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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-02-27 20:44:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-20 11:25:04 +0300 |
| commit | 5c2263d2911a29bb2bdb30e183af8f10bf2a3712 (patch) | |
| tree | 2b03a2acfa1560830520f34707e7e4d45cf24486 /arch/x86 | |
| parent | 43fcce9877aceb828b5cf30c0ab99835d8cfb63e (diff) | |
| download | linux-5c2263d2911a29bb2bdb30e183af8f10bf2a3712.tar.xz | |
KVM: nVMX: Consult only the "basic" exit reason when routing nested exit
commit 2ebac8bb3c2d35f5135466490fc8eeaf3f3e2d37 upstream.
Consult only the basic exit reason, i.e. bits 15:0 of vmcs.EXIT_REASON,
when determining whether a nested VM-Exit should be reflected into L1 or
handled by KVM in L0.
For better or worse, the switch statement in nested_vmx_exit_reflected()
currently defaults to "true", i.e. reflects any nested VM-Exit without
dedicated logic. Because the case statements only contain the basic
exit reason, any VM-Exit with modifier bits set will be reflected to L1,
even if KVM intended to handle it in L0.
Practically speaking, this only affects EXIT_REASON_MCE_DURING_VMENTRY,
i.e. a #MC that occurs on nested VM-Enter would be incorrectly routed to
L1, as "failed VM-Entry" is the only modifier that KVM can currently
encounter. The SMM modifiers will never be generated as KVM doesn't
support/employ a SMI Transfer Monitor. Ditto for "exit from enclave",
as KVM doesn't yet support virtualizing SGX, i.e. it's impossible to
enter an enclave in a KVM guest (L1 or L2).
Fixes: 644d711aa0e1 ("KVM: nVMX: Deciding if L0 or L1 should handle an L2 exit")
Cc: Jim Mattson <jmattson@google.com>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200227174430.26371-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 133b9b25e7c5..42c6ca05a613 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8711,7 +8711,7 @@ static bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason) vmcs_read32(VM_EXIT_INTR_ERROR_CODE), KVM_ISA_VMX); - switch (exit_reason) { + switch ((u16)exit_reason) { case EXIT_REASON_EXCEPTION_NMI: if (is_nmi(intr_info)) return false; |