| Age | Commit message (Collapse) | Author |
|---|
|
KVM/s390, KVM/x86 and common infrastructure changes for 5.20
x86:
* Permit guests to ignore single-bit ECC errors
* Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache
* Intel IPI virtualization
* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS
* PEBS virtualization
* Simplify PMU emulation by just using PERF_TYPE_RAW events
* More accurate event reinjection on SVM (avoid retrying instructions)
* Allow getting/setting the state of the speaker port data bit
* Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent
* "Notify" VM exit (detect microarchitectural hangs) for Intel
* Cleanups for MCE MSR emulation
s390:
* add an interface to provide a hypervisor dump for secure guests
* improve selftests to use TAP interface
* enable interpretive execution of zPCI instructions (for PCI passthrough)
* First part of deferred teardown
* CPU Topology
* PV attestation
* Minor fixes
Generic:
* new selftests API using struct kvm_vcpu instead of a (vm, id) tuple
x86:
* Use try_cmpxchg64 instead of cmpxchg64
* Bugfixes
* Ignore benign host accesses to PMU MSRs when PMU is disabled
* Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior
* x86/MMU: Allow NX huge pages to be disabled on a per-vm basis
* Port eager page splitting to shadow MMU as well
* Enable CMCI capability by default and handle injected UCNA errors
* Expose pid of vcpu threads in debugfs
* x2AVIC support for AMD
* cleanup PIO emulation
* Fixes for LLDT/LTR emulation
* Don't require refcounted "struct page" to create huge SPTEs
x86 cleanups:
* Use separate namespaces for guest PTEs and shadow PTEs bitmasks
* PIO emulation
* Reorganize rmap API, mostly around rmap destruction
* Do not workaround very old KVM bugs for L0 that runs with nesting enabled
* new selftests API for CPUID
|
|
Make UMIP an "allowed-1" bit CR4_FIXED1 MSR when KVM is emulating UMIP.
KVM emulates UMIP for both L1 and L2, and so should enumerate that L2 is
allowed to have CR4.UMIP=1. Not setting the bit doesn't immediately
break nVMX, as KVM does set/clear the bit in CR4_FIXED1 in response to a
guest CPUID update, i.e. KVM will correctly (dis)allow nested VM-Entry
based on whether or not UMIP is exposed to L1. That said, KVM should
enumerate the bit as being allowed from time zero, e.g. userspace will
see the wrong value if the MSR is read before CPUID is written.
Fixes: 0367f205a3b7 ("KVM: vmx: add support for emulating UMIP")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-12-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
This reverts commit 03a8871add95213827e2bea84c12133ae5df952e.
Since commit 03a8871add95 ("KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL
VM-{Entry,Exit} control"), KVM has taken ownership of the "load
IA32_PERF_GLOBAL_CTRL" VMX entry/exit control bits, trying to set these
bits in the IA32_VMX_TRUE_{ENTRY,EXIT}_CTLS MSRs if the guest's CPUID
supports the architectural PMU (CPUID[EAX=0Ah].EAX[7:0]=1), and clear
otherwise.
This was a misguided attempt at mimicking what commit 5f76f6f5ff96
("KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled",
2018-10-01) did for MPX. However, that commit was a workaround for
another KVM bug and not something that should be imitated. Mucking with
the VMX MSRs creates a subtle, difficult to maintain ABI as KVM must
ensure that any internal changes, e.g. to how KVM handles _any_ guest
CPUID changes, yield the same functional result. Therefore, KVM's policy
is to let userspace have full control of the guest vCPU model so long
as the host kernel is not at risk.
Now that KVM really truly ensures kvm_set_msr() will succeed by loading
PERF_GLOBAL_CTRL if and only if it exists, revert KVM's misguided and
roundabout behavior.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sean: make it a pure revert]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Attempt to load PERF_GLOBAL_CTRL during nested VM-Enter/VM-Exit if and
only if the MSR exists (according to the guest vCPU model). KVM has very
misguided handling of VM_{ENTRY,EXIT}_LOAD_IA32_PERF_GLOBAL_CTRL and
attempts to force the nVMX MSR settings to match the vPMU model, i.e. to
hide/expose the control based on whether or not the MSR exists from the
guest's perspective.
KVM's modifications fail to handle the scenario where the vPMU is hidden
from the guest _after_ being exposed to the guest, e.g. by userspace
doing multiple KVM_SET_CPUID2 calls, which is allowed if done before any
KVM_RUN. nested_vmx_pmu_refresh() is called if and only if there's a
recognized vPMU, i.e. KVM will leave the bits in the allow state and then
ultimately reject the MSR load and WARN.
