linux-stable.git/arch, branch v5.15.78

KVM: x86: emulator: update the emulation mode after CR0 write

2022-11-10T17:15:42+00:00

commit ad8f9e69942c7db90758d9d774157e53bce94840 upstream.

Update the emulation mode when handling writes to CR0, because
toggling CR0.PE switches between Real and Protected Mode, and toggling
CR0.PG when EFER.LME=1 switches between Long and Protected Mode.

This is likely a benign bug because there is no writeback of state,
other than the RIP increment, and when toggling CR0.PE, the CPU has
to execute code from a very low memory address.

Signed-off-by: Maxim Levitsky 
Message-Id: <20221025124741.228045-14-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: emulator: update the emulation mode after rsm

2022-11-10T17:15:42+00:00

commit 055f37f84e304e59c046d1accfd8f08462f52c4c upstream.

Update the emulation mode after RSM so that RIP will be correctly
written back, because the RSM instruction can switch the CPU mode from
32 bit (or less) to 64 bit.

This fixes a guest crash in case the #SMI is received while the guest
runs a code from an address > 32 bit.

Signed-off-by: Maxim Levitsky 
Message-Id: <20221025124741.228045-13-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: emulator: introduce emulator_recalc_and_set_mode

2022-11-10T17:15:42+00:00

commit d087e0f79fa0dd336a9a6b2f79ec23120f5eff73 upstream.

Some instructions update the cpu execution mode, which needs to update the
emulation mode.

Extract this code, and make assign_eip_far use it.

assign_eip_far now reads CS, instead of getting it via a parameter,
which is ok, because callers always assign CS to the same value
before calling this function.

No functional change is intended.

Signed-off-by: Maxim Levitsky 
Message-Id: <20221025124741.228045-12-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: emulator: em_sysexit should update ctxt->mode

2022-11-10T17:15:41+00:00

commit 5015bb89b58225f97df6ac44383e7e8c8662c8c9 upstream.

SYSEXIT is one of the instructions that can change the
processor mode, thus ctxt->mode should be updated after it.

Note that this is likely a benign bug, because the only problematic
mode change is from 32 bit to 64 bit which can lead to truncation of RIP,
and it is not possible to do with sysexit,
since sysexit running in 32 bit mode will be limited to 32 bit version.

Signed-off-by: Maxim Levitsky 
Message-Id: <20221025124741.228045-11-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Fix bad dereference on MTE-enabled systems

2022-11-10T17:15:41+00:00

commit b6bcdc9f6b8321e4471ff45413b6410e16762a8d upstream.

enter_exception64() performs an MTE check, which involves dereferencing
vcpu->kvm. While vcpu has already been fixed up to be a HYP VA pointer,
kvm is still a pointer in the kernel VA space.

This only affects nVHE configurations with MTE enabled, as in other
cases, the pointer is either valid (VHE) or not dereferenced (!MTE).

Fix this by first converting kvm to a HYP VA pointer.

Fixes: ea7fc1bb1cd1 ("KVM: arm64: Introduce MTE VM feature")
Signed-off-by: Ryan Roberts 
Reviewed-by: Steven Price 
[maz: commit message tidy-up]
Signed-off-by: Marc Zyngier 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221027120945.29679-1-ryan.roberts@arm.com
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: fully disable SGX if SECONDARY_EXEC_ENCLS_EXITING unavailable

2022-11-10T17:15:41+00:00

commit 1c1a41497ab879ac9608f3047f230af833eeef3d upstream.

Clear enable_sgx if ENCLS-exiting is not supported, i.e. if SGX cannot be
virtualized.  When KVM is loaded, adjust_vmx_controls checks that the
bit is available before enabling the feature; however, other parts of the
code check enable_sgx and not clearing the variable caused two different
bugs, mostly affecting nested virtualization scenarios.

First, because enable_sgx remained true, SECONDARY_EXEC_ENCLS_EXITING
would be marked available in the capability MSR that are accessed by a
nested hypervisor.  KVM would then propagate the control from vmcs12
to vmcs02 even if it isn't supported by the processor, thus causing an
unexpected VM-Fail (exit code 0x7) in L1.

Second, vmx_set_cpu_caps() would not clear the SGX bits when hardware
support is unavailable.  This is a much less problematic bug as it only
happens if SGX is soft-disabled (available in the processor but hidden
in CPUID) or if SGX is supported for bare metal but not in the VMCS
(will never happen when running on bare metal, but can theoertically
happen when running in a VM).

Last but not least, this ensures that module params in sysfs reflect
KVM's actual configuration.

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2127128
Fixes: 72add915fbd5 ("KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC")
Cc: stable@vger.kernel.org
Suggested-by: Sean Christopherson 
Suggested-by: Bandan Das 
Signed-off-by: Emanuele Giuseppe Esposito 
Message-Id: <20221025123749.2201649-1-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Mask off reserved bits in CPUID.8000001FH

2022-11-10T17:15:41+00:00

commit 86c4f0d547f6460d0426ebb3ba0614f1134b8cda upstream.

KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. CPUID.8000001FH:EBX[31:16] are reserved bits and
should be masked off.

Fixes: 8765d75329a3 ("KVM: X86: Extend CPUID range to include new leaf")
Signed-off-by: Jim Mattson 
Message-Id: <20220929225203.2234702-6-jmattson@google.com>
Cc: stable@vger.kernel.org
[Clear NumVMPL too. - Paolo]
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Mask off reserved bits in CPUID.80000001H

2022-11-10T17:15:41+00:00

commit 0469e56a14bf8cfb80507e51b7aeec0332cdbc13 upstream.

KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. CPUID.80000001:EBX[27:16] are reserved bits and
should be masked off.

Fixes: 0771671749b5 ("KVM: Enhance guest cpuid management")
Signed-off-by: Jim Mattson 
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Mask off reserved bits in CPUID.80000008H

2022-11-10T17:15:41+00:00

commit 7030d8530e533844e2f4b0e7476498afcd324634 upstream.

KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. The following ranges of CPUID.80000008H are reserved
and should be masked off:
    ECX[31:18]
    ECX[11:8]

In addition, the PerfTscSize field at ECX[17:16] should also be zero
because KVM does not set the PERFTSC bit at CPUID.80000001H.ECX[27].

Fixes: 24c82e576b78 ("KVM: Sanitize cpuid")
Signed-off-by: Jim Mattson 
Message-Id: <20220929225203.2234702-3-jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Mask off reserved bits in CPUID.8000001AH

2022-11-10T17:15:41+00:00

commit 079f6889818dd07903fb36c252532ab47ebb6d48 upstream.

KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. In the case of CPUID.8000001AH, only three bits are
currently defined. The 125 reserved bits should be masked off.

Fixes: 24c82e576b78 ("KVM: Sanitize cpuid")
Signed-off-by: Jim Mattson 
Message-Id: <20220929225203.2234702-4-jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman