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| author | Radim Krčmář | 2018-05-24 17:50:56 +0200 |
|---|---|---|
| committer | Radim Krčmář | 2018-05-25 21:33:31 +0200 |
| commit | 696ca779a928d0e93d61c38ffc3a4d8914a9b9a0 (patch) | |
| tree | 2c402b64e57a7e751e75cbc2cb2dac6256b7e73a /arch/x86/kvm/x86.c | |
| parent | kvm: x86: IA32_ARCH_CAPABILITIES is always supported (diff) | |
| download | kernel-qcow2-linux-696ca779a928d0e93d61c38ffc3a4d8914a9b9a0.tar.gz kernel-qcow2-linux-696ca779a928d0e93d61c38ffc3a4d8914a9b9a0.tar.xz kernel-qcow2-linux-696ca779a928d0e93d61c38ffc3a4d8914a9b9a0.zip | |
KVM: x86: fix #UD address of failed Hyper-V hypercalls
If the hypercall was called from userspace or real mode, KVM injects #UD
and then advances RIP, so it looks like #UD was caused by the following
instruction. This probably won't cause more than confusion, but could
give an unexpected access to guest OS' instruction emulator.
Also, refactor the code to count hv hypercalls that were handled by the
virt userspace.
Fixes: 6356ee0c9602 ("x86: Delay skip of emulated hypercall instruction")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e3103279eadd..b7618b30b7d6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6676,11 +6676,8 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) unsigned long nr, a0, a1, a2, a3, ret; int op_64_bit; - if (kvm_hv_hypercall_enabled(vcpu->kvm)) { - if (!kvm_hv_hypercall(vcpu)) - return 0; - goto out; - } + if (kvm_hv_hypercall_enabled(vcpu->kvm)) + return kvm_hv_hypercall(vcpu); nr = kvm_register_read(vcpu, VCPU_REGS_RAX); a0 = kvm_register_read(vcpu, VCPU_REGS_RBX); @@ -6701,7 +6698,7 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) if (kvm_x86_ops->get_cpl(vcpu) != 0) { ret = -KVM_EPERM; - goto out_error; + goto out; } switch (nr) { @@ -6721,12 +6718,11 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) ret = -KVM_ENOSYS; break; } -out_error: +out: if (!op_64_bit) ret = (u32)ret; kvm_register_write(vcpu, VCPU_REGS_RAX, ret); -out: ++vcpu->stat.hypercalls; return kvm_skip_emulated_instruction(vcpu); } |