KVM should not force the VMX MSRs in the first place. KVM taking control
of the MSRs was a misguided attempt at mimicking what commit 5f76f6f5ff96
("KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled",
2018-10-01) did for MPX. However, the MPX commit was a workaround for
another KVM bug and not something that should be imitated (and it should
never been done in the first place).
In other words, KVM's ABI _should_ be that userspace has full control
over the MSRs, at which point triggering the WARN that loading the MSR
must not fail is trivial.
The intent of the WARN is still valid; KVM has consistency checks to
ensure that vmcs12->{guest,host}_ia32_perf_global_ctrl is valid. The
problem is that '0' must be considered a valid value at all times, and so
the simple/obvious solution is to just not actually load the MSR when it
does not exist. It is userspace's responsibility to provide a sane vCPU
model, i.e. KVM is well within its ABI and Intel's VMX architecture to
skip the loads if the MSR does not exist.
Fixes: 03a8871add95 ("KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL VM-{Entry,Exit} control")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Add a helper to check of the guest PMU has PERF_GLOBAL_CTRL, which is
unintuitive _and_ diverges from Intel's architecturally defined behavior.
Even worse, KVM currently implements the check using two different (but
equivalent) checks, _and_ there has been at least one attempt to add a
_third_ flavor.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Mark all MSR_CORE_PERF_GLOBAL_CTRL and MSR_CORE_PERF_GLOBAL_OVF_CTRL bits
as reserved if there is no guest vPMU. The nVMX VM-Entry consistency
checks do not check for a valid vPMU prior to consuming the masks via
kvm_valid_perf_global_ctrl(), i.e. may incorrectly allow a non-zero mask
to be loaded via VM-Enter or VM-Exit (well, attempted to be loaded, the
actual MSR load will be rejected by intel_is_valid_msr()).
Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Since commit 5f76f6f5ff96 ("KVM: nVMX: Do not expose MPX VMX controls
when guest MPX disabled"), KVM has taken ownership of the "load
IA32_BNDCFGS" and "clear IA32_BNDCFGS" VMX entry/exit controls,
trying to set these bits in the IA32_VMX_TRUE_{ENTRY,EXIT}_CTLS
MSRs if the guest's CPUID supports MPX, and clear otherwise.
The intent of the patch was to apply it to L0 in order to work around
L1 kernels that lack the fix in commit 691bd4340bef ("kvm: vmx: allow
host to access guest MSR_IA32_BNDCFGS", 2017-07-04): by hiding the
control bits from L0, L1 hides BNDCFGS from KVM_GET_MSR_INDEX_LIST,
and the L1 bug is neutralized even in the lack of commit 691bd4340bef.
This was perhaps a sensible kludge at the time, but a horrible
idea in the long term and in fact it has not been extended to
other CPUID bits like these:
X86_FEATURE_LM => VM_EXIT_HOST_ADDR_SPACE_SIZE, VM_ENTRY_IA32E_MODE,
VMX_MISC_SAVE_EFER_LMA
X86_FEATURE_TSC => CPU_BASED_RDTSC_EXITING, CPU_BASED_USE_TSC_OFFSETTING,
SECONDARY_EXEC_TSC_SCALING
X86_FEATURE_INVPCID_SINGLE => SECONDARY_EXEC_ENABLE_INVPCID
X86_FEATURE_MWAIT => CPU_BASED_MONITOR_EXITING, CPU_BASED_MWAIT_EXITING
X86_FEATURE_INTEL_PT => SECONDARY_EXEC_PT_CONCEAL_VMX, SECONDARY_EXEC_PT_USE_GPA,
VM_EXIT_CLEAR_IA32_RTIT_CTL, VM_ENTRY_LOAD_IA32_RTIT_CTL
X86_FEATURE_XSAVES => SECONDARY_EXEC_XSAVES
These days it's sort of common knowledge that any MSR in
KVM_GET_MSR_INDEX_LIST must allow *at least* setting it with KVM_SET_MSR
to a default value, so it is unlikely that something like commit
5f76f6f5ff96 will be needed again. So revert it, at the potential cost
of breaking L1s with a 6 year old kernel. While in principle the L0 owner
doesn't control what runs on L1, such an old hypervisor would probably
have many other bugs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Restrict the nVMX MSRs based on KVM's config, not based on the guest's
current config. Using the guest's config to audit the new config
prevents userspace from restoring the original config (KVM's config) if
at any point in the past the guest's config was restricted in any way.
Fixes: 62cc6b9dc61e ("KVM: nVMX: support restore of VMX capability MSRs")
Cc: stable@vger.kernel.org
Cc: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Rename the exit handlers for VMXON and VMXOFF to match the instruction
names, the terms "vmon" and "vmoff" are not used anywhere in Intel's
documentation, nor are they used elsehwere in KVM.
