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From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Oliver Upton <oupton@google.com>
Subject: Re: [GIT PULL] KVM changes for Linux 5.6-rc4
Date: Mon, 02 Mar 2020 19:40:35 +0100	[thread overview]
Message-ID: <87zhcyfvmk.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <1582570669-45822-1-git-send-email-pbonzini@redhat.com>

Paolo Bonzini <pbonzini@redhat.com> writes:

>       KVM: nVMX: Don't emulate instructions in guest mode

I just discovered that this patch breaks Hyper-V on KVM completely;
Oliver's 86f7e90ce8 ("KVM: VMX: check descriptor table exits on
instruction emulation") doesn't fix it either. The breakage manifests
itself as

 qemu-system-x86-23579 [005] 22018.775584: kvm_exit:             reason EPT_VIOLATION rip 0xfffff802987d6169 info 181 0
 qemu-system-x86-23579 [005] 22018.775584: kvm_nested_vmexit:    rip fffff802987d6169 reason EPT_VIOLATION info1 181 info2 0 int_info 0 int_info_err 0
 qemu-system-x86-23579 [005] 22018.775585: kvm_page_fault:       address febd0000 error_code 181
 qemu-system-x86-23579 [005] 22018.775592: kvm_emulate_insn:     0:fffff802987d6169: f3 a5
 qemu-system-x86-23579 [005] 22018.775593: kvm_emulate_insn:     0:fffff802987d6169: f3 a5 FAIL
 qemu-system-x86-23579 [005] 22018.775596: kvm_inj_exception:    #UD (0x0)

We probably need to re-enable instruction emulation for something...

-- 
Vitaly


  parent reply	other threads:[~2020-03-02 18:40 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-24 18:57 [GIT PULL] KVM changes for Linux 5.6-rc4 Paolo Bonzini
2020-02-24 20:25 ` pr-tracker-bot
2020-03-02 18:40 ` Vitaly Kuznetsov [this message]
2020-03-03 10:58   ` Paolo Bonzini
2020-03-03 13:02     ` Vitaly Kuznetsov
2020-03-03 13:07       ` Paolo Bonzini
2020-03-03 13:38         ` Vitaly Kuznetsov

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