and while at it also return KSFT_SKIP on machines that do
not have SEV at all, instead of returning 0.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18 05:16:43 -05:00