Sadly, the exit reasons are exposed to userspace and so cannot be renamed
without breaking userspace. :-(
Fixes: ec378aeef9df ("KVM: nVMX: Implement VMXON and VMXOFF")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Inject a #UD if L1 attempts VMXON with a CR0 or CR4 that is disallowed
per the associated nested VMX MSRs' fixed0/1 settings. KVM cannot rely
on hardware to perform the checks, even for the few checks that have
higher priority than VM-Exit, as (a) KVM may have forced CR0/CR4 bits in
hardware while running the guest, (b) there may incompatible CR0/CR4 bits
that have lower priority than VM-Exit, e.g. CR0.NE, and (c) userspace may
have further restricted the allowed CR0/CR4 values by manipulating the
guest's nested VMX MSRs.
Note, despite a very strong desire to throw shade at Jim, commit
70f3aac964ae ("kvm: nVMX: Remove superfluous VMX instruction fault checks")
is not to blame for the buggy behavior (though the comment...). That
commit only removed the CR0.PE, EFLAGS.VM, and COMPATIBILITY mode checks
(though it did erroneously drop the CPL check, but that has already been
remedied). KVM may force CR0.PE=1, but will do so only when also
forcing EFLAGS.VM=1 to emulate Real Mode, i.e. hardware will still #UD.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216033
Fixes: ec378aeef9df ("KVM: nVMX: Implement VMXON and VMXOFF")
Reported-by: Eric Li <ercli@ucdavis.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Check that the guest (L2) and host (L1) CR4 values that would be loaded
by nested VM-Enter and VM-Exit respectively are valid with respect to
KVM's (L0 host) allowed CR4 bits. Failure to check KVM reserved bits
would allow L1 to load an illegal CR4 (or trigger hardware VM-Fail or
failed VM-Entry) by massaging guest CPUID to allow features that are not
supported by KVM. Amusingly, KVM itself is an accomplice in its doom, as
KVM adjusts L1's MSR_IA32_VMX_CR4_FIXED1 to allow L1 to enable bits for
L2 based on L1's CPUID model.
Note, although nested_{guest,host}_cr4_valid() are _currently_ used if
and only if the vCPU is post-VMXON (nested.vmxon == true), that may not
be true in the future, e.g. emulating VMXON has a bug where it doesn't
check the allowed/required CR0/CR4 bits.
Cc: stable@vger.kernel.org
Fixes: 3899152ccbf4 ("KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Split the common x86 parts of kvm_is_valid_cr4(), i.e. the reserved bits
checks, into a separate helper, __kvm_is_valid_cr4(), and export only the
inner helper to vendor code in order to prevent nested VMX from calling
back into vmx_is_valid_cr4() via kvm_is_valid_cr4().
On SVM, this is a nop as SVM doesn't place any additional restrictions on
CR4.
On VMX, this is also currently a nop, but only because nested VMX is
missing checks on reserved CR4 bits for nested VM-Enter. That bug will
be fixed in a future patch, and could simply use kvm_is_valid_cr4() as-is,
but nVMX has _another_ bug where VMXON emulation doesn't enforce VMX's
restrictions on CR0/CR4. The cleanest and most intuitive way to fix the
VMXON bug is to use nested_host_cr{0,4}_valid(). If the CR4 variant
routes through kvm_is_valid_cr4(), using nested_host_cr4_valid() won't do
the right thing for the VMXON case as vmx_is_valid_cr4() enforces VMX's
restrictions if and only if the vCPU is post-VMXON.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Restrict get_mt_mask() to a u8 and reintroduce using a RET0 static_call
for the SVM implementation. EPT stores the memtype information in the
lower 8 bits (bits 6:3 to be precise), and even returns a shifted u8
without an explicit cast to a larger type; there's no need to return a
full u64.
Note, RET0 doesn't play nice with a u64 return on 32-bit kernels, see
commit bf07be36cd88 ("KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for
get_mt_mask").
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220714153707.3239119-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Add a second CPUID helper, kvm_find_cpuid_entry_index(), to handle KVM
queries for CPUID leaves whose index _may_ be significant, and drop the
index param from the existing kvm_find_cpuid_entry(). Add a WARN in the
inner helper, cpuid_entry2_find(), to detect attempts to retrieve a CPUID
entry whose index is significant without explicitly providing an index.
Using an explicit magic number and letting callers omit the index avoids
confusion by eliminating the myriad cases where KVM specifies '0' as a
dummy value.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Merge bugfix needed in both 5.19 (because it's bad) and 5.20 (because
it is a prerequisite to test new features).
|
|
Windows 10/11 guests with Hyper-V role (WSL2) enabled are observed to
hang upon boot or shortly after when a non-default TSC frequency was
set for L1. The issue is observed on a host where TSC scaling is
supported. The problem appears to be that Windows doesn't use TSC
frequency for its guests even when the feature is advertised and KVM
filters SECONDARY_EXEC_TSC_SCALING out when creating L2 controls from
L1's. This leads to L2 running with the default frequency (matching
host's) while L1 is running with an altered one.
