From: Wei Huang <wei.huang2@amd.com>
To: Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
pbonzini@redhat.com, vkuznets@redhat.com, joro@8bytes.org,
bp@alien8.de, tglx@linutronix.de, mingo@redhat.com,
x86@kernel.org, jmattson@google.com, wanpengli@tencent.com,
bsd@redhat.com, dgilbert@redhat.com, mlevitsk@redhat.com
Subject: Re: [PATCH 1/2] KVM: x86: Add emulation support for #GP triggered by VM instructions
Date: Tue, 12 Jan 2021 23:03:58 -0600 [thread overview]
Message-ID: <94312672-3ad2-7cb5-9b03-c3a2fbf34a8f@amd.com> (raw)
In-Reply-To: <X/3jap249oBJ/a6s@google.com>
On 1/12/21 11:59 AM, Sean Christopherson wrote:
> On Tue, Jan 12, 2021, Sean Christopherson wrote:
>> On Tue, Jan 12, 2021, Wei Huang wrote:
>>> From: Bandan Das <bsd@redhat.com>
>>>
>>> While running VM related instructions (VMRUN/VMSAVE/VMLOAD), some AMD
>>> CPUs check EAX against reserved memory regions (e.g. SMM memory on host)
>>> before checking VMCB's instruction intercept.
>>
>> It would be very helpful to list exactly which CPUs are/aren't affected, even if
>> that just means stating something like "all CPUs before XYZ". Given patch 2/2,
>> I assume it's all CPUs without the new CPUID flag?
This behavior was dated back to fairly old CPUs. It is fair to assume
that _most_ CPUs without this CPUID bit can demonstrate such behavior.
>
> Ah, despite calling this an 'errata', the bad behavior is explicitly documented
> in the APM, i.e. it's an architecture bug, not a silicon bug.
>
> Can you reword the changelog to make it clear that the premature #GP is the
> correct architectural behavior for CPUs without the new CPUID flag?
Sure, will do in the next version.
>
next prev parent reply other threads:[~2021-01-13 5:05 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 6:37 [PATCH 1/2] KVM: x86: Add emulation support for #GP triggered by VM instructions Wei Huang
2021-01-12 6:37 ` [PATCH 2/2] KVM: SVM: Add support for VMCB address check change Wei Huang
2021-01-12 19:18 ` Sean Christopherson
2021-01-14 11:39 ` Maxim Levitsky
2021-01-14 12:04 ` Maxim Levitsky
2021-01-12 11:09 ` [PATCH 1/2] KVM: x86: Add emulation support for #GP triggered by VM instructions Maxim Levitsky
2021-01-12 21:05 ` Wei Huang
2021-01-12 12:15 ` Vitaly Kuznetsov
2021-01-12 15:11 ` Andy Lutomirski
2021-01-12 15:17 ` Maxim Levitsky
2021-01-12 15:22 ` Andy Lutomirski
2021-01-12 15:46 ` Bandan Das
2021-01-12 15:51 ` Andy Lutomirski
2021-01-12 17:56 ` Sean Christopherson
2021-01-13 4:55 ` Wei Huang
2021-01-12 21:50 ` Wei Huang
2021-01-12 14:01 ` Paolo Bonzini
2021-01-12 17:42 ` Sean Christopherson
2021-01-13 12:35 ` Paolo Bonzini
2021-01-15 7:00 ` Wei Huang
2021-01-17 18:20 ` Paolo Bonzini
2021-01-12 17:36 ` Sean Christopherson
2021-01-12 17:59 ` Sean Christopherson
2021-01-12 18:58 ` Andy Lutomirski
2021-01-13 5:15 ` Wei Huang
2021-01-14 11:42 ` Maxim Levitsky
2021-01-13 5:03 ` Wei Huang [this message]
2021-01-13 12:40 ` Paolo Bonzini
2021-01-12 19:40 ` Sean Christopherson
2021-01-12 20:00 ` Bandan Das
2021-01-14 11:47 ` Maxim Levitsky
2021-01-14 17:19 ` Sean Christopherson
2021-01-14 11:55 ` Maxim Levitsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=94312672-3ad2-7cb5-9b03-c3a2fbf34a8f@amd.com \
--to=wei.huang2@amd.com \
--cc=bp@alien8.de \
--cc=bsd@redhat.com \
--cc=dgilbert@redhat.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=mlevitsk@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).