From: Paolo Bonzini <pbonzini@redhat.com>
To: Wanpeng Li <wanpeng.li@linux.intel.com>,
Ben Serebrin <serebrin@google.com>
Cc: kvm@vger.kernel.org, stable@vger.kernel.org, luto@amacapital.net,
jankiszka@siemens.com
Subject: Re: [PATCH] KVM: VMX: Preserve host CR4.MCE value while in guest mode.
Date: Fri, 17 Apr 2015 12:16:18 +0200 [thread overview]
Message-ID: <5530DD72.7010801@redhat.com> (raw)
In-Reply-To: <20150417051007.GA3080@kernel>
On 17/04/2015 07:10, Wanpeng Li wrote:
>> >
>> >Before the change, if guest CR4.MCE==0, then the machine check is
>> >escalated to Catastrophic Error (CATERR) and the machine dies.
> Could you point out which section of SDM describes that the machine check
> is escalated to a CATERR if CR4.MCE==0?
It's under the description of "Interrupt 18--Machine-Check Exception (#MC)":
The machine-check mechanism is enabled by setting the MCE flag in
control register CR4. [...] If the machine-check mechanism is not
enabled (the MCE flag in control register CR4 is clear), a
machine-check exception causes the processor to enter the shutdown
state.
This of course also applies whenever the non-root mode CR4 (*not* the
shadow CR4 in the VMCS!) has the MCE flag cleared.
Paolo
next prev parent reply other threads:[~2015-04-17 10:16 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-16 18:58 [PATCH] KVM: VMX: Preserve host CR4.MCE value while in guest mode Ben Serebrin
2015-04-16 20:42 ` Venkatesh Srinivas
2015-04-17 5:10 ` Wanpeng Li
2015-04-17 10:16 ` Paolo Bonzini [this message]
2015-04-17 16:03 ` Benjamin Serebrin
2015-04-19 22:59 ` Wanpeng Li
2015-04-17 8:55 ` Greg KH
2015-04-17 10:10 ` Paolo Bonzini
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