Keep SECONDARY_EXEC_TSC_SCALING in secondary exec controls for L2 when
it was set for L1. TSC_MULTIPLIER is already correctly computed and
written by prepare_vmcs02().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220712135009.952805-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Update the Processor Trace (PT) MSR intercepts during a filter change if
and only if PT may be exposed to the guest, i.e. only if KVM is operating
in the so called "host+guest" mode where PT can be used simultaneously by
both the host and guest. If PT is in system mode, the host is the sole
owner of PT and the MSRs should never be passed through to the guest.
Luckily the missed check only results in unnecessary work, as select RTIT
MSRs are passed through only when RTIT tracing is enabled "in" the guest,
and tracing can't be enabled in the guest when KVM is in system mode
(writes to guest.MSR_IA32_RTIT_CTL are disallowed).
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20220712015838.1253995-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
The result of gva_to_gpa() is physical address not virtual address,
it is odd that UNMAPPED_GVA macro is used as the result for physical
address. Replace UNMAPPED_GVA with INVALID_GPA and drop UNMAPPED_GVA
macro.
No functional change intended.
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/6104978956449467d3c68f1ad7f2c2f6d771d0ee.1656667239.git.houwenlong.hwl@antgroup.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
Windows 10/11 guests with Hyper-V role (WSL2) enabled are observed to
hang upon boot or shortly after when a non-default TSC frequency was
set for L1. The issue is observed on a host where TSC scaling is
supported. The problem appears to be that Windows doesn't use TSC
scaling for its guests, even when the feature is advertised, and KVM
filters SECONDARY_EXEC_TSC_SCALING out when creating L2 controls from
L1's VMCS. This leads to L2 running with the default frequency (matching
host's) while L1 is running with an altered one.
Keep SECONDARY_EXEC_TSC_SCALING in secondary exec controls for L2 when
it was set for L1. TSC_MULTIPLIER is already correctly computed and
written by prepare_vmcs02().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Fixes: d041b5ea93352b ("KVM: nVMX: Enable nested TSC scaling")
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20220712135009.952805-1-vkuznets@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
On VMX, there are some balanced returns between the time the guest's
SPEC_CTRL value is written, and the vmenter.
Balanced returns (matched by a preceding call) are usually ok, but it's
at least theoretically possible an NMI with a deep call stack could
empty the RSB before one of the returns.
For maximum paranoia, don't allow *any* returns (balanced or otherwise)
between the SPEC_CTRL write and the vmenter.
[ bp: Fix 32-bit build. ]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
Prevent RSB underflow/poisoning attacks with RSB. While at it, add a
bunch of comments to attempt to document the current state of tribal
knowledge about RSB attacks and what exactly is being mitigated.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
For legacy IBRS to work, the IBRS bit needs to be always re-written
after vmexit, even if it's already on.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
On eIBRS systems, the returns in the vmexit return path from
__vmx_vcpu_run() to vmx_vcpu_run() are exposed to RSB poisoning attacks.
Fix that by moving the post-vmexit spec_ctrl handling to immediately
after the vmexit.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
Convert __vmx_vcpu_run()'s 'launched' argument to 'flags', in
preparation for doing SPEC_CTRL handling immediately after vmexit, which
will need another flag.
This is much easier than adding a fourth argument, because this code
supports both 32-bit and 64-bit, and the fourth argument on 32-bit would
have to be pushed on the stack.
Note that __vmx_vcpu_run_flags() is called outside of the noinstr
critical section because it will soon start calling potentially
traceable functions.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
Move the vmx_vm{enter,exit}() functionality into __vmx_vcpu_run(). This
will make it easier to do the spec_ctrl handling before the first RET.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
The recent mmio_stale_data fixes broke the noinstr constraints:
vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x15b: call to wrmsrl.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x1bf: call to kvm_arch_has_assigned_device() leaves .noinstr.text section
make it all happy again.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
|
|
Rely on try_cmpxchg64 for re-reading the PID on failure, using READ_ONCE
only right before the first iteration.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
This patch enables MCG_CMCI_P by default in kvm_mce_cap_supported. It
reuses ioctl KVM_X86_SET_MCE to implement injection of UnCorrectable
No Action required (UCNA) errors, signaled via Corrected Machine
Check Interrupt (CMCI).
Neither of the CMCI and UCNA emulations depends on hardware.
Signed-off-by: Jue Wang <juew@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220610171134.772566-8-juew@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Use vcpu_get_perf_capabilities() when querying MSR_IA32_PERF_CAPABILITIES
from the guest's perspective, e.g. to update the vPMU and to determine
which MSRs exist. If userspace ignores MSR_IA32_PERF_CAPABILITIES but
clear X86_FEATURE_PDCM, the guest should see '0'.
Fixes: 902caeb6841a ("KVM: x86/pmu: Add PEBS_DATA_CFG MSR emulation to support adaptive PEBS")
Fixes: c59a1f106f5c ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220611005755.753273-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Revert the hack to allow host-initiated accesses to all "PMU" MSRs,
as intel_is_valid_msr() returns true for _all_ MSRs, regardless of whether
or not it has a snowball's chance in hell of actually being a PMU MSR.
That mostly gets papered over by the actual get/set helpers only handling
MSRs that they knows about, except there's the minor detail that
kvm_pmu_{g,s}et_msr() eat reads and writes when the PMU is disabled.
I.e. KVM will happy allow reads and writes to _any_ MSR if the PMU is
disabled, either via module param or capability.
This reverts commit d1c88a4020567ba4da52f778bcd9619d87e4ea75.
Fixes: d1c88a402056 ("KVM: x86: always allow host-initiated writes to PMU MSRs")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220611005755.753273-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Do not clear manipulate MSR_IA32_PERF_CAPABILITIES in intel_pmu_refresh(),
i.e. give userspace full control over capability/read-only MSRs. KVM is
not a babysitter, it is userspace's responsiblity to provide a valid and
coherent vCPU model.
Attempting to "help" the guest by forcing a consistent model creates edge
cases, and ironicially leads to inconsistent behavior.
Example #1: KVM doesn't do intel_pmu_refresh() when userspace writes
the MSR.
Example #2: KVM doesn't clear the bits when the PMU is disabled, or when
there's no architectural PMU.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220611005755.753273-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Give userspace full control of the read-only bits in MISC_ENABLES, i.e.
do not modify bits on PMU refresh and do not preserve existing bits when
userspace writes MISC_ENABLES. With a few exceptions where KVM doesn't
expose the necessary controls to userspace _and_ there is a clear cut
association with CPUID, e.g. reserved CR4 bits, KVM does not own the vCPU
and should not manipulate the vCPU model on behalf of "dummy user space".
The argument that KVM is doing userspace a favor because "the order of
setting vPMU capabilities and MSR_IA32_MISC_ENABLE is not strictly
guaranteed" is specious, as attempting to configure MSRs on behalf of
userspace inevitably leads to edge cases precisely because KVM does not
prescribe a specific order of initialization.
Example #1: intel_pmu_refresh() consumes and modifies the vCPU's
MSR_IA32_PERF_CAPABILITIES, and so assumes userspace initializes config
MSRs before setting the guest CPUID model. If userspace sets CPUID
first, then KVM will mark PEBS as available when arch.perf_capabilities
is initialized with a non-zero PEBS format, thus creating a bad vCPU
model if userspace later disables PEBS by writing PERF_CAPABILITIES.
Example #2: intel_pmu_refresh() does not clear PERF_CAP_PEBS_MASK in
MSR_IA32_PERF_CAPABILITIES if there is no vPMU, making KVM inconsistent
in its desire to be consistent.
Example #3: intel_pmu_refresh() does not clear MSR_IA32_MISC_ENABLE_EMON
if KVM_SET_CPUID2 is called multiple times, first with a vPMU, then
without a vPMU. While slightly contrived, it's plausible a VMM could
reflect KVM's default vCPU and then operate on KVM's copy of CPUID to
later clear the vPMU settings, e.g. see KVM's selftests.
Example #4: Enumerating an Intel vCPU on an AMD host will not call into
intel_pmu_refresh() at any point, and so the BTS and PEBS "unavailable"
bits will be left clear, without any way for userspace to set them.
Keep the "R" behavior of the bit 7, "EMON available", for the guest.
Unlike the BTS and PEBS bits, which are fully "RO", the EMON bit can be
written with a different value, but that new value is ignored.
Cc: Like Xu <likexu@tencent.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Message-Id: <20220611005755.753273-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Use kvm_vcpu_map() to get/pin the backing for vmcs12's APIC-access page,
there's no reason it has to be restricted to 'struct page' backing. The
APIC-access page actually doesn't need to be backed by anything, which is
ironically why it got left behind by the series which introduced
kvm_vcpu_map()[1]; the plan was to shove a dummy pfn into vmcs02[2], but
that code never got merged.
Switching the APIC-access page to kvm_vcpu_map() doesn't preclude using a
magic pfn in the future, and will allow a future patch to drop
kvm_vcpu_gpa_to_page().
[1] https://lore.kernel.org/all/1547026933-31226-1-git-send-email-karahmed@amazon.de
[2] https://lore.kernel.org/lkml/1543845551-4403-1-git-send-email-karahmed@amazon.de
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220429010416.2788472-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Compute the number of PTEs to be filled for the 32-bit PSE page tables
using the page size and the size of each entry. While using the MMU's
PT32_ENT_PER_PAGE macro is arguably better in isolation, removing VMX's
usage will allow a future namespacing cleanup to move the guest page
table macros into paging_tmpl.h, out of the reach of code that isn't
directly related to shadow paging.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614233328.3896033-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Move the per-vCPU apicv_active flag into KVM's local APIC instance.
APICv is fully dependent on an in-kernel local APIC, but that's not at
all clear when reading the current code due to the flag being stored in
the generic kvm_vcpu_arch struct.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614230548.3852141-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Drop the unused @vcpu parameter from hwapic_isr_update(). AMD/AVIC is
unlikely to implement the helper, and VMX/APICv doesn't need the vCPU as
it operates on the current VMCS. The result is somewhat odd, but allows
for a decent amount of (future) cleanup in the APIC code.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614230548.3852141-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Update vmcs12->guest_bndcfgs on intercepted writes to BNDCFGS from L2
instead of waiting until vmcs02 is synchronized to vmcs12. KVM always
intercepts BNDCFGS accesses, so the only way the value in vmcs02 can
change is via KVM's explicit VMWRITE during emulation.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614215831.3762138-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Save BNDCFGS to vmcs12 (from vmcs02) if and only if at least of one of
the load-on-entry or clear-on-exit fields for BNDCFGS is enumerated as an
allowed-1 bit in vmcs12. Skipping the field avoids an unnecessary VMREAD
when MPX is supported but not exposed to L1.
Per Intel's SDM:
If the processor supports either the 1-setting of the "load IA32_BNDCFGS"
VM-entry control or that of the "clear IA32_BNDCFGS" VM-exit control, the
contents of the IA32_BNDCFGS MSR are saved into the corresponding field.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614215831.3762138-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Rename the fields in struct nested_vmx used to snapshot pre-VM-Enter
values to reflect that they can hold L2's values when restoring nested
state, e.g. if userspace restores MSRs before nested state. As crazy as
it seems, restoring MSRs before nested state actually works (because KVM
goes out if it's way to make it work), even though the initial MSR writes
will hit vmcs01 despite holding L2 values.
Add a related comment to vmx_enter_smm() to call out that using the
common VM-Exit and VM-Enter helpers to emulate SMI and RSM is wrong and
broken. The few MSRs that have snapshots _could_ be fixed by taking a
snapshot prior to the forced VM-Exit instead of at forced VM-Enter, but
that's just the tip of the iceberg as the rather long list of MSRs that
aren't snapshotted (hello, VM-Exit MSR load list) can't be handled this
way.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614215831.3762138-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
If a nested run isn't pending, snapshot vmcs01.GUEST_IA32_DEBUGCTL
irrespective of whether or not VM_ENTRY_LOAD_DEBUG_CONTROLS is set in
vmcs12. When restoring nested state, e.g. after migration, without a
nested run pending, prepare_vmcs02() will propagate
nested.vmcs01_debugctl to vmcs02, i.e. will load garbage/zeros into
vmcs02.GUEST_IA32_DEBUGCTL.
If userspace restores nested state before MSRs, then loading garbage is a
non-issue as loading DEBUGCTL will also update vmcs02. But if usersepace
restores MSRs first, then KVM is responsible for propagating L2's value,
which is actually thrown into vmcs01, into vmcs02.
Restoring L2 MSRs into vmcs01, i.e. loading all MSRs before nested state
is all kinds of bizarre and ideally would not be supported. Sadly, some
VMMs do exactly that and rely on KVM to make things work.
Note, there's still a lurking SMM bug, as propagating vmcs01's DEBUGCTL
to vmcs02 across RSM may corrupt L2's DEBUGCTL. But KVM's entire VMX+SMM
emulation is flawed as SMI+RSM should not toouch _any_ VMCS when use the
"default treatment of SMIs", i.e. when not using an SMI Transfer Monitor.
Link: https://lore.kernel.org/all/Yobt1XwOfb5M6Dfa@google.com
Fixes: 8fcc4b5923af ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614215831.3762138-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
If a nested run isn't pending, snapshot vmcs01.GUEST_BNDCFGS irrespective
of whether or not VM_ENTRY_LOAD_BNDCFGS is set in vmcs12. When restoring
nested state, e.g. after migration, without a nested run pending,
prepare_vmcs02() will propagate nested.vmcs01_guest_bndcfgs to vmcs02,
i.e. will load garbage/zeros into vmcs02.GUEST_BNDCFGS.
If userspace restores nested state before MSRs, then loading garbage is a
non-issue as loading BNDCFGS will also update vmcs02. But if usersepace
restores MSRs first, then KVM is responsible for propagating L2's value,
which is actually thrown into vmcs01, into vmcs02.
Restoring L2 MSRs into vmcs01, i.e. loading all MSRs before nested state
is all kinds of bizarre and ideally would not be supported. Sadly, some
VMMs do exactly that and rely on KVM to make things work.
Note, there's still a lurking SMM bug, as propagating vmcs01.GUEST_BNDFGS
to vmcs02 across RSM may corrupt L2's BNDCFGS. But KVM's entire VMX+SMM
emulation is flawed as SMI+RSM should not toouch _any_ VMCS when use the
"default treatment of SMIs", i.e. when not using an SMI Transfer Monitor.
Link: https://lore.kernel.org/all/Yobt1XwOfb5M6Dfa@google.com
Fixes: 62cf9bd8118c ("KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS")
Cc: stable@vger.kernel.org
Cc: Lei Wang <lei4.wang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614215831.3762138-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Use try_cmpxchg64 instead of cmpxchg64 (*ptr, old, new) != old
in pi_try_set_control. cmpxchg returns success in ZF flag, so this
change saves a compare after cmpxchg (and related move instruction
in front of cmpxchg):
b9: 88 44 24 60 mov %al,0x60(%rsp)
bd: 48 89 c8 mov %rcx,%rax
c0: c6 44 24 62 f2 movb $0xf2,0x62(%rsp)
c5: 48 8b 74 24 60 mov 0x60(%rsp),%rsi
ca: f0 49 0f b1 34 24 lock cmpxchg %rsi,(%r12)
d0: 48 39 c1 cmp %rax,%rcx
d3: 75 cf jne a4 <vmx_vcpu_pi_load+0xa4>
patched:
c1: 88 54 24 60 mov %dl,0x60(%rsp)
c5: c6 44 24 62 f2 movb $0xf2,0x62(%rsp)
ca: 48 8b 54 24 60 mov 0x60(%rsp),%rdx
cf: f0 48 0f b1 13 lock cmpxchg %rdx,(%rbx)
d4: 75 d5 jne ab <vmx_vcpu_pi_load+0xab>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Reported-by: kernel test robot <lkp@intel.com>
Message-Id: <20220520143737.62513-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
When handling userspace MSR filter updates, recompute interception for
possible passthrough MSRs if and only if KVM wants to disabled
interception. If KVM wants to intercept accesses, i.e. the associated
bit is set in vmx->shadow_msr_intercept, then there's no need to set the
intercept again as KVM will intercept the MSR regardless of userspace's
wants.
No functional change intended, the call to vmx_enable_intercept_for_msr()
really is just a gigantic nop.
Suggested-by: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220610214140.612025-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Pull kvm fixes from Paolo Bonzini:
"While last week's pull request contained miscellaneous fixes for x86,
this one covers other architectures, selftests changes, and a bigger
series for APIC virtualization bugs that were discovered during 5.20
development. The idea is to base 5.20 development for KVM on top of
this tag.
ARM64:
- Properly reset the SVE/SME flags on vcpu load
- Fix a vgic-v2 regression regarding accessing the pending state of a
HW interrupt from userspace (and make the code common with vgic-v3)
- Fix access to the idreg range for protected guests
- Ignore 'kvm-arm.mode=protected' when using VHE
- Return an error from kvm_arch_init_vm() on allocation failure
- A bunch of small cleanups (comments, annotations, indentation)
RISC-V:
- Typo fix in arch/riscv/kvm/vmid.c
- Remove broken reference pattern from MAINTAINERS entry
x86-64:
- Fix error in page tables with MKTME enabled
- Dirty page tracking performance test extended to running a nested
guest
- Disable APICv/AVIC in cases that it cannot implement correctly"
[ This merge also fixes a misplaced end parenthesis bug introduced in
commit 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC
ID or APIC base") pointed out by Sean Christopherson ]
Link: https://lore.kernel.org/all/20220610191813.371682-1-seanjc@google.com/
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (34 commits)
KVM: selftests: Restrict test region to 48-bit physical addresses when using nested
KVM: selftests: Add option to run dirty_log_perf_test vCPUs in L2
KVM: selftests: Clean up LIBKVM files in Makefile
KVM: selftests: Link selftests directly with lib object files
KVM: selftests: Drop unnecessary rule for STATIC_LIBS
KVM: selftests: Add a helper to check EPT/VPID capabilities
KVM: selftests: Move VMX_EPT_VPID_CAP_AD_BITS to vmx.h
KVM: selftests: Refactor nested_map() to specify target level
KVM: selftests: Drop stale function parameter comment for nested_map()
KVM: selftests: Add option to create 2M and 1G EPT mappings
KVM: selftests: Replace x86_page_size with PG_LEVEL_XX
KVM: x86: SVM: fix nested PAUSE filtering when L0 intercepts PAUSE
KVM: x86: SVM: drop preempt-safe wrappers for avic_vcpu_load/put
KVM: x86: disable preemption around the call to kvm_arch_vcpu_{un|}blocking
KVM: x86: disable preemption while updating apicv inhibition
KVM: x86: SVM: fix avic_kick_target_vcpus_fast
KVM: x86: SVM: remove avic's broken code that updated APIC ID
KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base
KVM: x86: document AVIC/APICv inhibit reasons
KVM: x86/mmu: Set memory encryption "value", not "mask", in shadow PDPTRs
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 MMIO stale data fixes from Thomas Gleixner:
"Yet another hw vulnerability with a software mitigation: Processor
MMIO Stale Data.
They are a class of MMIO-related weaknesses which can expose stale
data by propagating it into core fill buffers. Data which can then be
leaked using the usual speculative execution methods.
Mitigations include this set along with microcode updates and are
similar to MDS and TAA vulnerabilities: VERW now clears those buffers
too"
* tag 'x86-bugs-2022-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation/mmio: Print SMT warning
KVM: x86/speculation: Disable Fill buffer clear within guests
x86/speculation/mmio: Reuse SRBDS mitigation for SBDS
x86/speculation/srbds: Update SRBDS mitigation selection
x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data
x86/speculation/mmio: Enable CPU Fill buffer clearing on idle
x86/bugs: Group MDS, TAA & Processor MMIO Stale Data mitigations
x86/speculation/mmio: Add mitigation for Processor MMIO Stale Data
x86/speculation: Add a common function for MD_CLEAR mitigation update
x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug
Documentation: Add documentation for Processor MMIO Stale Data
|
|
s390:
* add an interface to provide a hypervisor dump for secure guests
* improve selftests to show tests
x86:
* Intel IPI virtualization
* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS
* PEBS virtualization
* Simplify PMU emulation by just using PERF_TYPE_RAW events
* More accurate event reinjection on SVM (avoid retrying instructions)
* Allow getting/setting the state of the speaker port data bit
* Rewrite gfn-pfn cache refresh
* Refuse starting the module if VM-Entry/VM-Exit controls are inconsistent
* "Notify" VM exit
|
|
Neither of these settings should be changed by the guest and it is
a burden to support it in the acceleration code, so just inhibit
this code instead.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220606180829.102503-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
into HEAD
KVM/riscv fixes for 5.19, take #1
- Typo fix in arch/riscv/kvm/vmid.c
- Remove broken reference pattern from MAINTAINERS entry
|
|
Add an on-by-default module param, error_on_inconsistent_vmcs_config, to
allow rejecting the load of kvm_intel if an inconsistent VMCS config is
detected. Continuing on with an inconsistent, degraded config is
undesirable in the vast majority of use cases, e.g. may result in a
misconfigured VM, poor performance due to lack of fast MSR switching, or
even security issues in the unlikely event the guest is relying on MPX.
Practically speaking, an inconsistent VMCS config should never be
encountered in a production quality environment, e.g. on bare metal it
indicates a silicon defect (or a disturbing lack of validation by the
hardware vendor), and in a virtualized machine (KVM as L1) it indicates a
buggy/misconfigured L0 VMM/hypervisor.
Provide a module param to override the behavior for testing purposes, or
in the unlikely scenario that KVM is deployed on a flawed-but-usable CPU
or virtual machine.
Note, what is or isn't an inconsistency is somewhat subjective, e.g. one
might argue that LOAD_EFER without SAVE_EFER is an inconsistency. KVM's
unofficial guideline for an "inconsistency" is either scenarios that are
completely nonsensical, e.g. the existing checks on having EPT/VPID knobs
without EPT/VPID, and/or scenarios that prevent KVM from virtualizing or
utilizing a feature, e.g. the unpaired entry/exit controls checks. Other
checks that fall into one or both of the covered scenarios could be added
in the future, e.g. asserting that a VMCS control exists available if and
only if the associated feature is supported in bare metal.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220527170658.3571367-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Sanitize the VM-Entry/VM-Exit control pairs (load+load or load+clear)
during setup instead of checking both controls in a pair at runtime. If
only one control is supported, KVM will report the associated feature as
not available, but will leave the supported control bit set in the VMCS
config, which could lead to corruption of host state. E.g. if only the
VM-Entry control is supported and the feature is not dynamically toggled,
KVM will set the control in all VMCSes and load zeros without restoring
host state.
Note, while this is technically a bug fix, practically speaking no sane
CPU or VMM would support only one control. KVM's behavior of checking
both controls is mostly pedantry.
Cc: Chenyi Qiang <chenyi.qiang@intel.com>
Cc: Lei Wang <lei4.wang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220527170658.3571367-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
